基于高阻并联避雷器接地方式的柔性直流配电网保护方法  

Protection Method of Flexible DC Power Distribution Network Based on Grounding Mode with High Resistor and Arrester in Parallel

作　　者：贾勇勇 高尚 司鑫尧[1] 石勇 詹昕[5] 王建华 JIA Yongyong;GAO Shang;SI Xinyao;SHI Yong;ZHAN Xin;WANG Jianhua(Electric Power Research Institute of State Grid Jiangsu Electric Power Co.,Ltd.,Nanjing 210003,China;School of Electrical Engineering,Southeast University,Nanjing 210096,China;Jiangsu Provincial Key Laboratory of Smart Grid Technology and Equipment,Southeast University,Nanjing 210096,China;NR Electric Co.,Ltd.,Nanjing 211102,China;Yangzhou Power Supply Company of State Grid Jiangsu Electric Power Co.,Ltd.,Yangzhou 225000,China)

机构地区：[1]国网江苏省电力有限公司电力科学研究院,江苏省南京市210003 [2]东南大学电气工程学院,江苏省南京市210096 [3]江苏省智能电网技术与装备重点实验室,东南大学,江苏省南京市210096 [4]南京南瑞继保电气有限公司,江苏省南京市211102 [5]国网江苏省电力公司扬州供电公司,江苏省扬州市225000

出　　处：《电力系统自动化》2020年第10期166-173,共8页Automation of Electric Power Systems

基　　金：国家重点研发计划资助项目(2018YFB0904700)。

摘　　要：针对柔性中压直流配电网系统直流线路单极接地故障检测困难的问题,提出一种高阻并联避雷器接地的新型接地方式及其包含自适应放大系数的保护策略。首先讨论了现有的柔性直流配电网接地方式的优缺点,提出了基于联结变压器中性点经高阻并联避雷器的新型接地方式。然后通过理论推导分析了新型接地方式在交直流侧接地故障下的过电压机理和故障特征,根据不同故障下的电压电流特性,提出了相应的直流线路保护策略,实现了差动保护在直流配电网发生故障时准确快速地进行故障识别和故障选线。最后以仿真实例验证了新型接地方式的有效性和所提出的保护方法的可靠性。To solve the difficult problem of monopolar grounding fault detection in flexible medium-voltage DC power distribution network,this paper proposes a new grounding mode with high resistor and arrester in parallel and a protection strategy including adaptive amplification factor.Firstly,advantages and disadvantages of the existing grounding modes in flexible DC distribution network are discussed.A new grounding mode with high resistor and arrester in parallel via the neutral point of the coupling transformer is proposed.Secondly,the overvoltage mechanism and fault characteristics of the new grounding mode are analyzed by theoretical derivation with AC/DC grounding faults.According to voltage and current characteristics in different fault conditions,the DC line protection strategy is developed.It realizes the accurate and rapid fault identification of differential protection with faults in DC network.Finally,the effectiveness of the new grounding mode and the reliability of the proposed protection method are verified by simulation example.

关 键 词：避雷器 接地 柔性直流配电网 过电压 保护 

分 类 号：TM721.1[电气工程—电力系统及自动化] TM862