FERC/NERC Determined 36% of Misops (Misoperations) Could be Attributed to Issues that Protective System Commissioning Programs Should Have Detected

Summary:

FERC and NERC conducted an assessment of Entity Protective System Commissioning Programs by the review of eight registered entities and one contractor organization (PSC contractor). ‘Event Description’ and ‘Corrective Action’ MIDAS fields were used to determine PSC impact on Misops. The clear message is that "All Entities should review their PSC programs for adequate detail. Entities should consider including how to perform the commissioning tests that are required for each specific project. All Entities should follow the guidance provided in the Annex A of the IEEE WG I-25 guide".

Additional Discussion:

High-level Overview

Consistent reviews of participant Commissioning Programs were conducted using IEEE WG I-25. Staff from each Regional Entity proposed candidate responsible entities for participation based on either a relatively high misoperation rate or a relatively low misoperation rate as compared with other registered entities in the region. The joint staff review team reduced the list of participants to eight representative registered entities across the Regional Entities’ footprints based on entity size, location, and events, and the joint staff review team added one independent contractor with experience working with NERC registered entities on protection system installation and commissioning.
Eight registered entities and one PSC contractor Participated

• All participants but one had a formal commissioning program; however, none of the participants’ programs were as comprehensive as the IEEE WG I-25 guide recommends. • No participant maintained a centralized document that contained all five key elements of an effective PSC program.
• Selected based on geographical locations and performance data such as events and Misop rates.
• Surveys and Interviews on participants’ PSC programs and Procedures.
• Used the IEEE WG I-25 guide as a benchmark.
• Team discussed and agreed upon the best practices, opportunities for improvement, and related recommendations.

Eight Elements of a Commissioning Program Procedure

1. Planning and sequencing
2. Print and technical review
3. Preparing installed equipment for modification
4. Equipment and device acceptance testing
5. Equipment isolation
6. Functional testing
7. Operational (or in-service load) checks
8. Documentation

Key Operational/Functional Recommendations

• All Entities should implement end-to-end testing for all bulk electric system communication-based protection schemes as recommended by the IEEE WG I-25 guide. Communication failures are one of the top three causes for Misoperations. Recommendation
• All Entities should perform current testing on all phases to ground, phase-to-phase, and 3-phase faults. This will ensure that CT ratios, CT and polarity, and polarization of ground elements is correct for all fault scenarios.
• CT circuit errors represent a significant portion of misops primarily due to incorrect CT ratios, incorrect CT polarity, and CT’s left in the shorted position. Entities should perform:
  • A final walk-down process to ensure that CT and VT circuits are correct prior to being placed in service.
  • In-service loading is above the minimum equipment requirements so that sufficient current magnitude is available for accurate measurement.
  • Operational tests and measurements include current and voltage magnitude, phase angle and polarity with respect to the primary quantities.
  • Operational measurements from different relays, meters, fault recorders, SCADA transducers, and other devices that use the same voltage and current signals should be compared with each other to ensure similar measured quantities at each device.

Associated Files:

• Joint_Commissioning_Testing_Webinar_20220302 (1)
• Protection System Commissioning Program Review Project