基于改进双端法的高压交流输电线路故障定位

Improvement of fault location of transmission line based on twin-terminal voltage traveling wave

现有输电线路行波故障测距方法由于受行波波速的不确定性以及输电线路弧垂的影响,容易出现较大的定位误差。为此,提出了一种无需波速和线路长度整定的线路故障行波定位方法。利用线路两端的行波信号检测装置记录故障电压行波波头到达时间,同时根据电压行波折反射过程中的传播路径列出关于距离、速度和时间的方程组,经过数学变换可以消去线路弧垂的影响,并在线路上实时在线测量行波速度。用PSCAD软件对双端结构的输电线路进行了仿真,实验结果表明该方法具有好的适应性,在实际测距中对线路电气参数依赖性低,不受故障类型,故障位置和过渡电阻等因素的影响,定位误差较小,原理简单,具有较高的准确性和良好的适用性。

Due to the uncertainty of traveling wave velocity and the influence of transmission line sag,the existing traveling wave fault location methods are prone to large positioning errors.Therefore,a traveling wave fault location method is proposed,which does not need the setting of wave speed and line length.The traveling wave signal detection device at both ends of the line is used to record the arrival time of the fault voltage traveling wave head.At the same time,according to the propagation path of the voltage traveling wave in the process of refraction and reflection,the equations about distance,speed and time are listed.After mathematical transformation,the influence of the line sag can be eliminated,and the traveling wave speed can be measured on line in real time.The PSCAD software is used to simulate the transmission line with two terminal structure.The experimental results show that the method has good adaptability.In the actual location,it has low dependence on the electrical parameters of the line,and is not affected by the fault type,fault location and transition resistance.The positioning error is small,the principle is simple,and it has high accuracy and good applicability.