Document 2248082

Table of Contents
Executive Summary .................................................................................................................................... 6 1 Introduction ......................................................................................................................................... 11 2 Calgary Sub-Region Overview .......................................................................................................... 12 2.1 2.2 2.3 Description of Calgary Sub-Region .......................................................................................................... 12 Existing Transmission System ................................................................................................................. 14 Existing Constraints in System ................................................................................................................. 16 3 Study Assumptions and Methodology ............................................................................................. 17 3.1 3.2 3.3 3.4 3.5 Load Assumptions.................................................................................................................................... 17 Generation Assumptions .......................................................................................................................... 20 Future Transmission Project Assumptions ............................................................................................... 21 Community Consultation .......................................................................................................................... 23 Summary of Study Case Assumptions ..................................................................................................... 23 4 Need Assessment ............................................................................................................................... 24 4.1 4.2 4.3 4.4 4.5 Near-term Need Assessment Results ...................................................................................................... 24 4.1.1 Near-term Category A Analysis .................................................................................................... 24 4.1.2 Near-term Category B Analysis .................................................................................................... 24 4.1.3 Near-term Category C Analysis .................................................................................................... 27 Medium-term Need Assessment Results ................................................................................................. 27 4.2.1 Medium-term Category A Analysis ............................................................................................... 27 4.2.2 Medium-term Category B Analysis ............................................................................................... 28 4.2.3 Medium-term Category C Analysis ............................................................................................... 31 Long-term Need Assessment Results ...................................................................................................... 32 4.3.1 Long-term Category A Analysis .................................................................................................... 32 4.3.2 Long-term Category B Analysis .................................................................................................... 33 Need Assessment by Area ....................................................................................................................... 37 4.4.1 Calgary Area ................................................................................................................................. 37 4.4.2 Airdrie Area ................................................................................................................................... 41 Need Assessment Summary .................................................................................................................... 43 5 Alternative Development and Screening ......................................................................................... 45 5.1 5.2 5.3 Calgary Area Alternatives ........................................................................................................................ 45 5.1.1 Calgary Area Alternative 1 ............................................................................................................ 47 5.1.2 Calgary Area Alternative 2 ............................................................................................................ 49 5.1.3 Calgary Area Alternative 3 ............................................................................................................ 51 5.1.4 Calgary Area Alternative 4 ............................................................................................................ 53 5.1.5 Calgary Area Alternative 5 ............................................................................................................ 55 5.1.6 Calgary Area Alternative 6 ............................................................................................................ 57 Airdrie Area Alternatives .......................................................................................................................... 59 5.2.1 Airdrie Area Alternative 1 .............................................................................................................. 59 5.2.2 Airdrie Area Alternative 2 .............................................................................................................. 61 5.2.3 Airdrie Area Alternative 3 .............................................................................................................. 63 5.2.4 Airdrie Area Alternative 4 .............................................................................................................. 65 Alternative Screening ............................................................................................................................... 67 5.3.1 Calgary Area Alternative Screening .............................................................................................. 67 5.3.2 Airdrie Area Alternative Screening ................................................................................................ 68 6 Alternative Evaluation ........................................................................................................................ 69 6.1 6.2 March 2014
Technical Evaluation ................................................................................................................................ 69 Calgary Area Alternatives ........................................................................................................................ 69 Calgary Sub-Region Plan
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6.3 6.4 6.5 6.6 6.7 6.2.1 Category A - System Normal (N-0) ............................................................................................... 69 6.2.2 Category B - Single Element Outage (N-1) ................................................................................... 69 6.2.3 Category C5 - Select Double Circuit Tower Outage (N-2) ............................................................ 70 Airdrie Area Alternatives .......................................................................................................................... 75 6.3.1 Category A - System Normal (N-0) ............................................................................................... 75 6.3.2 Category B - Single Element Outage (N-1) ................................................................................... 75 6.3.3 Category C5 - Selected Double Circuit Tower Outage (N-2) ........................................................ 75 Staging of Alternatives ............................................................................................................................. 75 6.4.1 Near-term Staging ........................................................................................................................ 75 6.4.2 Medium-term Staging ................................................................................................................... 85 System Losses ......................................................................................................................................... 95 High Level Land Impact Assessment ....................................................................................................... 95 TFO Assessment ..................................................................................................................................... 96 7 Selection of Preferred Plan................................................................................................................ 97 7.1 7.2 Calgary Area Preferred Alternative .......................................................................................................... 97 Airdrie Area Preferred Alternative ............................................................................................................ 97 8 Detailed Analysis for Preferred Plan ................................................................................................ 99 8.1 8.2 8.3 Near-term Assessment ............................................................................................................................ 99 8.1.1 Power Flow Studies ...................................................................................................................... 99 8.1.2 Maintenance Condition Studies .................................................................................................... 99 8.1.3 Category C7 Power Flow Studies ............................................................................................... 100 8.1.4 Dynamic Stability Studies ........................................................................................................... 100 8.1.5 Voltage Stability Studies ............................................................................................................. 100 8.1.6 Short Circuit Studies ................................................................................................................... 101 Medium-term Assessment ..................................................................................................................... 101 8.2.1 Power Flow Studies .................................................................................................................... 101 8.2.2 Category C7 Power Flow Studies ............................................................................................... 101 8.2.3 Dynamic Stability Studies ........................................................................................................... 102 8.2.4 Voltage Stability Studies ............................................................................................................. 102 8.2.5 Short Circuit Studies ................................................................................................................... 102 Long-term Assessment .......................................................................................................................... 103 8.3.1 Power Flow Studies .................................................................................................................... 103 8.3.2 Short Circuit Studies ................................................................................................................... 103 9 Impact of Preferred Plan on System Performance........................................................................ 104 9.1 9.2 Impact on Remedial Action Schemes .................................................................................................... 104 Nodal Capacity ....................................................................................................................................... 104 10 Summary of Preferred Plan ............................................................................................................. 106 10.1 10.2 Calgary Area Preferred Alternative ........................................................................................................ 106 Airdrie Area Preferred Alternative .......................................................................................................... 108 List of Tables
Table E-1: Calgary Area Preferred Alternative ........................................................................................................ 7 Table E-2: Airdrie Area Preferred Alternative .......................................................................................................... 9 Table 2.3-1: Existing Remedial Action Schemes in Calgary Sub-Region ............................................................. 16 Table 3.1-1: Forecast Calgary / Airdrie Areas and South Region Load ................................................................ 18 Table 3.1-2: Calgary Sub-Region Customer Projects ........................................................................................... 20 Table 3.2-1: Calgary Sub-Region Existing Generation ......................................................................................... 20 Table 3.2-2: Calgary Sub-Region Proposed Generation and Customer Projects ................................................. 21 Table 3.5-1: Summary of Study Scenarios............................................................................................................ 23 Table 4.1-1: Near-term Category B Need Assessment Thermal Results .............................................................. 25 March 2014
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Table 4.1-2: Near-term Category C5 Need Assessment Thermal Results ............................................................ 27 Table 4.2-1: Medium-term Category A Need Assessment Thermal Results ......................................................... 28 Table 4.2-2: Medium-term Category B Need Assessment Thermal Results ......................................................... 28 Table 4.2-3: Medium-term Category C5 Need Assessment Thermal Results ....................................................... 31 Table 4.3-1: Long-term Category A Need Assessment Thermal Results .............................................................. 32 Table 4.3-2: Long-term Category A Need Assessment Voltage Results ............................................................... 33 Table 4.3-3: Long-term Category B Need Assessment Thermal Results .............................................................. 34 Table 4.3-4: Long-term Category B Need Assessment Voltage Deviation Results ............................................... 35 Table 4.3-5: Long-term Category B Need Assessment Voltage Results ............................................................... 35 Table 4.4-1: Calgary Area Category A Thermal Violations ................................................................................... 37 Table 4.4-2: Calgary Area Category A Voltage Violations .................................................................................... 37 Table 4.4-3: Calgary Area Category B Thermal Violations ................................................................................... 38 Table 4.4-4: Calgary Area Category C5 Thermal Violations ................................................................................. 40 Table 4.4-5: Airdrie Area Category A Thermal Violations ..................................................................................... 41 Table 4.4-6: Airdrie Area Category A Voltage Violations ...................................................................................... 41 Table 4.4-7: Airdrie Area Category B Thermal Violations ..................................................................................... 42 Table 4.4-8: Airdrie Area Category C5 Thermal Violations ................................................................................... 42 Table 4.5-1: Summary of Need Assessment......................................................................................................... 43 Table 5.1-1: Calgary Area System Issues and Conceptual Solutions ................................................................... 46 Table 5.2-1: Airdrie Area System Issues and Conceptual Solutions ..................................................................... 59 Table 5.3-1: Comparison of Alternatives - Calgary Area ....................................................................................... 67 Table 5.3-2: Comparison of the Alternatives - Airdrie Area ................................................................................... 68 Table 6.2-1: Long-term Category B Thermal Violations for Calgary Alternatives .................................................. 70 Table 6.2-2: Long-term Category C5 Thermal Violations for Calgary Alternative 1............................................... 71 Table 6.2-3: Long-term Category C5 Thermal Violations for Calgary Alternative 2............................................... 72 Table 6.2-4: Long-term Category C5 Thermal Violations for Calgary Alternative 3............................................... 73 Table 6.2-5: Long-term Category C5 Thermal Violations for Calgary Alternative 4............................................... 74 Table 6.4-1: Calgary Area Development Sequence in Near-term- Alternatives 1, 2, 3 and 4 ............................... 76 Table 6.4-2: Airdrie Area Development Sequence in Near-term - Alt 1, 2 and 4 ................................................... 77 Table 6.4-3: Near-term Category B Results for Calgary Alternative 1 ................................................................... 79 Table 6.4-4: Near-term Category B Results for Calgary Alternative 2 ................................................................... 79 Table 6.4-5: Near-term Category B Results for Alternative 3A.............................................................................. 79 Table 6.4-6: Near-term Category B Results for Alternative 4A.............................................................................. 79 Table 6.4-7: Near-term Category C5 Results for Alternative 1 .............................................................................. 80 Table 6.4-8: Near-term Category C5 Results for Alternative 2A ........................................................................... 81 Table 6.4-9: Near-term Category C5 Results for Alternative 2B ........................................................................... 82 Table 6.4-10: Near-term Category C5 Results for Alternative 3A ......................................................................... 83 Table 6.4-11: Near-term Category C5 Results for Alternative 4A ......................................................................... 84 Table 6.4-12: Calgary Area Development Sequence - Alt 1, 2, 3 and 4................................................................ 85 Table 6.4-13: Medium-term Category C5 Results for Alternative 1 ....................................................................... 86 Table 6.4-14: Medium-term Category C5 Results for Alternative 2A .................................................................... 86 Table 6.4-15: Medium-term Category C5 Results for Alternative 2B .................................................................... 86 Table 6.4-16: Medium-term Category C5 Results for Alternative 3A .................................................................... 86 Table 6.4-17: Medium-term Category C5 Results for Alternative 4A .................................................................... 86 Table 6.5-1: Relative System Losses for Calgary Area Alternatives ..................................................................... 95 Table 6.5-2: Relative System Losses for Airdrie Area Alternatives ....................................................................... 95 Table 7.1-1: Comparison of Calgary Area Alternatives ......................................................................................... 97 Table 7.2-1: Comparison of Airdrie Area Alternatives ........................................................................................... 98 Table 8.1-1: Near-term Maintenance Condition Results ..................................................................................... 100 Table 8.1-2: P-V Analysis Summary – Near-term Winter Peak - Calgary Area .................................................. 101 Table 8.1-3: P-V Analysis Summary – Near-term Winter Peak - Airdrie Area .................................................... 101 March 2014
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Table 8.2-1: P-V Analysis Summary – Medium-term Winter Peak- Calgary Area .............................................. 102 Table 8.2-2: P-V Analysis Summary – Medium-term Winter Peak- Airdrie Area ................................................ 102 Table 9.1-1: Remedial Action Scheme Changes ................................................................................................ 104 Table 9.2-1: Estimated Available Capacity for Additional Generation ................................................................. 105 Table 10.1-1: Calgary Area Preferred Alternative ............................................................................................... 106 Table 10.2-1: Airdrie Area Preferred Alternative ................................................................................................. 108 List of Figures
Figure E-1: Calgary Area Proposed Development .................................................................................................. 8 Figure E-2: Airdrie Area Proposed Development .................................................................................................. 10 Figure 2.1-1: Geographical Map of Alberta ........................................................................................................... 13 Figure 2.2-1: Calgary Sub-Region Transmission Configuration ............................................................................ 15 Figure 3.1-1: Forecast Calgary / Airdrie Areas and South Region Load ............................................................... 19 Figure 4.1-1: Calgary Sub-Region Near-term Thermal Overloads (Category A and B) ........................................ 26 Figure 4.2-1: Calgary Sub-Region Medium-term Thermal Overloads (Category A and B) ................................... 30 Figure 4.3-1: Calgary Sub-Region Long-term Thermal Overloads (Category A and B) ....................................... 36 Figure 4.5-1: Calgary Sub-Region Need Assessment Summary (Near-term to Long-term) ................................. 44 Figure 5.1-1: Calgary Area – Alternative 1 ............................................................................................................ 48 Figure 5.1-2: Calgary Area – Alternative 2 ............................................................................................................ 50 Figure 5.1-3: Calgary Area – Alternative 3 ............................................................................................................ 52 Figure 5.1-4: Calgary Area – Alternative 4 ............................................................................................................ 54 Figure 5.1-5: Calgary Area – Alternative 5 ............................................................................................................ 56 Figure 5.1-6: Calgary Area – Alternative 6 ............................................................................................................ 58 Figure 5.2-1: Airdrie Area – Alternative 1 .............................................................................................................. 60 Figure 5.2-2: Airdrie Area – Alternative 2 .............................................................................................................. 62 Figure 5.2-3: Airdrie Area – Alternative 3 .............................................................................................................. 64 Figure 5.2-4: Airdrie Area – Alternative 4 .............................................................................................................. 66 Figure 6.4-1: Calgary Area Alternative 1 ............................................................................................................... 87 Figure 6.4-2: Calgary Area Alternative 2A (Near-term and Medium-term) ............................................................ 88 Figure 6.4-3: Calgary Area Alternative 2B ............................................................................................................ 89 Figure 6.4-4: Calgary Area Alternative 3A ............................................................................................................ 90 Figure 6.4-5: Calgary Area Alternative 4A ............................................................................................................ 91 Figure 6.4-6: Airdrie Area Alternative 1 ................................................................................................................. 92 Figure 6.4-7: Airdrie Area Alternative 2 ................................................................................................................. 93 Figure 6.4-8: Airdrie Area Alternative 4 ................................................................................................................. 94 Figure 10.1-1: Calgary Area Preferred Alternative .............................................................................................. 107 Figure 10.2-1: Airdrie Area Preferred Alternative ................................................................................................ 109 List of Appendices
APPENDIX A – Community Consultation Summary
APPENDIX B – Detailed Study Scenarios
APPENDIX C – 2017, 2022, 2032 Need Assessment Results
APPENDIX D – Power Flow Single Line Diagram for 2017, 2022 & 2032 Need Assessment
APPENDIX E – Power Flow Single Line Diagram for 2032 Alternative Development
APPENDIX F – Power Flow Single Line Diagram for Staging of the Preferred Plan
APPENDIX G – Dynamic Study Results for the Preferred Plan
APPENDIX H – Voltage Stability Results for the Preferred Plan
APPENDIX I – High Level Land Impact Assessment
APPENDIX J – Short Circuit Results for the Preferred Plan
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Executive Summary
The AESO Calgary Sub-Region Plan (CARP) is comprehensive 20-year transmission study and plan that
identifies the enhancements required in the Calgary and Airdrie transmission systems for years 2017,
2022 and 2032 planning horizons:



Near-term (1-5 years):
Medium-term (6-10 years):
Long-term (11-20 years):
2012 - 2017
2018 - 2022
2023 - 2032
The CARP is one of six regional plans that collectively cover the entire province of Alberta, all of which
are integrated into the AESO Long-term Plan (LTP). The CARP satisfies the AESO’s legislated mandate
to develop transmission system plans to enable the long-term development of the transmission system in
a timely and efficient manner. The regional plans are intended to be used as the basis for specific needs
identification documents that result from the regional plan. In addition, the regional plans also provide
evidence for compliance with some of the required Alberta Reliability Standards1.
The Calgary Sub-Region planning studies were conducted using the AESO’s 2012 Long Term Outlook2
(2012 LTO).
The Calgary Sub-Region (AESO planning areas 6 and 57) is expected to experience several reliability
issues over the 20 year planning horizon (to 2032) primarily related to thermal overload issues under
contingency situations.
The Need Assessment performed as part of the CARP identified the reliability violations expected in the
near-term, medium-term and long-term.
In the near-term, there were no voltage violations observed in the Calgary or Airdrie planning areas.
However, the results showed that there were overloads in the north Calgary 69 kV system (NW Calgary)
and the 138 kV lines emanating from Beddington SS-162 and Janet 74S. An emerging issue was
associated with the Calgary downtown network load where the outage of a 138 kV circuit (e.g. 2.82L or
2.83L) overloaded the opposite circuit. For the Airdrie area, overloads on 138 kV circuits were also
observed due to existing low line ratings as well as load and generation conditions in the area.
In the medium-term, there were no voltage violations observed in the Calgary or Airdrie planning areas.
However, with the increased load levels, the overload issues observed in the near-term have now
become more severe in addition to more overloaded lines in the same general areas. Further, some
Category A overloads were observed under certain scenarios.
In the long-term, under no contingency conditions (Category A), some voltage issues are observed where
main bus voltages are slightly below nominal voltage. In addition, there are several overloaded
transmission lines, some greater than 150% under Category A conditions. Under first outage conditions
(Category B), more overloaded transmission facilities are observed beyond those identified in the
medium-term with overloads extending to the south part of Calgary.
The Calgary area preferred plan is summarized in Table E-1 below.
1
Some of the Requirements in the TPL-001-AB, TPL-002-AB, TPL-003-AB, FAC-002 and FAC-014
Differences between the 2012 Long-term Outlook (2012 LTO) and 2012 Long-term Outlook Update (2012 LTOU) are considered
relatively small for the south region.
2
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Table E-1: Calgary Area Preferred Alternative
Horizon
Development
Downtown load supply Convert SS-8 to 240 kV substation with 2 new 240/138 kV 400 MVA transformers and a new
240 kV line from East Calgary 5S to SS-8 240 kV
New 138 kV line from SS-47 to SS-36
Near-term
North Calgary 69 kV network upgrade to 138kV
929L connected to Beddington SS-162 in an in-out configuration
New 138 kV line from SS-22 to SS-23 (maintenance flexibility)
New 240/138 kV NW Calgary substation and associated 138 kV lines
Medium-term
FATD West double circuit 240 kV line from Foothills 237S to Sarcee 42S
New 240 kV lines from Beddington SS-162 to SS-8 240kV
New 138 kV line from SS-27 to SS-3 and Normally open 3.82L from SS-3 to SS-8
Long-term
New 138 kV line from Janet 74S to SS-37
Add Var support devices in north Calgary
Figure E-1 below shows the proposed development for the Calgary area.
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Figure E-1: Calgary Area Proposed Development
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The Airdrie area preferred plan is summarized in Table E-2 below.
Table E-2: Airdrie Area Preferred Alternative
Horizon
Development
East Crossfield 64S Upgrade 901L Tap converted to In-Out configuration at East Crossfield 64S
One new 240/138 kV 200 MVA transformer at East Crossfield 64S
Upgrade the existing 138 kV lines 752L from East Crossfield 64S to Airdrie Tap to Summit
653S to higher capacity line
Upgrade the existing 138 kV line 688L from Summit 653S to Summit tap to East Airdrie
199S to higher capacity line
Near-term
Upgrade the existing 138 kV line 611L from Drycreek 186S to Balzac with higher capacity
line
New 138 kV line from East Crossfield 64S to East Airdrie 199S3
New 138 kV line from Beddington 162S to Dry Creek 186S4
Normally open (N.O.) 138 kV line from East Airdrie 199S Dry Creek 186S
Upgrade /install protection systems as necessary to facilitate the above system
reinforcements
Medium-term
Long-term
New 138 kV D/C line from new POD5 to the new 138kV line between Beddington 162S and
Dry Creek 186S
No transmission developments proposed.
Figure E-2 below shows the proposed development for the Airdrie area.
3
As per the feedback from TFO, this development could be built as double circuit with existing transmission lines.
As per the feedback from TFO, this development could be built as double circuit with existing transmission lines.
5
The connection of new PoD depends on the timing and location of this new substation.
4
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Figure E-2: Airdrie Area Proposed Development
To Red Deer
63S
West
Crossfield
316S
901AL
752L
East
Crossfield
64S
653S
Nose Creek
284S
688L
East Airdrie
199S N.O.
631L
DryCreek
186S
New PoD
Legend
N.O.
Future Circuit
Existing Circuit
Future Substation
Existing Substation
69 kV Circuit
138 kV Circuit
240 kV Circuit
500 kV Circuit
HVDC line
Normally Open Circuit
69 kV Substation
611L
Balzac
391S
918L
Beddington
162S
932L
138 kV Substation
240 kV Substation
500 kV Substation
Near-term Development
Medium-term Development
Long-term Development
Disclaimer: This diagram is a simplified representation
of the physical system configuration. Technical details
have been simplified for illustration purposes. It does not
accurately display the geographical location of facilities.
To Janet
74S
The existing Remedial Action Schemes (RAS) in Calgary and Airdrie areas were also reviewed. The
results of the studies showed that a number of RASs would no longer be required after the proposed
facilities in the CARP are energized as identified in the mitigation plan. The AESO will undertake detailed
operational studies prior to energization of planned transmission facilities and make decision on either
removal or disabling the specific RAS associated with the energized facility.
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1 Introduction
The primary purpose of the long-term regional plans is to provide overall direction and focus for
transmission development in the province of Alberta for each planning region over the 20-year planning
horizon. The regional plans are intended to be used as the basis for specific needs identification
documents that result from the regional plan. In addition, the regional plan also provides evidence for
compliance with some of the required Alberta Reliability Standards6.
The AESO intends to update the Long-term regional plans bi-annually to take into account changes in
projects, forecast, and policy and thereby provide a reference document for overall Alberta transmission
development over the planning horizon on a continuing basis.
This AESO 2013 Calgary Sub-Region Long-term Plan (CARP) was developed using AESO’s twenty year
Long-term load and generation forecast, also known as the AESO 2012 Long-term Outlook (2012 LTO) 7.
The need assessment and alternative evaluation studies were conducted in accordance with the Alberta
Reliability Standards and AESO Transmission Reliability Criteria.
Other important considerations in identifying the twenty year southern Alberta regional transmission
developments include relative economic assessments, potential environmental, societal and land use
impact, existing utility corridors, major municipal plans, Alberta Land Stewardship Act (ALSA) regional
plans, and stakeholder feedback. Stakeholder engagement provides meaningful information to the AESO
system planning process and is an essential component of the CARP. The AESO has conducted
preliminary stakeholder consultation in the form of discussions with municipalities. Further consultation
with landowners, industry and various agencies will occur at the Need Identification Document (NID)
stage where the AESO will look to filing a NID with the AUC for approval of a particular transmission
enhancement.
This CARP includes a preliminary implementation schedule and milestones for the identified transmission
system expansion and enhancements that are anticipated to occur within the next five years. To ensure
timely implementation of these needed system developments, the AESO will file a NID for AUC approval
in advance of the scheduled need. Future requests from market participants for transmission system
access will be filed with the AUC in standalone NIDs, as required, and will assume the various CARP
components to be in-service for the date specified, unless new information indicates otherwise.
6
7
Some of the Requirements in the TPL-001-AB, TPL-002-AB, TPL-003-AB, FAC-002, FAC-014 and VAR-001-AB R11
http://www.aeso.ca/downloads/AESO_2012_Long-term_Outlook_bookmarked.pdf
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2 Calgary Sub-Region Overview
The section provides an overview of the Calgary Sub-Region, including a description of the existing
transmission system and its corresponding constraints.
2.1
Description of Calgary Sub-Region
The Calgary Sub-Region is part of the South Region and is comprised of AESO planning areas 6
(Calgary) and 57 (Airdrie). The City of Calgary is situated on the Bow River in the south of the province,
in an area of foothills and prairie, approximately 80 km east of the front ranges of the Canadian Rockies.
The city is located in the grassland and parkland natural regions of Alberta. As of the 2011 census, the
City of Calgary had a population of about 1.1 million making it the largest city in Alberta, and the third
largest municipality and fifth largest metropolitan area in Canada.
Located about 294 km south of Edmonton, Statistics Canada defines the area between these cities as the
Calgary–Edmonton corridor. Economic activity in Calgary is mostly centered on the petroleum industry
and agriculture. In 1988, Calgary became the first Canadian city to host the Olympic Winter Games.
The City of Airdrie is located about 15 km north of the City of Calgary with a population of about 50,000,
and is located within the Calgary–Edmonton corridor.
The Calgary area is a major load center for the south region and the province with close to 15% of
Alberta’s total load requirement. The City of Calgary and the surrounding area continue to see increased
demand as the population continues to grow.
The Calgary Sub-Region economy is driven in large part by the energy sector resulting in gradual
population growth with associated commercial and residential demand growth. The forecasted annual
peak load growth in the sub-region is on the order of 40 to 50 MW per year.
Major sources of generation in and around the Calgary Sub-Region are the ENMAX Calgary Energy
Centre, Balzac, Summit, Cavalier, and Carseland gas fired generating stations, and hydro plants on the
Bow River west of the city. The ENMAX Shepard combined cycle power station (~850 MW) is expected
to be online in early 2015, and the ENMAX Bonnybrook power station (~170 MW) is expected to be online
in the 2015/2016 time frame.
Figure 2.1-1 below shows a geographic map of Alberta, which includes the Calgary Sub-Region
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Figure 2.1-1: Geographical Map of Alberta
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2.2
Existing Transmission System
The existing regional Calgary/Airdrie transmission system has six main 240 kV source substations;
Sarcee 42S, East Calgary 5S, Janet 74S, SS-65, Beddington SS-162, and East Crossfield 64S. The
underlying transmission system within the cities of Calgary and Airdrie is composed of 138 kV and 69 kV
circuits delivering power to load stations. Langdon 102S (Bennett) is also a main substation located in
Area 6 as the termination point of the 500 kV line to Cranbrook, BC.
The existing transmission system in the Airdrie area is comprised of single circuit 138 kV lines fed from
240 kV source stations Beddington SS-162 and East Crossfield 64S from the south and north
respectively. This configuration creates a large single 138 kV loop in the Airdrie area.
Figure 2.2-1 below shows the existing transmission system in the Calgary Sub-Region.
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Figure 2.2-1: Calgary Sub-Region Transmission Configuration
Note: The Calgary Sub-Region only includes Areas 6 and 57.
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The largest intertie in Alberta is the 500 kV 1201L that connects the BC Hydro system at Cranbrook to the
AIES at Langdon 102S. This 500 kV circuit and two 138 kV circuits between Alberta and British Columbia
(BC) are collectively defined by the Western Electricity Coordinating Council (WECC) to be Path 1. The
Path 1 rating in export and import modes is 1000 MW and 1200 MW respectively. However, the actual
operating limit is lower due to system constraints. The AESO’s recommendation for restoring the Path 1
rating to its design value forms part of the South region plan (SRP).
In the near future, the Western Alberta Transmission Line (WATL) will terminate at Crossings station
(near Langdon). WATL is a HVDC transmission line from Sunnybrook station (near Genesee station)
west of Edmonton with a capacity 2000 MW in bi-pole operation and may be expanded further if required.
2.3
Existing Constraints in System
The existing Calgary Sub-Region transmission system is inadequate to support existing and forecast load
and generation requirements in the area. One of the AESO’s objectives in conducting the CARP is to
eliminate existing constraints, which are currently managed by operational procedures, including the
following Remedial Action Schemes (RAS) shown in Table 2.3-1 below.
Table 2.3-1: Existing Remedial Action Schemes in Calgary Sub-Region
Number
March 2014
Name
Function
Type
11
Temporary Bennet 520s
Underfrequency - Overpower RAS
U/F Trip to protect AB System from
external disturbance
WECC RAS
12
Temporary Bennet 520s
undervoltage – overpower RAS
U/V Trip to protect AB System from
internal and external disturbance
WECC RAS
15
Temporary 520s overvoltage
protection scheme
Over voltage protection to protect
equipment from damage
WECC RAS
24
Calgary Area UVLS Program
Protect area load from voltage
collapse
44
South Calgary transmission load
relief scheme
Protect line from overload by tripping
load
LAPS
49
ENMAX Crossfield 752L RAS
Protect line from overload by runback
and/or trip generation
LAPS
50
ENMAX Crossfield 688L RAS
Protect line from overload by runback
and/or trip generation
LAPS
133
Beddington 162S overload
mitigation scheme
Mitigate potential overload and other
reliability concerns in the area
LAPS
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3 Study Assumptions and Methodology
This section summarizes the load, generation and transmission assumptions made in this CARP as well
as the AESO’s community consultation process.
The study years selected to develop the long-term regional plan are 2017, 2022 and 2032 which
correspond to 5 years, 10 years and 20 years from 2012. The 2012 LTO forecast (load and generation)
was used to develop the cases for each of the study years. The 2017, 2022 and 2032 study years
represent the near-term, medium-term and long-term planning horizons respectively:



