Simulation Study on Space Charge Distribution of AC XLPE Cable under DC Voltage

With the increase of electricity demand, changing AC cable lines to DC cable lines can maximize the transmission capacity of the original transmission lines. The difference of electric field distribution in AC-DC cable lies in the accumulation of space charge. . The space charge accumulation is not considered in the design of AC XLPE cable insulation materials. In order to study the space charge accumulation and electric field distribution characteristics of AC XLPE cable under DC voltage, the influence of insulation temperature difference and reversal time on the electric field and space charge distribution of 500kV AC cable under the condition of polarity reversal is studied by using multi-physical field simulation software. The results show that the maximum transient field intensity is closely related to insulation temperature difference and voltage polarity reversal time. The research results lay a foundation for changing AC 500kV cable line to DC cable line.