Download WECC-0100 TPL-001-WECC-CRT-3 Response to Comment

WECC-0100 TPL-001-WECC-CRTP-3 System Performance
Drafting Team (DT)
Response to Comments / Posting 1
October 15, 2014 through December 1, 2014
Posting 1
The WECC-0100 TPL-001-WECC-CRT-3, System Performance Drafting Team (DT) thanks everyone who
submitted comments on the proposed documents.
Posting
This document was last posted for a 45-day public comment period from October 15, 2014 through
December 1, 2014.
WECC distributed the notice for the posting on October 14, 2014. The DT asked stakeholders to
provide feedback on the proposed document through a standardized electronic template. WECC
received comments from six companies representing five of the eight Industry Segments, as shown in
the table on the following page.
Location of Comments
All comments received on the document can be viewed in their original format on the project page
under the “Submit and Review Comments” accordion.
Changes in Response to Comment
After consideration of comments received, the DT made the following changes:
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Added
Reviewed
Edited
Changed
Effective Date
The targeted Effective Date for this document is January 1, 2016.
Action Plan
On January 8, 2015, the WECC Standards Committee (WSC) granted the DT additional time to post its
responses. A specific time for posting was not given by the WSC; however, the DT was encouraged to
meet the established procedural milestones. Responses were due for posting on January 1, 2015.
Comment Report Form for WECC-0100
2
Contacts and Appeals
If you feel your comment has been omitted or overlooked, please contact the Manager, WECC
Standards Processes, W. Shannon Black, at [email protected]. In addition, there is a WECC Reliability
Standards Appeals Process.
The WECC Standards Voting Sectors are:
1 — Transmission Sector
2 — Generation Sector
3 — Marketers and Brokers Sector
4 — Distribution Sector
5 — System Coordination Sector
6 — End Use Representative Sector
7 — State and Provincial Representatives Sector
8 — Other Non-Registered WECC Members and Participating Stakeholders Sector
Commenter
Organization
WECC Standards Voting Sectors
1
2
3
4
5
6
31
4
5
Edi Von Engeln
Cain Braveheart on behalf
of Chuck Matthews,
Electrical Engineer.
NV Energy
Bonneville Power
Administration
Hari Singh
Xcel Energy –
Public Service of
Colorado
Modesto Irrigation
District
6
Spencer Tacke, Senior
Electrical Engineer
7
8
Joshua Andersen
Orlando A. Ciniglio
1
Salt River Project
Idaho Power
Company
Responses 1 and 2 were software testing.
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Comment Report Form for WECC-0100
Index to Questions, Comments, and Responses
Question
1. The drafting team invites comments on all aspects of the proposed document.
3
Comment Report Form for WECC-0100
4
1. The drafting team invites comments on all aspects of the proposed ….
Summary Consideration: See summary in the preamble of this document.
Commenter
Edi Van Engeln
Yes
No
Comment
1. Is your organization actively participating with Modeling
Validation Working Group?
1. participating on the LMTF
2. Have you performed the Path rating studies with the
composite load model?
1. not really SNTI was our last path rating study and we
had not completed our model at that time
3. Have you performed the TPL studies with the composite
load model?
1. yes
4. How is the proposed WECC Criterion for TPL gauge with the
results found in Path and TPL studies with composite load
model? (is the criterion, relaxed, satisfactory or stringent
based on your study results)
The drafting team reviewed Mr. Von Engeln’s responses and concluded that he may have responded to the
WECC-0100 project in error. WECC staff was not able to reach Mr. Von Engeln for clarification. The drafting
team took no further action on the comment.
Bonneville Power
Administration
R1.1: Steady State Voltages
1. BPA believes the requirement should ensure applicable
entities apply their established "internal" criterion rather
than develop a one-size-fits-all criterion. Steady-state
voltages are system dependent where low voltage is
defined by minimum service to a utility's customers, and
high voltage limits are driven by equipment issues.
2. Regarding the proposed criterion posted, BPA believes the
meaning of the term "nominal" should be clarified as
individual entities use the term differently (e.g. base
voltage in simulations, equipment nominal voltage
specification, operating voltage schedule, etc.).
