计及冲击电晕的输电线路雷电过电压影响因素研究

Influence Factors Research on Lightning Overvoltage of Transmission Lines Considering the Effect of Impulse Corona

基于电磁暂态仿真软件PSCAD/EMTDC,在考虑了冲击电晕对雷电过电压影响的同时,研究雷电流波形与幅值、避雷线布置方式、杆塔塔型、导线布置方式(包括导线排列方式、导线分裂数)、接地电阻等因素变化时,杆塔塔顶或导线上雷电过电压的特点及其参数关系,用以找到各种情况下输电线路雷电过电压的关键影响因素。结果表明:冲击电晕对输电线路雷电过电压的影响很大;雷电流幅值与波形、杆塔塔型、接地电阻对输电线路的反击过电压有较大的影响;而雷电流幅值与波形、避雷线布置方式、导线分裂根数对输电线路的绕击过电压有较大的影响。

With the rapid development of power grid in extra and ultra high voltage level, lightning fault has become the primary factor which influences the safe operation of transmission lines. It is extremely important and further research lightning properties and accurate evaluation of the transmission line lightning overvoltage performance. Based on electromagnetic transient simulation program PSCAD/ EMTDC, the characteristic of lightning overvoltage and the relationship of parameters on tower top or conductors are studied; considering the effect of impulse corona, the lightning current waveform, amplitude, arrangement mode of ground wires, tower type, conductor configuration including arrangement mode and split number; when the grounding resistance changed, the key factors which affect back striking and shielding failure overvoltage of EHV AC transmission lines are found. The results show that the lightning overvoltage of transmission lines is greatly impacted by impulse corona; the transmission lines back striking overvohage is mainly affected by lightning current waveform, amplitude, tower type and grounding resistance; while the shielding failure overvoltage is mainly affected by lightning current waveform, amplitude, arrangement mode of ground wires and split number of conductors.