柔性直流送出系统交流线路的自适应距离保护方法  

Adaptive Distance Protection Method for AC Lines Connected with Flexible DC Transmission System

作　　者：洪丰 吴通华[1,2,3] 郑玉平 孙志攀[2,3] 周博昊 何佳伟 HONG Feng;WU Tonghua;ZHENG Yuping;SUN Zhipan;ZHOU Bohao;HE Jiawei(College of Energy and Electrical Engineering,Hohai University,Nanjing 210098,China;NARI Group Corporation(State Grid Electric Power Research Institute),Nanjing 211106,China;State Key Laboratory of Technology and Equipment for Defense Against Power System Operational Risks,Nanjing 211106,China;Key Laboratory of Ministry of Education on Smart Power Grids(Tianjin University),Tianjin 300072,China)

机构地区：[1]河海大学能源与电气学院,江苏省南京市210098 [2]南瑞集团有限公司(国网电力科学研究院有限公司),江苏省南京市211106 [3]电网运行风险防御技术与装备全国重点实验室,江苏省南京市211106 [4]智能电网教育部重点实验室(天津大学),天津市300072

出　　处：《电力系统自动化》2023年第22期25-32,共8页Automation of Electric Power Systems

基　　金：国家电网公司科技项目(5108-202240278A-2-0-XG)。

摘　　要：柔性直流系统接入使得电网故障特征发生明显改变,传统距离保护应用于柔性直流送出系统交流线路时存在不正确动作风险。针对该问题,指出了基于正序电压极化的距离保护动作特性受柔性直流系统控制策略影响的规律,阐明了柔性直流近端或电网侧背后发生相间故障时拒动或误动的机理。在此基础上,提出了结合暂态信息的自适应距离保护方法,利用故障初瞬自然响应阶段时域信息,构建快速方向判别元件,再结合方向判别结果自适应调整距离保护动作范围,保证距离保护正确动作。实时数字仿真试验结果验证了所提方法的有效性。The integration of flexible DC systems significantly changes fault characteristics of the power grid,and there is a risk of incorrect operation when the traditional distance protection is applied to AC lines connected with flexible DC transmission system.Aiming at this problem,the rules are pointed out that the operation characteristics of the distance protection based on positive-sequence voltage polarization are affected by the control strategy of the flexible DC system,and the mechanism of refusal or malfunction when a phase-to-phase fault occurs at the near end of the flexible DC system or behind the power grid side is clarified.On this basis,an adaptive distance protection method combining transient information is proposed,which utilizes the time-domain information of the natural response stage at the initial fault instant to construct a fast direction discrimination element.Then,combined with the direction discrimination results,the range of distance protection operation is adaptively adjusted to ensure the correct operation of the distance protection.The results of real-time digital simulation(RTDS)experiments verify the effectiveness of the proposed method.

关 键 词：距离保护 柔性直流 海上风电 逆变型电源 

分 类 号：TM773[电气工程—电力系统及自动化] TM721.1