Fault diagnosis using fuzzy sets

After a severe disturbance due to an electrical failure, the precise fault location is a critical problem for power system reconfiguration. It is not possible to start the reconfiguration procedures without knowing the distur bance origin and cause. Therefore, the fault diagnosis has to be performed as soon as possible in order to avoid further economical and social costs. In this paper, a new approach for fault diagnosis, using fuzzy sets, is pro posed. The system allows not only the fault location, but also the fault ty pe identification. Currents and voltages are analyzed using the fault phase -impedance and fuzzy sets. The system is part of an operator guidance tool that has been developed for the itaipu hydroelectric plant.