Stakeholder Comment and Reply Matrix AESO AUTHORITATIVE DOCUMENT PROCESS Generating Unit Technical

Stakeholder Comment and Reply Matrix
AESO AUTHORITATIVE DOCUMENT PROCESS
AESO Replies to TransAlta Letter dated January 18, 2013 concerning Proposed New ISO Rules Section 502.5 Version 2.0 Generating Unit Technical
Requirements and Section 502.6 Generating Unit Operating Requirements
1. ISO Rules
Stakeholder Comments and/or Alternative Proposal
AESO Replies
(c) New
Proposed New ISO Rules Section 502.5 Version 2.0 sets out the minimum
technical requirements for a legal owner connecting a generating unit to the
transmission system.
After considering stakeholder comments on proposed New ISO Rules Section
502.5, the AESO is proposing New ISO Rules Section 502.5 Version 2.0, which
includes the following key changes from proposed New ISO Rules Section 502.5:
1. Amended the language to improve clarity without any intended change to the
technical requirements;
2. References to existing and new generating units have been removed to avoid
confusion. Proposed New ISO Rules Section 502.5 Version 2.0 applies to
both new and existing generating units. This resulted in subsections 2 and 3
of proposed New ISO Rules Section 502.5 being removed in its entirety from
proposed New ISO Rules Section 502.5 Version 2.0;
3. Subsection 6 has been removed to improve clarity although elements of
subsection have been inserted into the appropriate relevant subsections;
4. Removed subsection 12.3 of proposed New ISO Rules Section 502.5 so that
this requirement can be more fully consulted on at some future time;
5. Amended subsection 15 to clarify what would be considered a simultaneous
trip of multiple generating units and to allow for the trip of a combustion
turbine to result in the trip of a steam turbine in combined cycle plants;
6. Removed the operating requirements and relocated these operating
requirements into proposed New ISO Rules Section 502.6 Generating Unit
Operating Requirements (“New ISO Rules Section 502.6”) such that proposed
New ISO Rules Section 502.5 Version 2.0 now only contains technical
AESO Replies to Stakeholder Comments: 2013-05-16
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requirements. Click here to access the Letter of Notice for proposed New ISO
Rules Section 502.6;
7. Removed content related to the submission of modeling data to eliminate
duplication with ISO OPP 1306 Reporting Equipment Changes;
8. Removed appendices where the content was determined to be informational
in nature;
.
9. Added an appendix relating to voltage-ride-through requirements for existing
generating units; and
10. Removed the subsection referencing reactive power requirements for
generating units with power purchase agreements. The AESO agreed with
stakeholder comments that a single section referencing the requirements for
all generating units was sufficient and improves clarity.
The AESO is seeking comments from stakeholders with regard to the following
matters:
1. In developing proposed New ISO Rules Section 502.5 Version 2.0, the AESO
did not intentionally change the intent of the technical requirements from
proposed New ISO Rules Section 502.5. If you disagree, please identify the
specific requirement(s) where you believe the intent has changed.
2. Proposed New ISO Rules Section 502.5 Version 2.0 remains consistent with
the AESO’s Generator and Load Interconnection Standard, except for the
specific requirements added, which are only applicable to new generating
units, and where the functional specification references ISO Rules Section
502.5, once effective, or if specific equipment is changed on planned basis. If
you disagree please identify the specific requirements that are not consistent
with the AESO’s Generator and Load Interconnection Standard.
3. Are there any subsections where stakeholders feel that language does not
clearly articulate the requirement for either the AESO or a market participant?
If yes, please indicate the subsections and suggest language that would
improve the clarity.
AESO Replies to Stakeholder Comments: 2013-05-16
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(d) Other
Stakeholders wishing to comment on specific provisions are requested to copy
the provision into this area and provide comments.
TransAlta Letter
1. TransAlta does not agree that it is appropriate to
reference the ESBI document in AESO response
68 of its reply to stakeholder comments. As set out
in its Scope, section 1.1, page 4, the ESBI
document only specified: 'the general technical
requirements for connecting (or upgrading) a new
(or previously isolated) generating facility to
Alberta's Interconnected Electric System". The
interconnection of existing units was handled by
ESBI through the Terms and Conditions of the tariff
and included Article4 (System Support Services),
Article 5 (Interconnection Requirements) and
Appendix E (System Support Services). The
Alberta Energy and Utilities Board in Decisions
2000-25 and 2000-46 severely limited the ability of
ESBI as the transmission administrator to compel
the provision of System Support Services as a
condition of connection. The findings of the Board
in these two decisions have not been challenged or
amended.
