【摘要】 近年来模块化多电平变换器在直流输电和电机驱动领域引起了广泛的关注。然而在电机驱动领域,输出低频时电容电压波动大的问题限制了其应用。提出了一种混合背靠背MMC拓扑,整流侧MMC采用全桥子模块和半桥子模块混合的结构,逆变侧MMC全部采用半桥子模块。分析了采用变直流母线电压的方法时电容电压的波动规律,并给出了系统的控制策略。电机在很大的转速范围内,电容电压波动基本恒定。最后,通过仿真验证了该拓扑结构及其控制策略的有效性。更多还原

【Abstract】 In recent years,modular multilevel converters has attracted extensive attention in the fields of direct current transmission and motor drives. However,in the field of motor drive,the large fluctuation of capacitor voltage at low output frequency limits its application. A hybrid back-to-back MMC topology is proposed. The rectifier side MMC adopts a hybrid structure of full-bridge submodules and half-bridge sub-modules,while the inverter side MMC adopts half-bridge sub-modules. The fluctuation law of capacitor voltage is analyzed when the DC bus voltage is changed,and the control strategy of the system is given. The voltage fluctuation of the capacitor is basically constant in large speed range of the motor. Finally,the effectiveness of the topology and its control strategy is verified by simulation.更多还原