Research On The Over-voltage And Insulation-Coordinating Optimization Of110kV Substation

Substation of different voltage levels woks as the hub of the same voltage level power system. If an accident occurs, it will cause power outages within a certain range. Most of the substation equipment insulation is not self-restore, requiring manual maintenance. So after the lighting accidents, the device can not turn to operation in time. This will seriously affect the security of the power grid. For the most of the substation lightning accidents are caused by lightning invasion wave over-voltage, so the research of the protective measures for the substation equipment over-voltage is very necessary.Modeling of the line tower, lightning, insulator flashover string, wire and major equipment in the substation is needed for lightning over-voltage simulation calculation. Modeling accuracy will directly affect the simulation results of lightning over-voltage substation. The response of the equipment invaded by lightning impulse is also affected by uncontrollable factors, including the lightning current waveform and amplitude, different lightning strike point, phase angle. This paper uses ATP-EMTP simulation program. This paper considers the feed lines and substations as a whole, lightning point is selected as the feed line, and also considers the factors of substation operation mode and the tower grounding resistance. The paper also proposes the lightning protection measures and makes recommendations on the original insulation design optimization, to reduce the construction costs.