APPENDIX A CONNECTION ASSESSMENT

APPENDIX A
CONNECTION ASSESSMENT
ATCO Electric
Connection Engineering Study
Report for AUC Application
ATCO Bauer 91 8S Transformer Addition
AESO P1 554
Revision: 2
Revision Date: 2016-02-08
Name
Prepared by:
Amanda Robertson,
P. Eng
Date
Signature
9o I
APEGA Permit to Practice P0850
Connection Engineering Study Report for AUC Application
Connection Engineering Study Report for AUC Application: ATCO Bauer 918S Transformer Addition
Executive Summary
Project Overview
ATCO Electric Ltd. (ATCO), in its capacity as the legal owner of distribution facilities (DFO), has
received a request for a 13 MW load increase at a customer site in the vicinity of the Town of
Vermilion. The DFO has submitted a system access service request (SASR) to the Alberta
Electric System Operator (AESO) to serve industrial load growth in the area.
The SASR includes a request for a Rate DTS, Demand Transmission Service, contract capacity
increase from 18 MW to 31 MW for the system access service provided at the existing Bauer
918S substation, and a request for transmission development (collectively, the Project). The
DFO also requested upgrades to the existing Bauer 918S substation.
The scheduled in-service date (ISD) for the Project is February 1, 2017.
This report details the system performance studies undertaken to assess the impact of the
Project on the Alberta Interconnected Electric System (AIES).
Existing system
The Project is geographically located in the AESO planning area of Lloydminster (Area 13),
which is part of the Central East sub-region (CE sub-region) within the AESO Central Region.
The Lloydminster area is located adjacent to the planning areas of Cold Lake (Area 28),
Vegreville (Area 56), and Wainwright (Area 32).
From a transmission system perspective, the CE sub-region mainly consists of 72 kV and
138/144 kV transmission systems. It is also supported by the 240 kV network through the
Marguerite Lake 826S, Battle River 757S, Nilrem 574S, and Hansman Lake 650S substations.
The CE sub-region is primarily supplied by the Battle River generation station in the
Alliance/Battle River area (Area 36), as well as generation resources in the Cold Lake area.
There are a number of existing constraints in the study area that are mitigated by remedial
action schemes (RASs). Following RAS activation, these constraints are managed in
accordance with the procedures set out in Section 302.1 of the ISO rules, Real Time Constraint
Management.
Study Summary
Study Area for the Project
The study area for the Project consists of the AESO planning areas that constitute the CE subregion, namely the Lloydminster (Area 13), Cold Lake (Area 28), Wainwright (Area 32),
Alliance/Battle River (Area 36), Provost (Area 37), and Vegreville (Area 56) areas. The study
area also includes the tie lines connecting these planning areas to neighbouring planning areas.
All transmission facilities within the study area were studied and monitored to assess the impact
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of the Project on the AIES, including any violations of the Reliability Criteria (as defined in
Section 2.1.1).
Studies Performed for the Project
Load flow analysis was performed for the 2016 winter peak (WP) and 2017 summer peak (SP)
pre- and post-connection scenarios.
Voltage stability analysis was performed only for the 2016 WP post-connection scenario.
Short-circuit analysis was performed for the 2016 WP pre- and post-connection scenarios, and
for the 2024 WP post-connection scenario to determine the short-circuit current levels in the
vicinity of the Project.
Results of the Pre-Connection Studies
The following is a brief summary of the pre-connection studies results. The pre-connection
studies results and applicable mitigation measures are shown in greater detail in Table E-1
below.
Category A (N-G-0) Conditions
Under Category A conditions, no Reliability Criteria violations were observed for any of the preconnection scenarios.
Category B (N-G-1) Contingency Conditions
The pre-connection load flow analysis identified a number of system performance issues under
Category B contingency conditions, including thermal criteria violations and voltage criteria
violations.
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Table E-1: Overview of Pre-Connection Studies Results
Condition
Scenario
Results
Mitigation Measure
Contingency
Result
2016 WP
--
--
--
2017 SP
--
--
--
Category A
2016 WP
Loss of the 138/25 kV
transformer at
Metiskow 648S
substation1
Area voltage collapse
Currently managed by real time
operational practices
Loss of the 138/25 kV
transformer at
Metiskow 648S
substation
Area voltage collapse
Currently managed by real time
operational practices
Thermal criteria
violation on the 144 kV
transmission line
7L130
Currently managed by real time
operational practices
Thermal criteria
violation on the 144 kV
transmission line 7L14
Currently managed by real time
operational practices
Loss of the 144 kV
transmission line 7L50
Thermal criteria
violation on a segment
of the 144 kV
transmission line 7L53
Currently managed by real time
operational practices
Loss of one of the
Vegreville 709S
substation
2
transformers
Thermal criteria
violation on a segment
of the 144 kV
transmission line 7L53
Currently managed by real time
operational practices
Loss of the 144 kV
transmission line 7L130
Thermal criteria
violation on a segment
of the 138 kV
transmission line 749L
Currently managed by real time
operational practices
Loss of the 144 kV
transmission line 7L14
Thermal criteria
violation on a segment
of the 138 kV
transmission line 749L
Currently managed by real time
operational practices
Loss of the 138 kV
transmission line 749L
Category B
2017 SP
1
While the loss of the 138/25 kV transformer at Metiskow 648S substation is considered a Category B (NG-1) event, this event would result in the simultaneous loss of the 138 kV bus and the 138 kV
transmission lines 749L, 703L, and 885L, due to the Metiskow 138 kV bus configuration.
2
While the loss of one of the Vegreville 709S substation transformers is considered a Category B (N-G-1)
event, this event would result in the simultaneous loss of the 144 kV bus at Vegreville 709S substation
and the 144 kV transmission lines 7L92, 7L77, and 7L65, due to the Vegreville 144kV bus configuration.
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Connection Alternative Examined for the Project
ATCO, as the DFO in the area southwest of the Town of Vermilion, examined and ruled out the
use of a distribution-based solution to serve the industrial load increase request.
One transmission alternative was identified for the Project and was studied to evaluate the
impact of the Project on the AIES. The connection alternative involves upgrading the existing
Bauer 918S substation, including adding a 144/4.16 kV transformer with a minimum
transformation capacity of 17.2 MVA, a 144 kV circuit breaker, and a 4.16 kV circuit breaker.
For this connection alternative, a transformer size of 15/20/25 MVA would be recommended
based on good electric industry practice and under advisement from the legal owner of
transmission facilities (TFO) regarding its asset management and inventory practices.
Results of the Post-Connection Studies
The following is a brief summary of the post-connection studies results. The post-connection
studies results and applicable mitigation measures are shown in greater detail in Table E-2,
below.
Category A (N-G-0) Conditions
Under Category A conditions, no Reliability Criteria violations were observed for any of the postconnection scenarios.
Category B (N-G-1) Contingency Conditions
The post-connection load flow analysis identified several Reliability Criteria violations in addition
to the system performance issues that were observed in the pre-connection studies.
Under Category B contingency conditions, exacerbated thermal criteria violations were
observed for the 2017 SP post-connection study scenarios. These violations were observed on
a segment of the 144 kV transmission line 7L53 (between the Bonnyville 700S substation and
the Lindbergh 969S substation tap).
The incremental thermal criteria violations on transmission line 7L53 were as follows:

6.8% increase over the pre-connection loading following the loss of the 144 kV
transmission line 7L50 (between the Battle River 757S and Buffalo Creek 526S
substations); and

4.8% increase over the pre-connection loading following the loss of one of the Vegreville
709S substation transformers.
Thermal criteria violations on transmission line 7L53 were also observed under the following
additional contingencies:

Loss of a 138/25 kV transformer at Buffalo Creek 526S; or

Loss of the 144 kV transmission line 7L65 (between the Vegreville 709S substation and
Vermilion 710S substations).
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The voltage stability criterion was met for all studied contingencies for the 2016 WP postconnection scenario.
Short-Circuit Analysis
The short-circuit analysis show that short-circuit current levels will not significantly increase with
the Project.
Table E-2: Overview of Post-Connection Studies Results
Results
Condition
Scenario
Contingency
Mitigation Measure
Impact after
Project
Result
2016 WP
--
--
--
--
2017 SP
--
--
--
--
2016 WP
Loss of the 138/25
kV transformer at
Metiskow 648S
substation
Area voltage
collapse
N/A
Continue to be
managed by real time
operational practices
Loss of the 138/25
kV transformer at
Metiskow 648S
substation
Area voltage
collapse
Category A
N/A
Continue to be
managed by real time
operational practices
Thermal criteria
violation on the
144 kV
transmission line
7L130
No
Continue to be
managed by real time
operational practices
Thermal criteria
violation on the
144 kV
transmission line
7L14
No
Continue to be
managed by real time
operational practices
Loss of the 144 kV
transmission line
7L50
Thermal criteria
violation on a
segment of the
144 kV
transmission line
7L53
Yes: 6.8%
increase over
pre-connection
loading
Continue to be
managed by real time
operational practices
Loss of one of the
Vegreville 709S
substation
transformers
Thermal criteria
violation on a
segment of the
144 kV
transmission line
7L53
Yes: 4.8%
increase over
pre-connection
loading
Continue to be
managed by real time
operational practices
Loss of the 144 kV
transmission line
7L130
Thermal criteria
violation on a
segment of the
138 kV
transmission line
No
Continue to be
managed by real time
operational practices
Loss of the 138 kV
transmission line
749L
Category B
2017 SP
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Results
Condition
Scenario
Contingency
Result
Impact after
Project
Mitigation Measure
749L
Loss of the 144 kV
transmission line
7L14
Thermal criteria
violation on a
segment of the
138 kV
transmission line
749L
Loss of a 138/25
kV transformer at
Buffalo Creek
3
526S
Thermal criteria
violation on a
segment of the
144 kV
transmission line
7L53
Loss of the 144 kV
transmission line
7L65
Thermal criteria
violation on a
segment of the
144 kV
transmission line
7L53
No
Continue to be
managed by real time
operational practices
Yes
Continue to be
managed by real time
operational practices
Yes
Continue to be
managed by real time
operational practices
Mitigation Measures
As indicated in Table E-1, Reliability Criteria violations that were identified in the pre-connection
studies are currently managed by real time operational practices.
As indicated in Table E-2, Reliability Criteria violations that were identified in the postconnection studies, including exacerbated thermal criteria violations, will continue to be
managed by real time operational practices.
Existing RASs in the area will not need to be modified and no new RASs will be required.
Conclusions and Recommendation
The connection assessment identified a number of pre-connection and post-connection system
performance issues. Real time operational practices are being used to manage the identified
pre-connection system performance issues, and will continue to be used to manage the
identified post-connection system performance issues. It is recommended that the Project be
connected using the identified connection alternative, and to continue the use of real time
operational practices to manage the system performance issues.
3
While the loss of a 138/25 kV transformer at Buffalo Creek 526S is considered a Category B (N-G-1) event, this
event would result in the simultaneous loss of the 138 kV bus at Buffalo Creek 526S substation and the 144 kV
transmission lines 7L129 and 7L50, due to the Buffalo Creek 138 kV bus configuration.
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Contents
Executive Summary .................................................................................................................................... 2 1. Introduction ....................................................................................................................................... 10 1.1. Project ......................................................................................................................................... 10 1.1.1. Project Overview.................................................................................................................. 10 1.1.2. Load Component ................................................................................................................. 10 1.1.3. Generation Component ....................................................................................................... 10 1.2. Study Scope ................................................................................................................................ 10 1.2.1. Study Objectives .................................................................................................................. 10 1.2.2. Study Area ........................................................................................................................... 11 1.2.3. Studies Performed ............................................................................................................... 15 1.3. Report Overview .......................................................................................................................... 15 2. Criteria, System Data, and Study Assumptions ............................................................................. 16 2.1. Criteria, Standards, and Requirements ....................................................................................... 16 2.1.1. Transmission Planning Standards and Criteria ................................................................... 16 2.1.2. Authoritative Documents (ADs) ....................................................................................... 17 2.2. Load and Generation Assumptions ............................................................................................. 17 2.2.1. Load Assumptions ............................................................................................................... 17 2.2.2. Generation Assumptions ..................................................................................................... 17 2.2.3. Intertie Flow Assumptions ................................................................................................... 18 2.3. System Projects........................................................................................................................... 18 2.4. Customer Connection Projects.................................................................................................... 18 2.5. Facility Ratings and Shunt Elements........................................................................................... 20 2.6. Voltage Profile Assumptions ....................................................................................................... 22 3. Study Methodology ........................................................................................................................... 23 3.1. Study Objectives.......................................................................................................................... 23 3.2. Study Scenarios .......................................................................................................................... 23 3.3. Connection Studies Carried Out.................................................................................................. 24 3.4. Load flow Analysis ....................................................................................................................... 24 3.4.1. Contingencies Studied ......................................................................................................... 25 3.5. Voltage Stability (P-V) Analysis ................................................................................................... 25 3.5.1. Contingencies Studied ......................................................................................................... 26 3.6. Short-Circuit Analysis .................................................................................................................. 26 4. Pre-Connection System Assessment ............................................................................................. 26 4.1. Pre-Connection Load Flow Analysis ........................................................................................... 26 5. Connection Alternative ..................................................................................................................... 30 5.1. Overview ...................................................................................................................................... 30 5.2. Connection Alternative Examined ............................................................................................... 30 6. Technical Analysis of the Connection Alternative ........................................................................ 31 6.1. Alternative 1 ................................................................................................................................. 31 6.1.1. Load flow Analysis (Alternative 1) ....................................................................................... 32 6.1.2. Voltage Stability Analysis .................................................................................................... 35 6.1.3. Mitigation Measures............................................................................................................. 35 6.2. Conclusions and Recommendations ........................................................................................... 37 7. Short-Circuit Analysis....................................................................................................................... 37 ATCO Electric
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7.1. Pre-Connection............................................................................................................................ 37 7.2. Post-Connection .......................................................................................................................... 38 8. Project Interdependencies ............................................................................................................... 39 9. Summary and Conclusion ................................................................................................................ 40 Attachments
Attachment A
Pre-Connection Load Flow Plots (2016WP and 2017SP)
Attachment B
Post Connection Load Flow Plots (2016WP and 2017SP)
Attachment C
Voltage Stability Curves
Figures
Figure 1-1: Existing CE Sub-Region Transmission Network ........................................................................................ 12 Figure 1-2: Project Area ............................................................................................................................................... 13 Tables