3. Regarding the proposed criterion posted, BPA believes
there is no technical justification for the high voltage for P0
events to be less than P1-P7 events. High voltage is driven
by equipment issues, and voltage up to that specified for
Comment Report Form for WECC-0100
5
Summary Consideration: See summary in the preamble of this document.
Commenter
Yes
No
Comment
contingencies may also be acceptable for all lines in service.
R1.2: Post-contingency steady-state voltage deviation
1. BPA suggests Requirement R1.2 be clarified that shunt
reactive devices (added to support and control voltages)
are assumed to be able to be switched to maintain an
acceptable post-contingency steady-state voltage deviation.
R1.3: Voltage stability
1. P2-P7 events should be clarified so the real power margin
1) applies after load shedding for events where load
shedding occurs as a result of the contingency; and 2) does
not apply to events where non-consequential load loss is
allowed.
R1.4: Transient voltage response
1. BPA proposes the term "Transient voltage response" is
changed to "Transient stability voltage response".
"Transient voltage response" can imply a shorter time
period that includes switching transients (milliseconds
versus cycles).
2. For P1 contingencies with 1-phase or no-fault, the primary
objective should be continuity of service to loads. For other
criterion contingencies, the primary objective should be
integrity of the grid including generators low "Voltage ridethrough" capabilities.
3. BPA believes simulations should be conducted to better
refine the voltage recovery parameters in the requirement.
Simulations should include several scenarios, stressed
conditions, and composite load models to help gauge the
minimum level of acceptable system performance.
R2: Cascading and uncontrolled islanding
1. First bullet: Reference to NERC PRC-023-2 – BPA
recommends this be revised to NERC PRC-023-3 as version
2 was retired October 1, 2014.
2. Third bullet: BPA requests clarification of the reference to
Comment Report Form for WECC-0100
6
Summary Consideration: See summary in the preamble of this document.
Commenter
Yes
No
Comment
R1.3.2. The requirement seems to refer to transient
stability requirements in R1.4.
3. BPA believes references to "TPL" in the document should
be "TPL-001-4" or referenced by a footnote as "NERC
Standard TPL-001-4".
4. BPA suggests referencing Attachment 2 from PRC-024-1 as
is not referenced in the document other than "Voltage ride
through" criteria as defined. Additionally, in PRC-024-1,
there is a list of "Voltage Ride-Through Curve Clarifications"
(1-5) that are not included in the document - - should they
be?
Requirement WR1.1: Steady State Voltages DONE
BPA suggests that the requirement should ensure applicable entities apply their established "internal"
criterion rather than develop a one-size-fits-all criterion. The following Rationale is included in the proposed
document.
Requirement WR1 is designed to set the minimum threshold at which the Transmission Planner (TP) and the
Planning Coordinator (PC) will examine their own systems. For purposes of examining their own systems, the
TP and PC can use a more stringent set of criteria than stated in Requirement WR1; however, they may not
impose a more stringent set of criteria on neighboring systems.
To help clarify Requirement WR1, the following Rationale block has been added.
Rationale for Requirement WR1:
“Requirement WR1 recognizes that each system has its own unique characteristics that need to be
addressed. Rather than lock each entity to a specific study parameter this Requirement sets a basal
study parameter coupled with a unique nominal value, established by the Transmission Planner and
the Planning Coordinator, to be used in the absence of either a more stringent or less stringent study
parameter.
In the context of this document the word “nominal” carries its common definition and is the base
voltage used in the entity’s Planning Assessment model. This voltage will vary from entity to entity.
Requirement WR1 does not preclude an entity from using either a more stringent or less stringent
criteria. However, when an entity uses a study criteria other than that required in requirement WR1,
it must make available the associated Planning Assessment showing the assumptions used (see later
Comment Report Form for WECC-0100
7
Summary Consideration: See summary in the preamble of this document.
Commenter
Yes
No
Comment
Requirement).”
This concept is further embellished in the Rationale box for Requirement WR1.2.
