基于投切状态矩阵的MMC系统电容电压均衡策略  

Capacitor Voltage Equalization Strategy of MMC System Based on Switching State Matrix

作　　者：余雪 刘开培[1] 周怿源 秦亮[1] YU Xue;LIU Kaipei;ZHOU Yiyuan;QIN Liang(School of Electrical Engineering and Automation,Wuhan University,Wuhan 430072,China)

机构地区：[1]武汉大学电气与自动化学院,武汉430072

出　　处：《高电压技术》2023年第3期1314-1325,共12页High Voltage Engineering

基　　金：国家自然科学基金面上项目(51977160)。

摘　　要：为了奠定模块化多电平换流器(modular multilevel converter,MMC)自平衡的理论依据,构建了MMC状态空间模型,证明了MMC电容电压的一致渐进稳定性。研究了MMC电容电压非均衡状态下的静态工作点,揭示了投切状态矩阵的秩和MMC电容电压静态工作点之间的关联。基于投切状态矩阵自平衡理论,针对控制频率较低或子模块数量较多时轮换速度慢的问题,提出了一种基于投切状态矩阵分组轮换的电容电压均衡控制策略,能够有效降低电容电压的波动率。最后,在Matlab/Simulink中搭建了MMC电磁暂态仿真模型,验证了所证结论的正确性和所提方法的有效性。In order to establish the theoretical basis of self balancing of modular multilevel converter(MMC),the MMC state space model is constructed,and the uniform asymptotic stability of MMC capacitor voltage is proved.The static op-erating point of MMC capacitor voltage under unbalanced state is studied,and the correlation between the rank of switching state matrix and the static operating point of MMC capacitor voltage is revealed.Based on the self balancing theory of switching state matrix,to solve the problem of slow rotation speed when the control frequency is low or the number of sub modules is large,a capacitor voltage balancing control strategy based on grouping rotation of switching state matrix is proposed,which can effectively reduce the fluctuation rate of capacitor voltage.Finally,the MMC electro-magnetic transient simulation model is built in Matlab/Simulink to verify the correctness of the verified conclusions and the effectiveness of the proposed method.

关 键 词：模块化多电平变流器 一致渐进稳定性 静态工作点 电容电压均衡 投切状态矩阵 分组轮换 

分 类 号：TM46[电气工程—电器]