220 kV同塔双回线路雷击闪络故障分析

Analysis of Lightning Flashover Fault on 220 kV Double Circuit Transmission Lines on the Same Tower

对某220kV同塔双回线路雷击闪络故障进行分析。根据故障巡视情况、雷电信息数据、故障录波情况、ATP-EMTP暂态仿真分析可综合判定本次双回同跳故障为雷电反击造成,具体过程为:雷电击中75#塔顶或相邻地线,雷电流由杆塔接地装置注入大地,导致75#杆塔塔顶及塔身电位升高,在双回线路的B、C两相形成反击过电压,引起绝缘子串闪络并发生线路同跳。提出根据线路通道的雷害评估结果来实施防雷整改,通过安装线路避雷器及在杆塔下方架设耦合地线的改造措施,显著提高了线路耐雷水平。

The lightning flashover failure of a 220 kV double-circuit transmission line is analyzed.According to the fault inspection situation,lightning information data,fault recording conditions,and ATP-EMTP transient simulation analysis,it can be comprehensively determined that the case of simultaneous tripping of double circuit lines was caused by lightning counterattack.The specific process is:the lightning hits 75 # tower top or adjacent ground line,lightning current is injected into the ground by the pole grounding device,which causes the potential of the tower top and tower body of 75 # rising,and counterattack over-voltage is formed in the B and C phases of the double-circuit line,causing the insulator string flashover and line trip.It is proposed to implement the lightning protection rectification based on the results of the lightning damage assessment of the line channel,and the lightning protection level of the line was significantly improved by the installation of line lightning arresters and the reconstruction measures of coupling ground lines under the tower.