Comprehensive Evaluation of Insulation Performance of DC XLPE Cables

In this paper, the conductivity test, breakdown characteristic test and space charge test of DC cross-linked polyethylene (XLPE) cable are carried out. The characteristics of XLPE materials under DC electric field are studied, and a comprehensive evaluation system of DC XLPE cable insulation is proposed. Results shows that the conductivity of DC XLPE insulation is more sensitive to the change of operating temperature and field strength. With the increase of temperature, the breakdown strength of XLPE is gradually reduced. Because of the existence of space charge in the DC electric field, there is an obvious electric field distortion in the XLPE insulation. The higher the temperature, the greater the distortion of the electric field, and the modification can be very slow through the nano modification.