基于新型相模变换的不对称输电线路故障定位

Fault Location of Asymmetric Transmission Lines Based on the New Phase-Mode Transformation

超高压输电线路采用不换位方式运行,导致线路参数不对称,故障定位精度降低.为此本文提出一种基于新型相模变换的不对称输电线路故障定位新方法.首先针对输电线路参数矩阵中心对称问题,使用新型相模变换进行初步解耦,继而寻求修正矩阵进行二次变换,实现不对称输电线路的精确解耦;进一步针对故障定位问题,考虑到传统双端法对同步性要求高,且不同频率的波速衰减情况也不相同,提出新型双端法进行行波测距,利用双端测量的不同极性行波时间差与被保护线路参数确定故障位置,无需考虑双端同步与波速修正问题.仿真结果验证了所提新方法在完成不对称线路精确解耦的基础上,可以实现高精度故障定位.

The UHV transmission line operation without transposition leads to asymmetry of line parameters,which causes low accuracy for fault location.In this paper,a new method for fault location of asymmetric transmission lines based on the new phase-mode transformation is proposed.Firstly,aiming at the problem of central symmetry of transmission line parameter matrix,a new phase mode transformation is used for preliminary decoupling.Secondly,the modified matrix is sought for secondary transformation in order to realize the accurate decoupling of asymmetric transmission lines.Finally,for the fault location problem,considering the high synchronization requirement and wave velocity attenuation of traditional double-ended method,a new double-ended method is proposed for traveling wave ranging.In this method,the time difference of traveling wave with different polarity measured by two terminals and the parameters of the protected line are used to determine the fault location,and the problems of double-terminal synchronization and wave velocity correction do not need to be considered.Simulation results show that the proposed method can achieve high-precision fault location on the basis of accurate decoupling of asymmetric lines.