by Eric Graftaas, Principal Power Systems Engineer, Midwest Reliability Organization
Understanding how generation facilities behave in extreme cold is increasingly important as winter weather continues to challenge bulk power system operations.
To help the industry learn from past winter outage events, the North American Electric Reliability Corporation’s (NERC) Failure Modes and Mechanisms Working Group (FMMWG) recently released two new visual charts that explain how both wind turbines and gas fired generators can fail during cold weather.
The Wind Generator Failures During Cold Weather chart shows how ice buildup on blades, frozen sensors, stiffened lubricants, and communication or control issues can lead to reduced output or tripping offline. Blade icing was widely seen during the February 2021 Winter Storm Uri and remains a common failure mode for wind generation.
The Gas Unit Fails to Generate During Cold Weather chart highlights challenges such as frozen valves, failed instrumentation, and low natural-gas pressure. It also illustrates how upstream gas supply problems during extreme cold can cascade into loss of electric generation.
Together, these diagrams make complex failure scenarios easier to understand and help Generator Owners and Operator visualize how weather, equipment limitations, and the fuel system interact during severe weather conditions.
Other Failure Modes and Mechanisms Diagrams
These two new cold-weather diagrams are part of a broader collection developed by the FMMWG. In addition to generation-focused charts, the group maintains FMM diagrams for many types of bulk power system equipment, including power transformers, instrument transformers, circuit breakers, capacitor banks, surge arresters, relays, power line carrier and substation batteries. These tools can help the industry strengthen maintenance practices and improve reliability.
The FMMWG will continue to expand their library as new insights emerge supporting a stronger, more resilient bulk power system. The group meets monthly via Webex and is looking for knowledgeable volunteers. If you are interested in contributing to the group or are in search of more information about these efforts, please contact [email protected] or [email protected]