Near-term (1-5 years):
Medium-term (6-10 years):
Long-term (11-20 years):
2012 - 2017
2018 - 2022
2023 - 2032
For each of the study years, the existing system performance was evaluated and summarized under
various system and contingency conditions as detailed in Section 4. This evaluation is referred to as the
Need Assessment and consisted of a power flow analysis of the specified study scenarios. Based on the
results of the Need Assessment, various improvement alternatives were developed and screened. The
selected alternatives were compared on the basis of the technical evaluation, system losses and high
level impact assessment. A preferred plan was selected based on the comparison and detailed dynamic
stability and voltage stability analyses were conducted for the selected study years.
3.1
Load Assumptions
The Calgary Sub-Region planning studies were conducted using the AESO’s 2012 Long Term Outlook8
(2012 LTO), which was the most current AESO corporate load forecast at the commencement of the
studies. Table 3.1-1 below provides the Calgary (area 6) and Airdrie (area 57) load forecast at planning
area extrema (peak/light) as well as the coincident South region extrema load for each study year.
Subsequent to the initiation of the analysis, the AESO published the AESO 2012 Long Term Outlook
Update (2012 LTOU), which is the update of the 2012 LTO. 2012 LTOU predicts average annual growth
rate 0.2% higher than 2012 LTO in next 20 years, with the increase due to acceleration of oil sands
production in the later years of the 2012 LTOU. The change is insignificant for Calgary Sub-Region.
Therefore there is no need to test the study results using 2012 LTOU.
For the dynamic studies, all loads that were not modeled as motors in the base cases were modeled
using the WECC default model of 20% induction motor load, 100% constant current and 100% constant
impedance load for the real and reactive components of the remainder of the Alberta Interconnected
Electric System (AIES) load, respectively.
8
Differences between the 2012 Long-term Outlook (2012 LTO) and 2012 Long-term Outlook Update (2012 LTOU) are considered
relatively small for the south region.
March 2014
Calgary Sub-Region Plan
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Table 3.1-1: Forecast Calgary / Airdrie Areas and South Region Load
2017 (MW)
Planning
Area
Description
6
57
2022 (MW)
2032 (MW)
SP
SL
WP
SP
SL
WP
Peak
Light
Calgary
1816
925
1917
2004
1021
2125
2566
1344
Airdrie
102
52
111
123
62
132
168
90
3387
1890
3511
3785
2109
3935
4423
2733
Southern Alberta
Figure 3.1-1 below illustrates the trend of the forecast by year and area/region. As can be seen in Table
3.1-1 and Figure 3.1-1, the Calgary area is approximately 50% of the total South Region load.
March 2014
Calgary Sub-Region Plan
Page 18
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Figure 3.1-1: Forecast Calgary / Airdrie Areas and South Region Load
Calgary Sub-Region Plan
March 2014
Page 19
Proprietary
Table 3.1-2 shows the customer projects in the Calgary Sub-Region.
Table 3.1-2: Calgary Sub-Region Customer Projects
Project
No.
3.2
Project Name
Project Type
In Service Date
1276
ENMAX No. 21 Substation Breaker Addition
Connection
Q1 2014
1314
1314 ENMAX 138/25kV POD Addition
Connection
Q1 2015
859
ENMAX No. 5 Sub Capacity Upgrades
Connection
Q3 2015
1107
ENMAX No. 47 Substation Transformer Addition
Connection
Q1 2014
1480
Enmax No.11 Substation-25kV Breaker Addition
Connection
Q1 2016
Generation Assumptions
Generation assumptions in the CARP study are based on the 2012 LTO. The WATL and EATL HVDC
lines, which are expected to be in service by 2017 or earlier, were dispatched according to the HVDC
dispatch methodology. Ongoing work with AltaLink and ATCO Electric will result in a refined dispatch
practice intended for the actual operation of the HVDC Lines. These changes will be taken into account
on a go forward basis from a planning perspective.
As shown in Table 3.2-1, there is approximately 602 MW of existing generation capacity connected in the
Calgary Sub-Region. Proposed new generation in the region, as indicated by the AESO project list (as of
October 2013) is provided in Table 3.2-2. The generation project list includes all active projects, including
connection, contract capacity and behind the fence projects, for which the AESO has received a system
access service request.
Table 3.2-1: Calgary Sub-Region Existing Generation
Machine Name
Area
Generation (MW)
Generation Type
Balzac
6-Calgary
2 GT x 47
1 ST x 26
Combined Cycle Gas
Turbine
Bearspaw
6-Calgary
1 x 18
Hydro
CEC
6-Calgary
1 GT x 170
1 ST x 150
Combined Cycle Gas
Turbine
Crossfield Energy Centre
57-Airdrie
3 x 48
Simple Cycle Gas
Turbine
Total Generation
March 2014
602
Calgary Sub-Region Plan
Page 20
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Table 3.2-2: Calgary Sub-Region Proposed Generation and Customer Projects
Project
No.
Project Name
Project Type
In Service Date
719
ENMAX Shepard Energy Centre
Connection
Q1 2015
921
ENMAX Bonnybrook Energy Centre
Connection
Q4 2015
The AESO is currently working on an Intertie Restoration Program9 in coordination with number of
stakeholders for the purpose of the CARP. In the CARP, the existing intertie capability was assumed for
2017. However, for the 2022 and 2032 study years, increased intertie capability was assumed to be
available up to 1200 MW import and 1000 MW export in order to assess the capability of the system.
3.3
Future Transmission Project Assumptions
The list of future transmission projects in Alberta is provided in Table 3.1-1 below. Note that this list is
based on information available at the commencement of the planning study for the purpose of modeling.
9
Alberta – WECC Intertie Restoration Program
March 2014
Calgary Sub-Region Plan
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Table 3.1-1: Future Transmission Projects
System
Addition No
1
2
Project
Number
West HVDC
CTI
East HVDC
CTI
In-Service Date (ISD)
Genesee – Langdon HVDC
2015
Heartland – West Brooks HVDC
2014
SATR (Southern Alberta Transmission
Reinforcement)
2015
Foothills Area Transmission Development (FATD)
2015
1
3
# 787
4
# 1117, # 1354
5
# 813
Red Deer Region Transmission Development
2015
6
# 786
Edmonton Region 240 kV Line Upgrades
2015
7
# 811
Central East Region Transmission Development
2017
8
# 812
Hanna Region Transmission Development
2017
9
# 850
South & West of Edmonton Area Development
2015
10
# 719
East Calgary 240 kV and 138 kV transmission
system Upgrades and the Shepard Energy Centre
Connection
2014
11
# 1266
LTP-KEG Sundance 500 kV
2020
12
# 1270
LTP-Otauwau-Slave Lake
2015
13
Reactors at Hotchkiss
2015
14
SVC at Fort Nelson
2015
15
# 1262
# 838
16
CTI
Grande Prairie – Little Smoky – Bicker dike
Transmission Development
Fort McMurray Area Bulk Transmission System
Reinforcement
Genesee-Livock –Thickwood 500 kV
2015/2016
Phase 1: 2016
2018-19
2013 – 2015 various
stages
17
# 1101
Christina Lake Area Development
18
# 1186
Fort McMurray 240 kV Transmission Development
2015
19
# 949
20
21
# 1267
Athabasca Area Transmission Development
2014
9L15 (Wesley Creek – Brintnell 240 kV) rerouting
from Brintnell to Livock
2014
Algar Area System Reinforcement
2015
22
942L in and out at Josephburg station
2015
23
9L930 in and out at Heart Lake station
2014
South Calgary 69 kV Reinforcement
2014
24
1.
Name
# 626
SATR Stage III not included
The following previously proposed system projects were not included in the studies to allow system
deficiencies to be identified considering the 2012 LTO and then alternative solutions to be reviewed or
identified. No system applications to the Alberta Utilities Commission (AUC) have been made for the
specific projects noted below.
1. P1118 FATD West.
2. P905 North Calgary system upgrade.
3. P947 Airdrie area transmission development.
March 2014
Calgary Sub-Region Plan
Page 22
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3.4
Community Consultation
During the course of developing the CARP, the AESO engaged several municipalities and counties in all
of the regions to gather an understanding of area plans for growth and development as well as concerns
and issues specific to the community. Appendix A provides the consultation summary.
3.5
Summary of Study Case Assumptions
The primary study scenarios were based on the 2012 LTO. To assess the impact of forecast variation on
the plan, the study also included the Environmental and High Co-generation forecast scenarios, as well
as some sensitivity scenarios10. A summary of the study scenarios is provided in Table 3.5-1 and a
complete set of the load and generation study scenarios is presented in Appendix B. The 2017, 2022 and
2032 study models created represent the near-term, medium-term and long-term planning horizons.
Table 3.5-1: Summary of Study Scenarios
10
Year
Load Scenarios
2017
Summer peak, Winter peak
Summer Light load
2022
Summer peak, Winter peak
Summer Light load
2032
Peak load and Light load
Generation Scenarios
2012 LTO, Environmental
and sensitivity scenarios
2012 LTO, High Cogeneration, Environmental
and sensitivity scenarios
2012 LTO, High Cogeneration, Environmental
and sensitivity scenarios
Total Conditions
17
20
9
2012 LTO, Section 8.
March 2014
Calgary Sub-Region Plan
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4 Need Assessment
The purpose of the Need Assessment is to identify transmission constraints in the study area. This
analysis is based on the Alberta Reliability Standards to test for capacity, security, performance,
operability and maintenance management under forecasted future load and generation conditions. The
analysis identifies the time, location and the type of criteria violations that are expected to occur, and the
implications if there is inadequate transmission.
The Need Assessment included a power flow analysis of the planned system under Category A, B and C
events to identify the need for transmission reinforcement in the near-term, medium-term and long-term
planning horizons. The power flow analysis was performed using the study scenarios outlined in Section
3.5. Category D events (extreme contingencies) as part of the TPL Compliance requirement will be
performed in accordance with the TPL-004 standard for selected major stations in Alberta.
The sections below present the highest observed loading for each monitored system element across the
various scenarios and the worst observed loading violations for each major contingency event across the
various scenarios. The detail results of the analysis are provided in Appendix C with corresponding
single line diagrams in Appendix D.
4.1
Near-term Need Assessment Results
This section summarizes the results of the power flow studies performed using the near-term study
scenarios as outlined in Section 3.5 and identifies existing system reliability criteria violations for the 2017
planning horizon. The following sections present the results of the system evaluation under Category A,
B and C5 conditions. The tabulated detailed need assessment results are provided in Appendix C and
single line power flow diagrams for system normal and the critical outages discussed in this section are
provided in Appendix D.
4.1.1 Near-term Category A Analysis
The steady-state performance of the near-term transmission system under Category A conditions was
analyzed, and the results show that the transmission line loadings and bus voltages were within
acceptable limits for all of the study scenarios for Calgary area. In the Airdrie area, the 138 kV line 688L
from Summit 653S to Summit Tap was loaded above 97% of its summer rating under Scenario SC3.
4.1.2 Near-term Category B Analysis
The steady-state performance of the near-term transmission system was analyzed under Category B
conditions. The results summarized in Table 4.1-1 below list the highest overloaded system elements
identified under first outage (Category B) conditions.
There were no voltage violations in the Calgary Sub-Region under Category B conditions.
March 2014
Calgary Sub-Region Plan
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Table 4.1-1: Near-term Category B Need Assessment Thermal Results
Area
Calgary
Overloaded Element
Contingency
Case
Rating
(MVA)
Maximum
Thermal
Loading (%)
1109L or 1080L from SS-25 to SS65
1080L or 1109L from SS-25 to SS65
SC6
489
96
11.83L from Beddington 162S to
SS-11
39.82L from Beddington 162S to
SS-39
SC6
313
99
39.82L from Beddington 162S to
SS-39
11.83L from Beddington 162S to
SS-11
SC12
287
108
37.82L from Janet 74S to SS-37
932L from Janet 74S to
Beddington 162S
SC7
287
105
SC17
318
133
2.82L from SS-2 to SS-5
2.83L from SS-2 to SS-5 to SS-13
SC8
392 (W)
108
SC17
318
135
SC8
286 (W)
137
2.83L from SS-2 to 2.83L Tap
Airdrie
2.82L from SS-2 to SS-5
21.61L from SS-21 to SS-34
15.60L from SS-15 to SS-21
SC3
37
118
36ST4
21.4TR
SC2
50
102
1.82L or 1.84L from SS-1 to SS-5
1.84L or 1.82L from SS-1 to SS-5
SC8
287
99
688L from East Airdrie 199S to
Nosecreek Tap
752L from East Crossfield 64S to
West Crossfield 316S to Summit
653S
SC3
121
106
611L from Drycreek 186S to
Balzac 391S
901L from Janet 74S to East
Crossfield 64S to Red Deer 63S
SC2
106
107
SC7
117 (W)
108
752L from East Crossfield 64S to
West Crossfield Tap
162.81L from Beddington 162S to
Balzac 391S
SC6
119
131
SC12
136 (W)
111
688L from Summit 653S to
Summit Tap
752L from East Crossfield 64S to
West Crossfield 316S to Summit
653S
SC3
121
118
SC12
142 (W)
99
752L from Summit 653S to West
Crossfield Tap
162.81L from Beddington 162S to
Balzac 391S
SC6
121
139
SC12
142 (W)
117
Note: It is assumed that the 138 kV line 9.80L (from SS-9 to SS-31) line rating can be increased to 287MVA by adjusting the CT limit
ratio to 1200A.
Figure 4.1-1 below highlights the thermal overload results under Category B conditions across all study
scenarios for the near-term.
March 2014
Calgary Sub-Region Plan
Page 25
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Figure 4.1-1: Calgary Sub-Region Near-term Thermal Overloads (Category A and B)
To Red Deer
63S
To Benalto
17S
West
Crossfield
316S
901AL
East
Crossfield
64S
752L
653S
929L/
925L
906L/
928L
Nose Creek
284S
57 Airdrie
901L
688L
East Airdrie
199S
631L
DryCreek
186S
611L
Balzac
391S
Beddington
162S
918L
932L
SS-47
44
Seebee
11.83L
SS-14
14.83L
36.81L
SS-11
11.82L
39.82L
SS-36
16.63L
SS-16
BEARSPAW
15.62L
7.84L
SS-15
50L
SS-7
11.81L
16.61L
16.60L
SS-27
SS-34
3.84L
21.61L
SS-13
SS-3
15.60L
SS-21
SS-22
3.82L
7.82L
SS-8
SS-28
Sarcee 28.80L
42S
38.83L
2.83L
1.85L 1.83L SS-5
2.83L
1.84L
1.81L
SS-1 1.82L
2.82L
1.80L
3L
SS-39
13.82L
1.82LSS-20
150L
22.81L
13.60L
SS-38
Bonnybrook
East Calgary 5S
693L
SS-10 916L
832L
2.81L
37.82L
SS-43
To
Strathmore
151S
SS-25
Shepard
24.81L
SS-24
936L/937L
SS-32
SS-33
765L
24.83L
SS-31
L
80
9.
9.83L
Janet
74S
23.80L
SS-23
SS-9
SS-30
SS-37
2.80L
833L
SS-12
45 Strathmore /
Blackie
37.81L
936L / 937L
SS-2
Crossings
Langdon 102S
1065L/1064L
6.82L
SS-6
40.81L
SS-41
SS-40
26.81L
SS-26
26.83L
924L/927L
To
Milo
356S
SS-65
Legend
N.O.
Future Circuit
Existing Circuit
Future Substation
Existing Substation
69 kV Circuit
138 kV Circuit
240 kV Circuit
500 kV Circuit
HVDC line
Normally Open Circuit
69 kV Substation
850L
41.84L
46 High River
54.81L
SS-54
Black Diamond
392S
158L
Hartell
512S
138 kV Substation
240 kV Substation
500 kV Substation
Near-term Identified Issues Medium-term Identified Issues
Long-term Identified Issues
March 2014
Okotoks
678S
To
Carseland
525S
Magcan
142S
812L
434L
High River
65S Foothills
237S
Disclaimer: This diagram is a simplified representation of
the physical system configuration. Technical details have
been simplified for illustration purposes. It does not
accurately display the geographical location of facilities.
To
Chappel
Rock
491S
Calgary Sub-Region Plan
Page 26
1201L
To
Windy
Flats
138S
Proprietary
4.1.3 Near-term Category C Analysis
The steady-state performance of the near-term transmission system was analyzed under Category C5
conditions. The results summarized in Table 4.1-2 below list the highest overloaded system elements
identified under double-circuit tower outage (Category C5) conditions.
There were no voltage violations in the Calgary Sub-Region under Category C5 conditions.
Table 4.1-2: Near-term Category C5 Need Assessment Thermal Results
Sub-Region
Contingency
Case
Rating
(MVA)
Maximum
Thermal
Loading (%)
985L-1003L from Janet 74S to SS25
SC17
287
99
SC17
318
99
SC16
255
110
24.82L from SS-65 to SS-24
SC17
260
175
26.81L from SS-26 to SS-32
SC17
260
104
26.83L from SS-65 to SS-26
SC17
260
118
Overloaded Element
2.81L from SS-2 to SS-9
2.82L from SS-2 to SS-5
23.80L from Janet 74S to SS-23
54.81L from SS-65 to SS-54
Calgary
936L-937L from Langdon 102S to
East Calgary 5S
985L-1003L from Janet 74S to SS25
SC17
267
96
65ST1
SC17
400
128
65ST2
SC17
400
128
916L from Sarcee 42S to East
Calgary 5S
SC1
408
104
SC1
489
96
SC1
489
96
1109L-1080L from SS-25 to SS-65
SC3
121
101
906L-928L from Sarcee 42S to
Benalto
SC3
121
102
936L-937L from Langdon 102S to
East Calgary 5S
SC3
121
104
936L from Langdon 102S to East
Calgary 5S
1064L-1065L from Langdon 102S
to Janet 74S
937L from Langdon 102S to East
Calgary 5S
688L from Summit 653S to
Summit Tap
Airdrie
Note: It is assumed that the 138 kV line 9.80L (from SS-9 to SS-31) line rating can be increased to 287MVA by adjusting the CT limit
ratio to 1200A.
4.2
Medium-term Need Assessment Results
This section summarizes the results of the power flow studies performed using the medium-term study
scenarios as outlined in Section 3.5 and identifies existing system reliability criteria violations for the
medium-term planning horizon. The following sections present the results of the system evaluation under
Category A, B and C5 conditions. The tabulated detailed need assessment results are provided in
Appendix C and single line power flow diagrams for system normal and the critical outages discussed in
this section are provided in Appendix D.
4.2.1 Medium-term Category A Analysis
The steady-state performance of the medium-term transmission system was analyzed under Category A
conditions. The results show that there were some transmission overloads in the Calgary Sub-Region as
provided in Table 4.2-1 below. All transmission voltages were within acceptable limits. The power flow
diagrams for Category A conditions for all the study scenarios are provided in Appendix D.
March 2014
Calgary Sub-Region Plan
Page 27
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Table 4.2-1: Medium-term Category A Need Assessment Thermal Results
Area
Overloaded Element
Contingency
Case
Rating
(MVA)
Maximum
Thermal
Loading (%)
Calgary
2.82L from SS-2 to SS-5
N-0
SC17
318
106
Airdrie
688L from Summit 653S to the
Tap
N-0
SC16
121
104
4.2.2 Medium-term Category B Analysis
The steady-state performance of the medium-term transmission system was analyzed under Category B
conditions. The results summarized in Table 4.2-2 below show the overloaded system elements identified
under first outage (Category B) conditions. The power flow diagrams for these Category B contingencies
are provided in Appendix D.
There were no voltage violations in the Calgary Sub-Region under Category B conditions.
Table 4.2-2: Medium-term Category B Need Assessment Thermal Results
Area
Airdrie
Overloaded Element
Case
Rating
(MVA)
Maximum
Thermal
Loading (%)
688L from East Airdrie 199S to
Nosecreek Tap
752L from East Crossfield 64S to
West Crossfield 316S to Summit
653S
SC16
120
107
631L from East Airdrie 199S to
Balzac 391S
901L from Janet 74S to East
Crossfield 64S to Red Deer 63S
SC4
106
100
SC4
106
123
611L from Drycreek 186S to
Balzac 391S
901L from Janet 74S to East
Crossfield 64S to Red Deer 63S
SC7
117 (W)
140
162.81L from Beddington 162S to
Balzac 391S
SC18
119
108
752L from East Crossfield 64S to
West Crossfield 316S to Summit
653S
SC16
121
120
932L from Janet 74S to
Beddington 162S
SC9
142 (W)
100
SC18
121
120
SC9
142 (W)
97
752L from East Crossfield 64S to
West Crossfield Tap
688L from Summit 653S to
Summit Tap
752L from Summit 653S to West
Crossfield Tap
March 2014
Contingency
688L/688AL
Calgary Sub-Region Plan
Page 28
Proprietary
Table 4.2-2 Continued
Area
Overloaded Element
Contingency
Case
Rating
(MVA)
Maximum
Thermal
Loading (%)
11.83L from Beddington 162S to
SS-11
39.82L from Beddington 162S to
SS-39
SC18
313
107
39.82L from Beddington 162S to
SS-39
11.83L from Beddington 162S to
SS-11
SC18
287
109
936L or 937L from Langdon 102S
to East Calgary 5S
937L or 936L from Langdon 102S
to East Calgary 5S
SC1
489
102
1003L or 985L from Janet 74S to
SS-25
985L or 1003L from Janet 74S to
SS-25
SC17
977
95
916L from East Calgary 5S to
Sarcee 42S
320PGT3
SC14
408
102
765L from Janet 74S to
Strathmore 151S
1106L from SS-65 to Foothills
237S
SC1
85
110
37.82L from Janet 74S to SS-37
932L from Janet 74S to
Beddington 162S
SC17
287
124
23.80L from Janet 74S to SS-23
37.82L from Janet 74S to SS-37
SC17
255
104
SC17
318
155
2.82L from SS-2 to SS-5
2.83L from SS-2 to SS-5 to SS-13
SC8
392 (W)
126
SC19
287
156
SC7
287 (W)
163
Calgary
2.83L from SS-2 to 2.83L Tap
2.82L from SS-2 to SS-5
1109L or1080L from SS-25 to SS65
1080L or 1109L from SS-25 to SS65
SC16
489
98
50L from SS-21 to Bearspaw 44S
7.82L from Sarcee 42S to SS-7
SC7
96 (W)
96
21.61L from SS-21 to SS-34
15.60L from SS-15 to SS-21
SC6
37
143
37
128
21.61L from SS-21 to SS-34
SC6
55
101
49
99
50
102
16.60L from SS-16 to SS-34
15.60L from SS-21 to SS-15
16.63L from SS-36 to SS-16
21.4TR
SC6
36ST4
1.82L or 1.84L from SS-1 to SS-5
1.84L or 1.82L from SS-1 to SS-5
SC17
287
121
3.82L from SS-3 to SS-8
37.82L from Janet 74S to SS-37
SC7
101
123
37.81L from SS-37 to SS-38
932L from Janet 74S to
Beddington 162S
SC17
287
101
24.81L from SS-24 to SS-31
26.83L from SS-65 to SS-26
SC17
287
94
Note: It is assumed that the 138 kV line 9.80L (from SS-9 to SS-31) line rating can be increased to 287MVA by adjusting the CT limit
ratio to 1200A.
Figure 4.2-1 below highlights the thermal overload results under Category A and B conditions across all
study scenarios for the medium-year study year; the bubbles identify overloaded lines.
March 2014
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Figure 4.2-1: Calgary Sub-Region Medium-term Thermal Overloads (Category A and B)
March 2014
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Page 30
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4.2.3 Medium-term Category C Analysis
The steady-state performance of the medium-term transmission system was analyzed under Category C5
conditions. The results summarized in Table 4.2-3 below show the overloaded system elements identified
under Category C5 conditions.
There were no voltage violations in the Calgary Sub-Region under Category C5 conditions.
Table 4.2-3: Medium-term Category C5 Need Assessment Thermal Results
Sub-Region
Overloaded Element
2.80L from SS-2 to SS-23
2.81L from SS-2 to SS-9
2.82L from SS-2 to SS-5
23.80L from Janet 74S to SS-23
Contingency
936L-937L
985L-1003L
1.80L-1.81L
1037L-1038L
1064L-1065L
1106L-1107L
1109L-1080L
901L-929L
924L-927L
925L-929L
985L-1003L
936L-937L
24.81L from SS-24 to SS-31
24.82L from SS-65 to SS-24
Calgary
26.81L from SS-26 to SS-32
26.83L from SS-65 to SS-26
37.82L from Janet 74S to SS-37
54.81L from SS-65 to SS-54
6.82L from SS-6 to SS-41
65.1TR
65.2TR
765L from Janet 74S to
Strathmore 151S
985L-1003L
936L-937L
985L-1003L
1106L-1107L
985L-1003L
916L from East Calgary 5S to
Sarcee 42S
March 2014
936L from Langdon 102S to East
Calgary 5S
937L from Langdon 102S to East
Calgary 5S
1064L-1065L
Langdon 102S 500/240kV
transformer
1037L-1038L
1106L-1107L
Calgary Sub-Region Plan
Page 31
Case
Rating
(MVA)
Maximum
Thermal
Loading (%)
SC14
SC17
SC2
SC19
SC6
SC17
SC17
SC17
SC19
SC17
SC17
SC14
SC7
SC1
SC8
SC7
SC17
SC7
SC17
SC17
SC7
SC8
SC17
SC17
SC17
SC17
SC17
SC17
SC8
SC17
SC1
SC8
260
287
318
318
318
318
318
318
318
318
318
255
287 (W)
255
287 (W)
287
260
321 (W)
260
260
287
287
287
267
159
400
400
85
90 (W)
85
408
494 (W)
106
115
105
105
110
105
107
110
105
108
118
126
111
122
110
105
189
122
113
132
109
101
100
107
103
141
141
170
121
126
131
106
SC1
489
113
SC1
489
113
SC1
SC14
1200
1200
105
103
Proprietary
Table 4.2-3 Continued
Sub-Region
Overloaded Element
688L from East Airdrie 199S to
Nosecreek Tap
Airdrie
688L from Summit 653S to
Summit Tap
Contingency
Maximum
Thermal
Loading (%)
Rating
(MVA)
Case
SC16