2.
AESO Replies to Stakeholder Comments: 2013-05-16
According to the AESO (response 26) Rule 502.5
is applicable to all generating units whether new,
existing or modified. Comparisons between the
ESBI document and Rule 502.5 would appear to be
inappropriate unless the ESBI Terms and
Conditions of the tariff as amended by the Board
Decisions are considered. TransAlta's February 14,
2012 letter to the AESO, containing TransAlta's
comments on the first draft of Rule 502.5,
explained in detail how Decision 2000-46 should be
reflected in Rule 502.5.
TransAlta continues to object to the Voltage Ride
Through Requirements Subsection 6 in Rule 502.5
version 2.0. The continuous operation capability of
the generator is 95%-105% of the generator rated
terminal voltage as per the IEEE (Institute of
Electrical and Electronics Engineers). Based on
this, there may be concerns with the continuous
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1. The requirements in final proposed New
ISO Rules Section 502.5 Version 2.0 are not
new and do not impose any additional
requirements on existing generators. In the
AESO’s opinion, final proposed New ISO
Rules Section 502.5 Version 2.0 remains
aligned with prior regulatory decisions and
ISO tariff provisions.
2. Firstly, the relationship between the stator
terminal voltage and the high side voltage of
the generator step up transformer is not oneto-one.
Secondly, the 90 – 110% at the high side
voltage of the generator step up transformer
operation of the generator for a voltage range of
90%-110% at the HV side of the GSU. This
requires study and should be included in technical
consultation.
is based on operating history of the
transmission system which aligns with
Reliability Standard PRC-024 Generator
Frequency and Voltage Protective Relay
Settings (“PRC-024”) which recently passed
the NERC successive ballot. In the NERC
replies to draft 5 of PRC-024, NERC
acknowledges that power systems are
commonly designed to operate between 90%
and 110%.
The NERC document Power Plant and
Transmission System Protection
Coordination and IEEE C37.106
recommends under and over voltage relays
settings that are in alignment with the 90110% requirement. In addition, the same
NERC document refers to 85% voltage as a
recoverable event which is more arduous that
the 90% parameter.
Finally, the AESO notes that there are
generating units connected to the
transmission system owned by different
market participants, including TransAlta,
which currently operate at greater than 105%
which would technically mean that these
units could be off line should a 105%
parameter be adopted.
In summary, since the 90–110% requirement
is consistent with NERC and IEEE and for
the additional reasons provided above, it is
the AESO’s opinion that this reflects good
operating practice and is necessary for
reliable operation of the Alberta
interconnected electric system.
3.
AESO Replies to Stakeholder Comments: 2013-05-16
TransAlta continues to believe the impact of Rule
502.5 version 2.0 is significant and requires a
technical consultation meeting to review, clarify and
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3. It is the AESO’s understanding that a
generating unit is generally maintained in a
manner consistent with the unit’s original
substantiate the requirements of each subsection.
Of particular concern (highlighted in AESO
response 71) is the AESO's assumption that an
owner's maintenance work is always undertaken in
order to maintain original as new capability,
meeting the original design basis. For the most part
this is customary practice in the early to midlife of
generators, however, this assumption is flawed
when applied to equipment that is operating
beyond the original design life. Prudent
maintenance and mitigations applied to manage
the reasonable probabilities of failure may in many
cases be inconsistent with what is required to
restore generators to an as-new condition.
Although the standard provides for an exemption to
be requested it is apparent that this\ process is
technically insufficient in that the justification
merely considers stability as the issue to be
addressed and provides no tolerance in terms of
equipment operating beyond the design life or
equipment found to be deficient in the original
design.
4.
TransAlta does not believe that an extension of the
consultation period will compromise the integrity of
the consultation process. While we recognize and
sympathize with the AESO's sense of urgency to
move forward this particular rule, TransAlta
respectfully submits that the concerns expressed
with respect to Rule 502.5 and Rule 502.6 suggest
more work is required.
design capabilities.
However, the AESO recognizes that a unit
may develop issues even when the legal
owner of the generating unit follows best
practices for maintenance. Final proposed
New ISO Rules Section 502.6, subsection
3(3) requires the legal owner to report these
issues to the AESO and develop a plan. In
addition, final propose New ISO Rules
Section 502.5 Version 2.0 allows for
variances for technical, economic, safety and
operational reasons.
