摘要
模块化多电平换流器MMC(modular multilevel converter)采用传统载波移相脉宽调制策略时附加的子模块电容电压平衡策略,会导致MMC每相电路中投入的子模块数量出现高频跳动。因此,桥臂电感上会出现很大的感应脉冲电压,进而产生较高频率的环流谐波,从而增加元器件的电压和电流应力。在研究传统载波移相调制策略及其在MMC中应用问题的基础上,对其实现过程进行改进,以保证在任意时刻MMC每相电路中投入的子模块数量恒定,从而避免上述问题。对所提改进载波移相调制策略进行详细分析,并给出相应的电容电压平衡控制策略。仿真和实验结果表明,采用改进载波移相调制策略后,桥臂环流幅值得到降低。
When a modular multilevel converter(MMC)adopts the traditional carrier phase-shifted pulse width modulation strategy,the additional capacitor voltage balance strategy for submodules will cause the number of submodules in each phase circuit of the MMC to jump at a high frequency.Therefore,a large induced pulse voltage will appear on the inductance of the bridge arm,which will generate a high-frequency harmonic circulating current,thereby increasing the voltage and current stress of components.Based on the study of the traditional carrier phase-shifted modulation strategy and its application to the MMC,the implementation process is improved to ensure that the number of submodules in each phase circuit of the MMC is constant at any time,so as to avoid the above problems.The improved carrier phase-shifted modulation strategy is analyzed in detail,and the corresponding capacitor voltage balance control strategy is given.Simulation and experimental results show that the circulating current amplitude of the bridge arm is reduced after adopting the improved carrier phase-shifted modulation strategy.
作者
董一诺
白志红
DONG Yinuo;BAI Zhihong(College of Electrical Engineering,Zhejiang University,Hangzhou 310027,China)
出处
《电源学报》
北大核心
2025年第2期96-104,共9页
Journal of Power Supply
基金
国家自然科学基金资助项目(51877194)。
关键词
模块化多电平换流器
载波移相调制
电容电压平衡
高次环流抑制
Modular multilevel converter(MMC)
carrier phase-shifted modulation
capacitor voltage balance
high-order circulating current suppression
