Effect of temperature on trap depth in polyethylene nannocomposite

In order to restrict the field distortion in the insulation of high voltage direct current (HVDC) cable under temperature gradient, this paper proposes a nano-filler, the addition of which can restrict the space charge accumulation of low density polyethylene (LDPE) under temperature gradient. To reveal the mechanism of the nannocomposite, the trap depth distribution of the pure LDPE and LDPE nannocomposites under different temperatures were tested based on the Pulsed Electro-Acoustic (PEA) method. The parameters of trap depth distribution were achieved by PEA method under different temperatures(20°C,40°C,60°C and 80°C), and the trap depth distribution under different temperatures were all calibrated to that of 20°C. The results indicated that the trap depths of LDPE decrease with increasing temperature, whereas the trap depths of LDPE nanocomposites changes inobviously with temperature variation. It is considered that, the result contributes to the restriction of space charge accumulation under temperature gradient.