摘要
行波保护作为直流线路主保护已广泛应用于高压直流输电领域,但在柔性直流电网中尚未应用。首先对柔性直流电网输电线路接地故障的特性进行了分析,并简要介绍了基于行波幅值的线路保护原理。在此基础上分析了行波保护与站内直流保护配合关系,描述了直流断路器动作原理以及与行波保护配合策略。PSCAD/EMTDC仿真表明,行波保护动作速度快,可在换流站闭锁前切除线路故障,并能够辨别区内和区外故障,保证电网稳定运行。行波保护具有速动性、可靠性、选择性,能够适用于柔性直流电网。
Traveling wave protection has been widely used in HVDC,but it has not been applied in flexible DC grid.This paper analyzes the characteristics of the pole-to-ground fault of the flexible HVDC line firstly,and briefly introduces the principle of the line protection based on the traveling wave amplitude.On the basis,the traveling wave protection coordination relationship with the DC protection is analyzed.And the action principle of DC breakers and coordination strategy with the traveling wave protection is described.PSCAD / EMTDC simulation show that the traveling wave protection can trip the fault line in front of the station block with fast action,and distinguish internal and external faults,ensure stable operation of DC grid.The traveling wave protection is suitable for flexible DC grid with speed,reliability and selectivity.
出处
《供用电》
2017年第3期51-56,共6页
Distribution & Utilization
基金
国家电网公司科技项目"±500kV柔性直流电网超高速保护关键技术研究"资助~~
