Contingency ranking for bulk system reliability criteria

The use of outage data and models for multiple outages to examine the likelihood of various contingencies is addressed. The authors discuss sources of outage data, followed by an examination of line, generator, and transformer failures. The probabilities of various contingencies that planners examine were calculated, with consideration given to the likelihood of outages during abnormal cold winter weather. A contingency ranking table summarizes the results, showing which events are more or less likely. The rankings are the foundation for the Bonneville Power Administration deterministic planning criteria