Use of the term “nominal” DONE
See above.
Technical Justification for High Voltage DONE
BPA suggests there is no technical justification for the high voltage for P0 events to be less than P1-P7
events. The drafting team recognizes that studied steady-state voltages will vary from one system to the
next. Requirement WR1, subsets WR1.1.1 and 1.1.2 allow the studying entities to establish a unique
nominal value that fits its specific system(s). In the context of Requirement WR1 “nominal” is uniquely
determined by the steadying entity. The Applicability section also acknowledges that certain elements may
be excluded from the WECC Criterion.
To address the issue, the drafting team has redrafted the Requirement as follows:
WR1. Each Transmission Planner and Planning Coordinator shall use the following basal criteria in its
Planning Assessment, unless otherwise specified in accordance with Requirements WR2 and WR3:
[Addresses NERC TPL R5 and R6]
1.1. Steady-state voltages at all applicable Bulk-Electric System (BES) buses shall stay within each
of the following limits:
1.1.1. 95 percent to 110 percent of the nominal customer requirement.
1.1.2. 90 percent to 110 percent of the nominal equipment protection level.
The drafting team further acknowledges that an exchange of this information is critical to establishing
accurate models. To meet this need the drafting team has added the following Requirement and associated
Rationale box.
WR2. Each Transmission Planner and Planning Coordinator that uses more stringent criteria in its
Planning Assessment than that stated in Requirement WR1 shall apply that criteria solely to its
own system.
Rationale for WR2: The purpose of this Requirement is to clarify that an entity may apply a more
stringent criterion to its own system; however, it may not impose that more stringent criterion to
any other system.
Comment Report Form for WECC-0100
8
Summary Consideration: See summary in the preamble of this document.
Commenter
Yes
No
Comment
WR3. Each Transmission Planner and Planning Coordinator that uses study criteria different from the
basal criteria in Requirement WR1 shall make its Planning Assessment available upon request.
Requirement WR1.2: Post-contingency Steady-State Voltage Deviation DONE
BPA suggests clarification of Requirement WR1.2 to show that shunt reactive devices are assumed to be able
to be switched to maintain an acceptable post-contingency steady-state voltage deviation.
The drafting team does not believe that manual switching should be assumed; rather, the existing practice of
automatic switching should be retained. Requirement WR1.2 has been redrafted as follows:
1.2 Post-Contingency steady-state low voltage deviation at each applicable BES bus serving load (having
no intermediate connection) shall not exceed eight percent for P1 events. [Addressing TPL R5]
The 1.2 Rationale box has been elaborated as follows:
“Rationale for Requirement WR1.2:
Requirement WR1.2 establishes a reasonable target that could be met by each entity without
incurring costs that would outweigh the benefits. Many legacy systems were not designed to meet
a more stringent threshold. The eight percent target of Requirement WR1.2 is established not by a
technical study; rather, it is established based on sound engineering judgment. Further, certain
entities are bound by state tariffs that establish the percentage rate specifically at eight percent.
By default, only automatic post-contingency actions including capacity or reactor switching are
considered when calculating voltage deviation.
Where the Transmission Planner or the Planning Coordinator apply less stringent criteria when
studying their own systems, the less stringent criteria would be permissible so long as other
Transmission Planners and Planning Coordinators were also allowed to apply the same less
stringent criteria to their own systems. For example, if an entity applied manual capacitor or
reactor switching to its own system the same criteria would be allowed for the systems of others.
By contrast, where the Transmission Planner or the Planning Coordinator applies more stringent
criteria to their own systems, that Transmission Planner or Planning Coordinator would not be
allowed to impose the more stringent criteria on any system other than its own.”
Comment Report Form for WECC-0100
9
Summary Consideration: See summary in the preamble of this document.