Table E-1: Overview of Pre-Connection Studies Results ............................................................................................... 4 Table E-2: Overview of Post-Connection Studies Results ............................................................................................. 6 Table 1-1: Summary of CETD Developments Not Yet In-Service ................................................................................ 14 Table 2-1: Post Contingency Voltage Deviations Guidelines for Low Voltage Busses ................................................. 17 Table 2-2: Forecast Area Load..................................................................................................................................... 17 Table 2-3: Local Generators in the Study Cases.......................................................................................................... 18 Table 2-4: Summary of System Projects Included in the Study Cases ........................................................................ 18 Table 2-5: Summary of Customer Connection Projects in Study Area ......................................................................... 19 Table 2-6: Summary of Key Transmission Line Ratings (MVA on a 138 kV base)....................................................... 20 Table 2-7: Summary of Key Shunt Elements in the Study Area ................................................................................... 22 Table 2-8: Summary of Voltage at Key Nodes in the Study Region ............................................................................. 23 Table 3-1: List of the Connection Study Scenarios ...................................................................................................... 24 Table 3-2: Summary of Studies Performed .................................................................................................................. 24 Table 3-3: Summary of Monitored Areas and Contingency Areas for Load Flow Analysis .......................................... 25 Table 4-1 Overview of pre-connection studies results.................................................................................................. 26 Table 4-2: Scenario 1, 2016 WP Pre-Connection: N-G-1 Voltage Criteria Violations and POD bus Deviations .......... 28 Table 4-3: Scenario 2, 2017 SP Pre-Connection: N-G-1 Line Loading Above Rate A (Continuous Summer Rating) .. 29 Table 4-4: Scenario 2, 2017 SP Pre-Connection: N-G-1 Voltage Criteria Violations and POD bus Deviations ........... 29 Table 6-1 Overview of post-connection studies results ................................................................................................ 31 Table 6-2: Scenario 3, 2016 WP Post-Connection: N-G-1 Voltage Criteria Violations and POD bus Deviations ......... 33 Table 6-3: Scenario 4, 2017 SP Post-Connection: N-G-1 Line Loading Above Rate A (Continuous Summer Rating) 34 Table 6-4: Scenario 4, 2017 SP Post-Connection: N-G-1 Voltage Criteria Violations and POD bus Deviations .......... 35 Table 6-5: Scenario 3, 2016 WP Post-Connection: Voltage Stability Results .............................................................. 35 Table 6-6: Scenario 3, 2016 WP Post-Connection: Voltage Criteria Violations and Mitigation ....................................36 Table 6-7: Scenario 4, 2017 SP Post-Connection: N-G-1 Line Loading Above Rate A and Mitigation ........................ 36 Table 6-8: Scenario 4, 2017 SP Post-Connection: N-G-1 Voltage Criteria Violations and Mitigation ........................... 37 Table 7-1: Summary of Short-Circuit Current Levels – Pre-Connection (2016 WP) ..................................................... 38 Table 7-2: Summary of Short-Circuit Current Levels – Post-Connection (2016 WP) ................................................... 38 Table 7-3: Summary of Short-Circuit Current Levels – Post-Connection (2024 WP) ................................................... 38 ATCO Electric
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1.
Introduction
This Engineering Study Report presents the results of the study conducted to assess the impact
of the Project (as defined below) on the performance of the Alberta Interconnected Electric
System (AIES).
1.1.
Project
1.1.1. Project Overview
ATCO Electric Ltd. (ATCO), in its capacity as the legal owner of distribution facilities (DFO), has
received a request for a 13 MW load increase at a customer site in the vicinity of the Town of
Vermilion. The DFO has submitted a system access service request (SASR) to the Alberta
Electric System Operator (AESO) to serve industrial load growth in the area.
The SASR includes a request for a Rate DTS, Demand Transmission Service, contract capacity
increase from 18 MW to 31 MW for the system access service provided at the existing Bauer
918S substation, and a request for transmission development (collectively, the Project). The
DFO also requested upgrades to the existing Bauer 918S substation.
The scheduled in-service date (ISD) for the Project is February 1, 2017.
1.1.2. Load Component
The load increase associated with the Project is driven by new pump station load. The
requested 13 MW load addition at Bauer 918S has been studied using a 0.9 lagging power
factor, and is comprised of four 5750 HP motors started using a variable frequency drive (VFD)
at a pump station facility. When the VFD is not available, the motors will not be started.
1.1.3.
Generation Component
There is no generation component associated with the Project.
1.2.
Study Scope
1.2.1.
Study Objectives
The objectives of the study are the following:
•
Assess the impact of the Project on the performance of the AIES.
•
Identify any violations of the relevant criteria, standards or requirements of the AESO,
both pre- and post-connection of the Project.
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•
Recommend mitigation measures, if required, to enable the reliable connection of the
Project to the AIES.
1.2.2.
Study Area
1.2.2.1.
Study Area Description
The Project is geographically located in the AESO planning area of Lloydminster (Area 13),
which is part of the Central East sub-region (CE sub-region) within the AESO Central Region.
The Lloydminster area is located adjacent to the planning areas of Cold Lake (Area 28),
Vegreville (Area 56), and Wainwright (Area 32).
From a transmission system perspective, the CE sub-region mainly consists of 72 kV and 138/
144 kV transmission systems. It is also supported by the 240 kV network through the Marguerite
Lake 826S, Battle River 757S, Nilrem 574S, and Hansman Lake 650S substations. The CE subregion is primarily supplied by the Battle River generation station in the Alliance/Battle River
area (Area 36), as well as generation resources in the Cold Lake area. Figure 1-1 shows the
existing CE sub-region transmission network. Figure 1-2 shows the transmission network
surrounding the Project area.
The study area for the Project consists of the AESO planning areas that constitute the CE subregion, namely the Lloydminster, Cold Lake, Wainwright, Alliance/Battle River, Provost (Area
37), and Vegreville areas. The study area also includes the tie lines connecting these planning
areas to neighbouring planning areas. All transmission facilities within the study area were
studied and monitored to assess the impact of the Project on the AIES, including any violations
of the Reliability Criteria (as defined in Section 2.1.1).
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Figure 1-1: Existing CE Sub-Region Transmission Network
Coal Generator
69/72 kV
Gas Generator
138/144 kV
Wind Generator
138/144 kV Double Circuit
69 or 72 kV Substation
240 kV
138 or 144 kV Substation
240 kV Double Circuit
240 kV Substation
500 kV
Central
East Area
This diagram contains a simplified
version of the system configuration.
Technical detail has been simplified
for illustration purposes. It does not
indicate geographical locations of facilities.
ck
Bla )
t o 4S
L ( 15
15 e
11 pruc
S
AESO Planning Areas
Currency Date: 2016-01-27
25 Fort McMurray
PIKE
170S
L
445
Foster Creek (EC04)
UNDERWOOD
183S
FOSTER
CREEK
1200S
27 Athabasca / Lac La Biche
7
3
7L
IOR2
Nabiye
7L
7
7L587
6
14
7L
7L91
9L36
7L
5
Mahkeses
(IOR1)
LEMING
LAKE
715S
ETHEL LAKE
717S
7L
8
9
7L28
7L66
7L24
7L70
BONNYVILLE
700S
9
GRAND
CENTRE
846S
7LA24
3
7L1
NORBERG
936S
MAHKESES
889S
5
7L9
83
LACOREY
721S
7LA139
4
7L79
WHITEFISH
LAKE 825S
7L
1
16
7L
5
10
MAHIHKAN
837S
7L157
9L37
61
9L960/9L9
(to Whitefish
Lake 825S)
MAHNO
909S
4
7L160
BOURQUE
970S
MARGUERITE
LAKE 826S
794L (to Lac
La Biche 157S)
PRIMROSE
859S
5
NABIYE
942S
4
57
7L
9L22/9L81 (to
Heart Lake 898S)
WOLF
LAKE
822S
28 Cold Lake
Primrose #1 (PR1)
6
L8
BEARTRAP
940S
WHITBYLAKE
819S
7L92
7LA53
7L53
ST. PAUL
707S
VILNA
777S
LINDBERGH
969S
WATT LAKE
956S
7LA92
IRISH CREEK
706S
56 Vegreville
13 Lloydminster
7
7L11
VEGREVILLE
709S
7L130
7L14
7L77
7L65
7L
A
BAUER
918S
12
9
7L
9
12
KITSCOTY
705S
HILL
751S
7L42
NORTH HOLDEN
395S
VERMILION
710S
174L
(to Bardo
197S)
JARROW
252S
749L
METISKOW
648S
HAYTER
277S
715L
HANSMAN
LAKE 650S
948L
42 Hanna
ATCO Electric
PROVOST
545S
7L224 (to
Monitor
774S)
948L
748L
KILLARNEY
LAKE 267S
885L
SUNKEN
LAKE
221S
954L
769L
679
L
680
L
Bull Creek
#1-2
749AL
HUGHENDEN
213S
1047L
37 Provost
EDGERTON
899S
HRT EXPRESS
329S
966L (to
Pemukan
932S)
HALKIRK
615S
PAINTEARTH
863S
9L59 (to
Anderson
801S)
9L93
TINCHEBRAY
972S
13L50 (to
Newell
2075S)
6L02 (to Marion
Lake 873S)
6L03 (to
Sullivan
Lake 775S)
BIGFOOT
756S
L
9L948
9L16
CORDEL
755S
NILREM
574S
953L
6L08
9L20 (to
Nevis 766S)
B
703
70
3L
ROSYTH
296S
9L27
9L953
9
74
7L
WAINWRIGHT
51S
953L
1047L
Battle River
#3-5 (BR3-5)
79
9L L80
9
7LB
749
681L
TUCUMAN
478S
CLIPPER
656S
50
704AL
36 Alliance /
Battle River
BATTLE
RIVER 757S
05
6L
9L80 (to
Mannix Mine 765S)
7L701
7L
70
2
6L05
7LA701
BIG KNIFE
CREEK
7L
HARDISTY
377S
704L
702AL
702L
BRIKER
880S
61L
SEDGEWICK
137S
13L50 (to
Heathfield
2029S)
LLOYDMINSTER
716S
COCHIN PIPELINE
FABYAN 968S
703AL
STROME
223S
HEISLER
764S
BUFFALO
CREEK 526S
61AL
701L
32 Wainwright
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Figure 1-2: Project Area
7L139
7L70 (to
Bonnyville
700S)
WHITBYLAKE
819S
69 or 72 kV Substation
240 kV Substation
138 or 144 kV Substation
69/72 kV
138/144 kV
138/144 kV Double Circuit
This diagram contains a simplified
version of the system configuration.
Technical detail has been simplified
for illustration purposes. It does not
indicate geographical
locations of facilities.
7L53
ST. PAUL
707S
VILNA
777S
P1554 Area
Transmission
System
7L53 (to
Bonnville
700S)
7LA139
4 (to
7L79 La
Lac
7S
e 15
Bich
NORBERG
936S
7LA53
240 kV Double Circuit
P1554 Project Area
LINDBERGH
969S
AESO Planning Areas
Currency Date: 2015-08-13
7L92
28 - Cold Lake
56 - Vegreville
IRISH CREEK
706S
13 - Lloydminster
7L117
7LA92
WATT LAKE
956S
7L130
VEGREVILLE
709S
7L14
BAUER
918S
7L
A
NORTH
HOLDEN
395S
BIG KNIFE
CREEK 843S
1.2.2.2.
681L
704AL
TUCUMAN
478S
702L
36 - Alliance /
Battle River
769L
CLIPPER
656S
ttle
Ba )
(to 57S
50 er 7
L
7 iv
R
(to
9L y t h
76 os S )
R 96
2
NILREM
574S
B
703
953L/1047L
(to Junction)
BRIKER
880S
7LB
749
L
LLOYDMINSTER
716S
9
74
7L
61L
704L
HARDISTY
377S
679
L
680
L
7L702 (to Battle
River 757S)
7L701 (to Battle
River 757S)
702AL
701L
6L05
7LA701
COCHIN PIPELINE
FABYAN 968S
JARROW
252S
SEDGEWICK
137S
HILL
751S
9
BUFFALO
CREEK 526S
STROME
223S
HEISLER
764S
1
7L
61AL
32 - Wainwright
12
KITSCOTY
705S
7L42
174L (to
Bardo
197S)
VERMILION
710S
29
WAINWRIGHT
51S
HRT EXPRESS
329S
703L HUGHENDEN
213S
703
L
Meti
skow (to
64 8
S)
EDGERTON
899S
749L (to
Metiskow 648S)
7L77
7L65
37 - Provost
KILLARNEY
LAKE 267S
749AL
748L (to
Hayter 277S
Existing Constraints
There are a number of existing constraints in the study area that are mitigated by remedial
action schemes (RASs). Following RAS activation, these constraints are managed in
accordance with the procedures set out in Section 302.1 of the ISO rules, Real Time Constraint
Management (TCM Rule). As discussed in Section 6.1.3 of this report, the Project does not
affect the effectiveness of existing RASs in the study area, nor does the Project create the need
for new RASs in the study area.
1.2.2.3.
AESO Long-Term Plans
Transmission developments are planned as part of the approved Central East Transmission
Development (CETD) project to address constraints in the CE sub-region. The CETD
developments in/around the study area that are not in service yet are shown in Table 1-1.
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Table 1-1: Summary of CETD Developments Not Yet In-Service
Project
Project Name
ISD
811-4
St. Paul 707S & 7L139/7L70
Aug. 2016
811-25
Bonnyville 700S Transformer
addition
Oct. 2016
In addition to the CETD, the AESO 2015 Long-term Plan (2015 LTP)4 also includes the following
system developments in the CE sub-region in the near term (by 2020)5:

