DC/DC/AC混合型MMC变换器控制策略分析与设计

Analysis and Design of Control Strategy for DC/DC/AC MMC Converter

研究了一种可以实现电能不同形式综合利用的DC/DC/AC混合型模块化多电平变换器(MMC),该结构的变换器实现了电压变换功能的多样化。首先,分析了该种可以同时实现DC/DC与DC/AC混合电压变换的模块化多电平变换器拓扑结构;然后,利用功率正交原理,设计了DC/DC/AC混合型模块化多电平变换器的闭环控制策略;最后,在给定交流负载侧交流电流的前提下,实现了各个桥臂子模块电容电压的均衡控制。仿真结果验证了所提出的DC/DC/AC混合型模块化多电平变换器电压变换功能的可行性以及控制策略的有效性。

A novel DC/DC/AC converter based on modular multilevel is studied, which can not only realize comprehensive utilization of different forms of electrical energy, but also achieve the function of converter voltage transform diversification. First, this paper analyzes the topologies of the converter based on modular multilevel which can simultaneously realize DC/DC and DC/AC hybrid voltage transform. Then, according to the power orthogonal principle, this paper designs a closed loop control strategy of DC/DC/AC converter. Finally, on the premise of a given current of AC load side, the capacitor voltage balance of each bridge arm is implemented. The simulation results validate the voltage transformation function of the DC/DC/AC hybrid converter based on modular multilevel and the feasibility of the control strategy is effective.