A practical method estimates on - load tap changers' operation status

In this paper, the data fusion theory was has been utilized to develop a comparative diagnostic method in determining the operation status of the on - load tap changers mechanism. The ANSI/IEEE C57.139 and Duval triangle 2 have been widely adopted to diagnose the insulating oil of OLTC in industry. The OLTC's failure phenomenon has been divided into three kinds of conditions - coking, arcing, and overheating. Those failure examples analyzed in this paper have been categorized into coking and arching sets by developed correlation coefficient approach. The accurate diagnostic method, an approach better than the tradition one, has been verified in this paper. This method was is feasible on diagnosing the insulating oil of OLTC and to understand the status of internal operation.