10 kV 配电变压器高空电磁脉冲效应实验研究

The high-altitude electromagnetic pulse has the characteristics of high field strength amplitude, wide distribution range and wide spectrum range. It can be coupled into the distribution transformer through the cables in wide-area. The induced currents with large change rates may pose threats to the turn-to-turn insulation or even phase-to-phase insulation of the transformer. In this case, electromagnetic pulse effect experiments are carried out on typical 10 kV oil immersed distribution transformer and dry-type distribution transformer in this paper, where their effect phenomena and threshold laws are compared and analyzed. An equivalent experimental platform for electromagnetic pulse effect experiment of 10 kV distribution transformer is built, which is mainly composed of 10 kV equivalent distribution system and electromagnetic pulse injection system. As a result, three phase nanosecond pulse currents can be injected into the 10 kV distribution transformer in common mode. Based on the experimental platform, the power-off state and power-on state tests are carried out and the effect data are obtained. The results show that both oil immersed transformer and dry-type transformer have the certain ability to resist electromagnetic pulses when the amplitude of the injected current is lower than around 500 A.