121
112
SC16
120
113
1109L-1080L
SC16
121
110
901L-929L
SC16
121
127
906L-928L
SC16
121
112
925L-929L
SC16
121
108
901L-929L
936L-937L
SC3
121
112
Note: It is assumed that the 138 kV line 9.80L(from SS-9 to SS-31) line rating can be increased to 287MVA by adjusting the CT limit
ratio to 1200A.
4.3
Long-term Need Assessment Results
This section summarizes the results of the power flow studies performed using the long-term study
scenarios as outlined in Section 3.5 and identifies existing system reliability criteria violations for the longterm planning horizon. The following sections present the results of the system evaluation under
Category A and B conditions. The tabulated detailed need assessment results are provided in Appendix
C and single line power flow diagrams for system normal and the critical outages discussed in this section
are provided in Appendix D.
4.3.1 Long-term Category A Analysis
The steady-state performance of the long-term transmission system was analyzed under Category A
conditions. The results show that there were numerous overloads as listed in Table 4.3-1 below, some of
which were greater than 150%. The power flow diagrams for Category A conditions for all the study
scenarios are provided in Appendix D.
In Scenario SC2, where Path 1 is approximately 1200 MW import, wind is high and Calgary load at peak,
the 500kV line 1235L from Chapel Rock 491S to Langdon 102S and/or Langdon 500/240kV transformer
reached their capacities.
Table 4.3-1: Long-term Category A Need Assessment Thermal Results
Area
Calgary
Airdrie
Overloaded Element
Case
Rating
(MVA)
Maximum
Thermal
Loading (%)
96
936L or 937L from Langdon 102S to East Calgary
5S
916L from East Calgary 5S to Sarcee 42S
SC9
489
SC2
408
95
765L from Janet 74S to Strathmore 151S
SC3
85
161
37.82L from Janet 74S to SS-37
SC2
287
123
2.82L from SS-2 to SS-5
SC2
318
150
2.83L from SS-2 to 2.83L Tap
SC2
287
108
Langdon 500/240kV transformer
SC2
1200
101
688L from East Airdrie 199S to Nose creek Tap
SC4
121
100
688L from Summit 653S to Summit Tap
SC4
121
115
Note: It is assumed that the 138 kV line 9.80L (from SS-9 to SS-31) line rating can be increased to 287MVA by adjusting the CT limit
ratio to 1200A.
March 2014
Calgary Sub-Region Plan
Page 32
Proprietary
In addition, the normal system voltage in the Calgary area was slightly below the desired minimum
operating limit per AESO Transmission Reliability Criteria. Table 4.3-2 below presents some of the low
voltages observed in the Calgary and Airdrie areas.
Table 4.3-2: Long-term Category A Need Assessment Voltage Results
Area
Calgary
Bus and Substation
Case
V max
(pu)
V min
(pu)
Observed
Voltage
(pu)
555 (ENMX14S7 138.0 kV)
SC2
1.05
0.98
0.97
588 (ENMX8S 7 138.0 kV)
SC2
1.05
0.98
0.96
564 (ENMX36S7 138.0 kV)
SC2
1.05
0.98
0.97
596 (ENMX7S7 138.0 kV)
SC2
1.05
0.98
0.97
548 (ENMX10S7 138.0 kV)
SC2
1.05
0.98
0.97
569 (ENMX3S 7 138.0 kV)
SC2
1.05
0.98
0.96
581 (ENMX12S7 138.0 kV)
SC2
1.05
0.98
0.97
561 (ENMX11S7 138.0 kV)
SC2
1.05
0.98
0.97
550 (ENMX22S7 138.0 kV)
SC2
1.05
0.98
0.96
592 (ENMX41S7 138.0 kV)
SC2
1.05
0.98
0.97
568 (ENMX5S 7 138.0 kV)
SC2
1.05
0.98
0.96
567 (ENMX1S 7 138.0 kV)
SC2
1.05
0.98
0.96
559 (ENMX13S7 138.0 kV)
SC2
1.05
0.98
0.96
571 (ENMX43S7 138.0 kV)
SC2
1.05
0.98
0.97
187 (BEDDING1 240.0 kV)
SC9
1.05
0.98
0.96
591 (ENMX40S7 138.0 kV)
SC2
1.05
0.98
0.97
566 (ENMX20S7 138.0 kV)
SC2
1.05
0.98
0.96
585 (ENMX9S 7 138.0 kV)
SC2
1.05
0.98
0.97
594 (ENMX33S7 138.0 kV)
SC2
1.05
0.98
0.97
552 (ENMX21S7 138.0 kV)
SC2
1.05
0.98
0.97
587 (ENMX6S7 138.0 kV)
SC2
1.05
0.98
0.97
601 (2.83 TAP 138.0 kV)
SC2
1.05
0.98
0.97
4.3.2 Long-term Category B Analysis
The steady-state performance of the long-term transmission system was analyzed under Category B
conditions. The results summarized in Table 4.3-3 below show the overloaded system elements identified
under first outage (Category B) conditions. The power flow diagrams for Category B contingencies listed
in Table 4.3-3 below are provided in Appendix D.
March 2014
Calgary Sub-Region Plan
Page 33
Proprietary
Table 4.3-3: Long-term Category B Need Assessment Thermal Results
Area
Overloaded Element
Rating
(MVA)
Maximum
Thermal
Loading (%)
39.82L from Beddington 162S to
SS-39
11.83L from Beddington 162S to
SS-11
937Lor 936L from Langdon 102S
to East Calgary 5S
SC8
313
118
SC8
287
118
SC9
489
143
37.82L from Janet 74S to SS-37
SC9
481
108
SC7
977
105
SC8
400
117
74ST1 or 74ST2
916L from East Calgary 5S to
Sarcee 42S
5ST1a or 5ST2
74ST2 or 74ST1
SC2
400
110
5ST1a (or T2)
SC2
408
117
5ST2 or 5ST1a
SC9
400
117
21.80L from Sarcee 42S to SS-21
SC2
230
95
SC2
287
166
23.80L from Janet 74S to SS-23
7.82L from Sarcee 42S to SS-7
932L from Janet 74S to
Beddington 162S
37.82L from Janet 74S to SS-37
SC2
255
124
2.82L from SS-2 to SS-5
2.83L from SS-2 to SS-5 to SS-13
SC2
318
220
2.83L from SS-2 to 2.83L Tap
2.82L from SS-2 to SS-5
SC2
287
222
2.80L from SS-2 to SS-23
37.82L from Janet 74S to SS-37
SC2
260
99
65.1TR or 65.2TR
65.2TR or 65.1TR
SC2
400
114
54.81L from SS-65 to SS-54
26.83L from SS-65 to SS-26
SC2
267
97
13.82L from SS-13 to SS-22
SC2
171
105
SC8
260
116
50L from SS-21 to Bearspaw 44S
Langdon 102S 500/240kV
transformer
21.61L from SS-21 to SS-34
37.82L from Janet 74S to SS-37
11.83L from Beddington 162S to
SS-11
7.82L from Sarcee 42S to SS-7
1037L or 1038L from Foothills
237S to SC1
16.60L from SS-16 to SS-34
SC2
96
100
SC2
1200
111
SC2
37
161
16.60L from SS-16 to SS-34
21.61L from SS-21 to SS-34
SC2
37
160
15.60L from SS-15 to SS-21
21.61L from SS-21 to SS-34
SC2
55
105
16.63L from SS-16 to SS-36
21.4TR
SC2
49
139
13.60L from SS-13 to SS-27
21.4TR
SC2
63
97
36ST4
21.4TR
SC9
50
133
1.81L from SS-1 to SS-20
21.80L from Sarcee 42S to SS-21
SC2
155
100
1.82L or 1.84L from SS-1 to SS-5
1.84L or 1.82L from SS-1 to SS-5
SC2
287
152
3.82L from SS-3 to SS-8
37.82L from SS-37 to SS-38
SC2
101
138
26.83L from SS-65 to SS-26
54.81L from SS-65 to SS-54
SC2
260
116
24.82L from SS-65 to SS-24
SC2
260
114
SC2
287
110
SC2
287
128
24.81L from SS-24 to SS-31
26.83L from SS-65 to SS-26
932L from Janet 74S to
Beddington 162S
932L from Janet 74S to
Beddington 162S
26.83L from SS-65 to SS-26
SC2
287
119
32.83L from SS-32 to SS-40
54.81L from SS-65 to SS-54
SC2
159
100
22.81L from SS-22 to SS-39
38.83L from SS-38 to SS-39
37.81L from SS-37 to SS-38
March 2014
Case
11.83L from Beddington 162S to
SS-11
39.82L from Beddington 162S to
SS-39
936L or 937L from Langdon 102S
to East Calgary 5S
932L from Janet 74S to
Beddington 162S
985L or1003L from Janet 74S to
SS-25
162.1TR or 162.2TR
37.82L from Janet 74S to SS-37
Calgary
Contingency
1003L or 985L from Janet 74S to
SS-25
162.2TR or 162.1TR
Calgary Sub-Region Plan
Page 34
Proprietary
Table 4.3-3 Continued
Area
Overloaded Element
Contingency
Maximum
Thermal
Loading (%)
Rating
(MVA)
Case
688L from East Airdrie 199S to
932L from Janet 74S to
SC4
121
118
Nose creek Tap
Beddington 162S
631L from East Airdrie 199S to
64ST2
SC1
106
141
Balzac 391S
611L from Drycreek 186S to
901L from Janet 74S to East
SC1
106
170
Balzac 391S
Crossfield 64S to Red Deer 63S
Airdrie
752L from East Crossfield 64S to
611L from Drycreek 186S to
SC1
119
125
West Crossfield Tap
Balzac 391S
688L from Summit 653S to
932L from Janet 74S to
SC4
121
134
Summit Tap
Beddington 162S
752L from Summit 653S to West
688L/688AL
SC3
121
115
Crossfield Tap
Note: It is assumed that the 138 kV line 9.80L (from SS-9 to SS-31) line rating can be increased to 287MVA by adjusting the CT limit
ratio to 1200A.
Table 4.3-4 and Table 4.3-5 below present the voltage violations in the Calgary and Airdrie areas.
Table 4.3-4: Long-term Category B Need Assessment Voltage Deviation Results
Area
Contingency
Airdrie
901L
East Crossfield
240/138kV transformer
Airdrie
Case and Voltage Dip
Bus Number
SC1
SC7
SC9
4312 (E CROSS9 25.0 kV)
-13%
-12%
-12%
4312 (E CROSS9 25.0 kV)
-13%
-12%
-11%
Table 4.3-5: Long-term Category B Need Assessment Voltage Results
Area
Contingency
Bus and Substation
Case
V max
(pu)
V min
(pu)
Observed
Voltage (pu)
Airdrie
901L
156 (E CROSS4 240.0 kV)
SC2
1.1
0.9
0.89
Some immediate post contingency low voltage issues are noted in Table 4.3-4 above in the Airdrie area.
With the loss of the existing single auto-transformer at East Crossfield 64S or 901L with capacitor banks
in the Airdrie area in service, the voltage dip at East Crossfield 25kV exceeds 10%. With the outage of
901L, the voltage at East Crossfield 240 kV bus fell below 90%. This voltage issue was considered in
addition to the numerous thermal overload conditions observed and summarized in Table 4.3-3 above.
Figure 4.3-1 below highlights the thermal overload results under Category A and B conditions across all
study scenarios for the long-term study year; the bubbles identify overloaded lines.
March 2014
Calgary Sub-Region Plan
Page 35
Proprietary
Figure 4.3-1: Calgary Sub-Region Long-term Thermal Overloads (Category A and B)
March 2014
Calgary Sub-Region Plan
Page 36
Proprietary
4.4
Need Assessment by Area
The need for transmission system development is driven primarily by Category A and B contingency
violations. The following sections summarize the reliability violations in the Calgary Sub-Region as
observed in each of the planning areas.
4.4.1 Calgary Area
The results of the power flow analysis for the Calgary Area to assess the performance of the system
under Category A, B and C are summarized in this section.
There were no thermal or voltage violations in the Calgary Area under Category A conditions in nearterm. However, there were several overloads on the 138 kV circuits in the medium-term and long-term as
shown in Table 4.4-1 below. The loading on the 500 kV line 1235L from Chapel Rock 491S to Langdon
102S and/or Langdon 500/240 kV transformer will be addressed by the AESO’s Intertie Restoration
Program which is currently in progress.
Table 4.4-1: Calgary Area Category A Thermal Violations
Rating
(MVA)
Overloaded Element
Near-Term
Maximum
Thermal
loading (%)
Medium-Term
Maximum
Thermal
loading (%)
106
Long-term
Maximum
Thermal
loading (%)
150
2.82L from SS-2 to SS-5
318
936L or 937L from Langdon 102S to East Calgary 5S
489
916L from East Calgary 5S to Sarcee 42S
408
95
765L from Janet 74S to Strathmore 151S
85
161
37.82L from Janet 74S to SS-37
287
123
2.83L from SS-2 to 2.83L Tap
287
106
Langdon 500/240kV transformer
1200
101
96
There were also low voltage violations observed in the long-term study year as shown in Table 4.4-2
below.
Table 4.4-2: Calgary Area Category A Voltage Violations
Bus and Substation
127 (BEDDING2 138.0 kV)
V max
(pu)
V min
(pu)
Near-term
Worst
Observed
Voltage (pu)
Medium-term
Worst
Observed
Voltage (pu)
1.05
0.98
Long-term
Worst
Observed
Voltage (pu)
0.98
0.98
158 (LANGDON2 500.0 kV)
1.05
1
162 (E CALGAR 240.0 kV)
1.05
0.98
0.98
187 (BEDDING1 240.0 kV)
1.05
0.98
0.97
187 (BEDDING1 240.0 kV)
1.05
0.98
0.96
198 (BALZAC 7 138.0 kV)
1.05
0.98
0.98
202 (SARCEE 7 138.0 kV)
1.05
0.98
0.97
552 (ENMX21S7 138.0 kV)
1.05
0.98
0.96
559 (ENMX13S7 138.0 kV)
1.05
0.98
0.96
579 (ENMX31S7 138.0 kV)
1.05
0.98
0.97
585 (ENMX9S 7 138.0 kV)
1.05
0.98
0.97
592 (ENMX41S7 138.0 kV)
1.05
0.98
0.97
March 2014
Calgary Sub-Region Plan
Page 37
Proprietary
There were no voltage violations in the Calgary Area under Category B conditions in near-term, mediumterm study years. However, there were several overloads observed in the near-term, medium-term and
long-term as shown in Table 4.4-3 below. The results show a progressive increase in overload level and
number of overloaded elements in the area from the near-term planning horizon to the long-term planning
horizon.
Table 4.4-3: Calgary Area Category B Thermal Violations
Overloaded Element
Contingency
Rating
(MVA)
Near-term
Maximum
Thermal
loading (%)
Medium-term
Maximum
Thermal
loading (%)
Long-term
Maximum
Thermal
loading (%)
100
99
121
152
95
105
118
1.81L from SS-1 to SS-20
21.80L from Sarcee 42S to SS-21
155
1.82L or 1.84L from SS-1 to SS-5
1.84L or 1.82L from SS-1 to SS-5
287
1003L or 985L from Janet 74S to
SS-25
985L or 1003L from Janet 74S to
SS-25
977
11.83L from Beddington 162S to
SS-11
39.82L from Beddington 162S to
SS-39
313
99
107
1109L or 1080L from SS-25 to SS65
1080L or 1109L from SS-25 to SS65
489
96
98
13.60L from SS-13 to SS-27
21.4TR
63
97
13.82L from SS-13 to SS-22
37.82L from Janet 74S to SS-37
171
105
15.60L from SS-15 to SS-21
21.61L from SS-21 to SS-34
55
101
105
16.60L from SS-16 to SS-34
21.61L from SS-21 to SS-34
37
128
160
16.63L from SS-16 to SS-36
21.4TR
49
99
139
162.1TR or 162.2TR
162.2TR or 162.1TR
400
2.80L from SS-2 to SS-23
37.82L from Janet 74S to SS-37
2.82L from SS-2 to SS-5
2.83L from SS-2 to SS-5 to SS-13
2.83L from SS-2 to 2.83L Tap
2.82L from SS-2 to SS-5
117
260
99
318
133
155
392 (W)
108
126
287
135
156
287 (W)
137
163
118
143
220
222
15.60L from SS-15 to SS-21
37
16.60L from SS-16 to SS-34
37
161
21.80L from Sarcee 42S to SS-21
7.82L from Sarcee 42S to SS-7
230
95
22.81L from SS-22 to SS-39
11.83L from Beddington 162S to
SS-11
260
116
23.80L from Janet 74S to SS-23
37.82L from Janet 74S to SS-37
255
104
124
24.81L from SS-24 to SS-31
26.83L from SS-65 to SS-26
287
94
119
24.82L from SS-65 to SS-24
26.83L from SS-65 to SS-26
260
114
26.83L from SS-65 to SS-26
54.81L from SS-65 to SS-54
260
116
3.82L from SS-3 to SS-8
37.82L from Janet 74S to SS-37
101
32.83L from SS-32 to SS-40
54.81L from SS-65 to SS-54
159
36ST4
21.4TR
50
37.81L from SS-37 to SS-38
932L from Janet 74S to
Beddington 162S
287
37.82L from Janet 74S to SS-37
932L from Janet 74S to
Beddington 162S
287
21.61L from SS-21 to SS-34
March 2014
Calgary Sub-Region Plan
Page 38
123
138
102
133
101
128
124
166
100
102
105
Proprietary
Table 4.4-3 Continued
Overloaded Element
Contingency
Rating
(MVA)
Near-term
Maximum
Thermal
loading (%)
Medium-term
Maximum
Thermal
loading (%)
Long-term
Maximum
Thermal
loading (%)
38.83L from SS-38 to SS-39
932L from Janet 74S to
Beddington 162S
287
39.82L from Beddington 162S to
SS-39
11.83L from Beddington 162S to
SS-11
287
50L from SS-21 to Bearspaw 44S
7.82L from Sarcee 42S to SS-7
96
54.81L from SS-65 to SS-54
26.83L from SS-65 to SS-26
267
97
5ST1a or 5ST2
5ST2 or 5ST1a
400
117
110
108
109
118
96
100
65.1TR or 65.2TR
65.2TR or 65.1TR
400
114
74ST1 / 74ST2
74ST2 / 74ST1
400
110
765L from Janet 74S to
Strathmore 151S
1106L from SS-65 to Foothills
237S
85
110
916L from East Calgary 5S to
Sarcee 42S
320PGT3
408
102
5ST1a (or T2)
408
117
932L from Janet 74S to
Beddington 162S
37.82L from Janet 74S to SS-37
481
108
936L or 937L from Langdon 102S
to East Calgary 5S
937Lor 936L from Langdon 102S
to East Calgary 5S
489
Langdon 102S 500/240kV
transformer
1037L or 1038L from Foothills
237S to SC1
1200
102
143
111
Note: It is assumed that the 138 kV line 9.80L (from SS-9 to SS-31) line rating can be increased to 287MVA by adjusting the CT limit
ratio to 1200A.
Category C5 contingency analysis was performed for the near-term and medium-term study years only.
There were no voltage violations in the Calgary area under Category C5 conditions in near-term and
medium-term study years. However, there were several overloads observed in the near-term and
medium-term study years as shown in Table 4.4-4 below. The results show a progressive increase in
overload level and number of overloaded elements in the area from the near-term study year to the
medium-term study year.
March 2014
Calgary Sub-Region Plan
Page 39
Proprietary
Table 4.4-4: Calgary Area Category C5 Thermal Violations
Overloaded Element
Contingency
Rating
(MVA)
Near-term
Maximum
Thermal
loading (%)
2.80L from SS-2 to SS-23
936L-937L
2.81L from SS-2 to SS-9
985L-1003L from Janet 74S to SS-25
287
1.80L-1.81L
318
105
1037L-1038L
318
105
1064L-1065L
318
110
1106L-1107L
318
105
1109L-1080L
318
107
901L-929L
318
110
924L-927L
318
105
2.82L from SS-2 to SS-5
260
Medium-term
Maximum
Thermal
loading (%)
106
318
985L-1003L
318
99
118
255
110
126
936L-937L from Langdon 102S to East
Calgary 5S
24.81L from SS-24 to SS-31
936L-937L from Langdon 102S to East
Calgary 5S
24.82L from SS-65 to SS-24
985L-1003L from Janet 74S to SS-25
24.83L from SS-65 to SS-24
985L-1003L from Janet 74S to SS-25
260
985L-1003L from Janet 74S to SS-25
260
26.83L from SS-65 to SS-26
37.82L from Janet 74S to SS37
54.81L from SS-65 to SS-54
115
925L-929L
23.80L from Janet 74S to SS23
26.81L from SS-26 to SS-32
99
108
287 (W)
111
287
105
260
189
321 (W)
122
175
113
985L-1003L from Janet 74S to SS-25
260
985L-1003L from Janet 74S to SS-25
260
104
985L-1003L from Janet 74S to SS-25
936L-937L from Langdon 102S to East
Calgary 5S
985L-1003L from Janet 74S to SS-25
260
287
287
100
985L-1003L from Janet 74S to SS-25
267
107
132
118
109
985L-1003L from Janet 74S to SS-25
267
6.82L from SS-6 to SS-41
985L-1003L from Janet 74S to SS-25
159
103
65.1TR
985L-1003L from Janet 74S to SS-25
400
141
65.2TR
985L-1003L from Janet 74S to SS-25
400
65ST1
985L-1003L from Janet 74S to SS-25
400
128
65ST2
985L-1003L from Janet 74S to SS-25
400
128
765L from Janet 74S to
Strathmore 151S
1106L-1107L
96
141
85
170
90 (W)
121
985L-1003L from Janet 74S to SS-25
85
916L from East Calgary 5S to
Sarcee 42S
1064L-1065L from Langdon 102S to
Janet 74S
408
936L from Langdon 102S to
East Calgary 5S
937L from Langdon 102S to
East Calgary 5S
1064L-1065L from Langdon 102S to
Janet 74S
1064L-1065L from Langdon 102S to
Janet 74S
1037L-1038L
1200
105
1106L-1107L
1200
103
Langdon 102S 500/240kV
transformer
March 2014
Calgary Sub-Region Plan
Page 40
126
104
494 (W)
131
106
489
96
113
489
96
113
Proprietary
4.4.2 Airdrie Area
The results of the power flow analysis for the Airdrie Area to assess the performance of the system under
Category A, B and C are summarized in this section.
There were no thermal or voltage violations in the Airdrie Area under Category A conditions in near-term
study year. However, there were overloads on the 138 kV circuits in the medium-term and long-term
study year as shown in Table 4.4-5 below.
Table 4.4-5: Airdrie Area Category A Thermal Violations
Rating
(MVA)
Overloaded Element
688L from Summit 653S to Summit Tap
121
688L from East Airdrie 199S to Nosecreek Tap
121
Near-term
Maximum
Thermal
loading (%)
Medium-term
Maximum
Thermal
loading (%)
104
Long-term
Maximum
Thermal
loading (%)
115
100
There were also low voltage violations observed in the long-term study year as shown in Table 4.4-6
below.
Table 4.4-6: Airdrie Area Category A Voltage Violations
Bus and Substation
177 (AIRDRIE 138.0 kV)
V max
(pu)
V min
(pu)
1.05
0.98
Near-term
Worst
Observed
Voltage
(pu)
Mediumterm Worst
Observed
Voltage
(pu)
Long-term
Worst
Observed
Voltage
(pu)
0.98
There were several overloads observed in the near-term, medium-term and long-term study years under
Category B conditions as shown in Table 4.4-7 below. The results show a progressive increase in
overload level and number of overloaded elements in the area from near-term to long-term.
March 2014
Calgary Sub-Region Plan
Page 41
Proprietary
Table 4.4-7: Airdrie Area Category B Thermal Violations
Overloaded Element
Contingency
611L from Drycreek 186S to
Balzac 391S
901L from Janet 74S to East
Crossfield 64S to Red Deer 63S
631L from East Airdrie 199S to
Balzac 391S
688L from East Airdrie 199S to
Nosecreek Tap
688L from Summit 653S to
Summit Tap
117 (W)
108
117
121
118
142 (W)
99
932L from Janet 74S to
Beddington 162S
142 (W)
611L from Drycreek 186S to
Balzac 391S
162.81L from Beddington 162S to
Balzac 391S
752L from Summit 653S to West
Crossfield Tap
Medium-term
Maximum
Thermal
loading (%)
123
64ST2
901L from Janet 74S to East
Crossfield 64S to Red Deer 63S
752L from East Crossfield 64S to
West Crossfield 316S to Summit
653S
932L from Janet 74S to
Beddington 162S
752L from East Crossfield 64S to
West Crossfield 316S to Summit
653S
162.81L from Beddington 162S to
Balzac 391S
752L from East Crossfield 64S to
West Crossfield Tap
106
Near-term
Maximum
Thermal
loading (%)
107
Rating
(MVA)
688L/688AL
Long-term
Maximum
Thermal
loading (%)
170
106
141
106
100
120
106
107
121
118
120
121
134
100
119
129
136 (W)
111
108
119
125
121
139
142 (W)
117
121
120
142 (W)
97
115
There are no existing double circuit transmission towers connection stations in the Airdrie area except for
a short section of double circuit 138 kV monopoles leading to Dry Creek 186S. Table 4.4-8 shows the
Category C5 thermal violations observed in the Airdrie area.
Table 4.4-8: Airdrie Area Category C5 Thermal Violations
Overloaded Element
Contingency
688L from East Airdrie 199S to
Nose Creek Tap
901L-929L
688L from Summit 653S to
Summit Tap
1109L-1080L from SS-25 to
SS-65
901L-929L
906L-928L from Sarcee 42S
to Benalto
925L-929L
936L-937L from Langdon
102S to East Calgary 5S
March 2014
Rating
(MVA)
Near-term
Maximum
Thermal
loading (%)
121
Calgary Sub-Region Plan
Page 42
121
112
101
121
121
110
127
102
121
121
Medium-term
Maximum
Thermal
loading (%)
112
108
104
112
Proprietary
4.5
Need Assessment Summary
Table 4.5-1 below summarizes the need for transmission reinforcement in the Calgary Sub-Region.
Figure 4.5-1 below shows areas with criteria violations under Category A and Category B outages for the
near-term, medium-term, and long-term study years.
Table 4.5-1: Summary of Need Assessment
Area
Need Summary
Limited transmission capacity on the existing 138 kV system to transfer generation
into the area and to accommodate forecasted load growth.
Need Period
Near through
long-term
Calgary (Area 6)
Limited transmission capability on the existing 69 kV system to accommodate
forecasted load growth.
Airdrie (Area 57)
Limited transmission capacity on the existing 138 kV system due to low capacity of
existing transmission lines.
Near through
long-term
Near through
long-term
In addition, the Need Assessment results also showed that the 500 kV line from Chapel Rock 491S to
Langdon 102S and the Langdon 102S 500/240 kV transformer overloaded under high import (Path 1,
approximately 1200 MW) and high wind scenario. This intertie issue will be studied as part of AESO’s
Intertie Restoration Program, which is currently in progress.
March 2014
Calgary Sub-Region Plan
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Proprietary
Figure 4.5-1: Calgary Sub-Region Need Assessment Summary (Near-term to Long-term)
To Red Deer
63S
To Benalto
17S
West
Crossfield
316S
901AL
East
Crossfield
64S
752L
901L
929L/925L
653S
906L/
928L
Nose Creek
284S
57
Airdrie
688L
East Airdrie
199S
631L
DryCreek
186S
611L
Balzac
391S
YY
Beddington
162S
918L
44
Seebee
932L
SS-47
SS-49
11.83L
SS-14
14.83L
36.81L
SS-11
11.82L
39.82L
SS-36
16.63L
SS-16
BEARSPAW
15.62L
7.84L
50L
SS-15
SS-7
11.81L
16.61L
16.60L
SS-27
21.61L
6 Calgary
SS-13
SS-3
SS-22
3.82L
1.82LSS-20
1.80L
3L
3.84L
15.60L
7.82L
150L
SS-39
13.82L
SS-34
SS-21
22.81L
13.60L
1.85L 1.83L SS-5
2.83L
1.84L
1.81L
SS-1 1.82L
2.82L
SS-28
Sarcee 28.80L
42S
693L
38.83L
2.83L
SS-8
SS-38
Bonnybrook
East Calgary 5S
SS-10
916L
832L
2.80L
833L
37.82L
Janet
74S
765L
To
Strathmore
151S
24.83L
SS-25
Shepard
SS-31
8
9.
9.83L
23.80L
SS-23
SS-9
0L
SS-43
SS-30
SS-37
2.81L
SS-12
45 Strathmore /
Blackie
37.81L
936L / 937L
SS-2
24.81L
SS-24
SS-32
SS-33
Crossings
Langdon 102S
936L/937L
1065L/1064L
6.82L
SS-6
40.81L
SS-41
SS-40
26.81L
924L/927L
To
Milo
356S
SS-65
SS-26
26.83L
850L
N.O.
54.81L
SS-54
Future Circuit
Existing Circuit
Future Substation
Existing Substation
69 kV Circuit
138 kV Circuit
240 kV Circuit
500 kV Circuit
HVDC line
Normally Open Circuit
69 kV Substation
46 High River
Black Diamond
392S
158L
Hartell
512S
240 kV Substation
March 2014
Okotoks
678S
Magcan
142S
812L
434L
High River
65S Foothills
237S
138 kV Substation
500 kV Substation
Near-term Identified Issues Medium-term Identified Issues
Long-term Identified Issues
To
Carseland
525S
41.84L
Legend
Disclaimer: This diagram is a simplified representation of
the physical system configuration. Technical details have
been simplified for illustration purposes. It does not
accurately display the geographical location of facilities.
To
Chappel
Rock
491S
Calgary Sub-Region Plan
Page 44
1201L
To
Windy
Flats
138S
Proprietary
5 Alternative Development and Screening
Alternatives were formulated with consideration to the type of violations, the geographic location of
transmission constraints, projected in-service dates of need, the long term load and generation forecasts,
and the geography of the study area.
The basic guidelines adopted in devising the alternatives include:




Facilities that are 138 kV and 240 kV voltage levels. It was not necessary to investigate 500 kV
facilities because the load and generation forecasts are well below the transfer capabilities of the
500 kV facilities.
Rebuilding of existing facilities to higher capacities.
Build new facilities to alleviate existing constraints.
Reactive support devices to improve system voltages.
Line lengths were estimated based upon review of geographic maps including Google Earth and
knowledge of local area and allowance was made for uncertainty in actual routing. The alternatives
development assumed existing substations could be expanded; however, TFOs will validate this
assumption in their high level assessment of the proposed alternatives.
The sections below describe the proposed alternatives for each area. It should be noted that the
proposed alternatives serve the system needs over the 20 year planning horizon and beyond and thus
are considered to be ultimate transmission development for the 20 years planning horizon.
5.1
Calgary Area Alternatives
The existing transmission system issues identified in the Calgary Area are summarized in Table 5.1-1
below.
March 2014
Calgary Sub-Region Plan
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Table 5.1-1: Calgary Area System Issues and Conceptual Solutions
Issues Identified
Conceptual Solutions
Rationale
1. New 138 kV cables from SS-2
to SS-1 or SS-8
OR
Downtown load supply: significant
overloads identified on the 138 kV
cables to supply load at SS-1, SS-5,
and SS-8 in near through long term
2. Convert existing SS-8 to a
new 240/138 kV source
substation. New 240 kV lines
from East Calgary, Beddington
SS-162 or Sarcee 42S.
OR
1. Additional capacity at 138 kV.
2. Additional capacity at 240 kV
bypass 138 kV circuits.
3. Flow control increase flow from
other source and decrease flow
on overloaded circuits.
3. Power flow control device (e.g.
phase shifting transformer or
FACTs device).
North 69 kV load supply: overloads
on the 69 kV network in near
through long term.
Partial or full conversion of 69 kV
network to 138 kV.
Address capacity and equipment
condition.
1. New 240/138 kV station in
north west Calgary and
associated new 138 kV lines.
Other north Calgary issues:
overload on 138 kV lines in north
Calgary network as well as
240/138kV transformers at
Beddington SS-162 and Janet 74S
OR
1. Additional capacity in north
Calgary
2. Convert SS-36 to 240 kV and
upgrade associated 138 kV lines
2. Similar to 1.
AND
3. Address overloads on the 138
kV lines between Janet 74S and
Beddington SS-162.
3. In-out 929L at Beddington SS162.


