WECC-0100 Scope, Content & Status Update Rikin Shah, PAC Orlando Ciniglio, IPC WECC TSS Meeting, Salt Lake City, UT January ,

A little history… WECC-0100 DT was formed (~ August 2013) to address the substance of WR3 Requirement of the previous version of TPL-001-WECC-CRT-2.1 (TPL) and Requirements R5 & R6 imposed by NERC TPL Requirements WR1,WR2,WR4 & WR5 were approved for retirement by ballot on October, Table W-1 will not migrate to this document, but its intent will be capture by the combined language of WR1,WR2 and WR3 (new criterion document). There has been some shuffling as to whether this should be a RBS, CRT or even a regional Standard – When the dust settled, Criteria took the title. The final product of the DT is the new WECC Criterion – TPL-001-WECC-CRT-3 document 2

TPL-001-WECC-CRT-2.1- WR1,2,4,5 (ret.) 3 WR1 = compliance w/ WECC’s disturbance/performance table W-1 + common mode of 2 adjacent ckts on separate towers if MTBF < 30 years  Category C + common mode of 2 generator units connected to the same switchyard  not cascade + loss of multiple bus sections due to failure or delayed clearing of bus tie or sectionalizing breaker  Category D + potential to adjust contingency category level after Board approval. WR4 = Performance for unsuccessful reclosing same as no reclosing WR5 = Category D contingencies must not result in cascading unless MTBF > 300 years. + any contingency that has resulted in cascading, must be mitigated to prevent cascading in the future or demonstrate MTBF > 300 years. WR2 = Option to apply different performance requirements than those in table W-1 for internal impacts: If less stringent other systems are permitted same performance in that part of the system If more stringent, these requirement may not be applied to other systems.

WECC Table W-1 4

TPL-001-WECC-CRT-2.1-WR3 to be addressed by new criterion document 5

TPL-001-4, R5 & R6 to be addressed by new criterion document 6

TPL-001-WECC-CRT-3 (WR1) 7

TPL-001-WECC-CRT-3 (WR1 cont.) 8

TPL-001-WECC-CRT-3 (WR1.3) 9

TPL-001-WECC-CRT-3 (WR1.4) 10

TPL-001-WECC-CRT-3 (WR1.4) 11

TPL-001-WECC-CRT-3 (WR2) 12

WECC-0100: WR3 WR3 states that "Each Transmission Planner and Planning Coordinator that uses a less stringent criterion 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).” Similar to prior criterion requirement. If you use a less stringent criteria or have developed an exception for certain part of your system, then you have to allow other transmission planners or planning coordinators to use the same less stringent criteria or exception for that part of the transmission system.

WECC-0100: WR4 WR4. Each Transmission Planner and Planning Coordinator shall use the following threshold criteria to identify the potential for Cascading or uncontrolled islanding. An entity is allowed to use these criteria to identify instability due to Cascading or uncontrolled islanding as long as it does not impose it on others: When 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 the highest seasonal facility rating for the BES facility studied. If the trip setting is known to be different than the 125% threshold, the known setting should be used. When transient stability voltage response occurs at any applicable BES bus outside of the criteria stated in Requirement WR1.3 of this document. When either unrestrained successive load loss occurs or unrestrained successive generation loss occurs.

WECC-0100:WR4 Rationale & Clarifying Points WR4 is not the definition for Cascading or uncontrolled seperation. WR4 essentially defines some of the precursors that could potentially lead to cascading or uncontrolled seperation. If any of the signs mentioned in WR4 are observed during a planning event, further investigation should be performed to ensure they don’t result in cascading or uncontrolled seperation. The 125% mentioned in bullet 1 of WR4 should only be used if the facility trip settings are unknown. The amount of successive load loss or successive generation loss is left upto the Transmission Planner or Planning Coordinator as this could be very prescriptive and could vary from system to system. A particular transmission planner could use WR4 as definition of cascading or uncontrolled seperation for its own system, but cannot impose the same definition on other Transmission Planners/ Planning Coordinators for the same system. (Just like WR2)

WECC-0100: WR5 WR5. Each Transmission Planner and Planning Coordinator shall use the following minimum criteria when identifying voltage stability: WR5.1 For transfer paths, all P0-P1 events shall demonstrate a positive reactive power margin at a minimum of 105 percent of transfer path flow. WR5.2 For transfer paths, all P2-P7 events shall demonstrate a positive reactive power margin at a minimum of percent of transfer path flow. WR5.3 For load areas, all P0-P1 events shall demonstrate a positive reactive power margin at a minimum of 105 percent of forecasted peak load. WR5.4 For load areas, all P2-P7 events shall demonstrate a positive reactive power margin at a minimum of percent of forecasted peak load.

WECC-0100: WR5 Rationale and Clarifying Points The intent of WR5 is to ensure the voltage stability of transfer paths as well as the system as a whole during peak load or peak transfer conditions. A positive reactive power margin can be demonstrated by a valid steady state power flow solution. –Solution includes actions of reactive devices and load tap changers appropriate for the time frame being studied. Higher margin required for the high probability events (P0, P1) and lower margin required for low probability events (P2- P7)

WECC-0100: WR6 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 within 30 days. The requirement ensure free flow of information between entities performing transmission planning analysis.

WECC-0100: Future Steps Fifth round of comment period for the “WECC Criterion – TPL- 001-WECC-CRT-3” closed on January 18 th, WECC-0100 Drafting team will address all the received comments. If substantive comments are received that require changes to the Criterion, then a new version would be posted for another round of comments, If not… Upon finalization of the criterion, it will be sent to WECC Standards Committee for approval and balloting.

Status of new Criterion Document day comment period for document version 5 ended on January 18 th

Questions ? 21