Add voltage reinforcement at Strome substation east of Camrose, Irish Creek substation
north of Kitscoty and Whitby Lake substation near Vilna;

Add new 240/144 kV substation near Vermilion;

Add new 240 kV line from Tinchebray substation northeast of Halkirk to new substation
near Vermilion energized at 144 kV;

Reconfigure 144 kV lines in vicinity of Vermilion to terminate at new substation;

Add new 240 kV line from Hansman Lake substation southeast of Hughenden to
Edgerton substation energized at 144 kV;

Rebuild 144 kV line from Vermilion to Irish Creek to higher capacity;

Add voltage reinforcement in the Cold Lake area.
4
The 2015 LTP document is available on the AESO website.
5
The 2015 LTP identifies the near-term transmission developments in the CE sub-region on pages 44-45.
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1.2.3.
Studies Performed
The following studies were performed for the pre-connection analysis:
•
Load flow analysis (Category A conditions and Category B contingencies)
•
Short-circuit analysis (Category A conditions)
The following studies were performed for the post-connection analysis:
1.3.
•
Load flow analysis (Category A conditions and Category B contingencies)
•
Voltage stability analysis (Category A conditions and Category B contingencies)
•
Short-circuit analysis (Category A conditions)
Report Overview
The Executive Summary provides a high-level summary of the report and its conclusions.
Section 1 provides an introduction of the Project. Section 2 describes the criteria, system data,
and study assumptions used in this study. Section 3 presents the study methodology used in
this study. Section 4 discusses the pre-connection system assessment. Section 5 presents the
connection alternatives examined. Section 6 provides a technical analysis of the postconnection system assessment for the alternatives selected for further study. Section 7 provides
a short-circuit analysis for the pre- and post-connection as well as the future post-connection
information. Section 8 discusses project interdependencies. Section 9 presents the conclusions
and recommendations of this study.
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2.
Criteria, System Data, and Study Assumptions
2.1.
Criteria, Standards, and Requirements
2.1.1.
Transmission Planning Standards and Criteria
The Transmission Planning (TPL) Standards, which are included in the Alberta Reliability
Standards, and the AESO’s Transmission Planning Criteria – Basis and Assumptions6
(collectively, the Reliability Criteria) were applied to evaluate system performance under
Category A system conditions (i.e., all elements in-service) and following Category B
contingencies (i.e., single element outage), prior to and following the studied alternatives. Below
is a summary of Category A and Category B system conditions.
Category A, often referred to as the N-0 condition, represents a normal system with no
contingencies and all facilities in service. Under this condition, the system must be able to
supply all firm load and firm transfers to other areas. All equipment must operate within its
applicable rating, voltages must be within their applicable range, and the system must be stable
with no cascading outages.
Category B events, often referred to as an N-1 or N-G-1 with the most critical generator out of
service, result in the loss of any specified single system element under specified fault conditions
with normal clearing. These elements are a generator, a transmission circuit, a transformer or a
single pole of a DC transmission line. The acceptable impact on the system is the same as
Category A. Planned or controlled interruptions of electric supply to radial customers or some
local network customers, connected to or supplied by the faulted element or by the affected
area, may occur in certain areas without impacting the overall reliability of the interconnected
transmission systems. To prepare for the next contingency, system adjustments are permitted,
including curtailments of contracted firm (non-recallable reserved) transmission service electric
power transfers.
The TPL standards, TPL-001-AB-0 and TPL-002-AB-0, have referenced Applicable Ratings
when specifying the required system performance under Category A and Category B events.
For the purpose of applying the TPL standards to the studies documented in this report,
Applicable Ratings are defined as follows:
6

Seasonal continuous thermal rating of the line’s loading limits.

