中文摘要：

直流接地极线路是从换流站的中性母线处引出,通过架设双导线并联的接地极引线连接到极址处,其极址电阻很小。从中性母线向接地极线路视入,接地极线路就是一个确定的多导体传输线（multiconductor transmission lines,MTL）系统,且其起端电压和起端电流可测,而基于反射原理的测距装置往往出现未能对接地极线路瞬时性故障进行及时捕捉、准确测距的情况。基于此,提出一种利用＂构造方向电流＂来快速判断接地极线故障,并选出故障接地极线的方法。对故障前数据进行小波变换,选其含有直流分量的小波系数来获取直流分量,实现极址电阻在线准确计算和监测。在接地极线故障正确选线和极址电阻准确计算的基础上,提出了基于π型等效线路模型的谐波分量阻抗测距方法。仿真和现场实测数据表明,该测距算法对于接地极线路近端故障有很高的测距精度。

英文摘要：

HVDC electrode line is the line from neutral bus at converter station to pole site connected to ground via small resistance of double parallel grounding wires. HVDC electrode line is a deterministic multi-conductor transmission line（MTL） system seen from neutral bus to grounding line. Voltage and current of line start can be measured, but distance measuring device based on reflection principle often fails in timely capture of transient fault and accurate fault location. Current constructed with direction is used to determine fault and discriminate faulted electrode line. Wavelet coefficients containing DC component is used to calculate DC component, achieving accurate calculation of electrode site resistor. Based on this, fault location method based on π-type equivalent circuit model of line and harmonic impedance components is proposed. Simulation and measurement results show that this location algorithm has high accuracy for fault location near measurement place.