NERC offers grid reliability key findings, recommendations

A new report from the North American Electric Reliability Corporation that offers an overview of bulk power system (BPS) performance in 2017 from a reliability perspective includes six key findings in areas such as cyber and physical security and hurricanes, as well as related recommendations.

NERC, which released its “State of Reliability 2018” report on June 21, said that the report focuses on BPS performance during 2017 as measured by a predetermined set of reliability indicators. Based on these metrics, the BPS provided an adequate level of reliability during 2017.

Analysis of 2017 events and data drives six key findings, NERC said.

In one key finding, NERC said that the BPS showed improved resilience during NERC Category 5 events.

Specifically, the report said that Hurricanes Harvey and Irma resulted in NERC Category 5 events, the highest severity level within NERC’s event analysis process. “While wind and water damage were record setting, the restoration efforts and subsequent recovery times were improved from historical benchmarks,” NERC said.

In terms of recommendations tied to this key finding, NERC said that one recommendation is to emphasize participation in mutual assistance programs.

“Mutual assistance agreements provided essential personnel, equipment, and material following Hurricanes Harvey and Irma,” the report noted. “NERC should encourage participation with assistance from government and non-governmental authorities where applicable.”

The public power community played a key role in mutual assistance efforts for Harvey and Irma.

Inverter disconnects

Another key finding is that inverter disconnects during transmission disturbances present an emerging risk.

The report notes that a number of events have resulted in the widespread loss of BPS-connected inverter-based resources for different reasons.

NERC initiated an Inverter-Based Resource Performance Task Force, which studied inverter performance under a variety of circumstances and informed industry of potential risks and their mitigation in 2017 and continues to do so as long as the need exists, NERC said. For example, the report notes that NERC in May 2018 developed a second “Level II” alert to further analyze inverter information and evaluate the extent of conditions associated with emerging issues.

A third key finding is that there was no loss of load due to cyber or physical security events despite continually evolving threats.

“In 2017, there were no reported cyber or physical security incidents that resulted in a loss of load. Nonetheless, grid security, particularly cyber security, is an area where NERC and the industry must continually improve defenses as threats continue to rapidly evolve,” the report said.

Recommendations tied to this finding include expanding the use of systems such as the Cybersecurity Risk Information Sharing Program (CRISP).

The Electricity Information Sharing and Analysis Center “should identify and evaluate opportunities to lower the cost of participation to include more entities, explore Department of Energy (DOE) funding for broader participation of defense critical electric infrastructure” utilities, and support American Public Power Association and National Rural Electric Cooperative Association member participation, the report said.

The remaining three key findings were as follows:

  • Transmission outages caused by failed protection system equipment, AC substation equipment, or human error all show a decreasing trend for the last five years;
  • Frequency response performance trends, while remaining acceptable, are showing varied results by interconnection; and
  • Protection systems misoperations rates, while remaining a high priority, have declined for the fifth consecutive year.

The full report is available here.