FUZZY EXPERT-SYSTEM FOR FAULT-DIAGNOSIS IN POWER-SYSTEMS

Fault diagnosis of power system plays a crucial role in power system m onitoring and control that ensures a stable supply of electrical power to consumers. In the case of multiple faults or incorrect operation o f protective devices, fault diagnosis requires judgment of complex con ditions of various levels, especially considering the unavoidable unce rtainties that occur during operation involving the fault location and other information available. This paper presents a methodology for fa ult diagnosis far complex electrical power systems, which is based on fuzzy logic and expert system to deal with the uncertainties. Expert k nowledge concerning normal and faulted operation is acquired via knowl edge acquisition techniques. A fuzzy logic expert system for fault dia gnosis of power system is developed which uses as input status change of the operated circuit breakers and relays. The fuzzy expert system r equires much less memory space to stare active databases than those us ed by conventional expert systems. The fuzzy expert system first ident ifies a short list of possible fault sections and deals with one possi ble fault section at a time. It then conducts inference to determine t he most likely fault sections and the associated fault section sequenc es. Several study cases are given in this paper to demonstrate salient features of the proposed method.