混合多端直流输电线路快速保护及自适应重启方法实用化研究  

Application Research on Fast Line Protection and Adaptive Restarting Methods for Multi-terminal Hybrid LCC/MMC HVDC Transmission Lines

作　　者：张晨浩 宋国兵[1] 董新洲[2] 黄金海 ZHANG Chenhao;SONG Guobing;DONG Xinzhou;HUANG Jinhai(School of Electric Engineering,Xi'an Jiaotong University,Xi'an 710049,Shaanxi Province,China;State Key Lab of Control and Simulation of Power Systems and Generation Equipments(Dept.of Electrical Engineering,Tsinghua University),Haidian District,Beijing 100084,China;XJ Electric Co.,Ltd.,Xuchang 461000,Henan Province,China)

机构地区：[1]西安交通大学电气工程学院,陕西省西安市710049 [2]电力系统及发电设备控制和仿真国家重点实验室(清华大学电机系),北京市海淀区100084 [3]许继电气股份有限公司,河南省许昌市461000

出　　处：《中国电机工程学报》2021年第11期3873-3884,共12页Proceedings of the CSEE

基　　金：国家重点研发计划(2016YFB0900603);国家电网公司科技项目(52170218000M)。

摘　　要：混合多端直流被用于解决多直流馈入导致的逆变侧同时换相失败问题。快速保护与自愈技术是混合多端直流输电技术发展的关键。该文将行波在混合多端系统不同线路边界处的折反射等效为传递函数,在此基础上分别推导出混合多端系统不同线路边界处的故障电压及其首极值时间表达式。结果表明区内故障时故障电压的首极值时间小于区外故障时故障电压的首极值时间,由此提出基于故障电压首极值时间的直流线路快速保护方案。同时,为了提高直流系统的不间断供电能力,在保护动作清除故障后,利用特征信号注入的方法判别故障性质,自适应的重启直流系统。将所提出的快速保护和自适应重启算法写入超高速保护样机,并在乌东德混合三端RTDS仿真平台做全系统闭环测试。测试结果表明,所提出的快速保护方案能快速可靠的识别直流线路的区内、外故障,耐过渡电阻能力达500Ω,提出的自适应重启方法可正确判别直流线路故障性质,提高直流系统的供电可靠性。The multi-terminal hybrid LCC/MMC HVDC has been applied to overcome the simultaneous commutation failure problem caused by the multi-infeed LCC-HVDCs. The fast line protection and fault self-recovery method are key technologies for the multi-terminal hybrid HVDC system. In this paper, the reflection and refraction of the fault traveling waves at different kinds of line terminals were characterized by transfer functions. Then the expressions of the fault voltage as well as its first peak time at different line terminals were derived respectively. The conclusion proved that the first peak time of fault voltage for internal faults was smaller than that for external faults, and a fast dc line protection scheme was proposed. Moreover, the signal-injection-based adaptive restarting method was adopted after fault clearance, ensuring the uninterruptible power supply of the dc system. Both algorithms were implemented to the ultra-high-speed protection prototype and validated by the Wudongde three-terminal hybrid HVDC RTDS test system. The test results show that the proposed protection method can quickly and correctly identify line faults, even with 500Ω fault impedance. The adaptive restarting method can correctly identify fault property, improving the reliability of the dc system.

关 键 词：混合多端直流 快速保护 自适应重启 超高速保护样机 全系统闭环测试 

分 类 号：TM77[电气工程—电力系统及自动化]