Commenter
Yes
No
Comment
Requirement WR1.3: Voltage stability
BPA suggests that P2-P7 events should be clarified so the real power margin: 1) applies after load shedding
for events where load shedding occurs as a result of the contingency; and 2) does not apply to events where
non-consequential load loss is allowed. PENDING
Requirement WR1.4: Transient Voltage Response
BPA proposed that the term "Transient voltage response" be changed to "Transient stability voltage
response" because "Transient voltage response" can imply a shorter time period that includes switching
transients (milliseconds versus cycles). PENDING
BPA proposes that for P1 contingencies with 1-phase or no-fault, the primary objective should be continuity
of service to loads. For other criterion contingencies, the primary objective should be integrity of the grid
including generators low "Voltage ride-through" capabilities. PENDING
BPA suggests that simulations should be conducted to better refine the voltage recovery parameters in the
requirement. Simulations should include several scenarios, stressed conditions, and composite load models
to help gauge the minimum level of acceptable system performance. PENDING
Requirement R2: Cascading and Uncontrolled Islanding
PRC Reference DONE
BPA suggests that the first bullet reference to NERC PRC-023-2 be changed to NERC PRC-023-3 as version 2
was retired October 1, 2014. This change has been made with the caveat that the drafting team will be
making every endeavor to avoid incorporation by reference of any extrinsic documents. References such as
the PRC may be drafted out in subsequent versions.
BPA suggests referencing Attachment 2 from PRC-024-1 as it is not referenced in the document other than
"Voltage ride through" criteria as defined. Additionally, in PRC-024-1, there is a list of "Voltage Ride-Through
Curve Clarifications" (1-5) that are not included in the document. The drafting team has considered BPA’s
request and notes that the team will endeavor to delete all “incorporation by reference” in subsequent
postings. WECC Criteria are designed to be free-standing documents that are not predicated on status and
Comment Report Form for WECC-0100
10
Summary Consideration: See summary in the preamble of this document.
Commenter
Yes
No
Comment
content of extrinsic documents.
Numbering References DONE
BPA suggests that as to the third bullet, the reference to Requirement WR1.3.2 may be inaccurate and
should be changed to R1.4 because the requirement seems to refer to transient stability requirements in
R1.4. The drafting team appreciates BPA’s observation. Numbering references will continue to change and
be corrected each time changes are made to the document. DONE
TPL References
BPA believes references to "TPL" in the document should be "TPL-001-4" or referenced by a footnote as
"NERC Standard TPL-001-4". DONE
The drafting team reviewed the document and concluded that all references are accurate as submitted. No
changes were made. Incidentally, references to the “TPL” such as those included in the brackets at the end
of Requirement will be removed in the final version. They are currently included only as a reference point.
Hari Singh, Xcel Energy Public Service of
Colorado
Xcel Energy (Public Service of Colorado) provides the following
comments for consideration by the WECC-0100 Drafting Team:
Steady-state Voltage Limits (R1.1) – Please clarify that these are
the default voltage limits for system normal and post-contingency
system conditions, and an individual TP/PC may choose to use
more restrictive voltage limits for its footprint. Note that the
suggested approach is identical to what has been adopted by the
Reliability Coordinator for implementing its SOL Methodology for
[the] Operations Horizon, and this approach lends itself well to be
used in the Planning Horizon.
Steady-state Post-contingency Voltage Deviation (R1.2) – No
technical justification has been provided to support the 8% limit
and discontinue usage of the existing Table W-1 Post-Transient
Voltage Deviation limits of 5% for single (Cat-B or event P1)
contingencies and 10% for multiple (Cat-C or events P2-P7)
contingencies. Absent a technical justification for change, the
existing Table W-1 Post-Transient Voltage Deviation limits must be
retained.
Transient Voltage Response (R1.4) – Again, no technical
justification is provided for discontinuing usage of the existing
Table W-1 Transient Voltage Dip magnitude-duration limits for the
Comment Report Form for WECC-0100
11
Summary Consideration: See summary in the preamble of this document.
Commenter
Yes
No
Comment
Cat-B (event P1) and the Cat-C (events P2-P7) contingencies.
Therefore, it is hard to appreciate why the proposed transient
voltage response/recovery magnitude-duration limit uses 80%
voltage magnitude consistent with the existing Table W-1
magnitude limit, but allows recovery duration of 10 seconds (i.e.