Overloads on 138 kV lines in
south Calgary network including
the 138 kV lines coming out of
SS-65 as well as the 240/138 kV
transformer at SS-65.
Overloads on 240kV lines
between Sarcee 42S, Janet 74S
and SS-25
1. FATD West lines from
Foothills 237S to Sarcee 42S
OR
2. FATD West lines terminated at
SS-6 or SS-41 with upgrades
of local 138 kV lines coming
11
out of SS-6 / SS-41 .
1. Evacuate high local generation
in south east Calgary and wind
power in southern Alberta.
2. Similar to 1.
Six alternatives were evaluated for the Calgary area, which include both 240 kV and 138 kV level
facilities. The descriptions of these alternatives are presented in the following sections.
11
This option was examined and was viewed as less desirable than completing the 240kV loop to Sarcee.
March 2014
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Proprietary
5.1.1 Calgary Area Alternative 1
Alternative 1 includes the following developments:
1. Downtown supply
a. Two new 138 kV circuits approximately 5 km with minimum rating of approximately 300 MVA
each to connect SS-2 to SS-1 (or SS-8)
b. New 2 x 54 MVAr capacitor banks at SS-1 (or SS-8)
2. North 69 kV network upgrade to 138 kV system
3. New 240/138 kV Lochend 75S substation and new 138 kV lines from Lochend 75S to SS-49 (or
SS-47), SS-14, and SS-36
4. 929L connected to Beddington in an in-out configuration
5. New 138 kV line from SS-23 to SS-22
6. New 138 kV line from Janet to SS-37
7. New capacitor banks: 54 MVAr at SS-22; 54 MVAr at SS-13
8. FATD West double circuit 240 kV lines from Foothills 237S to Sarcee 42S
The simplified diagram for Alternative 1 is shown in Figure 5.1-1 below.
March 2014
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Page 47
Proprietary
Figure 5.1-1: Calgary Area – Alternative 1
March 2014
Calgary Sub-Region Plan
Page 48
Proprietary
5.1.2 Calgary Area Alternative 2
Alternative 2 includes the following developments:
1. Downtown supply: convert the existing SS-8 to 240/138 kV substation to be completed with:
a. Two 240/138 kV 400 MVA transformers
b. New 240 kV circuit from East Calgary 5S to SS-8 240 kV
c.
New 240 kV circuit from Beddington SS-162 to SS-8 240 kV
d. New 2 x 54 MVAr capacitor banks at SS-1
2. North 69 kV network upgrade to 138 kV system
3. New 240/138 kV Lochend 75S substation in northwest and new 138kV lines from Lochend 75S to
SS-49 (or SS-47), SS-14, and SS-36
4. 929L connected to Beddington SS-162 in an in-out configuration
5. Normally open (N.O.) 3.82L and new 138 kV line from SS-27 to SS-3
6. New 138 kV line from SS-23 to SS-22
7. New 138 kV line from Janet to SS-37
8. New capacitor banks: 54 MVAr at SS-22 and 54 MVAr at SS-13
9. FATD West double circuit 240 kV lines from Foothills 237S to Sarcee 42S
The simplified diagram for Alternative 2 is shown in Figure 5.1-2 below.
March 2014
Calgary Sub-Region Plan
Page 49
Proprietary
WATL
To Sunnybrook
Figure 5.1-2: Calgary Area – Alternative 2
985L/1003L
32.83L
24.82L
33.84L
33.83L
31.84L
30.81L
1109L/1080L
6.80L
L
80
9.
1107L
1106L
850L
646L
March 2014
Calgary Sub-Region Plan
Page 50
Proprietary
5.1.3 Calgary Area Alternative 3
Alternative 3 includes the following developments:
1. Downtown supply: convert the existing SS-8 to 240/138kV substation to be completed with
a. Two 240/138 kV 400 MVA transformers
b. New 240 kV circuit from East Calgary to SS-8 240 kV
c.
New 240 kV 400 MVA phase shifting transformer (PST) at Beddington is assumed although a
solid state flow control device may also be considered.
d. New 240 kV circuit from Beddington PST to SS-8 240 kV
e. New 2 x 54 MVAr capacitor banks at SS-1
2. North 69kV network upgrade to 138kV system
3. New 240/138 kV Lochend 75S substation and new 138 kV lines from Lochend 75S to SS-49 (or
SS-47), SS-14, and SS-36
4. 929L connected to Beddington in an in-out configuration
5. Rebuild 3.82L underground cable with higher capacity cable (~300 MVA).
6. New 138kV line from SS-23 to SS-22
7. New 138kV line from Janet 74S to SS-37
8. New capacitor banks: 54 MVAr at SS-22; 54 MVAr at SS-13
9. FATD West double circuit 240 kV lines from Foothills 237S to Sarcee 42S
The simplified diagram for Alternative 3 is shown in Figure 5.1-3 below.
March 2014
Calgary Sub-Region Plan
Page 51
Proprietary
WATL
To Sunnybrook
Figure 5.1-3: Calgary Area – Alternative 3
985L/1003L
32.83L
24.82L
33.84L
33.83L
31.84L
30.81L
1109L/1080L
6.80L
L
80
9.
1107L
1106L
850L
646L
March 2014
Calgary Sub-Region Plan
Page 52
Proprietary
5.1.4 Calgary Area Alternative 4
Alternative 4 includes the following developments:
1. Downtown supply: convert the existing SS-8 to 240/138 kV substation to be completed with:
a. Two 240/138 kV 400 MVA transformers
b. New 240 kV circuit from Sarcee to SS-8 240 kV
c.
New 240 kV circuit from Beddington to SS-8 240 kV
d. New 2 x 54 MVAr capacitor banks at SS-1
2. North 69 kV network upgrade to 138 kV system
3. New 240/138 kV Lochend 75S substation and new 138 kV lines from Lochend 75S to SS-49 (or
SS-47), SS-14, and SS-36
4. 929L connected to Beddington in an in and out configuration
5. Normally open (N.O.) 3.82L and new 138kV line from SS-27 to SS-3
6. Normally open (N.O.) 2.83L from SS-13 to the tap
7. New 138 kV line from SS-23 to SS-22
8. New 138 kV line from Janet 74S to SS-37
9. New capacitor banks: 54 MVAr at SS-22 and 54 MVAr at SS-13
10. FATD West double circuit 240 kV lines from Foothills 237S to Sarcee 42S
The simplified diagram for Alternative 4 is shown in Figure 5.1-4 below.
March 2014
Calgary Sub-Region Plan
Page 53
Proprietary
Figure 5.1-4: Calgary Area – Alternative 4
To Benalto
17S
To Red Deer
63S
901L
611L
906L/
928L
929L/
925L
YY
Beddington
162S
918L
75S
932L
44
Seebee
SS-49
SS-47
SS-14
11.83L
SS-11
11.82L
14.83L
SS-36
SS-16
36.81L
39.82L
11.81L
SS-27
BEARSPAW
50L
SS-15
SS-34
3.84L
21.61L
SS-7
SS-39
13.82L
SS-13
SS-3
SS-22
3.82L
SS-21
N.O.
1.82L
7.82L
SS-28
150L
28.80L
Sarcee 42S
38.83L
2.83L
SS-8
1.80L
3L
22.81L
16.60L
7.84L
N.O.
SS-20
1.85L 1.83L
SS-5
2.83L
1.84L
1.81L
1.82L
SS-1
2.82L
N.O.
East Calgary 5S Bonnybrook
693L
916L
SS-10
833L
832L
SS-12
To
Foothills
237S
SS-37
2.80L
2.81L
SS-43
Janet
74S
37.82L
23.80L
SS-23
765L
SS-25
Shepard
24.81L
SS-24
SS-32
SS-33
To
Strathmore
151S
24.83L
SS-31
L
80
9.
9.83L
45 Strathmore /
Blackie
37.81L
936L / 937L
SS-2
SS-9
SS-30
SS-38
936L/937L
Crossing
Langdon 102S
1065L/1064L
6.82L
SS-6
40.81L
SS-41
SS-40
26.81L
SS-26
To
Milo
356S
SS-65
26.83L
Legend
N.O.
Future Circuit
Existing Circuit
Future Substation
Existing Substation
69 kV Circuit
138 kV Circuit
240 kV Circuit
500 kV Circuit
HVDC line
Normally Open Circuit
69 kV Substation
924L/927L
850L
41.84L
46 High River
SS-54
Black Diamond
392S
To
Carseland
525S
54.81L
158L
Bigrock
Okotoks
678S
Magcan
142S
Hartell
512S
812L
138 kV Substation
240 kV Substation
500 kV Substation
Proposed Development
March 2014
Disclaimer: This diagram is a simplified representation of
the physical system configuration. Technical details have
been simplified for illustration purposes. It does not
accurately display the geographical location of facilities.
Calgary Sub-Region Plan
Page 54
To
Chappel
Rock
491S
High River 434L
65S
To Sarcee
42S
Foothills
237S
1201L
Proprietary
5.1.5 Calgary Area Alternative 5
Alternative 5 includes the following developments:
1. Downtown supply: convert the existing SS-8 to 240/138 kV substation to be completed with
a. Two 240/138 kV 400 MVA transformers
b. New 240 kV circuit from East Calgary 5S to SS-8 240 kV
c.
New 240 kV circuit from Sarcee 42S to SS-8 240 kV
d. New 2 x 54 MVAr capacitor banks at SS-1
2. North 69 kV network upgrade to 138 kV system
3. New 240/138 kV Lochend 75S substation and new 138 kV lines from Lochend 75S to SS-49 (or
SS-47), SS-14, and SS-36
4. 929L connected to Beddington SS-162 in an in and out configuration
5. Normally open (N.O.) 3.82L and new 138 kV line from SS-27 to SS-3
6. New 138 kV line from SS-23 to SS-22
7. New 138 kV line from Janet to SS-37
8. New capacitor banks: 54 MVAr at SS-22; 54 MVAr at SS-13
9. FATD West double circuit 240 kV lines from Foothills 237S to Sarcee 42S
The simplified diagram for Alternative 5 is shown in Figure 5.1-5 below.
March 2014
Calgary Sub-Region Plan
Page 55
Proprietary
Figure 5.1-5: Calgary Area – Alternative 5
March 2014
Calgary Sub-Region Plan
Page 56
Proprietary
5.1.6 Calgary Area Alternative 6
Alternative 6 includes the following developments:
1. Downtown supply: convert existing SS-8 to 240/138 kV station completed with
a. Two 240/138 kV 400 MVA transformers
b. New 240 kV circuit from East Calgary 5S to SS-8 240 kV
c.
New 240 kV circuit from Beddington SS-162 to SS-8 240 kV
d. New 2 x 54 MVAr capacitor banks at SS-1
2. North 69 kV network upgrade to 138 kV
3. Convert SS-36 to 240 kV and new line from SS-36 to SS-49 (or SS-47); rebuild the line from SS36 to SS-14
4. 929L connected to Beddington SS-162 in an in and out configuration
5. Normally open (N.O.) 3.82L and new 138 kV line from SS-27 to SS-3
6. New 138 kV line from SS-23 to SS-22
7. New 138 kV line from Janet 74S to SS-37
8. New capacitor banks: 54 MVAr at SS-22 and 54 MVAr at SS-13
9. FATD West double circuit 240 kV lines from Foothills 237S to Sarcee 42S
The simplified diagram for Alternative 6 is shown in Figure 5.1-6 below.
March 2014
Calgary Sub-Region Plan
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Figure 5.1-6: Calgary Area – Alternative 6
March 2014
Calgary Sub-Region Plan
Page 58
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5.2
Airdrie Area Alternatives
The existing transmission system issues identified in the Calgary Area are summarized in Table 5.2-1
below.
Table 5.2-1: Airdrie Area System Issues and Conceptual Solutions
Area
Issues Identified
Conceptual Solutions
1. Upgrade the overloaded
existing lines with higher
capacity lines.
Airdrie
Overload on the 138 kV line due to
load and generation condition and
low capacity of the existing
transmission lines.
OR
2. Breakup the existing single big
138 kV loop system to small
looped systems.
OR
3. New 240/138 kV source
substation.
Rationale
1. Additional 138 kV capacity on
same system topology.
2. Reduce flow through after
outage thereby relieving 138 kV
overloads.
3. Provides additional power
injection in middle of 138 kV
Airdrie system to reduce 138 kV
flows from SS-162 and East
Crossfield 64S while allowing for
provision of future POD east of
Airdrie.
Based on the AESO’s pre-consultation, a new point of delivery (POD) was assumed in the long-term and
possibly located in the southeast area of Airdrie. The load level at this POD in long-term was assumed to
be 30 MW (p.f. of 0.9) in addition to the forecasted area peak load in order to assess the impact of this
potential new POD. The proposed option to connect the new POD was dependent on the assumed
location of the new POD. If the location of the new POD changes, there may be other connection
alternatives for the new POD.
Four alternatives were evaluated for the Airdrie area, one of which includes both 240 kV and 138 kV level
facilities. The descriptions of these alternatives are presented in the following sections.
5.2.1 Airdrie Area Alternative 1
In Alternative 1, existing 138 kV lines were rebuilt with higher capacity conductor.
Alternative 1 includes the following developments:
1. 901L tap converted to in-out configuration at East Crossfield 64S
2. One new 240/138kV 200 MVA transformer at East Crossfield 64S
3. Upgrade existing 138 kV lines 752L from East Crossfield 64S to Airdrie tap to Summit 653S to
higher thermal capacity line (260MVA)
4. Upgrade existing 138 kV line 688L from Summit 653S to Nose Creek tap to East Airdrie 199S to
higher capacity line (260MVA)
5. Upgrade existing 138 kV line 631L from East Airdrie 199S to DryCreek 186S to higher capacity
line (260MVA)
6. Upgrade existing 138 kV line 611L from Drycreek 186S to Balzac with higher capacity line
(260MVA)
7. New 138 kV lines to connect New POD (approximately 5 km) to 611L.
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8. Upgrade /install protection systems as necessary to facilitate the above system reinforcements
The simplified diagram for Alternative 1 is shown in Figure 5.2-1 below.
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901L
925L/
929L
Figure 5.2-1: Airdrie Area – Alternative 1
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5.2.2 Airdrie Area Alternative 2
Alternative 2 breaks up the existing 138 kV network into two smaller 138 kV loops to prevent the cross
flows.
Alternative 2 includes the following developments:
1. 901L tap converted to in and out configuration at East Crossfield 64S
2. One new 240/138 kV 200 MVA transformer at East Crossfield 64S
3. Upgrade existing 138 kV lines 752L from East Crossfield 64S to Airdrie tap to Summit 653S to
higher capacity line (177 MVA)
4. Upgrade the existing 138 kV line 688L from Summit 653S to Summit tap to East Airdrie 199S to
higher capacity line (177 MVA)
5. Upgrade the existing 138 kV line 611L from Drycreek 186S to Balzac with higher capacity line
(177 MVA)
6. Build a new 138 kV line from East Airdrie 199S to East Crossfield 64S (approximately 30 km, 177
MVA)
7. Normally open (N.O.) 631L from East Airdrie 199S to Drycreek 186S
8. New 138 kV line from Beddington to DryCreek 186S (approximately 13 km, 177 MVA)
9. New 138 kV lines to connect the New POD to the newly proposed 138 kV line between
Beddington 162S and DryCreek 186S (approximately 5 km, 177 MVA) in an in/out configuration
10. Upgrade /install protection systems as necessary to facilitate the above system reinforcements
The simplified diagram for Alternative 2 is shown in Figure 5.2-2 below.
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901L
929L
925L
Figure 5.2-2: Airdrie Area – Alternative 2
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5.2.3 Airdrie Area Alternative 3
Similar to Alternative 2, Alternative 3 also breaks up the existing 138 kV network into two smaller 138 kV
loops to prevent cross flows.
Alternative 3 includes the following developments:
1. 901L tap converted to in and out configuration at East Crossfield 64S
2. One new 240/138 kV 200 MVA transformer at East Crossfield 64S
3. Upgrade the existing 138 kV lines 752L from East Crossfield 64S to Airdrie tap to Summit 653S to
higher capacity line (177 MVA)
4. Upgrade the existing 138 kV line 688L from Summit 653S to Nosecreek tap and from Nose Creek
tap to the joint to higher capacity line (177 MVA)
5. Build a new 138 kV line from 688L joint to East Crossfield 64S (approximately 20 km, 177 MVA)
6. Normally open (N.O.) 688L from the joint to East Airdrie 199S
7. Upgrade the existing 138 kV line 611L from Drycreek 186S to Balzac with higher capacity line
(177 MVA)
8. New 138 kV line from Beddington 162S to DryCreek 186S (approximately 13 km, 177 MVA)
9. New 138 kV lines from New POD to the newly proposed 138kV line between Beddington 162S
and DryCreek 186S (approximately 5 km, 177 MVA) in an in/out configuration
10. Upgrade /install protection systems as necessary to facilitate the above system reinforcements
The simplified diagram for Alternative 3 is shown in Figure 5.1-3.
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Figure 5.2-3: Airdrie Area – Alternative 3
To Red Deer
63S
West
Crossfield
316S
901AL
752L
East
Crossfield
64S
653S
Nose Creek
284S
N.O.
688L
East Airdrie
199S
631L
DryCreek
186S
Legend
N.O.
Future Circuit
Existing Circuit
Future Substation
Existing Substation
69 kV Circuit
138 kV Circuit
240 kV Circuit
500 kV Circuit
HVDC line
Normally Open Circuit
69 kV Substation
New PoD
611L
Balzac
391S
Beddington
162S
932L
138 kV Substation
240 kV Substation
500 kV Substation
Proposed Development
March 2014
Disclaimer: This diagram is a simplified representation
of the physical system configuration. Technical details
have been simplified for illustration purposes. It does not
accurately display the geographical location of facilities.
Calgary Sub-Region Plan
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To Janet
74S
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5.2.4 Airdrie Area Alternative 4
Alternative 4 adds a new 240/138 kV source station to provide supply to the load growth in the Airdrie
area.
Alternative 4 includes the following developments:
1. 901L tap converted to In-Out configuration at East Crossfield 64S
2. Upgrade the existing 138 kV lines 752L from East Crossfield 64S to Airdrie tap to Summit 653S to
higher capacity line (177 MVA)
3. Upgrade the existing 138 kV line 688L from Summit 653S to Nosecreek tap and from Nose Creek
tap to the joint to higher capacity line (177 MVA)
4. One new 240/138 kV station assumed to be approximately 12 km east of Dry Creek 186S station
including one 240/138 kV 200 MVA transformer
5. Approximately 300 metres of new double circuit 240 kV line to connect 929L to new source
station in an in and out configuration
6. Approximately 12 km of new double circuit 138 kV line to loop in and out connection between the
new station and 631L south of East Airdrie 199S.
7. Upgrade the existing 631L from East Airdrie 199S to the north circuit of D/C to new source station
with higher capacity line (177 MVA)
8. Upgrade the existing 611L from Dry Creek 186S to Balzac with high capacity line (177 MVA).
9. Approximately 2 km of new double circuit 138 kV line to connect the south circuit at new POD in
an in and out configuration.
10. Upgrade /install protection systems as necessary to facilitate the above system reinforcements
The simplified diagram for Alternative 4 is shown in Figure 5.2-4 below.
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901L
925L/
929L
Figure 5.2-4: Airdrie Area – Alternative 4
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5.3
Alternative Screening
As part of the Alternative Screening process, the six Calgary Area alternatives and the four Airdrie Area
alternatives were evaluated. 4 Calgary alternatives and 3 Airdrie alternatives are shortlisted for detailed
evaluation..
5.3.1 Calgary Area Alternative Screening
Table 5.3-1 below summarizes the alternatives considered for the Calgary area.
Table 5.3-1: Comparison of Alternatives - Calgary Area
Alternative
Advantages

