The theft of grounding wire of high-voltage cable has a great impact on the stable operation of the power grid. To study the temperature field distribution after the loss of grounding wire of high voltage cable and improve the level of fire prevention, ANSYS finite element software is used to simulate the temperature field distribution and the cable sheath protector is  tested in this paper. The results show that: When the grounding wire is cut, the suspended potential of the metal sheath of the cable will be greatly increased. Combined with the analysis of the temperature field, it can be obtained that when the line trips, the temperature of the cable core and main insulation has reached about 350 ℃, which is far more than the normal operation of the cable. The allowable temperature of the simulation results is consistent with the actual monitoring data. Finally, based on the above research and analysis, the fire prevention measures for high-voltage cables are proposed, which can provide reference for high-voltage cable fire prevention.
 

high-voltage cable; temperature; grounding fault; fire prevention measures