Study Of Ultrasonic Location For Partial Discharge In Transformer

Power Transformer is main equipment in Electric Power system, it is important to the safety of electrical network. Deteriorations of the insulation is the major frequent malfunctions, the most crucial cause is partial discharge (PD). So detection and location the Transformer inner partial discharge source is the key task of transformer maintenance, it is also emphasized by electric power operating utility. The method for ultrasonic location of transformer PD is the main method of the current transformer insulation detection. At present, the two outstanding issues of the ultrasonic location are eliminating interference and the location algorithm. In view of the two questions, the main researches are as follows:(1)The equivalent circuit of PD was constructed by the PD theory. Resorting to the method of electrical-mechanical-ultrasonic analogy to invest the mechanism of PD(2)The study of the ultrasonic signal's propagating rules inside simulative transformer. Design test plans to demonstrate the rules of ultrasonic on tenuation, velocity and route.(3)The way of wavelet packet transform was presented to eliminate interferences basing on the characteristics of the interferences on field PD measurement. The capability of eliminating interferences by this way was analyzed by computer simulation.(4)Coming up with Genetic Algorithm to compute the coordinate of PD, the deviation was limited in the bounds of acceptability.(5)Upgrading for the Ultrasonic positioning system .Basing on laboratory tests and field applications, the result showed that the function of ultrasonic positioning system was effective.