基于组合行波原理的高压架空线—电缆混合线路故障测距方法

分析了架空线-电缆混合线路故障后的行波的传播过程以及行波折、反射的现象。在此基础上,针对35kV及以上的高压架空线-电缆混合线路提出了一种基于两种行波原理相组合的故障测距方法。利用双端原理根据混合线路故障初始行波到达两端的时间差进行故障区段的选择,用单端原理进行初步故障测距,结合故障初始行波到达线路两侧的时间差由单端原理给出准确结果。本方法的优点在于得到的测距结果是单端测距原理的结果,消除了双端原理测距中混合线路长度误差及线路两侧准确时间同步问题对测距精度的影响,进而提高了测距准确性与可靠性。ATP仿真表明,所提出的混合线路组合行波故障测距方法是可行的,并且故障测距精度得到明显提高。

Fault location method based on combined travelling wave principle for high-voltage overhead-cable lines

For 35 kV and above high-voltage overhead-cable lines, the paper analyzes the wave propagation process and the wave’s refraction and reflection phenomena after the failure. On this basis, the paper proposes a theory based on two waves combined ranging method. First, according to double-end principle, we choose the fault zone based on the initial wave arrival time errors at both ends in the mixed-lines fault. And then we use single-ended principles to give preliminary fault location. Finally, we give the accurate results by single-ended principles combined initial wave arrival time at both ends in the mixed-lines fault. The advantages of this method is that the results is obtained from single-ended ranging principle, eliminating the influence on accuracy by the mixed line length’s error and circuit accurate time synchronization on both sides in the double-end principle ranging, so as to improve the accuracy and reliability of ranging. ATP simulations show that the proposed high-voltage overhead-cable’s fault location scheme of combined wave is feasible and fault location accuracy is improved obviously.