Utility Experience Performing Probabilistic Risk Assessment for Operational Planning of Electric Power Systems

EPRI has developed a Probabilistic Risk/Reliability Assessment (PRA) method under Power Delivery Reliability Initiative, which has been successfully implemented by various energy companies in planning studies of growing complexity. Unlike the traditional deterministic contingency analysis, PRA combines a probabilistic measure of the likelihood of undesirable events with a measure of the consequence of the events (that is, the impact) into a single reliability index – Probabilistic Reliability Index (PRI). EPRI internally developed the PRI program that uses contingency analysis results as well as the transmission facility outage information as the input to compute and graphically display the reliability indices. This paper presents an application of PRI program to study the transmission network of New York Power Authority (NYPA), demonstrating that the PRA method significantly improves the ability of conducting effective transmission operational planning.