Effect of Temperature on Space Charge Characteristics of Ethylene Propylene Dine Monomer

Ethylene propylene diene monomer (EPDM) is widely used in MV/HV power cables which are strongly affected by the space charge and the temperature is an important operating factor related closely to its insulation performance. In this paper, the type of DCJ30M-10kV EPDM was used for samples with a thickness of 600 μm after vulcanization and pretreatment and the space charge distribution under depolarization condition was measured by PEA method after polarizing under −10 kV/mm in a temperature control drying oven for 30 min over a broad temperature ranged from 20 to 160 °C. In addition, the dielectric spectrum and conductivity were also be measured by broadband dielectric spectroscopy for a well understanding about the effects of temperature on the space charge characteristic of EPDM. The results showed that the charge injection and impurity ionization which affect the accumulation and migration of the carriers were promoted with the rise of temperature and it caused the formation of positive space charge packet. The behavior characteristics can be divided into two stages based on the migration of space charge packet in EPDM. The mechanism of the space charge packet migration can be explained by the theory of “trap filling”.