WECC Criterion – TPL-001-WECC-CRT-3Page 1 of 19
Criterion Development
This section is maintained by the drafting team during the development of the document and will be removed when the document is approved by the WECC Board of Directors (Board).
Document Scope
This document is designed to address the substance of TPL-001-WECC-CRT-2.1 (TPL), Requirement WR3 and the requirements imposed by NERC TPL-001-4, Requirements R5 and R6. Standard Authorization Request (SAR) WECC-0100 also provides for review and disposition of Table W-1 associated with the WECC TPL. Once the Requirements of this document are more fully developed the drafting team will revisit the need to edit, modify, or delete the table.
Procedural Background
On September 5, 2012, the WECC Board of Directors (Board) adopted a recommendation by the Regional Criteria Work Group (RCWG) changing the designation of this document from a WECC Criterion (CRT) to a WECC Regional Business Practice (RBP). On June 24, 2014, the Board reversed that decision and designated this document as a CRT.
In further keeping with the September 5, 2012 recommendation, on November 28, 2012, a Standard Authorization Request (SAR) was submitted to evaluate whether this document should be drafted as a WECC Regional Reliability Standard (RRS).
On December 19, 2012, the WECC Standards Committee (WSC) accepted the SAR as drafted with specific approval to assign an evaluation team to review the subject matter and return a recommendation to the WSC as to whether the document should be redrafted as an RRS.
On June 26, 2013, the WSC approved the evaluation team’s recommendation to ballot the retirement of TPL-001-WECC-RBP-2.1, WR1, WR2, WR4 and WR5. If approved the retirement would become effective coincident with the Effective Date of NERC’s TPL-001-4, because the content of the WECC Requirements will be resident in the NERC TPL-001-4.
On August 8, 2013, the WSC assigned the original drafting team, augmenting the team during later weeks.
On October 8, 2013, a WECC Ballot Pool voted to retire TPL-(012 through 014)-WECC-RBP-2.1, WR1, WR2, WR4 and WR5 of the Effective Date of NERC TPL-001-4. (The Effective Date is projected for approximately January 1, 2016. It should be noted that the TPL has a staggered Effective Date.)
On November 1, 2013, the WECC-0100 Drafting Team (DT):
- Reported completion of the tasks assigned in the WECC-0100 Standard Authorization Request (SAR);
- Requested the WECC Standards Committee (WSC) deem the WECC-0100 SAR complete; and,
- Requested the WSC accept the DT’s recommendation to proceed with informal drafting in support of an iterative SAR tailored to the remedial needs of TPL-001-WECC-RBP-2.1, System Performance, WR3 as well as a more granular implementation plan of TPL-001-4, Transmission System Planning Performance Requirements Requirement R5 and R6.
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:
- TPL-001-WECC-RBP-2.1. WR3;
- Table W-1; and,
- TPL-001-4, Requirements R5 and R6.
On December 5, 2013, the Board approved the decision to retire portions of the WECC TPL upon the Effective Date of the NERC TPL.
During June 2014, the Planning Coordinating Committee (PCC) conducted a straw poll concluding the most appropriate document categorization for this document should be that of a WECC Regional Criterion.
On June 24, 2014, the Board changed the designation of this document from that of a RBP to that of CRT.
Completed Actions / Date- SAR Filed.
- Review Team files Preliminary Recommendation.
- WSC approves ballot to retire WR1, WR2, WR4 and WR5.
- Notice of Joint Session to discuss retirement.
- Ballot Pool open asking for retirement of WR1, WR2, WR4 and WR5.
- WSC approves Drafting Team.
- Ballot Pool closed asking for retirement of WR1, WR2, WR4 and WR5.
- Joint Session to discuss retirement.
- Ballot open asking for retirement of WR1, WR2, WR4 and WR5.
- Drafting Team – First Meeting – Orientation.
- Ballot closed asking for retirement of WR1, WR2, WR4 and WR5. Retirement approved.
