考虑后续雷击的高压架空输电线路雷电过电压研究

Research on Lightning Overvoltage of High Voltage Overhead Transmission Lines Considering Subsequent Lightning Strikes

为进一步探究雷击对高压架空输电线路的影响,构建考虑后续雷击的高压架空输电线路模型,基于该模型开展暂态电位计算,分析首次雷击、后续雷击状态下暂态电位的波形变化。结果表明:绕击条件下,后续雷击高压架空输电线路过电压明显高于首次雷击,过电压上升时间大致为首次雷击的1/2,后续雷击对于高压架空输电线路的损害明显高于首次雷击。雷击杆塔塔顶条件下,首次雷击输电线路产生的过电压明显大于后续雷击,电压衰减过程的震荡频率明显高于后续雷击。基于此,在高压架空输电线路保护设计中应充分考虑后续雷击。

In order to further explore the impact of lightning strikes on high-voltage overhead transmission lines,a high-voltage overhead transmission line model considering subsequent lightning strikes is constructed.Based on this model,the transient potential is calculated and the waveform changes of the transient potential under the first and subsequent lightning strikes are analyzed.The results show that the overvoltage of the subsequent lightning strike is significantly higher than that of the first lightning strike,the rise time of the overvoltage is 1/2 of that of the first lightning strike,and the damage of the subsequent lightning strike to the high voltage overhead transmission line is significantly higher than that of the first lightning strike.Under the condition of lightning strike on the top of a tower,the overvoltage generated by the first lightning strike on the transmission line is obviously greater than that of subsequent lightning strikes,and the oscillation frequency during voltage attenuation is obviously higher than that of subsequent lightning strikes.Based on this,the subsequent lightning strike should be fully considered in the protection design of high voltage overhead transmission lines.