一种基于高频量衰减特性的特高压直流输电线路故障测距方法

直流输电线路故障时,高频故障暂态信号将沿线路向两端传播,线路对故障暂态信号高频分量有衰减作用。研究双极特高压直流输电线路频率特性,得到特高压直流输电线路对高频量有衰减作用,线路越长,衰减作用越剧烈的结论。研究基于高频量衰减特性的特高压直流输电线路单端故障测距原理,推导出故障点距测距装置安装点的距离公式,得到基于高频量衰减特性的特高压直流输电线路单端故障测距原理难以准确实现直流输电点线路故障测距的结论。研究基于高频量衰减特性的特高压直流输电线路双端故障测距原理,推导出故障点距测距装置安装点的距离公式,提出频带衰减概念,推导出基于频带衰减的故障距离计算公式。建立云广特高压直流输电系统实际参数仿真模型,对提出的基于高频量衰减特性的特高压直流输电线路双端故障测距原理进行仿真验证,仿真测距结果有较高的准确度。

A fault location method based on high frequency attenuation characteristic of UHVDC transmission line

When HVDC transmission lines fault, the high frequency transient signal travels along the lines, and the high frequency component attenuates during the course. The phase-model transform is analyzed, the frequency characteristic of double-poles UHVDC transmission lines is studied, and the conclusion that the UHVDC transmission lines attenuate the high frequency component, the UHVDC transmission line is longer, the attenuation is acuter is drawn. The single-ended fault location theory of UHVDC transmission line based on high frequency attenuation characteristic is studied, the distance calculation formula of fault position is deduced, and the conclusion that the single-ended fault location theory of UHVDC transmission line based on high frequency attenuation characteristic can not realize the fault location exactly is drawn. The double-ended fault location theory of UHVDC transmission line based on high frequency attenuation characteristic is studied, the distance calculation formula of fault position is deduced, the conception of frequency band attenuation is put forward, the distance calculation formula of fault position based on frequency band attenuation is deduced. The actual parameter simulation model of Yunnan-Guangdong UHVDC system is built up, and the double-ended fault location theory based on high frequency attenuation characteristic studied in this paper is simulated and the simulation location result is higher accurate.