考虑电晕损耗的220 kV变电站雷电入侵波过电压计算与影响因素分析

Calculation of Lightning Surge Overvoltage in 220 kV Substation and Analysis of Its Influencing Factors Considering Corona Loss

冲击电晕是影响变电站雷电入侵波过电压水平的关键因素,在入侵波过电压计算中需要考虑该因素对计算结果的影响。以天津某220 kV变电站为例,基于电磁暂态程序EMTP(Electro-magnetic Transient Program)建立了进线段与变电站相结合的仿真模型。在考虑电晕损耗的前提下,计算分析了冲击电晕、进线电缆及避雷器配置等因素对入侵波过电压的影响。结果表明:电晕损耗使过电压波形发生衰减和畸变;进线电缆末端过电压始终大于首端过电压,且电缆长度的增加使电缆首、末两端过电压幅值降低;在电缆首、末两端配置避雷器能有效抑制电缆与主变处的过电压。

Impulse corona is a key factor affecting the level of lightning surge overvoltage in a substation.Accordingly,it is necessary to consider its influence on the calculation results during the calculation of lightning surge overvoltage.In this paper,a 220 kV substation in Tianjin is taken as an example.Based on the Electro-magnetic Transient Program(EMTP),a simulation model that combines the incoming cable and the substation is established.The effects of factors such as impulse corona,incoming cable and arrester configurations on the overvoltage are calculated and analyzed on the premise of considering the corona loss.Results show that the waveform of overvoltage is attenuated and distorted by the corona loss.The overvoltage at the end of the incoming cable is higher than that at the head,and the amplitudes of overvoltage at both ends of the cable are reduced due to the increase in cable length.The overvoltage of the cable and the transformer is effectively restrained by installing arresters at both ends of the cable.