- Posting 1 - Open 45-day
- Posting 1 – Closed
- Posting 1 – Response to Comments Posted
15. Posting 2 – Open 30-day / February 4, 2015
16. Posting 2 – Closed / March 6, 2015
17. Posting 2 – Response to Comments Posted / March 17, 2015
18. Posting 3 – Open 30-day / July 24, 2015
19. Posting 3 - Closed / August 24, 2015
20. Posting 3 – Response to Comments Posted
Anticipated Actions / Date
- Version 4 Posted – Open 30-Day Comment Period
- Version 4 Posted – Closed
- DT meets for final Comments / Forward to WSC
- WSC Meets
- Open Ballot Pool
- Joint Session – Notice
- Close Ballot Pool
- Joint Session
- Open Ballot
- Ballot Closed
- WSC Meets
- Notice to WECC Board of Directors
- Board
Implementation Plan
Approvals Required
TPL-001-WECC-CRT-3, Transmission System Planning Performance
A WECC Criterion
Prerequisite Approvals
- WECC Ballot Pool
- WECC Standards Committee
- WECC Board of Directors
Applicable Entities
Planning Coordinator
Transmission Planner
Conforming Changes to Other Standards
None required.
Effective Date
The Effective Date is the later of January 1, 2016 or the Effective Date of TPL-001-4, Transmission System Planning Performance, Requirements R2-R6 and R8.
Justification
The effective date is targeted to coincide with the effective date of TPL-001-4, Transmission System Planning Performance.
Consideration of Early Compliance
The DT foresees no reliability-related issues if an entity chooses to implement the document early; however, entities should continue to adhere to approved WECC Criteria until they are retired.
Retirements
This document will replace TPL-001-WECC-CRT-“2” that is to be retired as of the Effective Date of this project.
New or Modified Term(s) Used in the WECC Glossary for WECC Criteria and Naming Conventions (WECC Glossary).
This section includes all new or modified terms used in the proposed criterion that will be included in the WECC Glossary upon applicable approval. The new or revised terms listed below will be presented for approval with the proposed document. Upon WECC Board of Director (Board) adoption, this section will be removed and the approved terms will be moved to the WECC Glossary.
Term(s): None proposed
A.Introduction
1.Title:Transmission System Planning Performance
2.Number:TPL-001-WECC-CRT-3
3.Purpose:To facilitate coordinatednear-term and long-term transmission planning for the Western Interconnection, and to facilitate the exchange of the associated planning information for normal and abnormal conditions.
This document applies to all transmission planning studies conducted within the Interconnection of the Western Electricity Coordinating Council (WECC).
4.Applicability:
4.1.Functional Entities:
4.1.1.Planning Coordinator
4.1.2.Transmission Planner G
4.2.Facilities[s1]:
4.2.1.This document applies to BulkElectric System (BES) Facilities. ………FACILITIES Facility. substation buses.
4.2.2.Each of the following buses elements is specifically excluded from this Criterion:
4.2.2.1.Non-BES buses.
4.2.2.2.Line side series capacitor buses
4.2.2.3.Line side series reactor buses
4.2.2.4.Dedicated shunt capacitor buses
4.2.2.5.Dedicated shunt reactor buses
4.2.2.6.Metering BUSES, fictitious BUSES, or other buses that model points of pointsof interconnection interconnection modeled solely for measuring electrical quantities; and,
4.2.2.7.Other buses specifically excluded by each Planning Coordinator or Transmission Planner internal to their system.
5.Effective Date:The Effective Date is the later of January 1, 2016 or the Effective Date of TPL-001-4, Transmission System Planning Performance, Requirements R2-R6 and R8.
B.Requirements and Measures
Rationale Blocks will be relocated to the Guidance section when the project is complete.
Rationale for Requirement WR1[s2]:WR1 is designed to state the base criteria at which the study must be conducted – unless otherwise specified. WR1 is the default whereas WR2 and WR3 allow for an exception to the default.
Neither WR2 nor WR3 changes the WR1 default; rather, both WRs create an allowable deviation fFrom orm the default. WR2 allows for a more stringent approach without changing the WR1 default. A more stringent approach may be used in accordance with WR2 so long as all the affected parties agree. Similarly, WR3 allows deviation from the default with the additional protection that when used, other Transmission Planners and Planning Coordinators are allowed to use the same criteria on that part of the system for the same category of planning events (e.g., P1 and P2).