Alt-1
Provides geographic diversity for the
downtown load supply.

Addition of flow control device at
Beddington provides flexibility in
controlling power flow in north Calgary
240 kV system.
Alt-3

Alt-4


Downtown Calgary load mainly supplied from
East Calgary 5S / SS-2 via 138 kV; less
geographic diversity than other alternatives.

Potential overload of existing transformers at
East Calgary, requiring reinforcement – either
replacing the transformer with higher capacity
ones, or 3rd transformer at East Calgary 5S /
SS-2 with limited space for further expansion
after ECTP.

Potentially high cost of U/G cables.

SS-2 has limited expansion
space/terminations.

Potential high cost of U/G cables and 240 kV
development in downtown area.

Additional cost for flow controller device in
short to medium term.

Introduces additional control complexity in real
time operations.

Potential higher cost than Alt-2.

Limited space and accessibility at Sarcee
station.

Higher cost than Alt2.

Limited space and accessibility at Sarcee
station.

Higher cost of rebuilding SS-36 to 240 kV (GIS
station) than Lochend 75S substation as
proposed in other alternatives

Limited future expandability for connecting
new generation and/or load at SS-36.
Includes fewer transmission equipment
in the downtown stations

Alt-2
Alt-5
Disadvantages
Provides geographic diversity for the
downtown load supply.
Provides geographic diversity for the
downtown load supply.
Alt-6
All the proposed alternatives satisfy the Alberta Reliability Standards.
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Alternative 5 provides geographic diversity for the downtown load supply, but with potentially higher cost
and limited space and accessibility at Sarcee 42S and also has a less desirable routing. Alternative 6 is
similar to developing Lochend 75S substation, but with less flexibility to connect future load or generation
due to the existing location of SS-36.
Based on the relative advantages and disadvantages of each of the Calgary area alternatives described
in Table 5.3-1 above, Alternatives 1, 2, 3 and 4 were selected for further studies.
5.3.2 Airdrie Area Alternative Screening
Table 5.3-2 below summarizes the alternatives considered for the Airdrie area.
Table 5.3-2: Comparison of the Alternatives - Airdrie Area
Alternative
Alt-1
Alt-2
Alt-3
Alt-4
Advantages
Disadvantages
Potential cross flow on the Airdrie 138 kV
system.

Meets reliability criteria

Eliminate cross flow

Meets reliability criteria.

Eliminate cross flow

Meets reliability criteria.

Provide a new source substation

Meets reliability criteria.
More 138 kV transmission development from
East Crossfield 64S to East Airdrie 199S.

More 138 kV transmission development from
East Crossfield 64S to Nose Creek 284S

Higher cost than Alt-2.

Higher cost than other alternatives.

