Probability Estimation of the Occurrence of Protection System Failures in Highly Distributed Generation Systems

Inhalt:
Due to safety critical nature of the protection system, the risk assessment should be an important factor in the selection of optimal power system protection scheme. The paper considers the probability calculation of the occurrence of protection failures in highly distributed generation systems, as a part of risk assessment study. Three calculation methods are used including fault tree analysis, Markov process and Monte Carlo simulation. The methods are illustrated using a case study of Loss-Of-Mains (LOM) protection which incorporates Rate-Of-Change-Of-Frequency (ROCOF) and Neutral Voltage Displacement (NVD) protections. The sources of risk include protection system equipment failures and non-detection failure conditions. The results obtained from the three proposed methods are compared and discussed.