Abstract：Modular multilevel converter (MMC) has been widely used due to its modularity, easy-to-expand structure and ideal sinusoidal output waveforms for high voltage direct current (HVDC) transmission. However, for high-voltage motor drive applications, MMC faces the problem of large capacitor voltage ripples at low speeds. A hybrid MMC (HMMC) topology has attracted attention because of its good capacitor voltage ripple suppression characteristics. This paper analyzes the characteristics of HMMC capacitor voltage ripple. The expressions of fundamental and second order components of capacitor voltage ripples are derived. Then the capacitor selection method is presented. In addition, from the aspects of the internal energy and circulation control of the HMMC and the external motor drive, this paper proposes an overall control method to efficiently and stably realize the high-voltage motor variable-frequency drives. The effectiveness of the proposed method is further verified by simulations and experiments.
周少泽, 李彬彬, 王景坤, 徐殿国. 改进型模块化多电平高压变频器及其控制方法[J]. 电工技术学报, 2018, 33(16): 3772-3781.
Zhou Shaoze, Li Binbin, Wang Jingkun, Xu Dianguo. A Hybrid Modular Multilevel High-Voltage Converter and Its Control Method. Transactions of China Electrotechnical Society, 2018, 33(16): 3772-3781.
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2018, Vol. 33 
