模块化多电平变换器模型预测控制策略研究

摘要

模块化多电平变换器(MMC)因其具有公共直流母线的模块化拓扑结构的特点而被广泛应用于高压直流输电、电能质量治理以及电气传动等领域.分析MMC拓扑结构,建立MMC数学模型,研究MMC运行控制规律;对MMC内部环流产生机理进行分析,推导了桥臂电流与内部环流的关系;分析了MMC模型预测控制策略.最后通过实验验证了模型预测控制策略能更有效地控制子模块电容电压平衡,减小环流幅值.%Modular multilevel converter (MMC)has been widely applied into HVDC,power quality control,electric drive and other fields due to its characteristic of modular topology of common DC bus.Topology structures of MMC were introduced,and then mathematical models of MMC were established as well as its regulation of operation control.The mechanism,quality and functions of circulation formation were analyzed.The relationship between current of bridge arm and circulating current was deduced.The model predictive control strategy of MMC was analyzed and the experimental results show that sub-module capacitor voltage is balanced and the circulating current amplitude is decreased effectively under the adopted control strategy.