远距离大容量特高压柔性直流受端续流过电压机理及抑制策略  

Continuous Overvoltage Mechanism and Suppression Strategy of Inverter Station of Long Distance and Large Capacity VSC-UHVDC System

作　　者：徐莹 樊林禛 李探 苑宾 赵峥 邹铁锐 XU Ying;FAN Linzhen;LI Tan;YUAN Bin;ZHAO Zheng;ZOU Tierui(State Grid Economic and Technological Research Institute Co.,Ltd.,Beijing 102209,China)

机构地区：[1]国网经济技术研究院有限公司,北京102209

出　　处：《高电压技术》2025年第2期538-546,共9页High Voltage Engineering

基　　金：国家电网有限公司总部管理科技项目(超长特高压柔性直流功率不平衡暂态冲击平抑关键技术研究)(5200-202456113A-1-1-ZN)。

摘　　要：特高压柔性直流系统含有大量的储能元件,当受端换流站发生接地故障闭锁后,仍会产生续流过电压。为了避免严重的续流过压危害设备和系统安全,研究了远距离、大容量特高压柔性直流系统受端换流变阀侧接地和±400k V母线接地等典型故障工况下直流系统的故障特性,以及续流过电压的产生机理,评估了续流过电压的影响因素,提出了过压抑制措施。研究结果表明:优化避雷器配置,可使高端换流阀上桥臂过电压降低38%,高端换流阀端间过电压降低29%。通过增加辅助控制策略,能够有效降低大能量避雷器应力,降低幅度在30%以上。通过搭建工程级的PSCAD/EMTDC电磁暂态仿真模型,验证了过电压机理的正确性和过电压抑制措施的有效性。研究成果可为我国首批特高压柔性直流工程建设提供理论支撑,有利保障直流系统的运行安全。The VSC-UHVDC system contains a large number of energy storage components,which is prone to serious continuous overvoltage when the inverter station is locked due to a ground fault.In order to avoid serious reverse current overvoltage hazards to the safety of equipment and system,the fault characteristics of the long distance VSC-UHVDC system under typical fault conditions such as faults on the valve side of transformer and±400 kV busbar are analyzed,the mechanism of continuous overvoltage is studied,the influences of the continuous voltage are evaluated,and some measures to suppress overvoltage are proposed.The research indicates that the optimal configuration scheme of arrester can effectively reduce the continuous voltage,which can reduce the overvoltage of the upper bridge arm of high voltage converter by 38%and the overvoltage between the terminals of high voltage converter valve by 29%.The auxiliary con-trol strategy can effectively reduce the stress of high energy arrester by more than 30%.The transient simulation model on the PSCAD/EMTDC is built to verify the correctness of overvoltage mechanism and the effectiveness of overvoltage suppression measures.The results can provide theoretical supports for the construction of the first batch of VSC-UHVDC projects in China,and are beneficial to ensuring the safety of DC system operation.

关 键 词：特高压柔性直流 续流过电压 影响因素 避雷器配置 故障特性 抑制策略 

分 类 号：TM7[电气工程—电力系统及自动化]