Analysis of field circuit combination of GIS switching over-voltage

During routine operation of GIS, fast transient over-voltage will be generated, which will threaten the safe operation of GIS. In this paper, the over-voltage analysis of the breakdown fault of the basin insulator occurred in the charging process of a 220kV GIS is carried out, and the electromagnetic field analysis model is established by using the finite element simulation software ANSYS Maxwell to extract the distribution parameters of GIS capacitance and inductance; the distribution parameters are imported into atp-emtp to establish the electromagnetic transient circuit analysis model, and the closing over-voltage of GIS under different states is simulated and calculated. It is considered that the induced voltage of GIS bus at the time of closing is the root cause of high amplitude over-voltage and breakdown of pot insulator.