不受波速影响的输电线路单端行波故障测距研究

Study of fault locating based on single terminal travelingwaves avoiding wave speed influence

现有输电线路行波故障测距方法,不论单端法还是双端法都会由于故障发生时行波波速的不确定,以及输电线路正常弧垂的影响,从而导致故障测距结果不精确。立足于现有输电线路行波故障测距原理,提出了一种新型的单端行波故障测距方法,通过小波变换得到故障初始行波、故障点反射行波和对端母线反射行波到达母线的时间,在此基础上求解3个距离与时间的方程,得到不受波速影响的故障测距结果。理论上该方法不受行波波速和线路弧垂的影响,仿真分析也证明了其正确性。

The existing methods of fault locating based on traveling waves,either single-terminal method or dual-terminal method,are not accurate enough,which is caused by the uncertainty of wave speed and the arc of transmission line. An accurate fault locating method based on single terminal traveling waves is presented,which avoids the influence of traveling wave speed and transmission line arc in theory. The arriving times of the traveling waves from the fault location,echo from fault location and echo from opposite bus bar can be measured by wavelet transform. Then three equations involving time and location are formed and the fault location is obtained avoiding the wave speed influence. The simulative results show its correctness.