基于差动电流与分布电容电流比值的直流线路纵联保护方案  

Pilot Protection Scheme for DC Lines Based on Ratio of Differential Current to Distributed Capacitive Current

作　　者：褚倍钰 李海锋[1] 彭光强[2] 梁远升[1] 王钢[1] CHU Beiyu;LI Haifeng;PENG Guangqiang;LIANG Yuansheng;WANG Gang(School of Electric Power,South China University of Technology,Guangzhou 510641,China;Electric Power Research Institute,EHV Power Transmission Company of China Southern Power Grid Co.,Ltd.,Guangzhou 510663,China)

机构地区：[1]华南理工大学电力学院,广东省广州市510641 [2]中国南方电网有限责任公司超高压输电公司电力科研院,广东省广州市510663

出　　处：《电力系统自动化》2024年第9期162-170,共9页Automation of Electric Power Systems

基　　金：国家自然科学基金资助项目(52077082);广东省基础与应用基础研究基金资助项目(2022A1515010906)。

摘　　要：分布电容电流会对直流线路纵联保护性能造成影响。文中以三端混合高压直流输电线路为对象,讨论分析了差动电流与分布电容电流比值的故障特征。由于差动电流和分布电容电流都会随着过渡电阻的增大而减小,采用差动电流与分布电容电流的比值作为判据,可以削弱过渡电阻对判据的影响,提高保护的灵敏性。基于此,提出了一种基于差动电流与分布电容电流比值的纵联保护方法。基于PSCAD/EMTDC的仿真验证表明,所提保护判据整定简单且天然具有故障选极功能,能可靠识别区内外故障,耐过渡电阻能力强且具有较高的灵敏性和可靠性。Distributed capacitive current affects the performance of DC line pilot protection.In this paper,the fault characteristics of the ratio of differential current to distributed capacitive current are discussed and analyzed on three-terminal hybrid high-voltage DC transmission line.Since both differential current and distributed capacitive current decrease with the increase of transition resistance,the ratio of differential current to distributed capacitive current is used as the criterion to weaken the influence of transition resistance on the criterion and improve the sensitivity of protection.On this basis,a pilot protection method based on the ratio of differential current to distributed capacitive current is proposed.Simulation verification based on PSCAD/EMTDC shows that the proposed protection criterion is simple to set and naturally has the function of fault pole selection,can reliably identify the internal and external faults,has strong resistance to transition resistance,and has high sensitivity and reliability.

关 键 词：直流输电 纵联保护 电流差动保护 分布电容电流 

分 类 号：TM773[电气工程—电力系统及自动化] TM721.1