Effect of the Rise Edge of the Pulse Voltage on Initiation and Growth Characteristics of the Electrical Tree of the Silicone Rubber

The large number of high-frequency pulse voltages generated by the frequent switching of power electronic equipment is one of the important reasons for the generation of electrical trees in its insulation materials. The purpose of this paper is to study the initiation and growth characteristics of silicone rubber electrical trees under different rising edge pulse voltages, and to explain the mechanism of the above experimental phenomenon from the influence of pulse rising edge on space charge vibration. In this paper, based on the steptype accumulation method, a silicone rubber electrical tree aging experimental platform is designed. The three characteristics of fractal dimension, expansion coefficient and cumulative damage of electric tree image analysis and their implementation methods are proposed. By changing the time of the rising edge of pulse voltage, the influence of the rising edge of pulse on the emergence and development of electric trees in silicone rubber is discussed. According to the characteristics of the electric tree, the mechanism of space charge vibration induced by pulsed electric field is analyzed, and it is concluded that the pulsed electric field will cause space charge vibration, and space charge vibration will produce a series of high-energy reactions to produce energy trees. The phenomenon of space charge vibration will intensify with the decrease of pulse rise time, which provides a theoretical basis for reducing the electrical fault of power electronic devices.