WECC - 0071System Performance Criteria1st Team Meeting Background

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1st Team Meeting

• Purpose

• What are we addressing?– NERC Standard– WRS1.– WRS1.1– New TPL-001– Process so far, how we got here….

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1st Team Meeting

• Purpose– The purpose of this request is to revise the

current TPL – (001 thru 004) – WECC – 1 – CR - System Performance Criteria requirement WRS1.1 to permit the more efficient use of rights-of-way while promoting the use of separate tower instead of multi-circuit towers and maintaining an acceptable level of reliability for the Western Interconnection. The use of separate towers is preferred to multi-circuit towers.

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1st Team Meeting

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1st Team Meeting

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1st Team Meeting

• Current Criteria within WECC:– WRS1.

• In addition to NERC Table 1, PAs and TPs shall comply with the WECC Disturbance-Performance Table, Table W-1, of Allowable Effects on Other Systems contained in this section when planning the Western Interconnection. Table W-1 does not apply internal to a Transmission Operator area.

– WECC Table W-1 – Voltage & Frequency Dip

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1st Team Meeting

• WRS1.1.– The NERC Category C.5 initiating event of a

non-three phase fault with normal clearing shall also apply to the common mode contingency of Two Adjacent Circuits on separate towers unless the event frequency is determined to be less than one in thirty years.

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1st Team Meeting• Definitions of:

– Common Corridor = Contiguous ROW or two parallel ROWs with Structure centerline separation less than the longest span of the two transmission circuits at the point of separation or 500 feet, whichever is greatest, between the two circuits.

– Adjacent Transmission Circuits = Transmission circuits within a Common Corridor with no other transmission circuits between them.

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1st Team Meeting

• New TPL-001

• P7: Multiple Contingency (Common Structure)– The loss of:– Any two adjacent (vertically or horizontally)

circuits on common structure 11

– Loss of a bipolar DC line– SLG– EHV, HV

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1st Team Meeting

• Continued from previous slide…• Interruption of Firm Transmission Service

Allowed 4

• YES• Non-Consequential Load Loss Allowed

• YES

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1st Team Meeting

• Process so far…• Numerous discussions at RS throughout 2009• Presented to PCC & OC twice last year

– Lively discussion with feedback from one end to the other

• RS began process…

• Based on White Paper written by RS– 2 supporting documents, SWAT & WIA

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1st Team Meeting

• On February 26, 2010 the Standards Request Routing Committee (SRRC) met via telephone to discuss assignment of WECC-0071, System Performance Criteria.  The SRRC concluded the Request was in scope and assigned drafting to the PCC.  Ms. Cabbell, chair of the PCC, assigned the drafting task to the Reliability Subcommittee with augmentation to be sought by Mr. Watkins, chair of the OC, to include operators from the OC.  If additional team expertise is needed Ms. Cabbell and her assigned drafting team chair are authorized to augment the team members as needed.

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1st Team Meeting

• Comments received during the 30 day comment period – abridged-

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1st Team Meeting

• Armie Perez, ZGlobal

• In the evaluation of the loss of lines in a ROW, my recollection is that the probability of N-2 is not really that much greater for 2 lines on the same tower versus separate towers. This should be confirmed.

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1st Team Meeting

• John Lucas, APS

• PCC should be assigned as the lead committee

• This is very timely and is urgently needed.

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1st Team Meeting

• Bill Pascoe, TransWest, LLC

• The request, as drafted, focuses narrowly on a particular common corridor issue for Category C events. TWE believes that common corridor issues related to Category D events are also important to the appropriate balancing of reliability and environmental/land use impacts for major new transmission lines being planned in WECC. TWE requests that the drafting team be directed to also consider common corridor issues for Category D events.

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1st Team Meeting

• Chuck Matthews, (Denise Koehn) BPA

• 1.  Although the primary purpose is revision of requirement WRS1.1, the purpose should be expanded to include the following, "In addition, other requirements in WECC-0071 may need to be revised based on other NERC Standards drafting efforts."  One reason for expanding this revision request is to provide more consistent terminology with the NERC Standards.

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1st Team Meeting

• Chuck Matthews, BPA continued

• The "Proposed WRS1.1" in the section "Detailed Description" should be removed and the first paragraph in that section changed accordingly.  The proposal seems to presuppose the outcome of the revised criteria.

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1st Team Meeting

• Darcy O’Connell, CAISO

• The California ISO supports Brian Keel's (SRP) suggestion on Revised TPL 1-4 project to remove restriction imposed by WECC under its requirement WRS1.1 to make it consistent with the NERC requirement.

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1st Team Meeting

• Potential Benefits of changing Criterion:– Potentially higher ratings on WRS1.1 limited Paths

• Higher values of remote generation

• Allow placing circuits within current definition without requirements

– Reduce environmental impacts, less ROW overall• Consolidation of facilities, construction and maintenance

– Increased use of existing ROWs to a corridor

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1st Team Meeting

• Author confession:• Proposed WRS1.1: The NERC Category C.5 shall also

apply to the common mode contingency of two Adjacent Transmission Circuits on separate towers unless the event frequency is determined to be less than one in 30 years. The fault to be used for this study shall be a single line-to-ground fault. The performance requirements of NERC Table 1 shall apply to this contingency and WECC Table W-1 shall not apply.

• Proposed to get started!• Team develops best solution for all of WECC!!

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1st Team Meeting

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1st Team Meeting

• Timeline?

• How to get to conclusion?

• Proposal Subteam?

• Next Meetings?

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