摘要
现阶段直流输电线路纵联保护单纯地采用叠加原理,未考虑直流输电系统的强非线性,保护在实际工程中存在适应性问题。针对此问题,提出一种纵联保护新方法。从保护方法的适应性角度出发,提出基于描述函数法的信号线性化处理技术。通过分析直流输电线路区内、外故障发生后一段时窗内反行波的传输特性,发现发生区内故障时,线路两端反行波波形间相似度较高;发生区外故障时,线路两端反行波波形间相似度较低;进而提出一种基于反行波的纵联保护方法,该方法利用Hausdorff距离算法度量线路两端反行波的相似度,构造直流输电线路故障识别判据。仿真结果表明,该保护方法能可靠区分直流线路区内、外故障,且在发生高阻接地故障时具有较高灵敏性。
At present,the longitudinal protection of the DC transmission line is simply superimposed without considering the strong nonlinearity of the DC transmission system,so it has adaptability problem in actual engineering. Aiming at this problem,a new method of longitudinal protection is proposed. From the perspective of the adaptability of the protection method,a signal linearization processing technique based on the description function method is proposed. By analyzing the transmission characteristics of the reverse traveling wave in a time window after the internal and external faults occur in the DC transmission line,it is found that the similarity between the reverse traveling wave waveforms of the two ends of the line is higher during the internal fault,while it is lower during the external fault. Then a longitudinal protection method based on reverse traveling wave is proposed,which uses Hausdorff distance algorithm to measure the similarity of the reverse traveling waves at two ends of the line and constructs the fault identification criteria for DC power transmission lines. The simulative results show that the proposed method can reliably distinguish internal and external faults in DC lines,and has high sensitivity when grounding fault with high resistance occurs.
作者
王永进
樊艳芳
WANG Yongjin;FAN Yanfang(School of Electrical Engineering,Xinjiang University,Urumqi 830047,China)
出处
《电力自动化设备》
EI
CSCD
北大核心
2020年第3期114-121,共8页
Electric Power Automation Equipment
基金
国家自然科学基金资助项目(51767023)
2017年度新疆维吾尔自治区自然科学基金联合资助项目(2017D01C028)。
关键词
特高压直流输电
叠加原理
适应性
描述函数法
反行波
HAUSDORFF距离
继电保护
UHVDC power transmission
superposition principle
adaptability
description function method
reverse traveling wave
Hausdorff distance
relay protection
