Space charge distribution in XLPE and epoxy resin under different temperature

Under high DC voltages, the space charge distribution can greatly distort the electric field and may cause premature failure of the insulation material. The development of space charge in the material is affected by several factors like electrical field, temperature and electrode materials. In this work, the pulsed electroacoustic (PEA) technique was used to measure the space charge distribution in epoxy resin and cross-linked polyethylene. Heterocharge accumulation near the anode and homocharge accumulation near the cathode could be observed in cross-linked polyethylene at room temperature, while only homocharge near the anode could be observed in epoxy resin under the same condition. The polarity of charge accumulation near the cathode and in the center will change in cross-linked polyethylene with the increase of the temperature. The shape of space charge distribution in epoxy resin won´t change with the increase of the temperature, while the charge density decreases.