Highest specified loading limits for transformers.

For Category A conditions: Voltage range under normal operating condition per AESO
Information Document ID# 2010-007RS. For the busses not listed in ID#2010-007RS,
Table 2-1 in the Transmission Planning Criteria – Basis and Assumptions applies.
Filed under a separate cover.
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
For Category B conditions: the extreme voltage range values per Table 2-1 in the
Transmission Planning Criteria – Basis and Assumptions.

Desired post-contingency voltage change limits for three defined post event timeframes
as provided in Table 2-1, below.
Table 2-1: Post Contingency Voltage Deviations Guidelines for Low Voltage Busses
Parameter and
Reference Point
Post Transient
(Up to 30 sec.)
Time Period
Post Auto Control
(30 sec. to 5 min.)
Post Manual Control
(Steady State)
± 10%
± 7%
± 5%
Voltage deviation from
steady state at low
voltage bus
2.1.2.
Authoritative Documents (ADs)
AESO Information document ID# 2010-007RS, General Operating Practices - Voltage Control,
which relates to Section 304.4 of the ISO rules, Maintaining Network Voltage, was used to
establish system normal (i.e., pre-contingency) voltage profiles for the study area. The TCM
Rule will be followed to assess any criteria violations identified as a result of the connection
studies.
2.2.
2.2.1.
Load and Generation Assumptions
Load Assumptions
The study area load forecast used for this connection study is reflected in Table 2-2 and is at
CE sub-region peak, which was based on the AESO 2014 Long-term Outlook (2014 LTO).
Table 2-2: Forecast Area Load
Forecast Peak Load
Area Name and Number
Season
Year
(MW)
CE sub-region Total
(Area 13, 28, 32, 36, 37, 56)
AIL without Losses
2.2.2.
Winter
2016
979.4
Summer
2017
922.5
Winter
2016
12,154.5
Summer
2017
11,440.4
Generation Assumptions
The study scenarios will assume the credible worst condition for the network, which is a no wind
scenario. Wind projects in the study area will be dispatched to zero in this study. Table 2-3
provides the list of non-wind generators and their dispatch levels in the study scenarios. Battle
River unit #5 is considered to be the critical generating unit in the CE sub-region, and will be
turned off in the load flow and voltage stability analysis.
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Table 2-3: Local Generators in the Study Cases
Generator
Name
Units
Symbol
Maximum
Capacity (MW)
Dispatch Level in the Study
Scenarios (MW)
2016 WP
2017 SP
1
FCG1
49
47
45
2
FCG2
49
47
45
1
MAHKE-G1
100.8
88
69
2
MAHKE-G2
100.8
88
69
1
NABIYE-2
90
64
56
2
NABIYE-3
90
64
56
1
PRIM
94.5
88
77
3
BAT3
162.6
149
149
4
BAT4
166.3
155
155
5
BAT5
407
Off
Off
Foster Creek
Mahkeses
Nabiye
Primrose
Battle River
2.2.3.
Intertie Flow Assumptions
The Alberta-BC and Alberta-Montana intertie points are deemed to be too far away to have any
material impact on the assessment of the requested connection. Therefore the intertie flows
were dispatched the same as in the published AESO’s base cases. The Alberta-Saskatchewan
intertie will be set to zero.
The HVDC systems are blocked in the study scenarios, since they are not expected to have any
material impact on the assessment of the requested connection.
2.3.
System Projects
Only the system projects in or near the study area that have an earlier ISD than the Project
were modelled in the study scenarios. These future system projects are shown in Table 2-4.
Table 2-4: Summary of System Projects Included in the Study Cases
System Facility Name
2.4.
Project ISD
CETD EN-4 - St. Paul Upgrades St. Paul 707S,
7L139/7L70
Aug. 2016
CETD EN-25 - Bonnyville 700S Transformer
addition
Oct. 2016
Customer Connection Projects
Table 2-5 identifies customer connection projects in the study area.
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Table 2-5: Summary of Customer Connection Projects in Study Area
Planning
Area
Queue
Position*
Project
Number
Project Name
ISD
Modelled** in the
Study cases
13
72
1554
ATCO Bauer 918S Transformer
Addition
Feb. 1, 2017
Yes
37
6
851
TransCanada Keystone KXL
Pumpstation #2-Eyre (Phase 1)
Jul 1, 2016
Yes
37
7
851
TransCanada Keystone KXL
Pumpstation #2-Eyre (Phase 2)
Jan. 1, 2017
Yes
28
N/A
901
Imperial Oil Cold Lake Expansion
Nabiye Plant (Phase 2)
Energized
Yes
32
17
937
Mainstream Wainwright Wind
Project
Jan. 3, 2018
Yes
32
N/A
1284
Nilrem 574S Expansion (formerly
Lagstaff)
Energized
Yes
28
N/A
1280
ATCO Bear Trap 940S Substation
Capacity Addition
Energized
Yes
13
N/A
1311
ATCO Irish Creek 706S Upgrades
(Load Addition)
Energized
Yes
32
N/A
1390
Fortis Tucuman 478S-25 kV
Breaker Addition
Energized
Yes
28
N/A
1240
ATCO Pengrowth Lindbergh 969S
Breaker Add
Energized
Yes
37
N/A
1366
Enbridge Sunken Lake Substation
Expansion
Energized
Yes
56
N/A
1350
Strome 223S Transformer Addition
Energized
Yes
28
N/A
1364
La Corey Area Capacity Increase
Energized
Yes
13
28
1250
E. ON Grizzly Bear Wind Facility
Dec. 15, 2017
Yes
36
37
1472
Fortis Genalta Bellshill DG
May 2, 2016
Yes
32
N/A
1454
Fortis Tucuman 478S-T2 25 kV
Feeder Breaker Addition
Energized
Yes
56
38
1410
ATCO Heartland Pump Station
Connection
Nov. 1, 2017
Yes
28
40
1492
Cenovus Kodiak New Substation
and Transmission Line
May 31, 2017
Yes
37
N/A
1495
Fortis Hayter 277S 42 MVA
Transformer and 25 kV Breaker
Addition
Energized
Yes
28
N/A
1514
Imperial Oil Mahkeses G1&G2
Control And Exciter System Repairs
Energized
Yes
37
58
1516
Enbridge Sunken Lake 221S
Transformer Change
July 1, 2017
No#
28
61
1524
AltaGas Kent Generation New POS
June. 1, 2017
No#
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Planning
Area
Queue
Position*
Project
Number
Project Name
ISD
Modelled** in the
Study cases
28
63
1571
ATCO Mahihkan Load Increase-25
KV Breaker Addition
Jan. 1, 2017
No#
Notes:
* Per the AESO Connection Queue posted in January 2016. The projects in the study area that have lower queue
positions than Project 1554 have not been listed in this table and were not modelled in the study cases.
** These projects are dispatched per the load and generation levels set out in Section 2.2.1 and Section 2.2.2.
# These projects had not yet passed Gate 2 of the AESO Connection Process at the beginning of this study;
therefore, they were not modelled in this study. These connection projects will not affect the results of this connection
assessment or the conclusions and recommendations contained in this report.
2.5.
Facility Ratings and Shunt Elements
Table 2-6 provides the ratings of the key existing transmission lines in the study area. Table 2-7
provides a summary of the shunt elements modelled in the study area.
Table 2-6: Summary of Key Transmission Line Ratings (MVA on a 138 kV base)
Line
Number
From
To
Voltage
(kV)
Summer Rating
(MVA)
Winter Rating
(MVA)
174L
Bardo 197S
Holden 395S
138
85
90
7L794
Whitby Lake 819S
Lac La Biche 157S
144
94
94
701L
North Holden 395S
Strome 223S
138
119
146
749L
Metiskow 648S
Killarney Lake Tap
138
121
149
749L
Edgertson 899S
Killarney Lake Tap
138
88
96
749AL
Killarney Lake 267S
Killarney Lake Tap
138
121
148
7L130
Vermillion 710S
Kitscoty 705S
144
72
86
7L14
Kitscoty 705S
Hill 751S
144
72
86
7L24
Bonnyville 700S
Grande Centre 846S
144
109
139
7L28
Ethel Lake 717S
Grande Centre 846S
144
109
139
7L35
Primrose Tap
Primrose 859S
144
140
143
7L42
Hill 751S
Lloydminster 716S
144
95
95
7L129
Vermillion 710S
Buffalo Creek 526S
144
109
139
7L50
Buffalo Creek 526S
Jarrow Tap
144
109
139
7L50
Jarrow tap
Battle River 757S
144
109
139
704L
Jarrow Tap
Jarrow 252S
138
85
90
704L
Tucuman 478S
Wainwright 515S
138
75
79
704AL
Wainright 515S
704L tap
138
121
148
7L53
Bonnyville 700S
Irish Creek 706S
144
72
86
7L117
Irish Creek 706S
Vermillion 710S
144
95
95
7L65
Vegreville 709S
Vermillion 710S
144
95
95
7L66
Leming Lake 715S
Ethel Lake 717S
144
109
139
7L139
St. Paul 707S
Whitby lake 819S
144
109
139
7L70
Bonnyville 700S
St. Paul 707S
144
109
139
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Line
Number
From
To
Voltage
(kV)
Summer Rating
(MVA)
Winter Rating
(MVA)
701L/7L701
Strome 223S
Battle River 757S
144
140
169
702L
Hardisty 377S
Sedgewick Tap 137S
139
87
135
7L702
Sedgewick Tap 137S
Battle River 757S
144
109
118
7L574
Wolf Lake 822S
Bourque 970S
144
247
286
748L
Killarney Lake 267S
Hayter 277S
138
119
146
749L
Edgerton 899S
PV Tap
138
88
96
7LB749
PV tap
Briker 880S
144
109
139
7L749
PV tap
Lloydminster
144
109
139
715L
Hansman Lake 650S
Provost 545S
138
98
132
7L77
North Holden 395S
Vegreville 709S
144
96
96
7L583
Bourque 970S
Leming Lake 715S
144
178.3
218.5
7L86
Wolf Lake 822S
Foster Creek 877S
144
139
143
7L587
Wolf Lake 822S
Marguerite Lake 826S
144
191.7
191.7
7L89
La Corey 721S
Bonnyville 700S
144
109
139
7L91
Leming Lake 715S
Marguerite Lake 826S
144
109
139
7L92
Whitby lake 819S
Vegreville 709S
144
94
94
7L95
Mahkeses 889S
Leming Lake 715S
144
190
190
7L105
Mahihkan 837S
MahNo 909S
144
109
139
7L146
Bourque 970S
Bonnyville 700S
144
191
191
7L157/7L160
Mahihkan 837S
Bourque 970S
144
178.3
218.5
7LA129
Bauer 918S
7L129 Tap
144
109
139
Note: Emergency line ratings will be provided, where applicable, for the pre- and post-connection study results.
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Table 2-7: Summary of Key Shunt Elements in the Study Area
Substation Name
and Number
Nominal
Number of
Bus
Voltage Switched
Shunt
(kV)
Blocks
Capacitors
Total at
Nominal
Voltage
(MVAr)
Reactors
Status in
Study
Number of
Switched
Shunt
Blocks
Total at
Nominal
Voltage
(MVAr)
Status in
Study
(on or off)
Marguerite Lake 826S
25
-
-
3
20
Switch as
required
Whitefish 825S
240
1
100
-
-
-
Bonnyville 700S
144
3
15
-
-
-
Vermillion 710S
144
1
25
-
-
-
Buffalo Creek 526S
138
1
15
-
-
-
Tucuman 478S
138
1
27
-
-
-
Hardisty 377S
138
1
44.9
-
-
-
-
-
-
Hill 751S
144
-
-
-
Lloydminster 716S
144
St. Paul 707S
25
Sunken Lake 221S
138
Killarney Lake 267S
138
Battle River 757S
72
2.6.
Switch as
required
1
27
1
20
1
25
-
-
-
1
20
-
-
-
1
2.4
-
-
-
1
4.8
-
-
-
1
18.1
-
-
-
1
9.1
-
-
-
2
10.9
-
-
-
1
9.19
-
-
-
Off
Voltage Profile Assumptions
The AESO Voltage Control Practice ID# 2010-007RS is used to establish normal system (i.e.,
pre-contingency) voltage profiles for key area busses prior to commencing any studies. Table 21 of the Transmission Planning Criteria – Basis and Assumptions applies for all the busses not
included in the ID# 2010-007RS. These voltages will be utilized to set the voltage profile for the
study base cases prior to load flow analysis. The key bus voltages for the study area for the
project are shown in Table 2-8.
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Table 2-8: Summary of Voltage at Key Nodes in the Study Region
AESO ID# 2010-007RS
Substation
Minimum
Nominal Operating
Voltage
Limit
(kV)
(kV)
Whitefish
Lake 825S
Pre-connection
Post-connection
Desired
Range (kV)
Maximum
Operating
Limit (kV)
2016 WP
2017 SP
2016 WP
2017 SP
240
253
255-265
275
264.4
266.6
264.4
266.6
Marguerite
Lake 826S
240
252
255-268
275
259.6
261.2
259.6
261.2
144
141
148-151
155
150.8
150.8
150.9
150.8
Hill 751S
144
137
143-149
151
147.4
146.9
146.2
145.6
Lloydminster
716S
144
137
142-149
151
147.3
146.8
146.2
145.5
240
250
250-260
260
256.8
256.5
256.8
257.3
Metiskow
648S
3.
Voltage in the Study Case (kV)
138
140
140-144
145
143.9
142.1
143.9
142.3
Hardisty
377S
138
140
140-144
145
143.4
140.5
143.3
140.6
Bonnyville
700S
144
140
147-150
155
147.9
148.7
147.8
148.5
Leming
Lake 715S
144
140
144-150
155
145.7
146.4
145.8
146.3
Battle River
757S
144
144
146-150
155
147.0
147.9
146.9
147.0
Killarney
Lake 267S
138
138
138-144
145
142.8
140.9
142.7
140.9
Study Methodology
All the studies were completed using PTI PSS/E version 33.
3.1.
Study Objectives
The objectives of the study are the following:
•
Assess the impact of the Project on the performance of the AIES.
•
Identify any violations of the relevant criteria, standards or requirements of the AESO,
both pre- and post-connection of the Project.
Recommend mitigation measures, if required, to enable the reliable integration of the
project to the AIES.
•
3.2.
Study Scenarios
The scheduled ISD for the Project is February 1, 2017. Hence, the study was conducted for the
2016 WP and 2017 SP. Short-circuit analysis was also completed for the 2024 WP. The study
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cases were derived from the published AESO’s 2014 Planning Base Case Suite and related
auxiliary data files.
Table 3-1 lists the scenario and load development considered for the Project in this study. The
new load power factor used for this study was 0.9 lagging.
Table 3-1: List of the Connection Study Scenarios
Scenario
Number
Study Scenario
Project Load
(MW)
Pre-Connection System
1
2016 WP
18
2
2017 SP
18
Post-Connection System
3.3.
3
2016 WP
31
4
2017 SP
31
Connection Studies Carried Out
The following studies were carried out for this connection study:
Table 3-2: Summary of Studies Performed
Scenario(s) Studied
3.4.
Studies Performed
System Conditions Studied
3, 4
Load Flow
Category A and B
--
3
Voltage Stability
Category B
1
3, 2024 WP7
Short-Circuit
Category A
PreConnection
PostConnection
1, 2
Load flow Analysis
Load flow analysis was conducted on all study scenarios to identify any thermal overloads or
transmission voltage violations as per the Reliability Criteria, and to identify any deviations from
the desired limits in Table 2-1. The purpose of the load flow analysis is to quantify any
incremental violations in the study area after the Project is connected.
Point-of-delivery (POD) low voltage bus deviations were assessed by first locking all tap
changers and area capacitors to identify any post-transient voltage deviations above 10%. Tap
7
For the 2024 WP short circuit studies, Battle River unit #3 was switched off because it is expected to
retire by 2019.
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changers were then allowed to move while capacitors remained locked to determine if any
voltage deviations above 7% were found in the area. Once all taps and capacitor controls were
allowed to adjust, voltage deviations above 5% were reported for both the pre-connection and
post-connection networks.
3.4.1.
Contingencies Studied
For the load flow analysis, the study area was monitored for voltage criteria and thermal criteria
violations under Category A conditions and under Category B contingency conditions. The
studied contingencies include all transmission single outages (Category B contingencies) within
the CE sub-region, as well as the tie lines connecting the study area to surrounding planning
area, as shown in Table 3-3.
Table 3-3: Summary of Monitored Areas and Contingency Areas for Load Flow Analysis
3.5.
Area
Number
Area Name
Voltage Range
13
Lloydminster
69 kV and above
28
Cold Lake
69 kV and above
32
Wainwright
69 kV and above
36
Alliance/Battle River
69 kV and above
37
Provost
69 kV and above
56
Vegreville
69 kV and above
Voltage Stability (P-V) Analysis
The objective of the voltage stability analysis is to determine the ability of the network to
maintain voltage stability at all the busses in the system under normal and abnormal system
conditions. The Power-Voltage (PV) curve is a representation of voltage change as a result of
increased power transfer between two systems. The reported incremental transfers will be to
the collapse point. As per the AESO requirements, no assessment based upon other criteria
such as minimum voltage will be made at the PV minimum transfer. Voltage stability analysis for
post-connection scenarios will be performed. For load connection projects, the load level
modelled in post-connection scenarios are the same or higher than in pre-connection scenarios.
Therefore, voltage stability analysis for pre-connection scenarios will only be performed if postconnection scenarios show voltage stability criteria violations.
The voltage stability analysis was performed according to the Western Electricity Coordinating
Council (WECC) Voltage Stability Assessment Methodology. WECC voltage stability criteria
states, for load areas, post-transient voltage stability is required for the area modeled at a
minimum of 105% of the reference load level for system normal conditions (Category A) and for
single contingencies (Category B). For this standard, the reference load level is the maximum
established planned load.
Typically, voltage stability analysis is carried out assuming the worst case scenarios in terms of
loading. The voltage stability analysis was performed by increasing load in the CE sub-region,
and increasing the corresponding generation in the following AESO Planning Areas:

