Research on XLPE Insulation Failure Characteristics of DC Cables in Fire Environmet

In order to study the insulation performance of DC XLPE cables in fire environment, the conductivity of XLPE used in DC cable was tested at different temperatures, and the breakdown field strength of XLPE at different high temperatures was measured, which was carried out in a high-temperature oven. Meanwhile, the field strength distribution inside the DC cable under high temperature environment was simulated. The research results show that long-term overload of XLPE cable or high ambient temperature can cause the electric field strength of the cable insulation to increase, which will induce various defects and eventually cause insulation breakdown.