Final proposed New ISO Rules Sections
502.5 Version 2.0 or 502.6 do not state that a
legal owner must restore the generator to an
as-new condition. In particular, the variance
allowed for in final proposed New ISO Rules
Section 502.6 is not restricted to stability; it is
broader and considers technical, economic,
safety, operational reasons.
4. Final proposed New ISO Rules Sections
502.5 Version 2.0 and 502.6 do not introduce
new requirements for existing generating
units. It is the AESO’s opinion that the
requirements in final proposed New ISO
Rules Sections 502.5 Version 2.0 and 502.6
are necessary for reliable operations of the
transmission system and consistent with
good operating practices.
In addition and based on other stakeholders
comments received, it appears that
stakeholders are generally satisfied with final
proposed ISO Rules Sections 502.5 Version
2.0 and 502.6; notwithstanding TransAlta’s
comments.
The AESO also notes that the consultation
AESO Replies to Stakeholder Comments: 2013-05-16
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process is not intended to achieve consensus
from industry.
Accordingly, the AESO will complete this
consultation process and move forward on
that basis. The AESO intends to file final
proposed New ISO Rules Sections 502.5
Version 2.0 and 502.6 with the Alberta
Utilities Commission in quarter 3, 2013.
5.
6.
AESO Replies to Stakeholder Comments: 2013-05-16
In May 2007 the AESO sent a letter to stakeholders
addressing reactive power. TransAIta responded
June 8, 2007 to the AESO letter. TransAIta never
received a reply to its letter and therefore the
issues surrounding reactive power continue
unresolved. The consultation process for ISO
Rules Section 502.5 is the forum to come to an
acceptable outcome for all parties. In our February
14, 2012 letter to the AESO as part of our
comments on the first draft Rule 502.5 we again
discussed the importance of reactive power and
the requirement for a separate meeting on this
issue to finally resolve it. TransAIta maintains that
the AESO should arrange such a meeting prior to
concluding consultations on Rule 502.5 and Rule
502.6.
In the November 29, 2012 AESO Reply to
Stakeholder Comments, the AESO summarizes the
written stakeholder comments into the following
points. TransAIta's comments on those points are
as follows:
A. TransAlta submits that the AESO has not
adequately addressed the comments from
Stakeholders regarding incentives and VARs.
In its February 14, 2012 letter attached to its
previous comments on Rule 502.5, TransAlta
referred the AESO to AEUB Decision 2000 46,
page 23 where the Alberta Energy and Utilities
Board (Board) ruled that "On and after January
1, 2001, the Board has no jurisdiction to require
the owner of a generating unit or a PPA Buyer
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5. The AESO agrees that reactive power
requirements in regards to the current AESO
Generator and Load Interconnection
Standard have been ongoing since this
standard came into effect. The AESO is of
the opinion that section 2(2) of both final
proposed New ISO Rules Section 502.5
Version 2.0 and final proposed New ISO
Rules Section 502.6 allows for variances.
The AESO recognizes that TransAlta has
concerns and will continue to meet with
TransAlta to further discuss these concerns.
6. Please see AESO Replies below.
A. The AESO has previously reviewed the
provision of reactive power on the
transmission system. That review
concluded that reactive power is critical
to maintaining reliable and efficient
operation.
The AESO does not consider that there
have been any fundamental changes to
transmission system operations that
to provide System Support Services (SSS) or
to do so at a particular price." On page 15 of
the same decision the Board noted that EAL
considered reactive power/voltage control
would be candidates for a non-hourly market
competitive procurement process such as an
RFP. The Duties of the Independent System
Operator as set out in the Electric Utilities Act
in Section 17(f) state that the Independent
System Operator has the duty: "to manage and
recover the costs for the provision of ancillary
services." Compelling generators to provide
reactive power for free does not adequately
address Section 17(f). Competitively procuring
reactive power requirements through an RFP
process as suggested in Decision 2000-46
does address Section 17(f).
The Electric Utilities Act has defined system
support services (EUA 1995, 1998 and 2000)
and ancillary services (EUA 2003 onwards) as
encompassing reactive power/voltage support.
