混合直流输电系统过电压抑制方法研究  

Research of Control Strategy of Suppressing Overvoltage on Hybrid-HVDC Transmission System

作　　者：张军 吴金龙 王先为 胡丁文 牛翀 ZHANG Jun;WU Jinlong;WANG Xianwei;HU Dingwen;NIU Chong(Xi'an XJ Power Electronics Technology Co.,Ltd.,Xi'an 710075,China)

机构地区：[1]西安许继电力电子技术有限公司,西安710075

出　　处：《高压电器》2019年第7期187-194,共8页High Voltage Apparatus

基　　金：国家电网科技项目~~

摘　　要：混合直流输电系统中逆变站采用电压源换流器,彻底解决了换相失败问题,未来在多馈入直流输电地区发展前景非常好。过电压水平对系统的安全稳定和工程可行性非常关键,因此对于LCC-MMC混合直流输电系统过电压水平的抑制策略研究十分有必要。文中首先研究了LCC-D-MMC混合直流输电系统的运行原理,进一步研究了过电压发生的机理;然后分析了LCC-MMC混合直流输电系统过电压影响因素,在此基础上提出了混合直流输电系统过电压抑制策略;最后在PSCAD/EMTDC软件中建立了LCC-MMC混合直流输电过电压仿真模型,对LCC-MMC过电压抑制策略进行了仿真验证。通过研究可知,MMC闭锁后存在的充电回路为混合直流输电系统过电压的主要因素,采用LCC电流指令快速响应策略可以有效的抑制系统过电压水平。In hybrid-HVDC transmission system,voltage source converter is used in inverter station,by this thecommutation failure would be avoided,it would be used widely for multi-infeed direct current system transmissionsystem in future. Overvoltage is very critical for power transmission stability and engineering feasibility of hybrid-HVDC transmission system. It is necessary and significant to research overvoltage control strategy on hybrid-HVDCtransmission system. Firstly,the operation and overvoltage mechanism of hybrid-HVDC transmission system are analyzed in this paper. Above this,overvoltage impact factors of hybrid-HVDC transmission system are comprehensivelyanalyzed. Based on this,the overvoltage control strategy would is proposed in detail. Finally,LCC-MMC hybrid-HVDC transmission system and model are built by PSCAD/EMTDC,and the overvoltage control strategy is simulat-ed. According to the analysis and result,the main factor of HVDC transmission system overvoltage is the chargingcircuit of sub-module,after MMC blocking. In addition,the overvoltage level of hybrid-HVDC transmission systemcould be suppressed effectively by LCC current order fast response strategy.

关 键 词：混合直流输电系统 过电压水平 电流指令快速响应 充电回路 

分 类 号：TM721[电气工程—电力系统及自动化]