POTF Status update

Paths Reviewed

• TOT-2a Path 31• Path 49• Path 66 North BPA

• The Path Operations issues we are experiencing are due in part to the fact that path limits are considered SOLs. The current paradigm marries operating limits and Transfer Capability into a single parameter for WECC paths – the historical OTC.

• This approach reveals inconsistencies and conflicts with real-time information and tools.

• What does it mean to “operate” a path in the operations horizon?• Why do we require WECC Paths to have SOLs? Are there better

ways to determine that we have acceptable system performance?

History of Path Operations

• Current paradigm reveals conflicts between Path SOLs and real-time information and tools:

• Path XYZ – thermally limited to 650 MW in the E>W direction. 650 MW is the Path SOL. Loss of line A results in line B reaching its emergency Facility Rating at path transfer levels of 650 MW E>W.

• When path flows exceed 650 MW TOPs mitigate – up to and including shedding load (for TOP-007-WECC-1 paths)

• When the Path SOL is being exceeded, what if real-time information or RTCA isn’t showing that the loss of line A results in line B exceeding its emergency Facility Rating?

• Is an SOL really being exceeded? NO• Inverse is also true – what if the Path SOL is not being exceeded, but the

underlying condition driving the establishment of the Path SOL is being violated? YES

Issues With Current Paradigm

• WECC and the POTF are considering the following:• What if a thermally limited Path SOL were not an SOL at all, rather the

facility ratings of the impacted facilities were the SOL?• What if the Path had a Transfer Capability instead of an SOL?• What if the Path Transfer Capability was observed for scheduling

purposes but not treated as an operational parameter?• Should we be using real-time information and tools such as real-time

contingency analysis to determine acceptable pre- and post-Contingency system performance?

• If a Path does not have an SOL, does a Path really need to be “operated”?

Challenging Questions Brett

Findings

• Path Operator is in practice responsible for outage reporting to assure correct topology and Path SOL’s to the WECC RC per the IRO-10 RC Data Request.

Findings

• Capital “D” Directives issued to Path Operator(s) for Path SOL exceedences.• Coordinated procedures that have been agreed

upon may result in other TOP’s receiving Directives.

Issues Identified For Some Paths

• Path Operator does not have specific authority to direct the TOP’s unless contracts provide that authority.

• Path Operators, have indicated that the counterparties have no incentive to enter into contracts assigning responsibility for path Exceedance.

• There is no single entity under the NERC Functional Model identified for path management.

• Path Operators have little Authority for the Path but in some cases have been held responsible for the Path SOL violation.

NERC Functional Model

• No true definition of Path Operator in Reliability requirements, responsible entities listed are RC, TOP, TO, BA, GO, GOP, LSE………….. No mention of Path Operator