基于改进双端法的高压输电线路故障定位研究

Study on Fault Location of High Voltage Transmission Lines Based on Improved Double Terminal Method

针对行波波速变化以及线路过长导致现有输电线路行波测距方法故障定位出现较大误差的问题,提出一种不考虑波速变化和输电线路长度的基于改进双端法的高压输电线路故障定位方法。所提方法通过在输电线路两端加装的检测装置,以记录故障行波波头的到达时刻;同时依据电压行波在传播路径上的折反射特性,列出其关于距离、速度和时间的方程组,然后经数学变换以消除线路长度对故障定位结果的影响。所提方法的仿真验证在PSCAD软件中进行,仿真结果表明,所提方法故障定位结果不受故障类型、故障位置、故障电阻等因素的影响,具有故障定位精确、操作简单等特点。

Aiming at the problem of large errors in fault location of existing transmission line traveling wave location methods due to changes in traveling wave velocity and line length,this paper proposes an improved two-terminal method based on high-voltage transmission line fault location without considering changes in wave velocity and transmission line length.The proposed method records the arrival time of the fault traveling wave head by installing detection devices at both ends of the transmission line.At the same time,based on the refraction and reflection characteristics of voltage traveling waves on the propagation path,the equations for distance,velocity,and time are listed.Then,mathematical transformation is performed to eliminate the influence of line length on fault location results.The simulation verification of the proposed method is conducted in PSCAD software.The simulation results show that the fault location results of the proposed method are not affected by factors such as fault type,fault location,and fault resistance,and have the characteristics of accurate fault location and simple operations.