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NERC Case Notes: Reliability Standard IRO-005-3.1a

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Midcontinent Independent System Operator, Inc. (MISO), FERC Docket No. NP15-14-000 (December 30, 2014)

Reliability Standard: IRO-005-3.1a

Requirement: R1

Violation Risk Factor: High

Violation Severity Level: Lower

Region: ReliabilityFirst

Issue: MISO self-certified that some of its facilities experienced a diminished ability to determine post contingency voltage and thermal conditions for six hours on January 30, 2013. Due to sequencing issues in MISO's remedial action scheme, a shift engineer implemented a corrupt contingency case file into the Energy Management System resulting in the real-time contingency database to operate with 2,626 less contingencies. Personnel were unable to identify the alarm for the incorrect number of contingencies because several additional alarms were ringing at the same time. However personnel became aware of and corrected the issue when several 69 kV lines experienced new post contingency overloads due to a trip in a transmission line.

Finding: ReliabilityFirst determined that the violation posed a moderate risk to the BPS reliability as MISO was not monitoring its RC effectively. However, MISO continued to perform real-time monitoring and there were no IROLs associated with the violations. While SOLs were exceeded they did not result in any post-contingency stability or voltage issues and there was no evidence of pre-contingent thermal, stability or voltage issues. In addition, four projected post-contingent SOLs did not exceed the BES parameters. MISO neither admitted nor denied the violations. In approving the settlement agreement, the NERC BOTCC found that issues related to MISO's Network Model were only associated with the monitoring of post-contingent element conditions and did not hinder MISO's ability to perform other monitoring functions. Moreover, the issues were not related, affected a small percentage of the facilities MISO monitors and were indicative of other technologies that depend on large amounts of data. This was MISO's first violation of the standard and none of the violations posed a serious or substantial threat to BPS reliability. While MISO self-reported the violations, they were delayed. But MISO did have an internal compliance program in place, which ReliabilityFirst considered a mitigating factor. MISO was cooperative throughout the duration of the violation and there was no evidence that it attempted to conceal the violations.

Penalty: $0 (aggregate for 4 violations)

FERC Order: Pending