Calgary (Area 6)
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
Sheerness (Area 43)

Fort McLeod (Area 53)
3.5.1.
Contingencies Studied
Voltage stability analysis was performed for the Category A condition and all Category B
contingencies in the study area for the 2016 WP post-connection scenario to determine the
system voltage stability margin in this winter peaking area.
3.6.
Short-Circuit Analysis
The short-circuit analysis was performed prior to and following the Project connection for the
2016 WP scenario, as well the long-term assessment using the post-connection 2024 WP study
scenario. The short-circuit analysis includes three-phase and single-line-to-ground faults. Fault
levels, in the form of currents in kilo amperes and per unit positive and zero sequence
impedances, are provided for all buses near the Project with all area generators on (except wind
generation).
4.
Pre-Connection System Assessment
4.1.
Pre-Connection Load Flow Analysis
Table 4-1 provides an overview of the pre-connection load flow analysis and applicable
mitigation measures. Please refer to Attachment A for load flow diagrams.
Table 4-1 Overview of pre-connection studies results
Condition
Category A
Category B
Results
Scenario
Contingency
Mitigation Measure
Result
2016 WP
--
--
--
2017 SP
--
--
--
2016 WP
Loss of the 138/25 kV
transformer at
Metiskow 648S
8
substation
Area voltage collapse
Currently managed by real time
operational practices
2017 SP
Loss of the 138/25 kV
transformer at
Metiskow 648S
substation
Area voltage collapse
Currently managed by real time
operational practices
8
While the loss of the 138/25 kV transformer at Metiskow 648S substation is considered a Category B (NG-1) event, this event would result in the simultaneous loss of the 138 kV bus and the 138 kV
transmission lines 749L, 703L, and 885L, due to the Metiskow 138 kV bus configuration.
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Condition
Scenario
Results
Contingency
Result
Loss of the 138 kV
transmission line 749L
4.1.1.1.
Mitigation Measure
Thermal criteria
violation on the 144 kV
transmission line
7L130
Currently managed by real time
operational practices
Thermal criteria
violation on the 144 kV
transmission line 7L14
Currently managed by real time
operational practices
Loss of the 144 kV
transmission line 7L50
Thermal criteria
violation on a segment
of the 144 kV
transmission line 7L53
Currently managed by real time
operational practices
Loss of one of the
Vegreville 709S
substation
9
transformers
Thermal criteria
violation on a segment
of the 144 kV
transmission line 7L53
Currently managed by real time
operational practices
Loss of the 144 kV
transmission line 7L130
Thermal criteria
violation of a segment
of the 138 kV
transmission line 749L
Currently managed by real time
operational practices
Loss of the 144 kV
transmission line 7L14
Thermal criteria
violation of a segment
of the 138 kV
transmission line 749L
Currently managed by real time
operational practices
Scenario 1 – 2016 WP
No Reliability Criteria violations were observed under Category A conditions.
No thermal criteria violations were observed under Category B contingency conditions.
Under the studied Category B contingency conditions, the following voltage criteria violations
were observed:

Area voltage collapse following the loss of the 138/25 kV transformer at Metiskow 648S
substation.
Please see Table 4-2: below and refer to Attachment A for load flow diagrams.
9
While the loss of one of the Vegreville 709S substation transformers is considered a Category B (N-G-1)
event, this event would result in the simultaneous loss of the 144 kV bus at Vegreville 709S substation
and the 144 kV transmission lines 7L92, 7L77, and 7L65, due to the Vegreville 144kV bus configuration.
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Table 4-2: Scenario 1, 2016 WP Pre-Connection: N-G-1 Voltage Criteria Violations and POD bus
Deviations
Substation
Name and
Number
Contingency
Bus
Number
Base
kV
138/25 kV
transformer at
Metiskow 648S
substation
Initial
Voltage
(kV)
Voltage Deviations for POD Busses Only
Post
Transient
(kV)
% Change
Post
Auto
(kV)
% Change
Post
manual
(kV)
% Change
for POD
Busses
Only
Area Voltage Collapse
4.1.1.2.
Scenario 2 – 2017 SP
No Reliability Criteria violations were observed under Category A conditions.
Under the studied Category B contingency conditions the following Reliability Criteria violations
were observed.
Voltage Criteria Violations:

Area voltage collapse following the loss of the 138/25 kV transformer at Metiskow 648S
substation, as previously noted in scenario 1.
Thermal Criteria Violations:

Line loading above emergency line ratings were observed on the 144 kV lines 7L130
(between the Vermilion 710S and Kitscoty 705S substations) and 7L14 (between the
Kitscoty 705S and Hill 751S substations) following the loss of the 138 kV line 749L
(between the Metiskow 648S and Edgerton 899S substations).

Line loading above the emergency line rating was observed on a segment of the 144 kV
line 7L53 (between the Bonnyville 700S substation and the Lindbergh 969S substation
tap) following two Category B contingencies:
Loss of transformer 701T at the Vegreville 709S substation, resulting in the
simultaneous loss of the 144 kV bus and the 144 kV transmission lines 7L92,
7L77, and 7L65; or
o Loss of the 144 kV line 7L50 (between the Battle River 757S and Buffalo Creek
526S substations).
Line loading below the emergency line rating was observed on a segment of the 138 kV
line 749L (between the Metiskow 648S substation and the Killarney Lake 267S
substation tap) following two Category B contingencies:
o Loss of the 144 kV line 7L14 (between the Kitscoty 705S and Hill 751S
substations); or
o Loss of the 144 kV line 7L130 (between the Vermilion 710S and Kitscoty 705S
substations).
o

Please see Table 4-3 and Table 4-4 below and refer to Attachment A for load flow diagrams.
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Table 4-3: Scenario 2, 2017 SP Pre-Connection: N-G-1 Line Loading Above Rate A
(Continuous Summer Rating)
Line
Pre-Contingency Post-Contingency
Rating
% Loading
Load
Load
Contingency
Limiting Branch
Normal/
%
%
Difference
Flow
Flow
Emergency
Loading
Loading
(MVA)*
(MVA)* (MVA)*
7L130 (Vermilion 710S
to Kitscoty 705S)
72 / 72
43.5
60.4
80.9
112.3
51.9
7L14 (Kitscoty 705S to
Hill 751S)
72 / 72
38.7
53.7
76.2
105.8
52.1
Vegreville 709S
Transformer
7L53 segment
(Bonnyville 700S to
Lindbergh 969S tap)
72 / 72
59.0
82.0
72.2
100.3
18.3
7L50 (Battle River
757S to Buffalo
Creek 526S)
7L53 segment
(Bonnyville 700S to
Lindbergh 969S tap)
72 / 72
59.0
82.0
77.3
107.3
25.3
7L14 (Kitscoty 705S
to Hill 751S)
749L segment
(Metiskow 648S to
Killarney Lake 267S
tap)
121 / 133
87.0
71.9
125.7
103.8
31.9
7L130 (Vermilion
710S to Kitscoty
705S)
749L segment
(Metiskow 648S to
Killarney Lake 267S
tap)
121 / 133
87.0
71.9
129.7
107.2
35.3
749L (Metiskow 648S
to Edgerton 899S)
*MVA using 138 kV base.
Table 4-4: Scenario 2, 2017 SP Pre-Connection: N-G-1 Voltage Criteria Violations and POD
bus Deviations
Contingency
Substation
Name and
Number
138/25 kV
transformer at
Metiskow 648S
substation
Bus
Number
Base
kV
Initial
Voltage
(kV)
Voltage Deviations for POD Busses Only
Post
Transient
(kV)
% Change
Post
Auto
(kV)
% Change
Post
manual
(kV)
% Change
for POD
Busses
Only
Area Voltage Collapse
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5.
Connection Alternative
5.1.
Overview
ATCO, as the DFO in the area southwest of the Town of Vermilion, examined and ruled out the
use of a distribution-based solution to serve the industrial load increase request.10
One transmission alternative was identified for the Project, and was studied to evaluate the
impact of the Project on the performance of the AIES.
5.2.
Connection Alternative Examined
Below is a description of the developments associated with the transmission alternative that was
examined for the Project.11
Add a transformer at the Bauer 918S substation
This connection alternative involves upgrading the existing Bauer 918S substation by adding a
second 144/4.16 kV transformer, and by adding a 144 kV breaker.
This alternative includes the following:

Add one 144/4.16 kV transformer with a minimum transformation capacity of 17.2 MVA;

Add a 144 kV circuit breaker; and

Add a 4.16 kV circuit breaker and associated equipment.
For this connection alternative, a transformer size of 15/20/25 MVA would be recommended
based on good electric industry practice and under advisement from the legal owner of
transmission facilities (TFO) regarding its asset management and inventory practices.
This connection alternative was studied to evaluate the impact of the Project on the
performance of the AIES.
10
The DFO’s analysis is reported in sections 5 and 6 of the ATCO Distribution Deficiency Report, Bauer
918S Transformer Addition, which is filed under a separate cover.
11
This alternative reflects more up to date engineering design than the alternative identified in the ATCO
Distribution Deficiency Report, Bauer 918S Transformer Addition, which is filed under a separate cover.
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6.
Technical Analysis of the Connection Alternative
6.1.
Alternative 1
Table 6-1 provides an overview of the post-connection analysis. Mitigation measures, where
applicable, are discussed in Section 6.1.3. Please refer to Attachment B for load flow diagrams.
Table 6-1 Overview of post-connection studies results
Results
Condition
Scenario
Contingency
Mitigation Measure
Impact after
Project
Result
2016 WP
--
--
--
--
2017 SP
--
--
--
--
2016 WP
Loss of the 138/25
kV transformer at
Metiskow 648S
substation
Area voltage
collapse
N/A
Continue to be
managed by real time
operational practices
Loss of the 138/25
kV transformer at
Metiskow 648S
substation
Area voltage
collapse
Category A
Continue to be
managed by real time
operational practices
Thermal criteria
violation on the
144 kV
transmission line
7L130
No
Continue to be
managed by real time
operational practices
Thermal criteria
violation on the
144 kV
transmission line
7L14
No
Continue to be
managed by real time
operational practices
Loss of the 144 kV
transmission line
7L50
Thermal criteria
violation on a
segment of the
144 kV
transmission line
7L53
Yes: 6.8%
increase over
pre-connection
loading
Continue to be
managed by real time
operational practices
Loss of one of the
Vegreville 709S
substation
transformers
Thermal criteria
violation on a
segment of the
144 kV
transmission line
7L53
Yes: 4.8%
increase over
pre-connection
loading
Continue to be
managed by real time
operational practices
Loss of the 138 kV
transmission line
749L
Category B
N/A
2017 SP
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Results
Condition
6.1.1.
Scenario
Contingency
Result
Impact after
Project
Mitigation Measure
Loss of the 144 kV
transmission line
7L130
Thermal criteria
violation of a
segment of the
138 kV
transmission line
749L
No
Continue to be
managed by real time
operational practices
Loss of the 144 kV
transmission line
7L14
Thermal criteria
violation of a
segment of the
138 kV
transmission line
749L
No
Continue to be
managed by real time
operational practices
Loss of a 138/25
kV transformer at
Buffalo Creek
12
526S
Thermal criteria
violation on a
segment of the
144 kV
transmission line
7L53
Loss of the 144 kV
transmission line
7L65
Thermal criteria
violation on a
segment of the
144 kV
transmission line
7L53
Yes
Continue to be
managed by real time
operational practices
Yes
Continue to be
managed by real time
operational practices
Load flow Analysis (Alternative 1)
6.1.1.1.
Scenario 3: 2016 WP Post-Connection
No Reliability Criteria violations were observed under Category A conditions.
No thermal criteria violations were observed under Category B contingency conditions.
Under the studied Category B contingency conditions, voltage criteria violations that were
identified in the pre-connection analysis were also observed in the post-connection analysis:

Area voltage collapse following the loss of the 138/25 kV transformer at Metiskow 648S
substation.
Please refer to Table 6-2 and Attachment B for load flow diagrams.
12
While the loss of a 138/25 kV transformer at Buffalo Creek 526S is considered a Category B (N-G-1) event, this
event would result in the simultaneous loss of the 138 kV bus at Buffalo Creek 526S substation and the 144 kV
transmission lines 7L129 and 7L50, due to the Buffalo Creek 138 kV bus configuration.
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Table 6-2: Scenario 3, 2016 WP Post-Connection: N-G-1 Voltage Criteria Violations and POD bus
Deviations
Substation
Name and
Number
Contingency
138/25 kV
transformer at
Metiskow 648S
substation
Bus
Number
Base
kV
Initial
Voltage
(kV)
Voltage Deviations for POD Busses Only
Post
Transient
(kV)
% Change
Post
Auto
(kV)
% Change
Post
manual
(kV)
% Change
for POD
Busses
Only
Area Voltage Collapse
6.1.1.2.
Scenario 4: 2017 SP Post-Connection
No Reliability Criteria violations were observed under Category A conditions.
Under the studied Category B contingency conditions, Reliability Criteria violations that were
identified in the pre-connection analysis were also observed in the post-connection analysis.
Voltage Criteria Violations Also Identified in the Pre-Connection Analysis (Scenario 2):

Area voltage collapse following the loss of the 138/25 kV transformer at Metiskow 648S
substation.
Thermal Criteria Violations Also Identified in the Pre-Connection Analysis (Scenario 2):

Line loading above emergency line ratings were observed on the 144 kV lines 7L130
(between the Vermilion 710S and Kitscoty 705S substations) and 7L14 (between the
Kitscoty 705S and Hill 751S substations) following the loss of the 138 kV line 749L
(between the Metiskow 648S and Edgerton 899S substations). The loading on each of
these transmission lines does not increase after this post-connection contingency.

