An Innovative Loss-of-Excitation Protection Based on the Fuzzy Inference Mechanism

A new loss-of-excitation protection based on fuzzy set theory has been presented. It makes use of conventional concepts of loss-of-excitation protection in synchronous generators (i.e., the behavior of internal voltage and apparent impedance trajectory). Instead of crisp values, a fuzzy inference mechanism is applied. To show the effectiveness of the proposed technique, comparisons are made with traditional protection methods by considering different generators sizes. The protection scheme proposed displays a secure and effective high-speed loss-of-excitation detection during power swings. Furthermore, the performance of the proposed method was not affected by generator parameters.