600 cycles) which is significantly longer (15 times) than the existing
40 cycles duration in Table W-1. Further, without any technical
justification, it is unclear why it is acceptable to have a voltage
recovery duration at load buses that is 3.33 times longer than the 3
seconds allowed at generator buses per the PRC-024 Attachment 2
Voltage Ride-Through Time Duration Curve?
Voltage Instability (R1.3) – This appears to be essentially the same
as the existing WR3, albeit stated somewhat differently. However,
the re-stated criteria in items (1) and (2) need a better description.
For example, it is unclear what is meant by "solve" in this context –
does it pertain to steady-state power flow simulation or
dynamic/transient stability time-progression simulation? How does
this voltage stability criteria correlate to the existing WECC Voltage
Stability Methodology document? Lastly, since voltage instability is
listed as one of three instability modes within R6 of NERC TPL-0014, shouldn't R1.3 be included under R2 which addresses the
remaining two instability modes of Cascading and uncontrolled
islanding?
Potential for Cascading and uncontrolled islanding (R2) – We agree
with the first bullet (thermal overload criterion) and the third
bullet (unacceptable transient voltage response) as the potential
precursors of uncontrolled system instability but cannot appreciate
how the second bullet's criterion of one generator pulling out of
synchronism can possibly lead to system-wide instability. Again,
technical justifications for each of the three bullets would be very
helpful.
WECC-0100 Regional Criterion's Scope – Xcel Energy strongly
recommends that the acceptable power oscillations damping
criterion required as per 4.1.3 in TPL-001-4 should also be
addressed within the scope of this project. In fact, we believe that
it is as important, if not more important, to have a common
criterion for acceptable power oscillations damping applicable in
the WECC region, similar to the system planning performance
Comment Report Form for WECC-0100
12
Summary Consideration: See summary in the preamble of this document.
Commenter
Yes
No
Comment
criteria already included in the project's scope.
4.1.3. For planning events P1 through P7: Power oscillations shall
exhibit acceptable damping as established by the Planning
Coordinator and Transmission Planner.
Table W-1 Revision – We support the concept of having a revised
version of Table W-1 within the scope of WECC-0100 project, as
stated on pages 3 and 4 of the posted draft TPL-001-WECC-CRT-3.
However, t appears that the expected quantitative content in any
revised Table W-1 has been addressed in the form of requirements
in the posted draft. Our preference is to have all the transmission
system performance criteria captured in tabular form within a
revised Table W-1, which may then be supplemented with
requirements to the extent needed to support the tabular criteria.
(Page 3) Revision of Table W-1 is within the scope of this project.
The drafting team understands that the Table is currently under
review by the WECC Reliability Subcommittee (RS). The team will
coordinate any changes with the RS.
(Page 4) The WSC agreed to expand the WECC-0100 drafting team
to include the entire Reliability Subcommittee, and accept the
drafting team's recommendation that further drafting continue on
remedial language for:
1) TPL-001-WECC-RBP-2.1. WR3;
2) Table W-1; and,
3) TPL-001-4, Requirements R5 and R6.
Requirement WR1.1 DONE
Xcel requests: 1) clarification that Requirement WR1.1 represents fault voltage limits for system normal and
post-contingency system conditions, and those individual TP/PCs may choose to use more restrictive voltage
limits for its footprint, and 2) technical support for WR1.2 and WR1.4.
The drafting team has added a number of Rationale Blocks to the document to further clarify the intent of
the Requirements and the Requirement subsets.
Comment Report Form for WECC-0100
13
Summary Consideration: See summary in the preamble of this document.
Commenter
Yes
No
Comment
Requirement WR1.3 (AKA: WR5) Voltage Instability DONE
Requirement WR1.3 has been redrafted and relocated to Requirement WR5 as follows:
WR5. Each Transmission Planner and Planning Coordinator shall identify voltage stability by maintaining
positive reactive power margin demonstrated by the following criteria:
5.1. For all P0-P1 events a power flow solution shall be reached at a minimum of 105 percent of
transfer path flow r forecasted peak load.
