基于行波全波形主频分量衰减特性的高压输电线路快速保护方法  

High-speed Protection Method for Transmission Line Based on the Dominant Frequency Component Attenuation Characteristics of Traveling-wave Full Waveform

作　　者：邓丰[1] 黄懿菲 祖亚瑞 曾哲 曾祥君[1] DENG Feng;HUANG Yifei;ZU Yarui;ZENG Zhe;ZENG Xiangjun(College of Electrical and Information Engineering,Changsha University of Science and Technology,Changsha 410114,Hunan Province,China;State Grid Shijiazhuang Power Supply Company,Shijiazhuang 050052,Hebei Province,China)

机构地区：[1]长沙理工大学电气与信息工程学院,湖南省长沙市410114 [2]国家电网石家庄供电公司,河北省石家庄市050052

出　　处：《中国电机工程学报》2022年第24期8864-8875,共12页Proceedings of the CSEE

基　　金：国家自然科学基金项目(52077008,52037001)。

摘　　要：现有单端行波保护方法提取的故障特征量难以综合反映故障位置和边界特性,易受过渡电阻等不同故障工况的影响,导致保护整定困难。该文深入分析了区内外故障初始反行波的传输路径差异,研究了线路参数及线路边界对行波幅值衰减的影响,确定以初始反行波各频段幅值衰减特性为依据提取故障特征量。在此基础上,利用连续小波变换分解包含初始反行波的行波信号,得到行波全波形,并构造随故障位置动态变化的行波全波形主频分量。理论分析发现:区内故障时行波全波形主频分量随故障距离增大而减小;线路边界导致区内外故障主频分量差异显著。据此提出一种基于行波全波形主频分量衰减特性的输电线路快速保护方法。该方法以动态变化的行波全波形主频分量设置保护判据,避免不同网络拓扑结构、故障工况对保护整定值的影响。仿真结果表明所提方法能快速、可靠判别区内外故障,在线路末端经300Ω过渡电阻故障时仅需1ms时间窗采样数据也能可靠动作,在不同故障工况下具有较强适应性。The fault features extracted from existing single-ended traveling wave protection are difficult to reflect fault location and boundary characteristics synthetically.Also,they are susceptible to fault resistance and other fault conditions.So it is difficult to set the protection.The transmission path difference of initial backward traveling wave between internal and external faults is analyzed.And the attenuation influence of line and boundary on traveling wave amplitude is also studied.Therefore,the amplitude attenuation characteristics of initial backward traveling wave in each band is determined to extract the fault feature.On this basis,Continuous Wavelet Transform(CWT)is used to obtain traveling wave full-waveform.The dominant frequency component of traveling wave full-waveform is constructed.Through theoretical analysis,it is found that the dominant frequency component decreases with the fault distance.And under the external fault,it decreases significantly than that under the internal fault.Therefore,a fast protection for transmission lines based on the above characteristic is proposed.The dynamic dominant frequency component of traveling wave full waveform is used to set the protection criterion to avoid the influence of different fault conditions on the setting value.Simulation results show that the proposed protection can distinguish the internal and external faults quickly and reliably.It can operate reliably only with 1ms sampling data when the fault with 300Ωresistance occurs at the line end.It presents strong adaptability under different fault condition.

关 键 词：输电线路 单端保护 行波全波形 主频分量 

分 类 号：TM76[电气工程—电力系统及自动化]