Analysis and Suggestions for a 220 kV GIS Trip Fault

GIS has significant advantages such as small footprint, strong pollution resistance, easy installation, and flexible operation, and is widely used in urban substations of 72.5kV and above in China. However, due to the lack of experience in the operation of fully enclosed electrical appliances in China, the testing items in the manufacturing and installation process are not complete enough, which may lead to unforeseen hidden dangers in actual use. This article analyzes the causes of an accident caused by the loosening of the fixing bolts between the contact and the contact seat in the busbar interval, during the operation of a 220 kV GIS, resulting in contact finger erosion, shell breakdown, and three phases grounding faults. Simulation methods are used to conduct simulation tests of the fault process. Feasible suggestions are proposed for identifying potential hazards of similar problems.