5.2. For all P2-P7 events a power flow solution shall be reached at a minimum of 102.5 percent of
transfer path flow or forecasted peak load.
Rationale box for Requirement WR5:
“Requirement WR5 is intended to ensure that a power flow solution is reached for each model
used.”
WR1.4 Table W-1 DONE
Addressing the Table W-1 is within the scope of the WECC-0100 Standards Authorization Request (SAR).
Once the Requirements are more fully developed the drafting team will revisit the need to retain, edit, or
adopt the existing Table. The team is concerned that a static table may not meet the needs of mandating
requirements. This item was listed as an action item in the December 16, 2014 meeting minutes and will be
further discussed.
WR2. Potential for Cascading and uncontrolled islanding PENDING
Xcel does not agree with the second bullet's criterion of one generator pulling out of synchronism can
possibly lead to system-wide instability. Xcel suggests that technical justification would be of value.
Scope DONE
During the drafting team’s meeting to respond to comments, Mr. Hari Singh explained his concerns
regarding the scope of the document as it pertains to damping. Within WECC, the Peak Reliability
Coordinator System Operating Limit methodology at Paragraph 37 includes a high level damping criteria.
The drafting team agreed to include the substance of that paragraph into the criterion. A Rationale block
and associated language were added as follows:
Comment Report Form for WECC-0100
14
Summary Consideration: See summary in the preamble of this document.
Commenter
Yes
No
Comment
WR1.4 Oscillations that do not show positive damping within a 30-second time frame shall be deemed
undamped.
Rationale: For purposes of Requirement WR1.4, positive damping in stability analysis is demonstrated by
showing that the amplitude of power angle or voltage magnitude oscillations after a minimum of 10 seconds
is less than the initial post-contingency amplitude. In any case, results that do not show positive damping
within a 30-second time frame shall be deemed undamped.
Footnote: This stipulation is not intended to require that transient stability simulations be run out to 30seconds all the time in order to ensure the system is stable and positively damped. Shorter runs are
permissible.
Spencer Tacke
For the new standard's [Requirement W]R1.4 requirement:
Senior Electrical
Engineer
The recovery voltage used to be 80% for no more than 40 cycles
(i.e. 2/3 of a second) instead of the proposed 80% for 600 cycles
(i.e., 10 seconds). Do we have any simulations or real time
disturbance data demonstrating stable system wide operation
when the voltage is that low (0.8 per unit) for that long (10
seconds)?
Modesto Irrigation
District
1231 11th Street
Modesto, CA 95354
If not, shouldn't the group developing this new standard generate
some simulations demonstrating this, before we ask the members
to approve such a requirement?
209-526-7414
[email protected]
Does the drafting team have any simulations or real-time disturbance data that demonstrates stable systemwide operation to support the criteria of Requirement WR1.4? PENDING
If not, will the drafting team be creating the simulations in support of the Requirement? PENDING
Joshua Andersen
Salt River Project comments are as follows:
Salt River Project
R1.1 bases limits on "nominal" voltages. We recommend defining
nominal voltage. If this is the system operating voltage then can
each Transmission Planner define a unique range for each BES bus?
If the nominal voltage for P0 started at 0.95 p.u. during P1 event
Joshua.Andersen@srpne
Comment Report Form for WECC-0100
15
Summary Consideration: See summary in the preamble of this document.
Commenter
Yes
t.com
No
Comment
and the nominal voltage went to 0.88 p.u, would that be a violation
for R1.1 Part 2? This is less than 8% deviation but outside the
bounds specified in Part 2.
R1.2: Are there any requirements for voltage deviation? Suppose
the nominal system voltage was 0.96 p.u. and with P2 events the
nominal went to 0.89 p.u. even though the deviation is not 8% or
10%, would this violate R1.1 Part 2?
R1.3: We recommend separating out transfer path flow and
forecasted peak load into two separate items. Please clarify what
the 105% and 102.5% applies to. We suggest “Solve with a precontingency flow with at least 105% of transfer path flow” and
“Solve with a pre-contingency load with at least 105% of
forecasted peak load”.