In the context of Requirement WR1, the word “nominal[s3]” carries its common definition and could be, for example, either the base voltage or the operatingvoltage as established in the entity’s Planning Assessment. What constitutes “nominal” is determined by each entity and can vary from one entity to the next. This voltage will vary from entity to entity.
TE ISSUE 6. UNLESS OTHERWISE SPECIFIED BY THE ENTITIY THE NOMINAL VOLTAGE WILL DEFAULT TO THE KV CLASS THAT IS SPECIFIED IN THE WECC BASE CASES. (WITH EXCEPTION OF THE 500 KV CLASS WHERE DEFAULT NOMINAL WOULD BE SPECIFIED AS 525 KV.
Requirement WR1.1.2, refers to the post automatic equipment adjustment effect prior to manual adjustment.
WR1.Each[s4] Transmission Planner and Planning Coordinator shall use the following default base 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:
1.1.195 percent to 105 percent of nominal for P0[1] event (system normal pre-contingency powerflow[s5][s6]);
1.1.2 90 percent to 110 percent of nominal for P1-P7[2] events (post-contingency powerflow).
Rationale for Requirement WR1.2:Requirement WR1.2 establishes a 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 THE EXISTENCE OGF SOME state tariffs that establish the percentage rate specifically at 8 eightpercent[s7].
By default, only automatic post-contingency actions occurring in the studied timeframe, including capacitor or reactor switching, are considered when calculating voltage deviation.
For P1 there is no high voltage deviation requirement. For P2-P7, there is no low or high voltage deviation requirement.
BES bus serving load is the bus with direct transformation from BES level voltage to distribution level voltage that serves load.
SEE ATTACHED A FOR FINGER DIAGRAM FOR WR1.3 AND 1.4
1.2.Post[s8]-Contingency steady-state low voltage deviation at each applicable BES bus SERVING LOAD serving load (having no intermediate connection[s9]) shall not exceed eight percent for P1 events (POWERFLOW). [Addressing TPL R5]
1.3.Transient[s10] stability voltage response at applicable BES buses serving load (having no intermediate connection)shall recover to at least 80[s11] percent of pre-contingency voltage within 210 seconds of[s12] the initiating event for all P1-P7 category events[s13].
1.4 FOLLOWING FAULT CLEARING AND VOLTAGE RECOVERY ABOVE 80%, For[s14][s15] voltage[s16] swings subsequent to fault clearing and the first voltage recovery above 80%, voltage dips at each applicable BES bus serving load (having no intermediate buses) shall not dip below 70% of pre-contingency voltage for more than 30 cycles or remain below 80% of pre-contingency voltage for more than two seconds for all P1-P7 category events.
1.5For Contingencies without a fault (P2.1 category event), voltage dips at each applicable BES bus serving load (having no intermediate buses) shall not dip below 70% of pre-contingency voltage for more than 30 cycles or remain below 80% of pre-contingency voltage for more than two seconds.
Rationale for Requirement WR1.5 and 1.6The intent is not to require that transient stability simulations be run out to 30-seconds all the time in order to ensure the system is stable and positively damped. Shorter runs are permissible.
For purposes of Requirement WR1.6, 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 are considered to be undamped.
1.6[s17]All oscillations that do not show positive damping within a 30-second time frame shall be deemed unacceptable.
WM1.Each Transmission Planner and Planning Coordinator will have evidence that it used the base criteria in its Planning Assessment specified in Requirement WR1, unless otherwise allowed in accordance with Requirements WR2 and WR3.
Rationale for Requirement WR2[s18]:Planning Assessment is a NERC defined term. For purposes of Requirement R2, the requirement applies to all planning studies applied at the Western Interconnection level.
The rationale for Requirement WR2 is to ensure that planning entities do not impose more stringent requirements on systems other than their own. It may use more stringent criteria on its own system but may not impose more stringent criteria on others.
Transmission Planners and Planning Coordinators may mutually agree to use study criteria that is more stringent than that described in this document.
WR2. Each TP and PC that uses more stringent criteria in its Planning Assessment than that stated in Requirement WR1 shall apply that criteria only to its own system, except where otherwise agreed upon by all planning entities included in the Planning Assessment.