Potentially higher land impact with longer new
ROW
Based on the advantages and disadvantages of each of the Airdrie area alternatives described in Table
5.3-2 above, Alternatives 1, 2 and 4 were selected for further studies.
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6 Alternative Evaluation
This section summarizes the technical evaluation of the selected Calgary and Airdrie area alternatives,
the system losses and high level land impact associated with each alternative.
6.1
Technical Evaluation
The proposed alternatives described in Section 5 above for both Calgary and Airdrie areas were
evaluated in the near-term, medium-term and long-term horizons. The steady state system performance
was simulated for each alternative and the system performance was tested for compliance with the ARS.
Power flow diagrams for all the proposed alternatives are provided in Appendix E. The evaluation begins
with the long-term. Here the proposed developments in each Alternative were modeled in the long-term
study year and the steady state performance of this ultimate development was investigated to determine
they meet reliability criteria. In the subsequent sections, the AESO investigated and determined the
proper timing of facilities required for the near-term and medium-term. The following sections show the
power flow results for each of the Calgary and Airdrie area alternatives in the long-term.
6.2
Calgary Area Alternatives
The following sections show the power flow results for the four Calgary area alternatives.
6.2.1 Category A - System Normal (N-0)
No thermal and no voltage violations were observed under system normal conditions across all the study
scenarios in the long-term for all four Calgary alternatives.
6.2.2 Category B - Single Element Outage (N-1)
In the Calgary area, no voltage violations were observed under Category B contingencies, but thermal
violations or near thermal violations were observed under single element outages in the long-term horizon
and are summarized in Table 6.2-1 below. These thermal violations (except for Alternative 1) were
related to 240 kV lines and could be alleviated by re-dispatching HVDC flows.
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Table 6.2-1: Long-term Category B Thermal Violations for Calgary Alternatives
Overloaded
Element
936L or 937L from
Langdon 102S to
East Calgary 5S
Contingency
937L or 936L from
Langdon 102S to
East Calgary 5S
Case
Alternative
Rating
(MVA)
Observed
Thermal
Loading (%)
Observed
Loading
MVA
SC2
Alt1
489
97
486
SC2
Alt2
489
103
521
SC2
Alt3
489
97
488
SC2
Alt4
489
94
474
SC9
Alt2
489
99
498
East Calgary 5S
240/138kV
transformer T1 or
T2
East Calgary 5S
240/138kV
transformer T2 or
T1
SC2
Alt1
400
102
409
SC7
Alt1
400
100
400
SC9
Alt1
400
95
381
SC8
Alt1
489
104
528
1109L or 1080L
from SS-65 to SS25
1080L or 1109L
from SS-65 to SS25
SC8
Alt2
489
98
500
SC8
Alt3
489
96
490
SC8
Alt4
489
100
505
In all four Calgary alternatives, 936L and 937L were overloaded / highly loaded with the outage of the
other line in Case 2 (high wind, high import). Due to the low north-south SOK flow in this case, the WATL
HVDC was not dispatched in this case. The overload on 936L and 937L can be alleviated by redispatching WATL HVDC line.
Similarly, 1080L and 1109L were overloaded with the outage the other line in Case 8 in all four
alternatives. Since 1080L and 1109L are existing transmission lines with a summer rating of 489 MVA,
the observed overloads can be alleviated by re-dispatching the WATL/EATL HVDC lines or upgrading the
lines with a higher capacity conductor.
765L from Janet 74S to Strathmore 151S was observed to be overloaded under various cases for all four
alternatives. This overload issue is outside the Calgary/Airdrie areas and the reliability issue will be
addressed as part of the south regional plan for High River/Strathmore areas.
For Alternative 1 only, since the 240/138 kV 400 MVA transformers at East Calgary 5S serve as the main
source to supply the downtown load, each transformer was overloaded with the outage of the other. This
violation can be mitigated by upgrading both 400 MVA transformers (e.g. 600 MVA) or by installing a third
400 MVA transformer at East Calgary 5S.
6.2.3 Category C5 - Select Double Circuit Tower Outage (N-2)
All double circuit tower outages in the Calgary area were simulated12 across all scenarios over the longterm planning horizon.
The thermal violations observed in the four Calgary area alternatives under Category C5 outage
conditions are provided in Table 6.2-2 through Table 6.2-5 with corresponding mitigation measures. The
mitigation option illustrate that the Category C5 events can be relieved using appropriate operational
measures. However, other mitigation options may exist for the same Category C5 events and detailed
operational studies will be completed as proposed facilities get constructed to specify any requited
operating procedures.
12
Accepted practice in the WECC is double circuit tower circuits less than approximately 1.6 km do not need to be examined
although individual regions may elect to do so to evaluate potential system impacts.
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Table 6.2-2: Long-term Category C5 Thermal Violations for Calgary Alternative 1
Event
name
Overloaded Element
Rating
(MVA)
Case 1 (%)
Case 2 (%)
489
105
126
111
489
104
125
111
936L from Langdon
102S to East Calgary
5S
937L from Langdon
102S to East Calgary
5S
916L from Sarcee
42S to East Calgary
5S
East Calgary 5S
240/138kV
transformer T1
East Calgary 5S
240/138kV
transformer T2
1064L1065L
408
113
400
108
400
108
Case 7 (%)
Case 9 (%)
Re-dispatch WATL depending on the flow direction
Potential Mitigation Measures
985L1003L
-
If the flow is from north to south, then reducing the flow to Langdon 102S
If the flow is from south to north, then increasing the flow
SS-65 240/138kV
transformer T1
400
113
101
SS-65 240/138kV
transformer T2
400
113
101
26.83L from SS-65 to
SS-26
260
111
101
24.82L from SS-65 to
SS-24
260
141
120
Potential Mitigation Measures
112
113
Option 1: Trip two 240/138kV auto-transformers at SS-65
Option 2 (for case 7 – worst case. The other cases are less severe): Trip / Run
back Shepard gen to ~350MW (original gen output was ~850MW) and also
increase EATL flow (south to north) as much as possible
Option 3: Trip 1106L/1107L and trip / run back Shepard gen as appropriate
Note: It is assumed that the 138 kV line 9.80L CT limitation was removed and the line rating was restored to its thermal rating.
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Table 6.2-3: Long-term Category C5 Thermal Violations for Calgary Alternative 2
Event
name
1064L1065L
Rating
(MVA)
Case 1
(%)
Case 2
(%)
Case 4 (%)
936L from Langdon 102S to East
Calgary 5S
489
109
130
100
116
9367 from Langdon 102S to East
Calgary 5S
489
108
130
100
115
New 240kV line from East Calgary 5S
to SS-8 240kV
520
Overloaded Element
116
Case 9
(%)
102
Re-dispatch WATL depending on the flow direction
If the flow is from north to south, then reducing the flow
to Langdon 102S
Potential Mitigation Measures
-
985L1003L
Case 7
(%)
If the flow is from south to north, then increasing the flow SS-65 240/138 kV transformer T1
400
111
SS-65 240/138 kV transformer T2
400
111
26.83L from SS-65 to SS-26
260
107
24.82L from SS-65 to SS-24
260
110
110
138
118
Option 1: Trip two 240/138kV auto-transformers at SS-65
Option 2 (for case 7 – worst case. The other cases are less
severe): Trip / run back Shepard gen to ~350 MW (original gen
Potential Mitigation Measures
output was ~850 MW) and also increase EATL flow (south to north)
as much as possible
Option 3: Trip 1106L/1107L and trip / run back Shepard gen as
appropriate
Note: It is assumed that the 138 kV line 9.80L (from SS-9 to SS-31) line rating can be increased to 287MVA by adjusting the CT limit
ratio to 1200A.
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Table 6.2-4: Long-term Category C5 Thermal Violations for Calgary Alternative 3
Event
name
1064L 1065L
Rating
(MVA)
Case 1 (%)
Case 2 (%)
936L from Langdon 102S to East
Calgary 5S
489
107
128
114
937L from Langdon 102S to East
Calgary 5S
489
106
128
113
Overloaded Element
Case 7 (%)
Case 9 (%)
Re-dispatch WATL depending on the flow direction
-
Potential Mitigation Measures
985L 1003L
If the flow is from north to south, then reducing the flow
to Langdon 102S
If the flow is from south to north, then increasing the flow
65ST1
400
111
65ST2
400
111
26.83L from SS-65 to SS-26
260
107
24.82L from SS-65 to SS-24
260
110
111
139
119
Option 1: Trip two 240/138kV auto-transformers at SS-65
Option 2 (for case 7 – worst case. The other cases are less
severe): Trip / run back Shepard gen to ~350 MW (original gen
Potential Mitigation Measures
output was ~850 MW) and also increase EATL flow (south to
north) as much as possible
Option 3: Trip 1106L/1107L and trip / run back Shepard gen as
appropriate
Note: It is assumed that the 138 kV line 9.80L (from SS-9 to SS-31) line rating can be increased to 287MVA by adjusting the CT limit
ratio to 1200A.
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Table 6.2-5: Long-term Category C5 Thermal Violations for Calgary Alternative 4
Event name
1066L1067L
Overloaded Element
916L from Sarcee 42S to East
Calgary 5S
Rating
(MVA)
Case2
(%)
408
Potential Mitigation Measures
1064L1065L
Case1
(%)
Case4
(%)
Case7
(%)
Case9
(%)
104
Re-dispatch WATL to -100MW (original dispatch was 0MW)
936L from Langdon 102S to East
Calgary 5S
489
104
124
111
937L from Langdon 102S to East
Calgary 5S
489
103
123
110
916L from Sarcee 42S to East
Calgary 5S
408
117
145
104
117
Re-dispatch WATL depending on the flow direction
-
Potential Mitigation Measures
985L-1003L
If the flow is from north to south, then reducing the
flow to Langdon 102S
If the flow is from south to north, then increasing
the flow
65ST1
400
109
65ST2
400
109
26.83L from SS-65 to SS-26
260
106
24.82L from SS-65 to SS-24
260
108
107
136
116
Option 1: Trip two 240/138 kV auto-transformers at SS-65
Option 2 (for case 7 – worst case. The other cases are less
severe): Trip / run back Shepard gen to ~350 MW (original
Potential Mitigation Measures
gen output was ~850 MW) and also increase EATL flow
(south to north) as much as possible
Option 3: Trip 1106L/1107L and trip / run back Shepard gen
as appropriate
Note: It is assumed that the 138 kV line 9.80L (from SS-9 to SS-31) line rating can be increased to 287MVA by adjusting the CT limit
ratio to 1200A.
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6.3
Airdrie Area Alternatives
The following sections show the power flow results for the three Airdrie area alternatives.
6.3.1 Category A - System Normal (N-0)
No thermal and no voltage violations were observed under system normal conditions across all the study
scenarios in the long-term horizon for all three Airdrie alternatives.
6.3.2 Category B - Single Element Outage (N-1)
In the Airdrie area, no thermal and no voltage criteria violations were observed under Category B
contingencies for any of the alternatives in the long-term horizon across all study scenarios.
6.3.3 Category C5 - Selected Double Circuit Tower Outage (N-2)
There are no existing double circuit transmission towers connection stations in the Airdrie area except for
a short section of double circuit 138 kV monopoles leading to Dry Creek 186S.
If the proposed development in the Airdrie area was built as double circuit, some load and/or generation
could be dropped depending on the fault location. Note that any potential load/generation shedding
would meet the Category C system performance requirements..
6.4
Staging of Alternatives
As described in Section 5.3 above, Alternatives 1, 2, 3 and 4 for the Calgary area and Alternatives 1, 2
and 4 were selected for further detailed analysis. The above sections confirmed that the short listed
alternatives satisfy the ARS in the long-term horizon. The timing of the reinforcements in the near-term
and medium-term was determined by performing a staging analysis. This analysis was an iterative
process that included numerous combinations of developments required to meet the need. The resulting
staged reinforcements in each alternative satisfied the ARS.
The following sections summarize the staging sequences for the Calgary and Airdrie area alternatives in
the near-term and medium-term planning horizons and the corresponding power flow study results.
6.4.1 Near-term Staging
The development sequence in the near-term for each Calgary alternative is summarized in Table 6.4-1
below. For the Calgary downtown developments, two options were considered in each of the
alternatives.
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Table 6.4-1: Calgary Area Development Sequence in Near-term- Alternatives 1, 2, 3 and 4
System Need
 Downtown supply:
overload on 2.82L,
2.83L, 1.82L, and
1.84L
 North 69 kV lines
and 138/69 kV
transformer
overload
Alt 1
Alt 2
Option 2A: New 240 kV
cable energized at 138
kV from SS-2 to SS-8
initially.
New 138kV cable
from SS-2 to SS-1
Option 2B: Convert SS8 to 240 kV: 2 new
240/138 kV 400 MVA
transformers and a new
240 kV cable from East
Calgary to SS-8
Alt 3
Alt 4
Option 3A: Convert SS-8
to 240 kV: 1 new 240/138
kV transformer; assume
240/240 kV 600 MVA
phase shifting transformer
(PST) as flow control
device at Beddington; a
new 240 kV line from
Beddington to SS-8
Option 4A: Convert SS8 to 240 kV: 2 new
240/138 kV 400 MVA
transformers and a new
240 kV cable from
Sarcee to SS-8
Option 3B: Similar to Alt
2B
Option 4B: Similar to Alt
2B
Upgrade 69 kV
system to 138 kV
Upgrade 69 kV system
to 138 kV
Upgrade 69 kV system to
138 kV
Upgrade 69 kV system
to 138 kV
 Overloads on 138
kV lines out of
Beddington:
11.83L, 39.82L
New 138 kV line
from SS-47 to SS36
New 138 kV line from
SS-47 to SS-36
New 138 kV line from SS47 to SS-36
New 138 kV line from
SS-47 to SS-36
 Overload on 138 kV
line 37.82L
929L connected to
Beddington in-out
configuration
929L connected to
Beddington in-out
configuration
929L connected to
Beddington in-out
configuration
929L connected to
Beddington in-out
configuration
For the Airdrie area, the development sequences for Alternative 1, 2 and 4 in the near-term are
summarized in Table 6.4-2 below.
March 2014
Calgary Sub-Region Plan
Page 76
Proprietary
Table 6.4-2: Airdrie Area Development Sequence in Near-term - Alt 1, 2 and 4
Alternative
Proposed developments in the Near-term
901L Tap converted to In-Out configuration at East Crossfield 64S
One new 240/138kV 200MVA transformer at East Crossfield 64S
Upgrade the existing 138kV lines 752L from East Crossfield 64S to Airdrie Tap to Summit 653S to higher
capacity line
1
Upgrade the existing 138kV line 688L from Summit 653S to Summit tap to East Airdrie 199S to higher capacity
line
Upgrade the existing 138kV line 611L from Drycreek 186S to Balzac with higher capacity line
Upgrade the existing 138kV line 631L from East Airdrie 199S to Dry Creek 186S with higher capacity line
Upgrade / install protection systems as necessary to facilitate the above system reinforcements
901L Tap converted to In-Out configuration at East Crossfield 64S
One new 240/138kV 200MVA transformer at East Crossfield 64S
Upgrade the existing 138kV lines 752L from East Crossfield 64S to Airdrie Tap to Summit 653S to higher
capacity line
2
Upgrade the existing 138kV line 688L from Summit 653S to Summit tap to East Airdrie 199S to higher capacity
line
Upgrade the existing 138kV line 611L from Drycreek 186S to Balzac with higher capacity line
Build new 138 kV line from East Crossfield 64S to East Airdrie 199S
Build new 138 kV line from Beddington 162S to Dry Creek 186S
N.O. 138 kV line 631L from East Airdrie 199S to Dry Creek 186S
Upgrade / install protection systems as necessary to facilitate the above system reinforcements
901L tap converted to In-Out configuration at East Crossfield 64S
Upgrade the existing 138 kV lines 752L from East Crossfield 64S to Airdrie tap to Summit 653S to higher
capacity line
Upgrade the existing 138 kV line 688L from Summit 653S to Nosecreek tap and from Nose Creek tap to the joint
to higher capacity line
One new 240/138 kV station assumed to be approximately 12 km east of Dry Creek 186S station including one
240/138 kV 200 MVA transformer
4
Approximately 300 metres of new double circuit 240 kV line to connect 929L to new source station in an in and
out configuration
Approximately 12 km of new double circuit 138 kV line to loop in and out connection between the new station
and 631L south of East Airdrie 199S.
Upgrade the existing 631L from East Airdrie 199S to the north circuit of D/C to new source station with higher
capacity line
Upgrade the existing 611L from Dry Creek 186S to Balzac with high capacity line
Upgrade / install protection systems as necessary to facilitate the above system reinforcements
March 2014
Calgary Sub-Region Plan
Page 77
Proprietary
Power flow studies were performed to determine the development sequence for the four Calgary and
three Airdrie area alternatives. Power flow plots for each alternative are provided in Appendix E.
There were no Category A (system normal or N-0) and / or Category B (N-1) overloads observed for all
three Airdrie area alternatives and transmission voltages remained within acceptable limits across all
study cases.
There were no Category A (system normal or N-0) overloads observed for all four Calgary area
alternatives and the transmission voltages remained within acceptable limits across all study cases.
The Category B study results for the Calgary area are shown in Table 6.4-3 through Table 6.4-6 below.
The Category C5 study results are shown in Table 6.4-7 through Table 6.4-11 below including potential
mitigation options. The mitigation option illustrate that the Category C5 events can be relieved using
appropriate operational measures. However, other mitigation options may exist for the same Category C5
events and detailed operational studies will be completed as proposed facilities get constructed to specify
any requited operating procedures.
Based on the results summarized in Table 6.4-3 through Table 6.4-6, the follow items are noted:
1. For Alternative 1 (Table 6.4-3), the 240 kV lines 1080L/1109L from SS-25 to SS-65 were
highly loaded in Case 6 (zero wind, high north to south SOK flow – 2000 MW, high Calgary
local generatio). The flow could be reduced by re-dispatching WATL and EATL flow.
2. For Alternative 2 (Table 6.4-4),

For Alternative 2A, 240 kV lines 1080L/1109L from SS-25 to SS-65 were highly
loaded in Case 6. The flow on these lines could be reduced by re-dispatching WATL
and EATL flows.

For Alternative 2B, 240kV line 985L/1003L from Janet 74S to SS-25 was highly
loaded in Case 17 (environmental scenario). The flow on these lines could be
reduced by re-dispatching WATL and EATL flows.
3. For Alternative 3 (Table 6.4-5), with the angle of the phase shifting transformer at Beddington
set to 5 degrees:

Downtown 138 kV lines 2.82L and 2.83L were still overloaded or highly loaded under
different system conditions. These overloads could be alleviated by further adjusting
the angle of the phase shifting transformer.

240 kV lines 985L and 1003L were highly loaded in Case 17 (environmental
scenario). The flow on these lines could be reduced by re-dispatching WATL and
EATL flows.
4. For Alternative 4 (Table 6.4-6):
March 2014

240 kV lines 985L/1003L were highly loaded in Case 17 (environmental scenario). The
flow on these lines could be reduced by re-dispatching HVDC flows.

240 kV line 916L from Sarcee to East Calgary was highly loaded in Case 1 (High wind,
high import) with the loss of a large unit in the Wabamun area.

240 kV lines 1080L and 1109L from SS-25 to SS-65 were highly loaded in Case 6 (zero
wind, high north-south SOK flow – 2000 MW, high Calgary local generation). The loading
on these lines could be reduced by re-dispatching WATL and EATL flow.
Calgary Sub-Region Plan
Page 78
Proprietary
Table 6.4-3: Near-term Category B Results for Calgary Alternative 1
Contingency
Overloaded Element
Rating (MVA)
Thermal Loading (%)
Case
1080L / 1109L from
SS-25 to SS-65
1109L / 1080L from
SS-25 to SS-65
489
96
06
Table 6.4-4: Near-term Category B Results for Calgary Alternative 2
Contingency
1080L / 1109L from
SS-25 to SS-65
985L / 1003L from
Janet 74S to SS-25
Overloaded
Element
1109L / 1080L from
SS-25 to SS-65
1003L / 985L from
Janet 74S to SS-25
Rating
(MVA)
Thermal Loading (%)
Alt 2A
Alt2B
489
Case
96
06
977
95
17
Table 6.4-5: Near-term Category B Results for Alternative 3A
Contingency
Overloaded Element
Rating
(MVA)
Thermal
Loading (%)
Case
985L / 1003L from
Janet 74S to SS-25
2.83L from SS-2 to SS5 to SS-13
1003L / 985L from Janet 74S to
SS-25
977
96
17
2.82L from SS-2 to SS-5
318
95
17
2.82L from SS-2 to SS5
2.83L from SS-2 to 2.83L tap
286
97
05
2.83L from SS-2 to 2.83L tap
286
96
04
2.83L from SS-2 to 2.83L tap
286
95
02
2.83L from SS-2 to 2.83L tap
286
97
11
2.83L from SS-2 to 2.83L tap
286
97
15
2.83L from SS-2 to 2.83L tap
286
100
08
2.83L from SS-2 to 2.83L tap
286
96
01
2.83L from SS-2 to 2.83L tap
286
96
07
2.83L from SS-2 to 2.83L tap
286
100
10
2.83L from SS-2 to 2.83L tap
286
98
17
2.83L from SS-2 to 2.83L tap
286
96
09
Table 6.4-6: Near-term Category B Results for Alternative 4A
Contingency
985L / 1003L from Janet 74S to SS-25
Keephills 3
1214L
Genesee 3
2.83L from SS-2 to SS-5 to SS-13
Overloaded Element
985L / 1003L from Janet
74S to SS-25
916L from Sarcee 42S to
East Calgary 5S
916L from Sarcee 42S to
East Calgary 5S
916L from Sarcee 42S to
East Calgary 5S
2.82L from SS-2 to SS-5
Rating
(MVA)
Thermal
Loading (%)
Case
977
94
17
408
96
01
408
96
01
408
96
01
318
95
17
2.83L from SS-2 to tap
286
95
08
2.83L from SS-2 to tap
286
96
17
1109L / 1080L from SS-25
to SS-65
489
94
06
2.82L from SS-2 to SS-5
1080L / 1109L from SS-25 to SS-65
March 2014
Calgary Sub-Region Plan
Page 79
Proprietary
Table 6.4-7: Near-term Category C5 Results for Alternative 1
Event name
936L-937L from
Langdon 102S to
East Calgary 5S
Overloaded Element
23.80L from Janet
74S to SS-23
Rating
(MVA)
Case 1 (%)
Case 15 (%)
255
1064L-1065L from
Langdon 102S to
Janet 74S
489
102
489
102
408
109
102
65ST1
400
122
108
128
65ST2
26.83L from SS-65 to
SS-26
24.82L from SS-65 to
SS-24
26.81L from SS-26 to
SS-32
400
122
108
128
260
112
102
118
260
164
143
175
Potential Mitigation Measures
March 2014
105
Re-dispatch
WATL to
100MW
(original
dispatch was
250MW)
Potential Mitigation Measures
985L-1003L from
Janet 74S to SS25
Case 17 (%)
Re-dispatch
WATL to
100MW
(original
dispatch was
300MW)
Potential Mitigation Measures
936L from Langdon
102S to East Calgary
5S
937L from Langdon
102S to East Calgary
5S
916S from Sarcee
42S to East Calgary
5S
Case 16 (%)
260
103
Option 1: Trip two auto transformers at SS-65; and
Trip 138kV line 876L
Option 2 (for case 17 – worst case. The other cases
are less severe): Trip/run back Shepard gen to
~400MW (original output was ~850MW; Trip 138kV
line 24.81L from SS-24 to SS-31; and increase flow
on EATL (south to north) as much as possible
Option 3: Trip 1106L/1107L and trip / run back
Shepard gen as appropriate
Calgary Sub-Region Plan
Page 80
Proprietary
Table 6.4-8: Near-term Category C5 Results for Alternative 2A
Event name
Overloaded Element
936L-937L
from Langdon
102S to East
Calgary 5S
23.80L from Janet 74S
to SS-23
Rating
(MVA)
Case 1 (%)
Case 15 (%)
255
936L from Langdon
102S to East Calgary 5S
937L from Langdon
102S to East Calgary 5S
916L from Sarcee 42S
to East Calgary 5S
Re-dispatch WATL
to 100MW (original
dispatch was
300MW)
489
102
489
102
408
65ST1
400
122
108
128
65ST2
26.83L from SS-65 to
SS-26
24.82L from SS-65 to
SS-24
26.81L from SS-26 to
SS-32
400
122
108
128
260
112
102
118
260
164
143
175
Potential Mitigation Measures
March 2014
109
Re-dispatch WATL
to 100MW (original
dispatch was
250MW)
Potential Mitigation Measures
985L-1003L
from Janet
74S to SS-25
Case 17 (%)
104
Potential Mitigation Measures
1064L-1065L
from Janet
74S to
Langdon 102S
Case 16 (%)
260
103
Option 1: Trip two auto transformers at SS-65; and Trip
138kV line 876L
Option 2 (for case 17 – worst case. The other cases
are less severe): Trip/run back Shepard gen to ~400
MW (original output was ~850 MW; Trip 138 kV line
24.81L from SS-24 to SS-31; and increase flow on
EATL (south to north) as much as possible
Option 3: Trip 1106L/1107L and trip / run back Shepard
gen as appropriate
Calgary Sub-Region Plan
Page 81
Proprietary
Table 6.4-9: Near-term Category C5 Results for Alternative 2B
Event
name
1064L1065L from
Janet 74S
to Langdon
102S
Overloaded Element
Rating
(MVA)
Case 1 (%)
936L from Langdon 102S to East
Calgary 5S
489
106
937L from Langdon 102S to East
Calgary 5S
489
106
Case 17 (%)
65ST1
400
121
108
128
65ST2
400
121
108
128
26.83L from SS-65 to SS-26
260
111
101
117
24.82L from SS-65 to SS-24
260
164
143
174
26.81L from SS-26 to SS-32
260
102
Option 1: Trip two auto transformers at SS-65;
and Trip 138kV line 876L
Option 2 (for case 17 – worst case. The other
cases are less severe): Trip/run back Shepard
gen to ~400MW (original output was ~850 MW;
Trip 138 kV line 24.81L from SS-24 to SS-31;
and increase flow on EATL (south to north) as
much as possible
Option 3: Trip 1106L/1107L and trip / run back
Shepard gen as appropriate
Potential Mitigation Measures
March 2014
Case 16 (%)
Re-dispatch
WATL to 150
MW (original
dispatch was
250 MW)
Potential Mitigation Measures
985L1003L from
Janet 74S
to SS-25
Case 15 (%)
Calgary Sub-Region Plan
Page 82
Proprietary
Table 6.4-10: Near-term Category C5 Results for Alternative 3A
Event name
1064L-1065L
from Janet
74S to
Langdon
102S
Overloaded
Element
936L from Langdon
102S to East
Calgary 5S
937L from Langdon
102S to East
Calgary 5S
916L from Sarcee
42S to East Calgary
5S
Rating
(MVA)
Case 1 (%)
489
101
489
101
408
111
Case 17 (%)
65ST1
400
121
108
127
65ST2
400
121
108
127
260
111
101
117
260
164
143
175
26.83L from SS-65
to SS-26
24.82L from SS-65
to SS-24
26.81L from SS-26
to SS-32
Potential Mitigation Measures
March 2014
Case 16 (%)
Re-dispatch
WATL
to 125 MW
(original
dispatch was 250
MW)
Potential Mitigation Measures
985L-1003L
from Janet
74S to SS25
Case 15 (%)
260
102
Option 1: Trip two auto transformers at SS-65; and Trip
138 kV line 876L,
Option 2 (for case 17 – worst case. The other cases are
less severe): Trip/run back Shepard gen to ~300MW
(original output was ~850 MW; Trip 138 kV line 24.81L
from SS-24 to SS-31; and increase flow on EATL (south
to north) as much as possible
Option 3: Trip 1106L/1107L and trip / run back Shepard
gen as appropriate
Calgary Sub-Region Plan
Page 83
Proprietary
Table 6.4-11: Near-term Category C5 Results for Alternative 4A
Event name
936L-937L
from
Langdon
102S to East
Calgary 5S
Overloaded
Element
Rating
(MVA)
23.80L from
Janet 74S to
SS-23
Case 1 (%)
Case 8 (%)
Case 15 (%)
255
1064L-1065L
from Janet
74S to
Langdon
102S
Re-dispatch
WATL
to 200 MW
(original
dispatch was
300 MW)
489
103
489
103
408
130
494
116
Re-dispatch
WATL
to 0 MW
(original
dispatch was
250 MW)
Potential Mitigation Measures
985L-1003L
from Janet
74S to SS-25
Re-dispatch
WATL
to 0MW
(original
dispatch was
250 MW)
65ST1
400
121
108
128
65ST2
400
121
108
128
26.83L from SS65 to SS-26
260
112
102
117
24.82L from SS65 to SS-24
260
164
143
174
26.81L from SS26 to SS-32
260
103
Option 1: Trip two auto transformers at SS-65,
and trip 138 kV line 876L
Option 2 (for case 17 – worst case. The other
cases are less severe): Trip/run back Shepard
gen to ~300MW (original output was ~850 MW;
Trip 138 kV line 24.81L from SS-24 to SS-31;
and increase flow on EATL (south to north) as
much as possible
Option 3: Trip 1106L/1107L and trip / run back
Shepard gen as appropriate
Potential Mitigation Measures
March 2014
Case 17 (%)
102
Potential Mitigation Measures
936L from
Langdon 102S
to East Calgary
5S
937L from
Langdon 102S
to East Calgary
5S
916L from
Sarcee 42S to
East Calgary 5S
Case 16 (%)
Calgary Sub-Region Plan
Page 84
Proprietary
6.4.2 Medium-term Staging
For the Airdrie area, the development sequence for medium-term is similar to the proposed development
in near-term. Please note that the connection of the new POD depends on the timing and location for this
new substation.
For the Calgary area, the staging sequences in medium-term for each alternative are summarized in
Table 6.4-12. The staging shows the portions of each alternative that are needed in near-term and the
additional pieces of each alternative that are required in medium-term.
Table 6.4-12: Calgary Area Development Sequence - Alt 1, 2, 3 and 4
Medium-term System Additional Need
Additional Development Needed in Mediumterm
Alternative
Beddington 240/138 kV 400 MVA transformer reaching its
capacity under the outage of the other transformer
1, 2A, 2B, 4A
2.82L from SS-2 to SS-5 reaching its capacity / overloaded
under 2.83L outage
1, 2A, 2B,
3A,4A
23.80L from Janet to SS-23 overloaded
1, 2A
37.82L from Janet to SS-37 reaching its capacity