R1.4: Are there different provisions for three phase faults versus
single phase faults? Will this criteria be applicable to Path Rating
studies using the stress cases?
R2, bullet 1: Does this apply only to lines/transformers identified in
PRC-023-3 analysis, or should this apply to all BES
lines/transformers?
R2, bullet 3: Please clarify voltage ride-through.
Use the term “nominal” DONE
If the nominal voltage is the system operating voltage then can each Transmission Planner define a unique
range for each BES bus?
Please see the above response to BPA regarding the use of the term “nominal.”
Violations
SRP asks that where the nominal voltage for P0 started at 0.95 p.u. during P1 event and the nominal voltage
went to 0.88 p.u, would that be a violation for Requirement WR1.1, Part 2? PENDING
Comment Report Form for WECC-0100
16
Summary Consideration: See summary in the preamble of this document.
Commenter
Yes
No
Comment
SRP asks if there are any requirements for voltage deviation in Requirement WR1.2? (Suppose the nominal
system voltage was 0.96 p.u. and with P2 events the nominal went to 0.89 p.u. even though the deviation is
not 8% or 10%, would this violate R1.1 Part 2?) PENDING
SPR recommends for Requirement WR1.3, separating out transfer path flow and forecasted peak load into
two separate items. PENDING
SRP requests clarification as to what the 105% and 102.5% values apply to. SRP suggests adding the following
language: “Solve with a pre-contingency flow with at least 105% of transfer path flow” and “Solve with a precontingency load with at least 105% of forecasted peak load”. PENDING
In Requirement WR1.4, are there different provisions for three phase faults versus single phase faults?
PENDING
Will this criterion be applicable to Path Rating studies using the stress cases? PENDING
In Requirement WR2, bullet 1, does this apply only to lines/transformers identified in PRC-023-3 analysis, or
should this apply to all BES lines/transformers? PENDING
For Requirement WR2, bullet 3, please clarify what is meant by voltage ride-through. PENDING
Orlando A Ciniglio
Idaho Power Co
We have some serious reservations on R1.4 and its implications. This seem
simplistic view of Transient voltage response, and does not consider the im
low voltages will have on the new composite load model (not to mention g
impact on system response. Such a lenient requirement opens the doors to
Comment Report Form for WECC-0100
17
Summary Consideration: See summary in the preamble of this document.
Commenter
Yes
No
Comment
that would not have been considered acceptable in the past and that will e
exposure to unnecessary operational risks and reduction in System reliabili
Voltage recovery to 80% after 10 seconds? There might not be a system (in
recover to at that point.
I think we should also retain the PRC-024-1 curve at the end of the docume
the Guidance Section, yet to be finalized.)
In the meantime a simple example, that probably requires no validation an
considered a real problem, is the scenario where you allow voltages to stay
eight or less seconds, and then have them recover to 80% within 10secs. If
excursion results in tripping of generators in a neighboring area how can yo
be considered acceptable response? A similar scenario may result in loss of
amount of load. I am sure the lawyers will be knocking at your door pretty
You would meet your R1.4 criteria, but is this really the type of performanc
experience in our systems?
It is not unrealistic to think up a scenario where the voltage depression and
the 80% in 10 seconds criteria) might not be sufficient to cause cascading, i
uncontrolled separation, but enough for a few units to trip (inside or outsid
area)..
Would this be a violation of TPL-001-4, I think not. Thus relying on TPL-001this performance will probably not work .
Would we want to consider this performance acceptable? I hope not.
Note that a similar logic could also be applied to loads.
Idaho Power suggests that the voltage recovery to 80% after 10 seconds as drafted in Requirement WR1,4
may not be realistic, noting that there might not be an actual capable of recovery as required. PENDING
Comment Report Form for WECC-0100
18
Summary Consideration: See summary in the preamble of this document.
Commenter
Yes
No
Comment
Idaho Power suggests that the PRC-024-1 curve should be retained in the document, preferably in the
Guidance section. PENDING