WM2.Each TP and PC that uses more stringent criteria in its Planning Assessment than that stated in Requirement WR1 will have evidence that it applied those criteria only to its own system, except where otherwise agreed upon by all planning entities included in the Planning Assessment.
Rationale for Requirement WR3:The rationale is to ensure equity between planning entities. (Availability of differing criteria is addressed in Requirement WR6.)
WR3.Each Transmission Planner and Planning Coordinator that uses less stringent criteria in its Planning Assessment than that stated in Requirement WR1 shall allow other Transmission Planners and Planner Coordinators to have the same impact on that part of the system for the same category of planning events (e.g., P1, P2).
WM3. Each Transmission Planner and Planning Coordinator that uses less stringent criteria in its Planning Assessment than that stated in Requirement WR1 will have evidenced that it allowed other Transmission Planners and Planner Coordinators to have the same impact on that part of the system for the same category of planning events (e.g., P1, P2).
Rationale for Requirement WR4:- Requirement WR4 is designed to establish precautionary markers that whendiscovered warrant investigation. The Requirement is not intended to imply that the presence of any one of more of the bulleted conditions creates a de facto negative impact on reliability.
The specific amounts of unrestrained load loss addressed in WR4, bullet three, have not been specified. The drafting team suggests that due to the breadth of the possible permutations, the amount should be left to the sound engineering judgment of the planning entity.
In WR4, Bullet 1, the 125% threshold is imported from the Peak RC SOL Methodology.
WR4. Each[s21] Transmission Planner and Planning Coordinator shall usethe following minimum criteria when identifyingthe potential forCcascading or uncontrolled islanding:
- When[s22] a post contingency analysis results in STEADY STATE facility loading that is either in excess of a known BES facility trip setting,or exceeds 125% of[s23] the highest applicable seasonal facility rating for the BES facility studied., if the BES facility trip setting is not known than use
When a post con. [s24].
- Transient stability voltage response at any applicable BES bus outside of the criteria that is defined in Requirement WR1.3 of this document.
- If either unrestrained successive load loss occurs or unrestrained[s25] successive generation lossoccurs.
BACK AT 10 AFTER THE HOUR.
WM4.Each Transmission Planner and Planning Coordinator will have evidence that it used the indicators of Requirement WR4 to identify the potential for cascading or uncontrolled islanding.
Rationale for Requirement WR5:Requirement WR5 addresses “what” must be achieved and does not address “how” to doit.
For a review of “how” to achieve the goals, please refer to:
- The WECC Voltage Stability Assessment Methodology
- WECC Guide to WECC/NERC Planning Standards I.D: Voltage Support and Reactive Power, Prepared by:Reactive Reserve Working Group (RRWG), Under the auspices ofTechnical Studies Subcommittee (TSS); Approved byTSS, March 30, 2006
- Additional guidance is contained in Section 2.2 Voltage Stability of the Guide to WECC/NERC Planning Standards 1.D, Voltage Support and reactive Power, March 30, 2006.
Power flow solutions refer to post contingency conditions where the actions of reactive devices should be modeledfor the appropriate time frame being studied.
There is a higher likelihood of occurrence of a P0 to P1 category event; therefore, a higher margin (105%) is used. For P2-P7, there is a lower likelihood of occurrence; therefore, the lower margin (102.5%) is used.
WR5[s26].Each Transmission Planner and Planning Coordinator shall use the following minimum criteria when identifying voltage stability:
5.1All[s27]P0-P1 eventsshall demonstrate a positive reactive power margin at a minimum of 105 percent of transfer path flow.
5.2All P0-P1 eventsshall demonstrate a positive reactive power margin at a minimum of 105 percent of forecasted peak load.
5.3All P2-P7 eventsshall demonstrate a positive reactive power margin at a minimum of 102.5 percent of transfer path flow.
5.4All P2-P7 eventsshall demonstrate a positive reactive power margin at a minimum of 102.5 percent of forecasted peak load.
WM5. Each Transmission Planner and Planning Coordinator will have evidenced that it used the minimum criteria identified in Requirement WR5 to identify voltage stability.
Rationale for Requirement WR6:Requirement WR6 ensures the free flow of information between entities.
WR6. Each Transmission Planner and Planning Coordinator that uses study criteria different from the base criteria in Requirement WR1 shall make its criteria available upon request.