The PPAs in Article 2 and Schedule G, System
Support Services specifically identify reactive
power as a system support service that the
Buyer of the PPA would be entitled to sell. The
previous ISO, ESBI stated before the Board
that reactive power/voltage control would be a
candidate for an RFP. The current ISO, the
AESO stated before the Board in 2007 that the
AESO does not consider reactive power as an
ancillary service but rather a condition of
system access service and therefore no VAR
market initiative is necessary. TransAIta
submits this approach is inconsistent with
Alberta's electricity market.
B. The Stakeholders expressed concerns about
the potential time it could take to assess
whether generating units can meet the
requirements of Rule 502.5 and therefore an
effective date only six months out from the
AESO Replies to Stakeholder Comments: 2013-05-16
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require another review of this matter and
will continue to establish reactive power
requirements as a condition for
connecting to the transmission system.
For reference, the current meaning of
ancillary services as set out in the
Electric Utilities Act is:
“ancillary services means those services
required to ensure that the
interconnected electric system is
operated in a manner that provides a
satisfactory level of service with
acceptable levels of voltage and
frequency”.
B. In the AESO’s opinion, final proposed
New ISO Rules Sections 502.5 Version
2.0 does not introduce new requirements
for existing generating units. Therefore,
in the AESO’s opinion, allowing a six
completion of the Commission process would
not be sufficient. The AESO responded that
Rule 502.5 is consistent with the existing
"Technical Standard" and therefore no effort
should be required to meet the requirement of
Rule 502.5. TransAlta submits that the AESO
should accept the position of those generator
owners who state six months is insufficient.
C. The Stakeholders suggested that the operating
requirements be set out in a separate rule and
the AESO responded that it agreed with the
suggestion and relocated the operating
requirements into proposed New ISO Rules
Section 502.6. TransAIta appreciates the
response of the AESO to the Stakeholders
suggestion as there is now improved
delineation between design requirements and
operating requirements.
D. The Stakeholders found the references to new,
existing and modifications to generating units
confusing. The AESO has replied that they
have amended the language in Rule 502.5
such that it was essentially applicable to all
generating units. TransAIta believes there may
be a disconnect in the provisions set out in the
PPAs, Alberta Regulation 275/2000 and the
AESO Rule 502.5 version 2.0. It is unclear how
the existing AESO "Application Guideline for
Generator Interconnection Requirements Reactive Power" has been treated in Rules
502.5 and 502.6.
month period to implement the
requirements is sufficient.
C. The AESO acknowledges TransAlta’s
comment.
D. Final proposed New ISO Rules Section
502.5 Version 2.0 sets out the binding
requirements regarding the design of a
generating unit.
Final proposed New ISO Rules Section
502.6 sets out the binding requirements
regarding maintaining and operating a
generating unit.
With regard to Alberta Regulation
275/2000 the AESO assumes that
TransAlta is referring to Alberta
Regulation 175/2000 which is the Power
Purchase Arrangements Determination
Regulation.
It is the AESO’s opinion that there is not
a disconnect between the provisions set
out in Alberta Regulation 175/2000 and
final proposed New ISO Rules Section
502.5 Version 2.0 and final proposed
New ISO Rules Section 502.6.
AESO Replies to Stakeholder Comments: 2013-05-16
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In addition, the AESO will be removing
the Draft Application Guideline for
Generator Interconnection Requirements
- Reactive Power as it is the AESO’s
opinion that the binding requirements for
reactive power are set out in the AESO
Generator and Load Interconnection
Standard and the subsequent final
proposed New ISO Rules Sections 502.5
Version 2.0 and Section 502.6, and
Alberta Reliability Standards.
7. The Stakeholders raised concerns that some
existing generating units do not have functional
specifications and whether the AESO would be
developing functional specifications for those units.
The AESO replied it would not be developing
functional specifications but would work with
owners to develop a functional document setting
out key attributes. TransAIta suggests there
remains significant uncertainty surrounding the
words "develop a functional document setting out
key attributes".
8. The AESO response number 68 on reactive
power requirements in other jurisdictions
appears to be incomplete and does not cover a
number of important issues including the
following:
 Treatment of the existing generators upon
introduction of new requirements such as
0.95 pf lead/0.9 pf lag at MCR, voltage ride
through etc. including any compliance
costs. PJM recognizes grandfathered Mvar
capability in Section 5.2.1 of its Manual
14A: Generation and Transmission
Interconnection Process. ERCOT
recognizes different reactive power
requirements for existing generators in
operation before ERCOT's current
standard in Nodal Protocol Section 3.15(5)
AESO Replies to Stakeholder Comments: 2013-05-16
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7. For clarity and to reduce uncertainty the
AESO plans to work with legal owners to
develop the functional document.
