论文部分内容阅读
文章提出了一种新型的模块化多电平换流器拓扑结构,在中高压调速领域、交流柔性供电系统中有着广泛的应用前景.与传统的多电平换流器相比,其具有输出容量大、开关频率低(等于基波频率)、开关损耗小等优点.文章分析了模块化多电平拓扑结构的工作原理,并提出了一种基于采用最小谐波原则确定脉冲导通角度的基频开关调制策略,且给出了子模块电容电压平衡的控制方法;最后,基于Matlab软件平台搭建了一个11电平的模块化多电平换流器模型,验证了理论分析的有效性和正确性.“,”This paper presents a new modular multilevel converter(MMC) topology suitable for middle and high voltage converting systems and flexible AC transmission systems(FACTS).Compared to conventional multilevel converters,MMC has higher output and much lower switching frequency(50 Hz) resulting in lower switching losses.The operating principles of MMC topology is introduced,and a modified multilevel fundamental switching modulation scheme based on the minimization of total harmonic distortion(THD) is presented.A capacitor voltage balancing technique for the submodular unit is also proposed.The established simulation model of an 11-level MMC by Matlab software platform confirms the effectiveness and correctness of the modulation and balancing strategy presented in the paper.