基于波速优化与模量传输时间差的直流线路单端行波测距新算法

摘要

分析了直流故障行波的波速变化特性,发现线路参数的频变特性以及行波幅值的衰减使得行波波速随故障距离发生变化;在目前实际测距装置的分辨率下测距装置模量行波波速主要受故障距离影响.直流故障行波中线模与地模分量不同的色散特性是造成两者传输时间差随故障距离非线性递增的主要原因.基于上述结论,提出了基于波速优化与模量传输时间差的直流行波单端测距新算法,并结合工程实际,提出了波速曲线的获取与修正方法.在EMTDC环境下的算例分析证实了所提算法的有效性.%The variation characteristic of DC fault traveling wave speed is analyzed,and it is found that,the speed varies along with the fault distance due to the frequency-dependent characteristic of line parameters and the attenuation of wave amplitude; the modal traveling wave speed is mainly influenced by the fault distance with the resolution of the current distance measuring devices; the difference of dispersion characteristics between zero mode and aerial mode is the main cause of the nonlinear increase of their modal propagation time difference along with the fault distance,based on which,a one-end fault location algorithm is proposed for DC transmission line. Combined with an actual project,the way to obtain and correct the wave speed curve is introduced. Case study in EMTDC environment verifies its effectiveness.