Line loading above the emergency line rating was observed on a segment of the 144 kV
line 7L53 (between the Bonnyville 700S substation and the Lindberg 969S substation
tap) following two Category B contingencies. The loading on transmission line 7L53
increased after each these post-connection contingencies:

o
Loss of transformer 701T at the Vegreville 709S substation, resulting in the
simultaneous loss of the 144 kV bus and the 144 kV transmission lines 7L92,
7L77, and 7L65; or
o
Loss of the 144 kV line 7L50 (between the Battle River 757S and Buffalo Creek
526S substations).
Line loading below emergency line rating was observed on a segment of 138 kV line
749L (between the Metiskow 648S and the Killarney Lake 267S tap) following two
Category B contingencies. The loading due to these contingencies does not increase
after this post-connection contingency.
o
Loss of the 144 kV line 7L14 (between the Kitscoty 705S and Hill 751S
substations); or
o
Loss of the 144 kV line 7L130 (between the Vermilion 710S and Kitscoty 705S
substations).
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Thermal Criteria Violations Not Identified in the Pre-Connection Analysis:

Line loading exceeding the emergency line ratings on the 144 kV transmission line 7L53
(between the Bonnyville 700S substation and Lindbergh 979S substation tap) were
observed following two additional Category B contingencies, as follows:
o
Loss of transformer 701T at the Buffalo Creek 526S substation, which results in
the simultaneous loss of the 138 kV bus at Buffalo Creek 526S substation and
the 144 kV transmission lines 7L129 and 7L50;
o
Loss of the 144 kV transmission line 7L65 (between the Vegreville 709S and
Vermilion 710S substations)
Please refer to Table 6-3, Table 6-4, and to Attachment B.
Table 6-3: Scenario 4, 2017 SP Post-Connection: N-G-1 Line Loading Above Rate A (Continuous Summer
Rating)
Line
Pre-Connection
Post-Connection
Rating
% Loading
Load
Load
Contingency
Limiting Branch
Normal/
%
%
Difference
Flow
Flow
Emergency
Loading
Loading
(MVA)*
(MVA)* (MVA)*
7L130 (Vermilion 710S
to Kitscoty 705S)
72 / 72
80.9
112.3
80.5
111.8
-0.5
7L14 (Kitscoty 705S to
Hill 751S)
72 / 72
76.2
105.8
75.8
105.3
-0.5
Vegreville 709S
Transformer 701T13
7L53 segment
(Bonnyville 700S to
Lindbergh 969S tap)
72 / 72
72.2
100.3
75.7
105.1
4.8
Buffalo Creek 526S
14
Transformer 701T
7L53 segment
(Bonnyville 700S to
Lindbergh 969S tap)
72 / 72
69.1
96.0
73.6
102.2
6.2
7L14 (Kitscoty 705S
to Hill 751S)
749L segment
(Metiskow 648S to
Killarney Lake 267S
tap)
121 / 133
125.7
103.8
124.8
103.1
-0.7
7L130 (Vermilion
710S to Kitscoty
705S)
749L segment
(Metiskow 648S to
Killarney Lake 267S
tap)
121 / 133
129.7
107.2
128.7
106.4
-0.8
7L50 (Battle River
757S to Buffalo
Creek 526S)
7L53 segment
(Bonnyville 700S to
Lindbergh 969Stap)
72 / 72
77.3
107.3
82.2
114.1
6.8
7L65 (Vegreville
709S to Vermilion
710S)
7L53 segment
(Bonnyville 700S to
Lindbergh 969S tap)
72 / 72
69.0
95.9
72.2
100.2
4.3
749L (Metiskow 648S
to Edgerton 899S)
*MVA using 138 kV base.
13
Loss of transformer 701T at the Vegreville 709S substation would result in the simultaneous loss of the
144 kV bus and the 144 kV transmission lines 7L92, 7L77, and 7L65.
14
Loss of transformer 701T at the Buffalo Creek 526S substation would result in the simultaneous loss of
the 138 kV bus at Buffalo Creek 526S substation and the 144 kV transmission lines 7L129 and 7L50.
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Table 6-4: Scenario 4, 2017 SP Post-Connection: N-G-1 Voltage Criteria Violations and POD
bus Deviations
Substation
Name and
Number
Contingency
Bus
Number
Base
kV
Initial
Voltage
(kV)
138/25 kV
transformer at
Metiskow 648S
substation
Voltage Deviations for POD Busses Only
Post
Transient
(kV)
% Change
Post
Auto
(kV)
% Change
Post
manual
(kV)
% Change
for POD
Busses
Only
Area Voltage Collapse
6.1.2.
Voltage Stability Analysis
Voltage stability analysis was conducted for the post-connection 2016 WP scenario. The voltage
stability margins were met. The PV graphs for the worst three contingencies are provided in
Attachment C.
6.1.2.1.
Scenario 3: 2016 Winter Peak (2016 WP) Post Connection
The 2016 WP reference load in the study area is 979.4 MW. For the Category B contingency
condition, the minimum incremental MW transfer required to meet the 105% load criterion is
49.0 MW (0.05 x 979.4 = 49.0 MW). The average power factor 0.93 for the study area was used
for this analysis. Table 6-5 provides the voltage stability analysis results for system normal (N-0)
conditions and for the three worst contingencies. The voltage stability criterion was met for all
contingencies.
Table 6-5: Scenario 3, 2016 WP Post-Connection: Voltage Stability Results
Contingency
N-0
749L
7L50
7L95*
From
To
System Normal
Category B (Minimum Transfer = 49.0 MW)
Metiskow 648S
Edgerton 899S
Battle River 757S
Buffalo Creek 526S
Leming Lake 715S
Mahkeses 889S
Maximum
Meets
Incremental
Criteria?
Transfer (MW)
481.25
Yes
250.0
275.0
337.5
Yes
Yes
Yes
*Tripping of the plant at Mahkeses 889S results in the same maximum incremental transfer as
the loss of the 144 kV transmission line 7L95.
6.1.3.
Mitigation Measures
The connection assessment identified a number of pre-connection and post-connection system
performance issues. Real time operational practices are being used to manage the identified
pre-connection system performance issues.
Real time operational practices will continue to be used to manage the identified postconnection system performance issues.
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The Project does not affect the effectiveness of existing RASs in the study area, nor does the
Project create the need for new RASs in the study area.
Table 6-6, Table 6-7 and Table 6-8 summarize the applicable mitigation measures to manage
the post-connection system performance issues.
Table 6-6: Scenario 3, 2016 WP Post-Connection: Voltage Criteria Violations and Mitigation
Substation
Contingency Name and
Number
Bus
Number
Base
kV
Initial
Voltage
(kV)
138/25 kV
transformer
at Metiskow
648S
substation
Voltage Deviations for POD Busses Only
Post Transient (kV)
% Change
Post
Auto
(kV)
% Change
Post
manual
(kV)
% Change
for POD
Busses
Only
Mitigation
Continue to
be managed
by real time
operational
practices
Area Voltage Collapse
Table 6-7: Scenario 4, 2017 SP Post-Connection: N-G-1 Line Loading Above Rate A and Mitigation
Line Rating
Contingency
Limiting Branch
Normal/
Emergency
(MVA)*
Post-Connection
Load Flow
%
(MVA)*
Loading
7L130 (Vermilion 710S to
Kitscoty 705S)
72 / 72
80.5
111.8
7L14 (Kitscoty 705S to Hill
751S)
72 / 72
75.8
105.3
Vegreville 709S
Transformer 701T
7L53 segment (Bonnyville
700S to Lindbergh 969S
tap)
72 / 72
75.7
105.1
Buffalo Creek 526S
Transformer 701T
7L53 segment (Bonnyville
700S to Lindbergh 969S
tap)
72 / 72
73.6
102.2
7L14 (Kitscoty 705S to
Hill 751S)
749L segment (Metiskow
648S to Killarney Lake
267S tap)
121 / 133
124.8
103.1
7L130 (Vermilion 710S to
Kitscoty 705S)
749L segment (Metiskow
648S to Killarney Lake
267S tap)
121 / 133
128.7
106.4
7L50 (Battle River 757S
to Buffalo Creek 526S)
7L53 segment (Bonnyville
700S to Lindbergh
969Stap)
72 / 72
82.2
114.1
7L65 (Vegreville 709S to
Vermilion 710S)
7L53 segment (Bonnyville
700S to Lindbergh 969S
tap)
72 / 72
72.2
100.2
749L (Metiskow 648S to
Edgerton 899S)
ATCO Electric
Mitigation
Continue to be managed
by real time operational
practices
Continue to be managed
by real time operational
practices
February, 2016
36
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Connection Engineering Study Report for AUC Application: ATCO Bauer 918S Transformer Addition
Table 6-8: Scenario 4, 2017 SP Post-Connection: N-G-1 Voltage Criteria Violations and Mitigation
Substation
Contingency Name and
Number
Bus
Noumber
Initial
Base
Voltage
kV
(kV)
138/25 kV
transformer
at Metiskow
648S
substation
6.2.
Voltage Deviations for POD Busses Only
Post Transient (kV)
% Change
Post
Auto
(kV)
Area Voltage Collapse
% Change
Post
manual
(kV)
% Change
for POD
Busses
Only
Mitigation
Continue to
be managed
by real time
operational
practices
Conclusions and Recommendations
Only one connection alternative was examined for the Project, and was studied to evaluate the
impact of the Project on the performance of the AIES. The connection assessment identified a
number of pre-connection and post-connection system performance issues. Real time
operational practices are being used to manage the identified pre-connection system
performance issues and will continue to be used to manage the identified post-connection
system performance issues. It is recommended that the Project be connected using the
identified connection alternative, and to continue the use of real time operational practices to
manage the system performance issues.
7.
Short-Circuit Analysis
Short-circuit analysis was performed pre- and post-connection using the 2016 WP scenario with
all generation in service, except wind generation, in order to provide the maximum short-circuit
levels15 in the CE sub-region. The 2024 WP scenario was used for the long-term short-circuit
outlook analysis. Single-phase and three-phase fault currents were calculated as provided in the
following tables.
7.1.
Pre-Connection
Table 7-1 provides the 2016 WP short-circuit levels without the Project addition at Bauer 918S
substation.
15
Short-circuit current studies were based on modeling information provided to the AESO by third parties.
The authenticity of the modeling information has not been validated. Fault levels could change as a result
of system developments, new customer connections, or additional generation in the area. It is
recommended that these changes be monitored and fault levels reviewed to ensure that the fault levels
are within equipment operating limits. The information provided in this study should not be used as the
sole source of information for electrical equipment specifications or for the design of safety-grounding
systems.
ATCO Electric
February, 2016
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Connection Engineering Study Report for AUC Application: ATCO Bauer 918S Transformer Addition
Table 7-1: Summary of Short-Circuit Current Levels – Pre-Connection (2016 WP)
PrePositive Sequence
Base
3-Φ
1-Φ
Fault
Thevenin Source
Voltage
Fault
Fault
Voltage
Impedance (R1+jX1)
(kV)
(kA)
(kA)
(kV)
(pu)
Zero Sequence
Thevenin Source
Impedance (R0+jX0)
(pu)
Substation
Bus
Bauer 918S
1113
144
142.2
3.7
0.056002+j0.102466
3.6
0.026860+j0.124441
Buffalo Creek
526S
79
144
142.3
3.8
0.052327+j0.099384
3.1
0.055350+j0.179337
Drury 2007S
1047
144
143.0
3.5
0.060065+j0.110379
3.5
0.027118+j0.123025
Vermilion 710S
1383
144
143.0
3.9
0.055409+j0.096757
4.9
0.003378+j0.045074
7.2.
Post-Connection
Short-circuit levels are provided in Table 7-2, and Table 7-3 for the 2016 WP and 2024 WP
scenarios with the Project addition in service.
Table 7-2: Summary of Short-Circuit Current Levels – Post-Connection (2016 WP)
Substation
PreBase
3-Φ
Fault
Bus Voltage
Fault
Voltage
(kV)
(kA)
(kV)
Positive Sequence
Thevenin Source
Impedance (R1+jX1)
(pu)
1-Φ
Fault
(kA)
Zero Sequence
Thevenin Source
Impedance (R0+jX0)
(pu)
Bauer 918S
1113
144
141.2
3.7
0.057891+j0.101675
3.9
0.016079+j0.101755
Buffalo Creek
526S
79
144
141.5
3.8
0.054421+j0.099915
3.3
0.039105+j0.162776
Drury 2007S
1047
144
142.6
3.4
0.061386+j0.109622
3.5
0.026904+j0.121484
Vermilion 710S
1383
144
142.6
3.9
0.056911+j0.096005
4.9
0.003203+j0.043331
Table 7-3: Summary of Short-Circuit Current Levels – Post-Connection (2024 WP)
Substation
PreBase
3-Φ
Fault
Bus Voltage
Fault
Voltage
(kV)
(kA)
(kV)
Positive Sequence
Thevenin Source
Impedance (R1+jX1)
(pu)
1-Φ
Fault
(kA)
Zero Sequence
Thevenin Source
Impedance (R0+jX0)
(pu)
Bauer 918S
1113
144
145.5
5.1
0.033011+j0.080577
4.7
0.017701+j0.105244
Buffalo Creek
526S
79
144
144.0
4.5
0.039125+j0.089878
3.5
0.044498+j0.172069
Drury 2007S
1047
144
148.2
7.0
0.022253+j0.060292
7.2
0.010236+j0.057225
ATCO Electric
February, 2016
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Connection Engineering Study Report for AUC Application: ATCO Bauer 918S Transformer Addition
Substation
Vermilion 710S
8.
PreBase
3-Φ
Fault
Bus Voltage
Fault
Voltage
(kV)
(kA)
(kV)
1383
144
147.9
Positive Sequence
Thevenin Source
Impedance (R1+jX1)
(pu)
1-Φ
Fault
(kA)
Zero Sequence
Thevenin Source
Impedance (R0+jX0)
(pu)
0.026488+j0.067575
7.2
0.003664+j0.042007
6.2
Project Interdependencies
No project interdependencies were identified.
ATCO Electric
February, 2016
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Connection Engineering Study Report for AUC Application: ATCO Bauer 918S Transformer Addition
9.
Summary and Conclusion
The DFO has received a request for a 13 MW load increase at a customer site in the vicinity of
the Town of Vermilion. The DFO has submitted a SASR to the AESO to serve industrial load
growth in the area.
The SASR includes a request for a Rate DTS, Demand Transmission Service, contract capacity
increase from 18 MW to 31 MW for the system access service provided at the existing Bauer
918S substation, and a request for transmission development (collectively, the Project). The
DFO also requested upgrades to the existing Bauer 918S substation.
The scheduled in-service date (ISD) for the Project is February 1, 2017.
This report detailed the system performance studies undertaken to assess the impact of the
Project on the Alberta Interconnected Electric System (AIES).
The connection assessment identified a number of pre-connection and post-connection system
performance issues. Real time operational practices are being used to manage the identified
pre-connection system performance issues and will continue to be used to manage the
identified post-connection system performance issues. It is recommended that the Project be
connected using the identified connection alternative, and to continue the use of real time
operational practices to manage the system performance issues.
ATCO Electric
February, 2016
40
R2
ATTACHMENT A
Pre-Connection Load Flow Diagrams
(2016WP and 2017SP)
ATCO Electric R1 A‐1Pre‐ConnectionSystemLoadFlowDiagramsfor2016WPand
2017SP
The steady-state power flow diagrams for Category A, and B contingencies are provided in this
section. The following table presents the list of load flow diagrams. Load flow diagrams for
contingencies that resulted in voltage collapse are not shown.
Scenario
1
2
Table A‐1: List of Pre‐connection Power Flow Diagrams Description
System Condition
Normal (N-0)
N-1, Loss of 749L (899S to 648S)
N-1, Loss of 701T at 709S
2016WP
N-1, Loss of 7L50
N-1, Loss of 7L14
N-1, Loss of 7L130
Normal (N-0)
N-1, Loss of 749L (899S to 648S)
N-1, Loss of 701T at 709S
2017SP
N-1, Loss of 7L50
N-1, Loss of 7L14
N-1, Loss of 7L130
Page Number
A-1 / A-2
A-3 / A-4
A-5 / A-6
A-7 / A-8
A-9 / A-10
A-11 / A-12
A-13 / A-14
A-15 / A-16
A-17 / A-18
A-19 / A-20
A-21 / A-22
A-23 / A-24
ATCO Electric R1 ATTACHMENT B
Post-Connection Load Flow Diagrams
(2016WP and 2017SP)
ATCO Electric R1 B‐1Post‐ConnectionSystemLoadFlowDiagramsfor2016WPand
2017SP
The steady-state power flow diagrams for Category A, and B contingencies are provided in this
section. The following table presents the list of power flow diagrams. Load flow diagrams for
contingencies that resulted in voltage collapse are not shown.
Scenario
3
4
ATCO Electric Table B‐1: List of Post‐Connection Load Flow Diagrams Description
System Condition
Normal (N-0)
N-1, Loss of 749L (899S to 648S)
N-1, Loss of 701T at 709S
N-1, Loss of 7L50
2016WP
N-1, Loss of 701T at 526S
N-1, Loss of 7L65
N-1, Loss of 7L14
N-1, Loss of 7L130
Normal (N-0)
N-1, Loss of 749L (899S to 648S)
N-1, Loss of 701T at 709S
N-1, Loss of 7L50
2017SP
N-1, Loss of 701T at 526S
N-1, Loss of 7L65
N-1, Loss of 7L14
N-1, Loss of 7L130
Page Number
B-1 / B-2
B-3 / B-4
B-5 / B-6
B-7 / B-8
B-9 / B-10
B-11 / B-12
B-13 / B-14
B-15 / B-16
B-17 / B-18
B-19 / B-20
B-21 / B-22
B-23 / B-24
B-25 / B-26
B-27 / B-28
B-29 / B-30
B-31 / B-32
R1 ATTACHMENT C
Voltage Stability Curves (2016WP)
ATCO Electric R1 C‐12016WPPost‐ConnectionSystemVoltageStabilityAnalysisResults
The following figures show the PV curves for the most severe contingencies of 7L50, 7L95, and
749L. These contingencies were run for scenario 3: post-connection 2016WP. There is no plot
for the contingency of 648ST1, because this contingency resulted in voltage collapse.
Figure 1: Loss of 7L50 145
140
144 kV Bus Voltage (kV)
135
130
125
120
115
110
105
100
95
0.000
50.000
100.000
150.000
200.000
250.000
300.000
Incremental Load Transfer (MW)
Bauer
ATCO Electric Vermilion
Buffalo Creek
Minimum Transfer (B) = 49 MW
R1 Figure 2: Loss of 749L 144 kV Bus Voltage (kV)
140
130
120
110
100
90
0.000
50.000
100.000
150.000
200.000
250.000
300.000
Incremental Load Transfer (MW)
Bauer
Vermilion
Buffalo Creek
Minimum Transfer (B) = 49 MW
Figure 3: Loss of 7L95 145
144 kV Bus Voltage (kV)
140
135
130
125
120
115
0.000
50.000
100.000
150.000
200.000
250.000
300.000
350.000
400.000
Incremental Load Transfer (MW)
Bauer
ATCO Electric Vermilion
Buffalo Creek
Minimum Transfer (B) = 49 MW
R1