Analyzing And Avoiding The Over-voltage Of Single-phase Intermittent Arc Grounding In Wuhai Power System

Ground arc over-voltage had happened because of single phase grounding fault in Wuhai power system and damaged the cable connection and neutral grounding arc-suppression coil. Recently over-voltage leads to the damage of switchgear and transfomers. These accidents lead to economic loss and threatened the security operation of Wuhai power system. This paper analyzed the principle of ground arc over-voltage when the fault of single phase grounding happens in non-grounding neutral power system. The Matlab models of transmission line and arc are given. The Matlab/Simulink is used to simulate the ground arc over-voltage of the35kV parts of Shunda substation and Baoshan substation in Wuhai power system. The effects and characters of ground arc over-voltage are analyzed by the simulation. Based above, the restrain measure of using arc-suppression coil to restrain ground arc over-voltage is anylsed.