基于复频率信号注入的直流接地极线路故障测距方法  

Fault Location Method for DC Grounding Electrode Line Based on Composite-frequency Signal Injection

作　　者：张鑫华 何佳伟 李斌[2] 戴魏[1,2] 吴通华 叶善堃 ZHANG Xinhua;HE Jiawei;LI Bin;DAI Wei;WU Tonghua;YE Shankun(State Key Laboratory of Technology and Equipment for Defense Against Power System Operational Risks,Nanjing 211106,China;Key Laboratory of the Ministry of Education on Smart Power Grids(Tianjin University),Tianjin 300072,China)

机构地区：[1]电网运行风险防御技术与装备全国重点实验室,江苏省南京市211106 [2]智能电网教育部重点实验室(天津大学),天津市300072

出　　处：《电力系统自动化》2024年第17期109-118,共10页Automation of Electric Power Systems

基　　金：智能电网保护和运行控制国家重点实验室资助项目(SGTYHT/20-JS-221)。

摘　　要：在直流输电系统接地极线路配备阻抗监视系统的背景下,可利用高频测量阻抗特性实现故障距离的精确计算。然而,分析发现直流系统接地极线路在不同故障条件下可能产生相同的高频测量阻抗,这意味着测量阻抗与故障距离间不是一一映射关系,由单一测量阻抗难以得到准确的故障距离。文中分析了高频测量阻抗的重合特性随注入信号变化的特征,提出了基于复频率信号注入的故障测距方法,并给出了复频率的选定策略。该方法改进了基于高频测量阻抗幅相特性的接地极线路故障测距方法,实现了故障位置的准确计算。最后,通过仿真算例充分验证了所提测距方法的可行性和精确性。In the context of equipping impedance monitoring systems for grounding electrode lines in DC transmission systems,the accurate calculation of the fault distance can be achieved by using high-frequency measured impedance characteristics.However,the analysis shows that the grounding electrode line of the DC system may produce the same high-frequency measured impedance under different fault conditions,which means that the measured impedance has not a one-to-one mapping relationship with the fault distance,and it is difficult to obtain the accurate fault distance from a single measured impedance.The paper analyzes the coincidence characteristics of high-frequency measured impedance with the variation of injected signals,proposes a fault location method based on composite-frequency signal injection,and provides a strategy for selecting composite-frequencies.The fault location method based on high-frequency measured impedance amplitude-phase characteristics is improved,and the fault location is calculated accurately.Finally,the feasibility and accuracy of the proposed fault location method are fully verified through simulation cases.

关 键 词：直流输电系统 接地极线路 故障测距 高频测量阻抗 复频率信号注入 

分 类 号：TM862[电气工程—高电压与绝缘技术] TM721.1