Research On Substation Lightning Over-voltage Computing Modeling And Insulation Coordination

Substation is an important part of the power system, based on past operating experience and statistics, lightning invasion wave serious threat to the security and reliable of the substation electrical equipment. The substation station equipment is expensive, for most of the electrical equipment, its insulation no self-recovery capability, should therefore damaged, it will cause huge economic losses, especially for EHV substation, it is also may cause the collapse of the power grid or lead to massive blackouts. So it is necessary to study it.This paper reviews the substation lightning over-voltage computing modeling and insulation coordination, introduces the kind of lightning, thunder and lightning wave formation mechanism procedures on overhead lines. Discussion substation lightning invasion wave overvoltage computational modeling, analysis substation lightning invasion wave process, within the substation equipment modeling, the equivalent calculation circuit of transmission lines and various devices are given.According to the information of Yueyang South 500 k V substation, using ATP-EMTP simulation software to build a simulation model of the substation, discussed the substation operation mode, the location of lightning and the frequency system power affected the overvoltage.Simulation results showed that lightning the number two tower closed the gantry caused the maximum lightning over-voltage in substation;When direct lightning strokes transmission line the over-voltage large on the main transformer, and the over-voltage on other devices were large with back flashover, so when calculating the Lightning should consider back flashover and direct lightning strokes in both cases; Frequency power is also have a greater impact on over-voltage in substation. Finally, the article analyzes the insulation coordination and arrester protection scheme with the electrical equipment in the substation.Paper use bergeron algorithm and its improvement model for calculation of the actual substation made a depth analysis and research, the method of the modeling and calculation results can provide a good reference for lightning protection and insulation coordination design. It has practical significance and reference value.