Utility application experience of Probabilistic Risk Assessment method

Unlike the traditional deterministic contingency analysis, probabilistic risk assessment (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 index - probabilistic risk index (PRI). The developed PRA program uses contingency analysis results as well as the transmission facility outage information as input to compute and graphically display the risk indices. Kansas City Power & Light (KCP&L), Tri-State Generation and Transmission Association (TRI-STATE), and New York Power Authority (NYPA) have adopted PRA method and utilized PRA program to assess their transmission systems. This technical paper summarizes the utility applications of PRA program in system planning and operations planning area. These research studies have demonstrated that the PRA method significantly improves the ability of conducting effective transmission operations planning, long-term transmission expansion planning, and transmission project prioritization.