基于行波传播路径的不等长双回线路单端行波测距

Fault Location of Single-terminal Traveling Wave for Unequal-length Double-circuit Lines Based on Traveling Wave Propagation Path

由于雷击引起的闪络故障电流行波的初始行波幅值较大并且伴随着大量的振荡,而反映故障位置行波(故障点反射波和对端母线反射波)的幅值远小于故障初始行波的幅值,故在同一观测尺度上,难以辨识出故障行波性质;同时,在现场实际中,不存在完全等长的双回线路。基于此,分析了不等长双回线路于故障回线和健全回线量测端两个坐标轴上观测到的行波波头于时间轴的分布特点,提出了采用故障线路量测端和非故障线路量测端两个尺度上联合观测和辨识故障行波性质的方法,并采用同一观测端的故障线路和健全线路各自检测到一次属于它自己电流互感器所观测的故障初始行波波到时刻,实现了不等长双回线路故障测距。大量实测数据表明,于故障线路量测端和非故障线路量测端两个尺度上联合观测,特别是雷击闪络故障,能够可靠和正确地辨识故障行波的性质,实现不等长双回线路的可靠精确测距。

Because of the flashover fault caused by lightning stroke,the amplitude of the initial traveling wave of current traveling wave is large,and it is accompanied by a large number of oscillations.However,the amplitude of reflected traveling wave（the reflected wave of fault point and the reflected wave at the end bus）is much smaller than the amplitude of the initial traveling wave.Therefore,it is difficult to identify the reflected waves at fault points on the same observation scale.At the same time,there are no fully equal double circuit lines in the field.Based on this,the distribution characteristics of traveling waves observed on the time axis of the two coordinate axes of the unequal-length double-circuit on the fault line and the measurement end of perfect return line are analyzed.The method of joint observation and identification of fault traveling wave on two scales of fault line measurement end and non-fault line measuring end is proposed.The fault initial wave to the time which comes from fault line and sound line measurement end is used to realize the fault location of the unequal-length double circuit.A large number of measured data show that joint observation on two scales of fault line measurement terminal and nonfault line terminal,especially lightning stroke flashover fault,can identify the fault traveling wave reliably and correctly,and achieve reliable and precise ranging of unequal-length double circuit lines.