Special Protection System Reliability Assessment

Special protection systems (SPS) are sometimes perceived by the electric power industry as attractive alternatives to constructing new transmission facilities for maintaining system stability and security. One of the main concerns in the design of SPS is to assure whether the system could fit with the reliability requirements specification. Currently, there are only a few literatures that discuss the SPS reliability assessment. In one study conducted by the authors, some reliability evaluation techniques, including, reliability block diagram method, fault tree analysis, Markov modeling and Monte Carlo simulations, are applied to assess the probability that the decision process fails to respond as designed in an actual event-based SPS implemented by Taiwan Power Company (Taipower). Experiences acquired from using these methods for SPS reliability assessment and some recommendations are given in this paper.