输电线路延绵数千里,传统人工巡线方式查找雷击故障点费时费力。因此基于非接触式雷电流测量装置,结合行波测距和小波包理论,提出了一种新型分布式雷击故障定位方法。根据三相电流行波极性差异,提出了绕击、雷击避雷线和杆塔的雷击类型识别方法;针对绕击情况,进行了雷击是否闪络的判断、雷击区间范围和闪络侧的确定,推导了不同监测区间段内线路雷击点和闪络点定位公式;利用小波包变换提取行波波前到达时间进行定位计算。经EMTP-ATP软件仿真验证,该方法能准确地进行输电线路雷击故障定位,雷击点和闪络点定位误差均〈0.4%,具有重要的应用价值。
Transmission lines are thousands of miles long, so artificially searching lightning fault points on the lines is time-consuming and uneconomic. Therefore, adopting the non-contact measurement device of lightning current and com- bining with the traveling wave fault location, we proposed a distributed lightning fault location method. According to difference in wave polarity among the three phases, we put forward the lightning pattern recognition among lightning striking the ground wire, the tower or the phase. As for shielding failures, we firstly determined whether the flashover happened or not, and determined the lightning range and flashover side if it happened. Then we deduced formulas for lo- cating lightning and flashover in different lightning ranges. By using the wavelet packet transform (WPT), the wave arrival time was extracted for calculation. Simulations in EMTP-ATP show that, using the proposed method, the lightning fault location of transmission line can be calculated accurately, and the errors of striking point and flashover point are both less than 0.4%. Thus the proposed method is applicable.