特高压多端混合直流输电系统控制策略分析  

Analysis on Control Strategy of UHV Multi-terminal Hybrid HVDC Transmission System

作　　者：石万里 陈明佳 罗义晖 郭建祎 樊友平[2] SHI Wan-li;CHEN Ming-jia;LOU Yi-hui;GUO Jian-yi;FAN You-ping(Liuzhou Bureau of China Souther Power Grid Co.,Ltd.,EHV Transmission Company,Liuzhou 545000,China;School of Electrical Engineering and Automation,Wuhan University,Wuhan 430072,China)

机构地区：[1]中国南方电网有限责任公司超高压输电公司柳州局,广西柳州545000 [2]武汉大学电气与自动化学院,武汉430072

出　　处：《电力学报》2021年第6期483-490,共8页Journal of Electric Power

基　　金：“南方电网乌东德电站送电广东、广西特高压多端柔性直流示范工程”项目研究成果。

摘　　要：多端混合直流输电技术现如今已经成为区域能源互联的重要技术,昆柳龙直流输电工程的投建标志着我国多端混合直流输电技术进入新的发展期。多端直流输电技术在保证大容量输电的同时,其运行模式更为灵活,因此,针对昆柳龙直流工程专题展开多端直流输电技术控制策略研究,既能保证工程顺利进展,也能为后续发展提供借鉴。在详细对比分析主从控制、直流电压下垂控制、直流电压裕度控制这三种控制策略特性的基础上,立足于昆柳龙工程实际情况,其送端采用LCC作为整流换流站,受端采用MMC并联作为逆变换流站,提出了一种LCCMMC结构的多端系统的主从控制策略。在该策略中,将常规直流整流换流站采用定直流电流控制,指定一个受端柔性换流站采用直流电压控制,从而支撑整个系统的直流电压,该策略对送端换流站交流母线三相故障和受端换流站交流母线三相故障两种故障形式,都能够有效控制系统的直流电压和传输功率。通过PSCAD构建了一个三端混合直流系统模型,设置整流换流站为LCC结构,逆变换流站为MMC结构,从LCC发生故障及MMC1发生故障两种情况进行仿真,验证了该控制策略的有效性。仿真结果表明,该策略可以对昆柳龙系统的直流电压和功率传输实现有效控制,保证系统稳定运行,为今后多端混合直流输电系统设计提供参考。Multi-terminal hybrid DC transmission technology has now become an important technical component of regional energy interconnection.The construction of Kunliulong DC transmission project marks a new devel⁃opment period for my country’s multi-terminal hybrid DC transmission technology.The multi-terminal DC transmission technology guarantees large-capacity transmission while its operation mode is also more flexible.Therefore,a study on the control strategy of the multi-terminal DC transmission technology for the Kunliulong HVDC project can not only ensure the smooth progress of the project,but also be a follow-up development.Based on the detailed comparative analysis of the three control strategy characteristics of master-slave control,DC voltage droop control,and DC voltage margin control,and based on the actual situation of Kunliulong proj⁃ect,the sending end adopts LCC as rectifier station,and the receiving end adopts MMC parallel connection as converter station,a master-slave control strategy of multi-terminal system with LCC-MMC structure was pro⁃posed.In this strategy,the conventional DC rectifier-converter station adopts constant DC current control,and a receiving-end flexible converter station was designated to adopt DC voltage control,so as to support the DC voltage of the entire system.For the three-phase fault of the AC bus of the sending-side converter station and the three-phase fault of the AC bus of the receiving-side converter station,the DC voltage and transmission power of the system could be effectively controlled with this strategy.A three-terminal hybrid DC system model was constructed by PSCAD,and the rectifier converter station was set as LCC structure,and the inverter converter station was set as MMC structure.The two situations of LCC failure and MMC1 failure were simulated to verify the effectiveness of the control strategy.The simulation results showed that,the strategy can effectively control the DC voltage and power transmission of the Kunliulong system and ensure the stable ope

关 键 词：多端混合直流系统 协调控制策略 电网换相换流器(LCC) 模块化多电平换流器(MMC) PSCAD 

分 类 号：TM721.1[电气工程—电力系统及自动化]