广东背靠背柔性直流工程最后断路器过电压特性与优化  

Overvoltage Characteristics and Optimization of Last Breaker in Guangdong Back-to-Back VSC-HVDC Project

作　　者：宋长青 罗新 谢剑翔 郭铸 陈奥博 黄伟煌 SONG Changqing;LUO Xin;XIE Jianxiang;GUO Zhu;CHEN Aobo;HUANG Weihuang(Guangzhou Power Supply Bureau of Guangdong Power Grid Co.,Ltd.,Guangzhou 510620,China;State Key Laboratory of HVDC,Electric Power Research Institute,CSG,Guangzhou 510663,China)

机构地区：[1]广东电网有限责任公司广州供电局,广州510620 [2]直流输电技术全国重点实验室(南方电网科学研究院),广州510663

出　　处：《南方电网技术》2023年第12期10-17,共8页Southern Power System Technology

基　　金：广东电网有限责任公司广州供电局咨询项目(1500002022030201ZL00005);广东省重点领域研发计划资助项目(2019B11109001)。

摘　　要：广东背靠背柔性直流(简称柔直)工程交流侧仅有两条出线,且只有一个下一级变电站,换流器出现最后断路器的风险较高,工程中会配置最后断路器保护来防止设备过压损坏。为降低过电压特征以及提高最后断路器保护动作的时间裕度,基于广东背靠背柔直工程拓扑与控制策略开展了最后断路器三相和单相跳闸工况下的过压机理与特性研究。分析了柔直正负序调制波限幅取值范围,提出了一种柔直正负序调制波限幅优化降低过电压的方法,并开展了EMTDC仿真验证。研究结果表明,背靠背柔直过压特征与正负序控制强相关,且最后断路器单相跳闸比三相跳闸过压严重,换流变饱和特性会抑制过电压但会使控制响应更加复杂,采取所提方法可显著提升最后断路器保护动作的时间裕度。For Guangdong back-to-back volatage source converter-high voltage direct current(VSC-HVDC)project,there are only two outgoing lines on the AC side and only one lower level substation,the risk of the last circuit breaker appearing in the converter is high.In the project,the last circuit breaker protection will be configured to prevent equipment overvoltage damage.In order to reduce the overvoltage characteristics and improve the action time margin of the last breaker protection,based on the topology and control strategy of Guangdong back-to-back VSC-HVDC project,the overvoltage mechanism and characteristics under three-phase and single-phase tripping conditions are studied.Then the range of amplitude limit of the positive and negative sequence modulation signal is analyzed,and a method to reduce overvoltage characteristics by optimizing the amplitude limits is proposed,and EMTDC simulation is carried out.The results show that the overvoltage characteristics of back-to-back VSC-HVDC are strongly related to the positive and negative sequence control,and the overvoltage of single-phase tripping of the last breaker is more serious than that of three-phase tripping,the saturation characteristic of transformer will restrain overvoltage,but it will make the control response more complex.The method proposed in this paper can significantly improve the action time margin of the last breaker protection action.

关 键 词：背靠背柔性直流 换流器的最后断路器 正负序控制 断路器单相跳闸 过电压特性 

分 类 号：TM561[电气工程—电器]