MOA对750kVGIS-GIL系统侵入波防护效果的研究

雷电波沿着输电线路侵入变电所,对变电所设备构成了很大的威胁。在某750kVGIS变电站的基础上,建立了以气体绝缘输电线路(GIL)作为GIS出线的750kVGIS-GIL系统。通过雷击塔顶和绕击输电线路这两种雷击方式以及考虑地面倾角、接地电阻的影响,利用EMTP程序计算了当雷电波侵入GIS-GIL系统后引起的在隔离开关(DS)、断路器(CB)、电流互感器(CT)以及变压器上的雷电过电压,并根据各设备能够有效地抑制雷电侵入波,从而保证了该750kVGIS-GIL系统内部各设备的正常运行。

Study on the Protective Effect of MOA on Lightning Intruding Waves of 750kV Substation

Lightning surge intrudes substation along transmission line,which is the threat to the equipments within substation.On the basis of one 750kV substation,the 750kV GIS-GIL system that takes gas insulated line(GIL) as the outgoing line of GIS is established in this paper. Through two type of lightning stroke,that is lightning stroke on the top of a tower and shielding failure,considering the effects of ground angle and ground resistance,the lightning over-voltage on disconnecting switch(DS),circuit breaker(CB),current transformer(CT) and transformer are calcuated in this paper by EMTP when lightning waves intrude into the 750kV GIS-GIL system. According to the over-voltage values on the above equipment,the protective projects adopting metal oxide arrester(MOA) are correspondingly presented. The study indicates that MOA can effectively restrain lightning intruding waves and make sure that the equipments within 750kV GIS-GIL system can work normally.