模块化多电平变换器的同相层叠PWM策略

Phase Disposition PWM Strategy for Modular Multilevel Converter

针对模块化多电平变换器(MMC)的底层控制策略,提出了同相层叠正弦脉宽调制算法(PD-SPWM)。首先,建立了MMC的控制模型,介绍了其运行特征;其次,从理论上分析了PD-SPWM算法的实现过程,并在此基础上,进一步提出了桥臂子模块电容电压平衡控制算法;最后,在1.5 MW的五电平MMC柔性直流输电(MMCHVDC)样机上进行了相应的实验。试验结果表明所提出的调制算法有效,且是综合性能最优的MMC调制算法。

It presented the algorithm of Phase Disposition Sinusoidal Pulse Width Modulation （PD-SPWM）, aiming at the apparatus-level controller of modular multilevel converter（MMC）. Firstly, it established a control model of MMC, and introduced its operating characteristics. Secondly, the implementation process of the PD-SPWM algorithm was theoretically analyzed, furthermore, the bridge submodule capacitor voltage balancing control strategy was proposed. At last, a series of tests were operated in the 5-level prototype. The test results show that the proposed modulation algorithm is effective, and has the best overall performance for MMC modulation.