Subsection 2(3) of final proposed ISO Rules
Section 502.6 sets outs the information that
the AESO intends to gather from the legal
owner in order to develop the functional
document.
8. The approach taken by the organizations
referred to by TransAlta is generally aligned
with final proposed New ISO Rules Section
502.5 Version 2.0 and final proposed New
ISO Rules Section 502.6. Both final
proposed New ISO Rules Sections 502.5
Version 2,0 and final proposed New ISO
Rules Section 502.6 allow for deviations that
the AESO refers to as variances; some of the
other organizations refer to them as
grandfathering. However, these variances
are not automatic; there is a process for
reviewing and granting variances. This
process is similar to the process parties
would go through for grandfathering
recognition with other organizations.
and (6) Voltage Support.
Treatment of generator design
restrictions/design capability changes.
Treatment of the application of limiter
margins required to protect the generator
based on the individual unit's design/risk
considerations.
Treatment of the requirement of system
VARs (from both the grid and from the
generator owner). TransAIta requests the
AESO to provide the above details for
information and review by the
stakeholders, as a part of the on-going
stakeholder engagement, in order to arrive
at a mutually acceptable and equitable set
of requirements which would address the
stakeholder concerns.
With regard to the treatment of generator
design restrictions/design capability changes
the AESO assumes that the issue is design
versus operating capabilities. A legal owner
is required meet the requirements of final
proposed New ISO Rules Section 502.5
Version 2.0. If the legal owner encounters
operational issues, final proposed New ISO
Rules Section 502.6 allows for the legal
owner to notify the AESO of such issues and
provides flexibility with regard to addressing
the issue. This also applies to the treatment
of the application of limiter margins.
9. The AESO noted that stakeholders provided a
number of clarifying suggestions. The AESO
stated they have responded to the suggestions
in the comment matrix but disagreed with the
Stakeholder comments 1, 2, 3, 4, 7, 33, 35, 36,
55, 57, 63, 64, 68, 69, 72, 74, 78, 200, 104,
105, 216, 128, 125, 236, 237, 142, 145, 146,
192, 196, 201 and 202 as well as a large
number of comments (5, 6 and 8 for example)
referencing the comments of disagreement
listed. There appears to TransAIta to be
significant disagreement with the AESO
9. Based on the stakeholder comments
received from the second consultation on
final proposed New ISO Rules Section 502.5
Version 2.0, stakeholders appear to be
satisfied with the requirements,
notwithstanding TransAlta’s comments.



AESO Replies to Stakeholder Comments: 2013-05-16
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With regard to VARs, based on stakeholder
comments received from the second
consultation on proposed New ISO Rules
Section 502.5, stakeholders appear to be
satisfied with the VAR requirements,
notwithstanding TransAlta’s comments. In
addition, the VAR requirements represented
in final proposed New ISO Rules Section
502.5 Version 2.0 are aligned with other
jurisdictions in North America. For a listing of
these other jurisdictions please refer to the
AESO Reply Matrix for the first consultation
on proposed New ISO Rules Section 502.5
Version 1.0, AESO Reply 68.
Many of the comments received from
stakeholders during the first consultation
were with regard to clarity, which in the
AESO’s opinion have been addressed.
approach that would warrant additional
consultation.
10. TransAlta strives to achieve full compliance
with AESO Rules and Standards but TransAlta
must also operate its generators in accordance
with good operating practice (GOP)2
standards. Therefore the AESO Rules and
Standards applicable to generators designed
and built in the seventies and eighties must be
consistent with the applicable GOP standards.
Otherwise, the reliability of these older
generators could be adversely affected. In
TransAlta's view, this requires that the AESO
Rules and Standards recognize that older
generators face unique technical and design
challenges as it pertains to reliably providing
reactive power in the Alberta system.
AESO Replies to Stakeholder Comments: 2013-05-16
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10. The AESO acknowledges the concept of
Good Operating Practice.
The requirements for:




voltage ride-through for both new and
existing generating units;
reactive power;
reporting; and
variances
of final proposed New ISO Rules Sections
502.5 Version 2.0 and 502.6 are in alignment
with NERC and WECC, IEEE and other
ISO’s within North America. As such it is the
AESO’s opinion that final proposed New ISO
Rules Sections 502.5 Version 2.0 and
502.are in accordance with the concept of
Good Operating Practice.