高压直流输电线路两极短路接地故障测距研究

Research on Two-pole Short-circuit Earth Fault Location of High Voltage Direct Current Transmission Lines

小波分析已被广泛应用于高压直流输电线路的故障测距之中,但多数也仅局限于对单极接地故障的测距研究。在此基础上,提出利用小波变换的模极大值理论对两极短路接地故障进行分析。首先,在PSCAD中搭建出高压直流输电系统的仿真模型并进行故障线路仿真,得到故障时的暂态电流信号,最后,对电流行波进行小波分析实现故障测距。从仿真分析结果可知,该方法的定位误差不超过线路全长的0.5%,证明了小波变换的模极大值理论可适用于两极短路接地的故障测距中。

Currently,wavelet analysis has been widely applied to fault location of high voltage direct current（ HVDC）transmission lines,but it is only limited to the study range of monopolar earth fault. Based on this situation,the wavelet transform modulus maxima theory is put forward to analyze the two-pole short-circuit earth fault. First,the simulation model of HVDC transmission system is built in PSCAD and some simulations for fault lines are carried out to obtain the transient current signal. Hence,the fault location is realized by analyzing the traveling wave of the current using wavelet analysis. The simulation results show that the positioning error is less than 0. 5% of the line length,which proves the wavelet transform modulus maxima theory can be applied to two-pole short-circuit earth fault location of HVDC transmission lines.