Development of expert system for operation at substation

An expert system that offers support information in substation fault occurrence is described, focusing on a method for fault section estimation. This system edits fault information and estimates the fault section. With respect to the fault section. With respect to fault section estimation, a method that makes maximum use of sequential information on protective relay and circuit breaker operation even for complicated fault conditions involving multiple faults and incorrect operation or incorrect nonoperation of protective relays and circuit breakers. This system is undergoing field test in a commercial EHV substation, and so far normal operation is reported