Surface Charge Behaviors of Epoxy/AlN Nanocomposites under DC and Pulse Voltage

The regular conductor insulation of current lead in superconducting power equipment usually uses epoxy resin. It is easy to accumulate surface charge on the surface of epoxy resin during operation, which causes discharge and premature insulation damage. And the current lead insulation must bear the common effect of DC and pulse overvoltage in the HVDC transmission system. The current lead insulation is facing a more severe test. This paper investigated the effects of DC and pulse voltage on surface charge behaviors of epoxy/AlN nanocomposites with different content of nanoparticles. The experimental results indicate that the initial surface potential of composite insulation decreases first and then rises with the increase of pulse voltage after the polarity of DC and pulse voltage. The results can provide reference for the design of current lead insulation at normal temperature.