New 240/138 kV substation to be designated
Lochend for all alternatives

New 138 kV line from SS-22 to SS-23 for all
Alternatives
1, 2A,3A

Rebuild 3.82L with higher capacity conductor
for 3A,
3.82L from SS-3 to SS-8 overloaded
1, 2A,
2B,3A,4A

FATD West lines for all the alternatives
240 kV lines such as 936L/937L, 985L/1003L, 1109L/1080L,
etc. overloaded or highly loaded
1, 2A,
2B,3A,4A
Power flow studies were performed for the development sequence for all four Calgary alternatives in the
2022 study year. There were no Category A (N-0) or Category B (N-1) overloads observed for all the
Calgary and Airdrie area alternatives and transmission voltages remained within acceptable limits across
all study cases. Power flow diagrams for Category A and Category B conditions/contingencies are
provided in Appendix F.
The Category C5 study results are summarized and provided in Table 6.4-13 through Table 6.4-17 below
with potential mitigation options. The mitigation option illustrate that the Category C5 events can be
relieved using appropriate operational measures. However, other mitigation options may exist for the
same Category C5 events and detailed operational studies will be completed as proposed facilities get
constructed to specify any requited operating procedures.
March 2014
Calgary Sub-Region Plan
Page 85
Proprietary
Table 6.4-13: Medium-term Category C5 Results for Alternative 1
Event name
985L-1003L
from Janet
74S to SS-25
Overloaded Element
Rating
Case 17 (%)
Case 19 (%)
24.82L from SS-65 to
SS-24
260
125
123
Option 1: Trip two auto transformers at SS-65; and Trip 138 kV line 876L
Option 2: Trip / run back Shepard gen by ~300 MW (original output at 800-850
MW) and increase the EATL flow (south to north)
Option 3: Trip 1106L/1107L and trip/run back Shepard gen as appropriate
Potential Mitigation Measures
Table 6.4-14: Medium-term Category C5 Results for Alternative 2A
Event name
985L-1003L
from Janet
74S to SS-25
Overloaded Element
Rating
Case 17 (%)
Case 19 (%)
24.82L from SS-65 to
SS-24
260
126
124
Option 1: Trip two auto transformers at SS-65; and Trip 138 kV line 876L
Option 2: Trip/run back Shepard gen by ~300 MW (original output at 800-850
MW) and increase the EATL flow (south to north)
Option 3: Trip 1106L/1107L and trip/run back Shepard gen as appropriate
Potential Mitigation Measures
Table 6.4-15: Medium-term Category C5 Results for Alternative 2B
Event name
985L-1003L
from Janet
74S to SS-25
Overloaded Element
Rating
Case 17 (%)
Case 19 (%)
24.82L from SS-65 to
SS-24
260
124
122
Option 1: Trip two auto transformers at SS-65; and Trip 138kV line 876L
Option 2: Trip/run back Shepard gen by ~300 MW (original output at 800-850
MW) and increase the EATL flow (south to north)
Option 3: Trip 1106L/1107L and trip/run back Shepard gen as appropriate
Potential Mitigation Measures
Table 6.4-16: Medium-term Category C5 Results for Alternative 3A
Event name
985L-1003L
from Janet
74S to SS-25
Overloaded Element
24.82L from SS-65
to SS-24
Rating
Case 17 (%)
Case 19 (%)
260
126
123
Option 1: Trip two auto transformers at SS-65; and Trip 138 kV line 876L
Option 2: Trip/run back Shepard gen by ~300 MW (original output at 800-850
MW) and increase the EATL flow (south to north)
Option 3: Trip 1106L/1107L and trip/run back Shepard gen as appropriate
Mitigation Measures
Table 6.4-17: Medium-term Category C5 Results for Alternative 4A
Event name
Overloaded Element
Rating
Case 1
(%)
Case 6
(%)
Case 14
(%)
1064L-1065L
from Janet
74S to
Langdon 102S
916L from Sarcee 42S
to East Calgary 5S
408
101
108
100
24.82L from SS-65 to
SS-24
260
122
120
Option 1: Trip two auto transformers at SS-65;
and Trip 138 kV line 876L
Option 2: Trip/run back Shepard gen by ~300 MW
(original output at 800-850 MW)
Option 3: Trip 1106L/1107L and trip/run back
Shepard gen as appropriate
Mitigation Measures
March 2014
Case 19 (%)
Re-dispatch WATL (reduce
north-south flow)
Mitigation Measures
985L-1003L
from Janet
74S to SS-25
Case 17 (%)
Calgary Sub-Region Plan
Page 86
Proprietary
6.4.3 Summary of Staging
The timing of the reinforcement for the near-term, medium-term and long-term for the Calgary area
alternatives are shown in Figure 6.4-1 through Figure 6.4-5 while Figure 6.4-6 through Figure 6.4-8 show
the timing for the Airdrie area alternatives.
Figure 6.4-1: Calgary Area Alternative 1
To Red Deer
63S
To Benalto
17S
901L
611L
906L/
928L
929L/
925L
YY
Beddington
162S
918L
75S
932L
44
Seebee
SS-47
SS-49
SS-14
11.83L
SS-11
11.82L
SS-36 14.83L
36.81L
39.82L
SS-16
11.81L
SS-27
BEARSPAW
22.81L
16.60L
7.84L
50L
SS-15
3.84L
21.61L
SS-7
SS-13
SS-3
SS-22
3.82L
SS-21
1.82L
SS-20
1.85L 1.83L
SS-5
2.83L
1.84L
1.81L
1.82L
SS-1
2.82L
7.82L
28.80L
Sarcee 42S
SS-38
Bonnybrook
East Calgary 5S
SS-28
150L
38.83L
2.83L
SS-8
1.80L
3L
SS-39
13.82L
SS-34
693L
916L
SS-10
833L
832L
SS-12
2.80L
SS-43
Janet
74S
37.82L
23.80L
SS-23
To
Strathmore
151S
SS-25
Shepard
24.81L
SS-24
SS-32
SS-33
765L
24.83L
SS-31
L
80
9.
9.83L
SS-30
SS-37
2.81L
SS-9
To
Foothills
237S
45 Strathmore /
Blackie
37.81L
936L / 937L
SS-2
936L/937L
Crossings
Langdon 102S
1065L/1064L
6.82L
SS-6
40.81L
SS-41
SS-40
26.81L
SS-26
924L/927L
To
Milo
356S
SS-65
26.83L
Legend
N.O.
Future Circuit
Existing Circuit
Future Substation
Existing Substation
69 kV Circuit
138 kV Circuit
240 kV Circuit
500 kV Circuit
HVDC line
Normally Open Circuit
69 kV Substation
850L
41.84L
46 High River
SS-54
Black Diamond
392S
138 kV Substation
54.81L
158L
March 2014
Disclaimer: This diagram is a simplified representation of
the physical system configuration. Technical details have
been simplified for illustration purposes. It does not
accurately display the geographical location of facilities.
Calgary Sub-Region Plan
Page 87
Okotoks
678S
Magcan
142S
Hartell
512S
812L
240 kV Substation
500 kV Substation
Near-term Development
Medium-term Development
Long-term Development
Bigrock
To
Carseland
525S
To
Chappel
Rock
491S
High River 434L
65S
To Sarcee
42S
1201L
Foothills
237S
To
Windy
Flats
138S
Proprietary
Figure 6.4-2: Calgary Area Alternative 2A (Near-term and Medium-term)
To Red Deer
901L 63S
To Benalto
17S
611L
906L/
928L
929L/
925L
YY
Beddington
162S
918L
75S
932L
SS-47
SS-49
SS-14
11.83L
SS-11
11.82L
14.83L
SS-36
SS-16
39.82L
11.81L
SS-27
BEARSPAW
SS-34
3.84L
21.61L
SS-7
SS-22
3.82L
1.82L
SS-20
1.85L 1.83L
SS-5
2.83L
1.84L
1.81L
1.82L
SS-1
2.82L
7.82L
Sarcee 42S
SS-38
Bonnybrook
East Calgary 5S
SS-28
28.80L
693L
916L
SS-10
833L
832L
SS-12
37.82L
33.84L
30.81L
24.82L
40.81L
SS-41
SS-40
26.81L
SS-26
765L
SS-25
Shepard
26.83L
1065L/1064L
924L/927L
To
Milo
356S
SS-65
850L
46 High River
SS-54
Black Diamond
392S
54.81L
158L
Bigrock
Okotoks
678S
Magcan
142S
646L
Hartell
512S
812L
To
Carseland
525S
1107L
1106L
41.84L
850L
N.O.
Crossing
Langdon 102S
936L/937L
Legend
Future Circuit
Existing Circuit
Future Substation
Existing Substation
69 kV Circuit
138 kV Circuit
240 kV Circuit
500 kV Circuit
HVDC line
Normally Open Circuit
69 kV Substation
To
Strathmore
151S
SS-24
32.83L
33.83L
6.80L
24.81L
Janet
74S
1109L/1080L
SS-6
24.83L
SS-31
SS-32
SS-33
6.82L
23.80L
SS-23
985L/1003L
SS-30
SS-43
SS-37
2.80L
2.81L
L
80
9.
9.83L
45 Strathmore /
Blackie
37.81L
936L / 937L
SS-2
SS-9
To
Foothills
237S
38.83L
2.83L
SS-8
1.80L
3L
SS-13
SS-3
SS-21
150L
SS-39
13.82L
31.84L
SS-15
50L
22.81L
16.60L
7.84L
To Sunnybrook
36.81L
WATL
44
Seebee
138 kV Substation
240 kV Substation
500 kV Substation
Near-term Development
Medium-term Development
Long-term Development
March 2014
Disclaimer: This diagram is a simplified representation of
the physical system configuration. Technical details have
been simplified for illustration purposes. It does not
accurately display the geographical location of facilities.
Calgary Sub-Region Plan
Page 88
High River 434L
65S
To
Chappel
Rock
491S
To Sarcee
42S
1201L
Foothills
237S
To
Windy
Flats
138S
Proprietary
Figure 6.4-3: Calgary Area Alternative 2B
To Red Deer
63S
To Benalto
17S
611L
906L/
928L
929L/
925L
918L
YY
Beddington
162S
918L
75S
901L
932L
44
Seebee
SS-47
SS-49
SS-14
11.83L
SS-11
11.82L
14.83L
SS-36
SS-16
36.81L
39.82L
11.81L
SS-27
BEARSPAW
7.84L
50L
SS-15
SS-34
3.84L
N.O.
38.83L
2.83L
SS-20
1.85L 1.83L
SS-5
2.83L
1.84L
1.81L
1.82L
SS-1
2.82L
1.80L
7.82L
SS-28
Sarcee 42S
SS-22
3.82L
SS-8
1.82L
28.80L
SS-13
SS-3
SS-21
150L
SS-39
13.82L
21.61L
SS-7
3L
22.81L
16.60L
SS-38
Bonnybrook
East Calgary 5S
693L
916L
SS-10
833L
832L
SS-12
37.82L
SS-43
23.80L
SS-23
Janet
74S
To
Strathmore
151S
SS-25
Shepard
24.81L
SS-24
SS-32
SS-33
765L
24.83L
SS-31
L
80
9.
9.83L
SS-30
SS-37
2.80L
2.81L
SS-9
To
Foothills
237S
45 Strathmore /
Blackie
37.81L
936L / 937L
SS-2
Crossing
Langdon 102S
936L/937L
1065L/1064L
6.82L
Legend
N.O.
Future Circuit
Existing Circuit
Future Substation
Existing Substation
69 kV Circuit
138 kV Circuit
240 kV Circuit
500 kV Circuit
HVDC line
Normally Open Circuit
69 kV Substation
SS-6
40.81L
SS-41
SS-40
26.81L
500 kV Substation
Near-term Development
Medium-term Development
Long-term Development
March 2014
26.83L
To
Milo
356S
SS-65
850L
41.84L
46 High River
SS-54
Black Diamond
392S
138 kV Substation
240 kV Substation
SS-26
924L/927L
54.81L
158L
Bigrock
Okotoks
678S
Magcan
142S
Hartell
512S
812L
Disclaimer: This diagram is a simplified representation of
the physical system configuration. Technical details have
been simplified for illustration purposes. It does not
accurately display the geographical location of facilities.
To
Chappel Rock
491S
Calgary Sub-Region Plan
Page 89
To
Carseland
525S
High River 434L
65S
To Sarcee
42S
1201L
Foothills
237S
To
WindyFlats
138S
Proprietary
Figure 6.4-4: Calgary Area Alternative 3A
To Red Deer
901L 63S
To Benalto
17S
611L
906L/
928L
929L/
925L
YY
Beddington
162S
918L
75S
932L
SS-47
SS-14
SS-11
11.82L
14.83L
SS-36
SS-16
36.81L
PST
11.83L
39.82L
11.81L
SS-27
BEARSPAW
SS-15
SS-34
3.84L
21.61L
1.82L
SS-20
1.85L 1.83L
SS-5
2.83L
1.84L
1.81L
1.82L
SS-1
2.82L
7.82L
28.80L
Sarcee 42S
SS-38
Bonnybrook
East Calgary 5S
SS-28
150L
693L
916L
SS-10
833L
832L
SS-12
33.84L
30.81L
40.81L
SS-41
SS-40
26.81L
To
Milo
356S
Black Diamond
392S
Disclaimer: This diagram is a simplified representation of
the physical system configuration. Technical details have
been simplified for illustration purposes. It does not
accurately display the geographical location of facilities.
54.81L
158L
Okotoks
678S
Hartell
512S
812L
Magcan
142S
High River 434L
65S
To
Chappel
Rock
491S
Calgary Sub-Region Plan
Page 90
Bigrock
To
Carseland
525S
646L
March 2014
924L/927L
SS-65
26.83L
1107L
1106L
46 High River
SS-54
138 kV Substation
Near-term Development
Medium-term Development
Long-term Development
1065L/1064L
850L
41.84L
69 kV Substation
500 kV Substation
SS-26
Crossing
Langdon 102S
936L/937L
850L
Existing Substation
69 kV Circuit
138 kV Circuit
240 kV Circuit
240 kV Substation
SS-24
24.82L
33.83L
6.80L
SS-6
To
Strathmore
151S
SS-25
Shepard
1109L/1080L
6.82L
Legend
24.81L
765L
985L/1003L
SS-32
SS-33
24.83L
SS-31
L
80
9.
SS-43
Janet
74S
37.82L
23.80L
SS-23
SS-9
SS-30
SS-37
2.80L
2.81L
9.83L
45 Strathmore /
Blackie
37.81L
936L / 937L
SS-2
To
Foothills
237S
500 kV Circuit
HVDC line
38.83L
2.83L
SS-8
1.80L
Phase Shifting Transformer
Future Circuit
Existing Circuit
Future Substation
SS-22
3.82L
SS-21
3L
SS-13
SS-3
31.84L
SS-7
SS-39
13.82L
32.83L
50L
22.81L
16.60L
7.84L
To Sunnybrook
SS-49
WATL
44
Seebee
Foothills
237S
To Sarcee
42S
1201L
Proprietary
Figure 6.4-5: Calgary Area Alternative 4A
To Benalto
17S
To Red Deer
63S
901L
611L
906L/
928L
929L/
925L
YY
Beddington
162S
918L
75S
932L
44
Seebee
SS-49
SS-47
SS-14
11.83L
SS-11
11.82L
14.83L
SS-36
SS-16
36.81L
39.82L
11.81L
SS-27
BEARSPAW
50L
SS-15
SS-39
13.82L
SS-34
3.84L
21.61L
SS-7
SS-13
SS-3
SS-22
3.82L
SS-21
N.O.
1.82L
7.82L
SS-28
150L
28.80L
Sarcee 42S
38.83L
2.83L
SS-8
1.80L
3L
22.81L
16.60L
7.84L
N.O.
SS-20
1.85L 1.83L
SS-5
2.83L
1.84L
1.81L
1.82L
SS-1
2.82L
N.O.
East Calgary 5S Bonnybrook
693L
916L
SS-10
833L
832L
SS-12
To
Foothills
237S
SS-37
2.80L
2.81L
765L
SS-25
Shepard
24.81L
SS-24
SS-32
SS-33
To
Strathmore
151S
24.83L
SS-31
L
80
SS-43
Janet
74S
37.82L
23.80L
SS-23
9.
9.83L
45 Strathmore /
Blackie
37.81L
936L / 937L
SS-2
SS-9
SS-30
SS-38
936L/937L
Crossing
Langdon 102S
1065L/1064L
6.82L
SS-6
40.81L
SS-41
SS-40
26.81L
SS-26
To
Milo
356S
SS-65
26.83L
Legend
N.O.
Future Circuit
Existing Circuit
Future Substation
Existing Substation
69 kV Circuit
138 kV Circuit
240 kV Circuit
500 kV Circuit
HVDC line
Normally Open Circuit
69 kV Substation
924L/927L
850L
41.84L
46 High River
SS-54
Black Diamond
392S
To
Carseland
525S
54.81L
158L
Bigrock
Okotoks
678S
Magcan
142S
Hartell
512S
812L
138 kV Substation
240 kV Substation
500 kV Substation
Near-term Development
Medium-term Development
Long-term Development
March 2014
Disclaimer: This diagram is a simplified representation of
the physical system configuration. Technical details have
been simplified for illustration purposes. It does not
accurately display the geographical location of facilities.
Calgary Sub-Region Plan
Page 91
To
Chappel
Rock
491S
High River 434L
65S
To Sarcee
42S
Foothills
237S
1201L
Proprietary
Figure 6.4-6: Airdrie Area Alternative 1
To Red Deer
63S
West
Crossfield
316S
901AL
752L
925L/
929L
653S
Nose Creek
284S
901L
East
Crossfield
64S
688L
East Airdrie
199S
631L
DryCreek
186S
Legend
N.O.
Future Circuit
Existing Circuit
Future Substation
Existing Substation
69 kV Circuit
138 kV Circuit
240 kV Circuit
500 kV Circuit
HVDC line
Normally Open Circuit
69 kV Substation
611L
Balzac
391S
918L
New PoD
Beddington
162S
932L
138 kV Substation
240 kV Substation
500 kV Substation
Near-term Development
Medium-term Development
Long-term Development
March 2014
Disclaimer: This diagram is a simplified representation
of the physical system configuration. Technical details
have been simplified for illustration purposes. It does not
accurately display the geographical location of facilities.
To Janet
74S
Calgary Sub-Region Plan
Page 92
Proprietary
Figure 6.4-7: Airdrie Area Alternative 2
To Red Deer
63S
901AL
752L
East
Crossfield
64S
929L
925L
653S
Nose Creek
284S
901L
West
Crossfield
316S
688L
East Airdrie
199S N.O.
631L
DryCreek
186S
New PoD
Legend
N.O.
Future Circuit
Existing Circuit
Future Substation
Existing Substation
69 kV Circuit
138 kV Circuit
240 kV Circuit
500 kV Circuit
HVDC line
Normally Open Circuit
69 kV Substation
611L
Balzac
391S
918L
Beddington
162S
932L
138 kV Substation
240 kV Substation
500 kV Substation
Near-term Development
Medium-term Development
Long-term Development
March 2014
Disclaimer: This diagram is a simplified representation
of the physical system configuration. Technical details
have been simplified for illustration purposes. It does not
accurately display the geographical location of facilities.
To Janet
74S
Calgary Sub-Region Plan
Page 93
Proprietary
Figure 6.4-8: Airdrie Area Alternative 4
To Red Deer
63S
901AL
752L
East
Crossfield
64S
925L/
929L
653S
Nose Creek
284S
901L
West
Crossfield
316S
688L
East Airdrie
199S
631L
DryCreek
186S
New
Substation
Legend
N.O.
Future Circuit
Existing Circuit
Future Substation
Existing Substation
69 kV Circuit
138 kV Circuit
240 kV Circuit
500 kV Circuit
HVDC line
Normally Open Circuit
69 kV Substation
New PoD
611L
Balzac
391S
918L
Beddington
162S
932L
138 kV Substation
240 kV Substation
500 kV Substation
Near-term Development
Medium-term Development
Long-term Development
March 2014
Disclaimer: This diagram is a simplified representation
of the physical system configuration. Technical details
have been simplified for illustration purposes. It does not
accurately display the geographical location of facilities.
Calgary Sub-Region Plan
Page 94
To Janet
74S
Proprietary
6.5
System Losses
The AESO employed a simulation tool that utilizes PTI/Siemens PSS/E software package for calculating
the transmission system losses for a given system topology. Further, this tool also adopted AESO‘s
guidelines for dispatching WATL and EATL for every hour. System losses are calculated for every hour
using hourly load and generation dispatch conditions over the given year. These hourly losses are then
averaged over 8760 simulated hours to arrive at annual average MW losses. This process was repeated
for the near-term, medium-term and long-term study years. Then for each alternative, a liner equation
was fitted through regression analysis for use in interpolating losses for intermediate years.
Losses of one Alternative was chosen arbitrarily as base value and the relative losses of other
alternatives in a given study region/area were calculated by subtracting base loss value from the
estimated loss values of other Alternatives for each year. The relative losses thus derived would provide a
measure of efficiency of other Alternatives compared to the reference Alternative. The annual loss
savings (or increased costs) could be estimated based on energy prices and will be used in calculating
relative net present value of alternatives.
The system losses for the corresponding alternatives for Calgary and Airdrie areas are summarized in
Table 6.5-1 and Table 6.5-2 below.
Alternative 1 was selected as the base for comparing losses of all the Calgary area Alternatives
Table 6.5-1: Relative System Losses for Calgary Area Alternatives
2017 (MW)
2022 (MW)
2032 (MW)
Alt 1
0
0
Alt 2a
+0.1
+0.1
Alt 2b
0
-0.4
Alt 3
+0.5
+3.3
-17
Alt 4
+0.7
+0.1
-8.4
0
-15.2
Alternative 1 was selected as the base for comparing losses of all the Airdrie area Alternatives.
Table 6.5-2: Relative System Losses for Airdrie Area Alternatives
2017 (MW)
2022 (MW)
2032 (MW)
Alt 1
0
0
0
Alt 2
-0.1
-0.3
+0.1
Alt 4
-0.1
+1.1
+0.8
The results show that the relative losses among the alternatives are close.
6.6
High Level Land Impact Assessment
A qualitative approach was employed for identifying the potential land impacts(LIA) at the landscape
level since the LIA focuses on planning regions, rather than project alternatives within a region (i.e.,
transmission lines and substations). The AESO has reviewed the results of this qualitative analysis and
ensured the proposed Alternatives could be developed outside the existing environmentally sensitive
areas. Since no routing and siting work is part of this planning process, all the aspects (e.g. agricultural
impact, residential and visual impacts, electrical requirements) will be evaluated while developing the NID
March 2014
Calgary Sub-Region Plan
Page 95
Proprietary
applications in order to comply with AUC Rule 007. Details of the scope of work, assumptions and
methodology adopted for LIA are provided in Appendix I.
6.7
TFO Assessment
Both Transmission Facility Owners (TFOs), namely AltaLink (AML) and ENMAX Power, reviewed the
proposed alternatives and conducted a feasibility assessment of the alternatives. The feasibility
assessment included line and substation development, siting, land acquisition, environmental and
operational cycles. The feasibility assessment is based on available data and maps but did not include
any field visits. The TFOs concluded that the alternatives are feasible and recommended that detailed
siting, routing, and LIA including environmental impact assessment prior to filing the NID applications.
March 2014
Calgary Sub-Region Plan
Page 96
Proprietary
7 Selection of Preferred Plan
The selection of the preferred plan for the Calgary Sub-Region is summarized in the following sections.
7.1
Calgary Area Preferred Alternative
While all the four proposed alternatives in the Calgary area were technically feasible and satisfy Alberta
Reliability Standards, Alternative 2 was selected as the preferred alternative for the Calgary area due to
favorable geographic diversification for load supply and provision for long-term load growth.
Table 7.1-1 below summarizes the factors included in the selection of preferred alternative for the Calgary
area.
Table 7.1-1: Comparison of Calgary Area Alternatives
Measure
Alternative 2
(Preferred)
Alternative 1
Alternative 3
Alternative 4
Technical Factors
Alberta Reliability
Standards
Satisfied (Category C
mitigation required)
Satisfied (Category
C mitigation
required)
Satisfied with potential
operator involvement
(Category C mitigation
required)
Satisfied (Category C
mitigation required)
Capacity
Low
High
High
High
Diversity
Lowest
High
High
High
Economic Factors
System Losses
Medium
Low
Low
Low
Capital Cost
Lowest**
Medium
High
Highest
Environmental / Societal Factors
Land Impact Assessment
Medium
Medium
Medium
Medium
TFO Feedback
Feasible
More Feasible
Feasible
Feasible
** The cost for Calgary area alternative 1 could be significantly higher due to the potential siting issue at 5S / SS-2.
7.2
Airdrie Area Preferred Alternative
While all the three proposed alternatives in the Airdrie area were technically feasible and satisfy Alberta
Reliability Standards, Alternative 2 was selected as the preferred alternative for the Airdrie area.
Table 7.2-1 below summarizes the factors included in the selection of preferred alternative for the Airdrie
area.
March 2014
Calgary Sub-Region Plan
Page 97
Proprietary
Table 7.2-1: Comparison of Airdrie Area Alternatives
Measure
Alternative 1
Alternative 2
(Preferred)
Alternative 4
Technical Factors
Alberta Reliability
Standards
Satisfied
Satisfied
Satisfied
Capacity
Similar
Similar
Similar
Diversity
Low
Medium
High
Similar
Economic Factors
System Losses
Similar
Similar
Capital Cost
Medium
Medium
13
High
Environmental / Societal Factors
Land Impact Assessment
Medium
Medium
High
TFO Feedback
Feasible
Feasible
Feasible
13
As per the feedback from TFO, this development could be built as double circuit with existing transmission lines. The cost is
based on this assumption.
March 2014
Calgary Sub-Region Plan
Page 98
Proprietary
8 Detailed Analysis for Preferred Plan
The Calgary Sub-Region Preferred Plan consists of the selected Calgary area Alternative 2 and Airdrie
area Alternative 2 (see Sections 7.1 and 7.2 above).
Further analysis including transient stability, voltage stability, system performance under maintenance
conditions and short circuit studies were carried out to identify additional potential system issues for the
preferred alternative identified above. Detailed study results are summarized in the following sections.
Comprehensive dynamic studies were performed using the 2017 and 2022 study cases for the preferred
alternative. Generator rotor angles, generator MW outputs, bus voltages and frequencies were monitored.
Actual fault clearing times for transmission lines or standard clearing time when actual clearing time is not
available were used in the dynamic studies. Detailed study results are described below.
Voltage stability analysis was also performed for the Calgary and Airdrie areas. P-V analysis was
conducted to determine the system voltage stability margin with the proposed preferred alternatives inservice for the near-term and medium-term study years. The AESO’s Transmission Reliability Criteria
requires a minimum of 5% operating margin for system normal conditions (Category A) and for single
contingencies (Category B). A minimum of 2.5% operating margin is required for Category C
contingencies (N-2). The operating limit for each critical contingency was compared to the forecasted
system load level to determine whether the voltage stability criteria were met.
The results confirm that after implementation of the CARP, the system meets the voltage stability criteria;
detailed PV plots are given in Appendix H.
8.1
Near-term Assessment
This section summarizes the results of the power flow, dynamic stability, voltage stability and short circuit
analyses performed for the Calgary and Airdrie preferred alternatives in the near-term study year.
8.1.1 Power Flow Studies
The Category A, B and C5 power flow studies for the preferred Calgary and Airdrie alternatives
(Alternatives 2 for both), are discussed in Section 6.2 and 6.3 respectively.
8.1.2 Maintenance Condition Studies
The near-term system performance was assessed under Category B maintenance conditions. To
achieve this, a near-term summer study case was developed with an overall system load at approximately
75% of the expected system peak load. The base system representation at this reduced load level was
expected to give a representative view of potential reliability issues under planned maintenance
conditions.
The system performance was evaluated with major system elements (138kV and above) out of service for
maintenance reasons. The system elements included 240 kV and 138 kV transmission lines.
The following system conditions were assumed for the near-term maintenance case:
1. Load: approximately 75% of summer peak load
2. Generation dispatch: In merit
March 2014
Calgary Sub-Region Plan
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Proprietary
3. Wind: Average (approximately 30% of total maximum)
4. Intertie: Economic
The Category B maintenance condition results for the proposed development sequence for the preferred
Calgary alternative are shown in Table 8.1-1 below.
Table 8.1-1: Near-term Maintenance Condition Results
Contingency
37.81L - 39.82L
Overloaded
Element
Rating (MVA)
13.82L
171
Thermal Loading (%)
Alt 2A
Alt 2B
98
98
39. 82L - 37.81L
13.82L
171
95
94
39.82L – 37.82L
13.82L
171
114
113
37.82L – 39.82L
13.82L
171
114
114
The results indicate a potential overload condition on 13.82L under maintenance conditions. The
development of a new 138 kV line from SS-23 to SS-22 can address this potential overload condition by
providing additional 138 kV capacity to cover the maintenance outage and subsequent contingencies.
8.1.3 Category C7 Power Flow Studies
No thermal or voltage violations were observed under select Category C7 contingencies in the near-term
with the preferred Calgary and Airdrie alternatives in service.
8.1.4 Dynamic Stability Studies
Dynamic stability studies were performed for the preferred alternatives using the following three near-term
scenarios:
1. SC15 – High Wind and high local gen
2. SC16 – High import and high local gen
3. SC13 – High export and high local gen
The results confirm that the system remained stable during the simulated Category B and select Category
C contingencies with the preferred alternatives in service. The results of the dynamic stability analysis as
well as the simulation plots for critical contingencies are provided in Appendix G.
8.1.5 Voltage Stability Studies
The near-term P-V analysis results for N-0, N-1, and N-2 contingencies were performed using the winter
peak cases developed for the Calgary and Airdrie areas. The results for each of the areas are provided
in Table 8.1-2 and Table 8.1-3 below.
March 2014
Calgary Sub-Region Plan
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Proprietary
Table 8.1-2: P-V Analysis Summary – Near-term Winter Peak - Calgary Area
System Normal and Category B Contingencies
Forecasted
2017 Winter
Peak (MW)
105%
Margin
(MW)
Nose Point
(MW)
Meets
Voltage
Criteria?
Normal operation condition
1917
2013
2697
YES
Langdon 500/240kV transformer / 1201L
1917
2013
2615
YES
Category C5 Contingencies
Forecasted
2017 Winter
Peak (MW)
102.5%
Margin
(MW)
Nose Point
(MW)
Meets
Voltage
Criteria?
936L&937L from Langdon 102S to East Calgary 5S
1917
1965
2577
YES
Table 8.1-3: P-V Analysis Summary – Near-term Winter Peak - Airdrie Area
System Normal and Category B Contingencies
Forecasted
2017 Winter
Peak (MW)
105%
Margin
(MW)
Nose Point
(MW)
Meets
Voltage
Criteria?
Normal operation condition
111
117
328
YES
901L from Janet 74S to East Crossfield 64S
111
117
253
YES
The results showed that the Calgary and Airdrie 2017 system loads met the voltage stability criteria with
the preferred alternatives in place.
8.1.6 Short Circuit Studies
A short circuit analysis was performed based on system data14 available for the Calgary Sub-Region in
the near-term. The objective of short circuit analysis is to estimate fault levels for the existing system and
planned system. Detailed near-term short circuit levels are provided in Appendix J.
8.2
Medium-term Assessment
This section summarizes the results of the power flow, dynamic stability, voltage stability and short circuit
analyses performed for the Calgary and Airdrie preferred alternatives in the medium-term.
8.2.1 Power Flow Studies
The Category A, B and C5 power flow studies for the preferred Calgary and Airdrie alternatives
(Alternatives 2 for both), are discussed in Section 6.2 and 6.3 respectively.
8.2.2 Category C7 Power Flow Studies
No thermal or voltage violations were observed under select Category C7 contingencies in the mediumterm with the preferred Calgary and Airdrie alternatives in service.
14
Short circuit current calculation is based on modeling information provided to the AESO by third parties. Short circuit estimation is
subject to change. The information provided in this study is not intended to be used as the sole source of information for electrical
equipment specification and the design of public or worker safety-grounding systems.
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8.2.3 Dynamic Stability Studies
Dynamic stability studies were performed for the preferred alternatives using the following three mediumterm scenarios:
1. SC17 – High Wind and high local gen
2. SC6 – High import and high local gen
3. SC12 – High export and high local gen
The results confirm that the system remained stable during the simulated Category B and select Category
C5 and C7 contingencies with the preferred alternatives in service. The results of the dynamic stability
analysis as well as the simulation plots for critical contingencies are provided in Appendix G.
8.2.4 Voltage Stability Studies
The medium-term PV analysis results for N-0, N-1, and N-2 contingencies were performed using the
winter peak cases developed for the Calgary and Airdrie areas. The results for each of the areas are
provided in Table 8.2-1 and Table 8.2-2 below.
Table 8.2-1: P-V Analysis Summary – Medium-term Winter Peak- Calgary Area
System Normal and Category B Contingencies
Forecasted
2022 Winter
Peak (MW)
105%
Margin
(MW)
Nose Point
(MW)
Meets
Voltage
Criteria?
Normal operation condition
2125
2232
3070
YES
Langdon 500/240kV transformer / 1201L
2125
2232
2890
YES
Category C5 Contingencies
Forecasted
2022 Winter
Peak (MW)
102.5%
Margin
(MW)
Nose Point
(MW)
Meets
Voltage
Criteria?
936L&937L from Langdon 102S to East Calgary 5S
2125
2179
2920
YES
Table 8.2-2: P-V Analysis Summary – Medium-term Winter Peak- Airdrie Area
System Normal and Category B Contingencies
Forecasted
2022 Winter
Peak (MW)
105%
Margin
(MW)
Nose Point
(MW)
Meets
Voltage
Criteria?
Normal operation condition
132
139
335
YES
901L from Janet 74S to East Crossfield 64S
132
139
252
YES
The results showed that the Calgary and Airdrie medium-term system loads met the voltage stability
criteria with the preferred alternatives in place.
8.2.5 Short Circuit Studies
A short circuit analysis was performed based on system data15 available for the Calgary Sub-Region in
the medium-term. The objective of short circuit analysis is to estimate fault levels for the existing system
and planned system. Detailed medium-term short circuit levels are provided in Appendix J.
15
Short circuit current calculation is based on modeling information provided to the AESO by third parties. Short circuit estimation is
subject to change. The information provided in this study is not intended to be used as the sole source of information for electrical
equipment specification and the design of public or worker safety-grounding systems.
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8.3
Long-term Assessment
This section summarizes the results of the power flow analysis performed for the Calgary and Airdrie
preferred alternatives in the long-term study year.
8.3.1 Power Flow Studies
The Category A, B and C5 power flow studies for the preferred Calgary and Airdrie alternatives
(Alternatives 2 for both), are discussed in Section 6.2 and 6.3 respectively.
8.3.2 Short Circuit Studies
A short circuit analysis was performed based on system data16 available for the Calgary Sub-Region in
the long-term. The objective of short circuit analysis is to estimate fault levels for the existing system and
planned system. Detailed long-term short circuit levels are provided in Appendix J.
16
Short circuit current calculation is based on modeling information provided to the AESO by third parties. Short circuit estimation is
subject to change. The information provided in this study is not intended to be used as the sole source of information for electrical
equipment specification and the design of public or worker safety-grounding systems.
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9 Impact of Preferred Plan on System Performance
The following sections summarize the impact of the Preferred Plan on the need for Remedial Action
Schemes and the generation connection capacity of the transmission system.
9.1
Impact on Remedial Action Schemes
Table 9.1-1 shows the list of RASs in Calgary Sub-region post implementation of CARP. The mitigation
plan identifies those facilities that would eliminate the need for each RAS listed in this Table. A number of
RASs would no longer be required after the proposed facilities in the CARP are energized as identified in
the mitigation plan. The AESO will undertake detailed operational studies prior to energization of planned
transmission facilities and make decision on either removal or disabling the specific RAS associated with
the energized facility.
Table 9.1-1: Remedial Action Scheme Changes
Number
9.2
Name
Function
Type
Mitigation Plan
11
Temporary Bennet 520s
Underfrequency Overpower RAS
U/F Trip to protect AB System
from external disturbance
WECC RAS
Still needed
12
Temporary Bennet 520s
undervoltage –
overpower RAS
U/V Trip to protect AB System
from internal and external
disturbance
WECC RAS
FATD East project
15
Temporary 520s
overvoltage protection
scheme
Over voltage protection to
protect equipment from damage
WECC RAS
Still needed
24
Calgary Area UVLS
Program
Protect area load from voltage
collapse
44
South Calgary
transmission load relief
scheme
49
Safety Net
FATD East project
Protect line from overload by
tripping load
LAPS
Addition of SS-65
substation
ENMAX Crossfield 752L
RAS
Protect line from overload by
runback and/or trip generation
LAPS
Airdrie area plan
50
ENMAX Crossfield 688L
RAS
Protect line from overload by
runback and/or trip generation
LAPS
Airdrie area plan
133
Beddington 162S
overload mitigation
scheme
Mitigate potential overload and
other reliability concerns in the
area
LAPS
Calgary area plan
Nodal Capacity
An assessment of existing transmission system with preferred plan in service for facilitating connection of
loads or generations at several locations (nodes) in the Calgary area was performed for the near-term,
medium-term, long-term.
The estimated capacities are based on only steady state system performance that respect thermal or
voltage limits of transmission facilities for Category A and B contingencies. The estimated available
capacities are provided in Table 9.2-1. These estimated capacities represent the additional generation
that can be injected at each node.
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Note that the estimated capacities will also change over time as new loads and/or generations are
connected to the grid or retired from the transmission system.
Table 9.2-1: Estimated Available Capacity for Additional Generation
Area
Voltage Level
(kV)
6
Sarcee 42S
240
Generation
400
800
800
6
Janet 74S
240
Generation
0
0
0
6
SS-65
240
Generation
400
400
200
6
Lochend 75S
240
Generation
-
600
600
March 2014
Connection
Type
Estimated Available
Capacity (MW)
MediumLongNear-term
term
term
Transmission Connection Point
(Line or Substation)
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10 Summary of Preferred Plan
Sections 10.1 and 10.2 below summarize the preferred transmission development for the CARP.
Transmission projects are needed in the near-term for both the Calgary and Airdrie planning areas. The
recommended development sequences for the Preferred Plan are presented in the following sections.
10.1 Calgary Area Preferred Alternative
The development sequence for the preferred Calgary area alternative is summarized in Table 10.1-1
below.
Table 10.1-1: Calgary Area Preferred Alternative
Horizon
Development
Downtown load supply Convert SS-8 to 240 kV substation with 2 new 240/138 kV 400 MVA transformers and a
new 240 kV cable from East Calgary 5S to SS-8 240 kV
New 138 kV line from SS-47 to SS-36
Near-term
North Calgary 69 kV network upgrade to 138kV
929L connected to Beddington SS-162 in an in-out configuration
New 138 kV line from SS-22 to SS-23 (maintenance flexibility)
New 240/138 kV NW Calgary substation and associated 138 kV lines
Medium-term
FATD West double circuit 240 kV line from Foothills 237S to Sarcee 42S
New 240 kV lines from Beddington SS-162 to SS-8 240kV
New 138 kV line from SS-27 to SS-3 and Normally Open 3.82L from SS-3 to SS-8
Long-term
New 138 kV line from Janet 74S to SS-37
Add Var support devices in north Calgary
Figure 10.1-1 below shows the preferred alternative for the Calgary area.
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Figure 10.1-1: Calgary Area Preferred Alternative
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10.2 Airdrie Area Preferred Alternative
The development sequence for the preferred Airdrie area alternative is summarized in Table 10.2-1
below.
Table 10.2-1: Airdrie Area Preferred Alternative
Horizon
Development
East Crossfield 64S Upgrade 901L Tap converted to In-Out configuration at East Crossfield 64S
One new 240/138 kV 200 MVA transformer at East Crossfield 64S
Upgrade the existing 138 kV lines 752L from East Crossfield 64S to Airdrie Tap to Summit
653S to higher capacity line
Upgrade the existing 138 kV line 688L from Summit 653S to Summit tap to East Airdrie
199S to higher capacity line
Near-term
Upgrade the existing 138 kV line 611L from Drycreek 186S to Balzac with higher capacity
line
New 138 kV line from East Crossfield 64S to East Airdrie 199S17
New 138 kV line from Beddington 162S to Dry Creek 186S18
Normally open (N.O.) 138 kV line from East Airdrie 199S Dry Creek 186S
Upgrade /install protection systems as necessary to facilitate the above system
reinforcements
Medium-term
Long-term
New 138 kV D/C line from new POD to the new 138kV line between Beddington 162S and
Dry Creek 186S
No transmission developments proposed.
Figure 10.2-1 below shows the preferred alternative for the Airdrie area.
17
18
As per the feedback from TFO, this development could be built as double circuit with existing transmission lines.
As per the feedback from TFO, this development could be built as double circuit with existing transmission lines.
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Figure 10.2-1: Airdrie Area Preferred Alternative
To Red Deer
63S
901AL
752L
East
Crossfield
64S
929L
925L
653S
Nose Creek
284S
901L
West
Crossfield
316S
688L
East Airdrie
199S N.O.
631L
DryCreek
186S
New PoD
Legend
N.O.
Future Circuit
Existing Circuit
Future Substation
Existing Substation
69 kV Circuit
138 kV Circuit
240 kV Circuit
500 kV Circuit
HVDC line
Normally Open Circuit
69 kV Substation
611L
Balzac
391S
918L
Beddington
162S
932L
138 kV Substation
240 kV Substation
500 kV Substation
Near-term Development
Medium-term Development
Long-term Development
March 2014
Disclaimer: This diagram is a simplified representation
of the physical system configuration. Technical details
have been simplified for illustration purposes. It does not
accurately display the geographical location of facilities.
To Janet
74S
Calgary Sub-Region Plan
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