九边形MMC单端口断路故障下等效六边形MMC控制  

Equivalent Hexagonal MMC Control Under Single-port Open-circuit Fault of Nonagonal MMC

作　　者：王要强[1,2] 原博 刘文君 刘飞 梁军[1,4] WANG Yaoqiang;YUAN Bo;LIU Wenjun;LIU Fei;LIANG Jun(School of Electrical Engineering,Zhengzhou University,Zhengzhou 450001,China;Henan Engineering Research Center of Power Electronics and Energy Systems,Zhengzhou 450001,China;School of Electrical Engineering and Automation,Wuhan University,Wuhan 430071,China;School of Engineering,Cardiff University,Cardiff CF243AA,U.K.)

机构地区：[1]郑州大学电气工程学院,郑州450001 [2]河南省电力电子与电能系统工程技术研究中心,郑州450001 [3]武汉大学电气与自动化学院,武汉430071 [4]卡迪夫大学工程学院,卡迪夫CF243AA

出　　处：《高电压技术》2022年第10期4027-4038,共12页High Voltage Engineering

基　　金：国家自然科学基金(52007171,51877160)。

摘　　要：九边形模块化多电平变换器(modular multilevel converter,MMC)作为一种三端口直接型AC-AC变换器,具有高紧凑性、低频性能好的特点。当九边形MMC单端口发生断路故障时,将会影响其他2个端口的功率传输,为此,分析了九边形MMC和等效六边形MMC的工作原理、数学模型和桥臂功率特性,提出了一种九边形MMC单端口断路故障时的控制策略。所提控制策略在对应时间周期内为故障端口顶点所连2桥臂的H桥单元分配H桥单元脉冲信号和恒定脉冲信号以实现其交替运行,从而使九边形MMC在单端口断路故障下可等效为六边形MMC不间断运行。最后,分别在Matlab/Simulink和RTLAB仿真实验平台搭建仿真模型进行验证,结果表明:在九边形MMC单端口断路的情况下,所提控制策略实现了九边形MMC其他2个端口功率的正常传输,端口电压、电流迅速过渡并稳定到新的状态。As a three-port direct AC-AC converter,the nonagonal modular multilevel converter(MMC)has the characteristics of high compactness and good low frequency performance.When an open circuit fault occurs on a single port of the nonagonal MMC,the power transmission of the other two ports will be affected.To solve this problem,this paper analyzes the working principle,mathematical model and bridge arm power characteristics of the nonagonal MMC and the equivalent hexagonal MMC.Based on this,a control strategy is proposed for the single-port open-circuit fault of the nonagonal MMC.The proposed control strategy allocates the H-bridge unit pulse signal and constant pulse signal to the H-bridge unit of the two bridge arms,which are connected to the apex of the faulty port within the corresponding time period to realize its alternate operation,therefore,the nonagonal MMC can be operated under a single-port open circuit fault working temporarily as a hexagonal MMC.Finally,simulation models were built on Matlab/Simulink and RTLAB simulation experimental platforms to verify the results.The results show that,on condition that a single port of the nonagonal MMC is open,the proposed control strategy realizes the normal transmission of the power of the other two ports of the nonagonal MMC,and the port voltage and the port current quickly transit and stabilize to a new state.

关 键 词：分布式发电 级联多电平 多端口变换器 功率分析 功率控制 减端口运行 

分 类 号：TM46[电气工程—电器]