750kV敞开式变电站雷电侵入波的防护

雷电波沿着输电线路侵入变电站,对变电站设备构成了很大的威胁。为此笔者将某750kV敞开式变电站和进线段结合起来,根据具体的雷击条件,将雷电流直接作用于雷击点,把输电线路、铁塔、变电站内的连接线、母线和电气设备作为一个网络整体来考虑。采用国际通用的电磁暂态计算程序(EMTP)对雷电侵入波过电压进行了计算,给出了不同运行方式下不同避雷器配置方案的变电站设备上的绕击和反击雷电过电压最大值并进行了分析,最后提出了避雷器的布置方案。结果表明,MOA可以抑制南雷电侵入波产生的过电压,从而能够有效保护变电站设备。

Lightning Protection of 750 kV AIS Substation against Intruding Wave

Lightning surge intrudes substation along transmission line to endanger the equipments in a substation.Lightning overvoltage is generated by backflash and shielding failure on the overhead line.In this paper,the overvohage of 750 kV AIS substation caused hy lightning intruding wave is investigated,and the resulting overvoltage magnitudes at several basic points in the substation(including input line,bus bar and power transformer)are computed.A simulation model is established considering the electric equipments,transmission line,steel tower,inner connecting line,and bus bar together as a network.The lightning intruding overvoltage of different running modes and configuration schemes of MOA are calculated by using EMTP (electro-magnetic transient program),and an optimal MOA configuration is presented.The result shows that lightning protection of substation can be improved by introducing MOA and optimizing its configuration based on accurate overvohage analysis.