Path Operations post WECC TOP 007 Rob Witham, WAPA RMR TSS Supervisor

Transcription

1 Path Operations post WECC TOP 007 Rob Witham, WAPA RMR TSS Supervisor May 10, 2017 ISAS Salt Lake City, UT

2 WECC Standard TOP 007 WECC 1a Title: System Operating Limits Purpose: To limit instances where actual flows on Major WECC Transfer Paths exceed System Operating Limits (SOLs) for more than 30 minutes. Date Retired: April 1, 2017 there is no reliability need to continue the historical, path centric approach reflected in TOP 007 WECC 1a or to treat the facilities comprising the 40 Transmission paths subject to TOP 007 WECC 1a any differently than how all other facilities are treated under the continent wide TOP/IRO Reliability Standards. 2

3 Negative Impacts of Path Centric Operations Often mitigating problems that are not problems at all. Re dispatching generation, curtailing schedules, and even shedding load when real time tools indicate that reduced to no action is necessary? Path SOLs potentially masking actual reliability problems? 3

4 What about R2? The Transmission Operator shall not have the Net Scheduled Interchange for power flow over an interconnection or Transmission path above the path s SOL when the Transmission Operator implements its real time schedules for the next hour. Rendered unnecessary as it was redundant to other active standards and did not align with the NERC functional model. 4

5 POTF Recommendations 1. SOLs and TTCs are separate and distinguished, but they work together to ensure that reliability is achieved in realtime operations. 2. Paths that are not associated with transient or voltage stability limits will not have uniquely monitored SOLs; however, they will continue to have TTCs 3. TTC is the measure of maximum power transfer across a WECC Path that respects these SOLs pre and post Contingency. TTCs will still need to be determined through transfer analysis and prior studies. 4. TTCs are not operational parameters; however, they should still be monitored for situational awareness purposes 5

6 New SOL Paradigm Of the 40 Transmission paths, only two were identified as being limited by transient stability or voltage stability. One of the two stability limits has already been designated as an IROL (i.e., the NW Washington IROL). 25 Transmission paths are thermally limited. 15 of the Transmission paths are thermally based proxy limits (i.e., limitations placed on the path to address a post Contingency thermal limit exceedance on a non Path Facility). 6

7 New SOL Paradigm All BES Facilities in the Western Interconnection, would be monitored in the operations time horizon for pre and post Contingency performance in an iterative fashion as real time approaches via: 1. Seasonal assessments 2. IRO 017 outage coordination process studies 3. OPAs 4. RTAs. 7

8 System Operators will monitor: Real Time flow (in SCADA) and ensure that real time flow in each of the transmission facility is below its normal limit Real Time tools that calculate N 1 (or N 2) postcontingency flow and ensure that post contingency flow in each of the facility is below its emergency limit All congestion management is done with regards to the real time flow and N 1 (or N 2) post contingency flow (as calculated by Real Time tools) 8

9 Path management vs. Path Operations System operators must continue to maintain oversight of TTC along with the contracted allocations of the respective path participants 9

10 Day 1 Considerations Path participants (TO/TOP/TSP/RC) were to develop implementation plans as necessary on a path bypath basis It is important to distinguish operating practices and strategies from the SOL itself. How an entity remains within these SOLs can vary depending on the planning strategies, operating practices, and mechanisms employed by that entity. 10

11 Before April 1, 2017 External coordination USFMP Short term goals Identify qualified elements for each path Understand change in Desk to Desk dynamic Identify available versus necessary tools Operation/Management Procedures Training Longer term goals Development of new/additional tools Integration of RTE Desk Path TTC evaluation 11

12 TOT Management Procedures Revised and signed Path Management Procedures for TOT 1A, 2A, 3, and 5 completed by 4/20/17 Align with new reliability landscape Updates to participant allocation changes based on forced and planned outages (TOT2A & 5) Language added to enhance clarity to real time operational practices Provisions established to better balance unauthorized use penalties against operational limitations 12

13 Unscheduled Flow The elephant in the room The square peg, round hole dilemma Short term (based on tool availability) In hour, RTCA will drive USFMP step 1 3 Phase Shifting Transformer use Next hour, projected path flows against projected path TTC will drive USFMP step 4 curtailments Long term In hour and next hour will be based on RTCA and RT monitoring of path element flows 13

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17 Plan forward Development of new/additional tools (Summer 2017) Integration of RTE Desk (Winter 2017/18) Path TTC evaluation (2019) 17

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