基于全半桥混连拓扑换流阀的交流侧可控充电方法

The controllable AC side charging method for modular multilevel converter based on full and half bridge hybrid topology

全半桥混连拓扑换流阀在交流不控充电时全半桥模块电压不一致,通过对全半桥混连拓扑换流阀中全桥和半桥模块工作原理以及交流不控充电过程分析,本文提出了一种基于模块化多电平结构的全半桥混连拓扑换流阀交流侧可控充电方法。该方法通过可控充电提高模块的平均电压,并保持桥臂内所有模块的电压平衡。搭建了基于全半桥混连拓扑的MMC柔性直流输电PSCAD仿真模型,验证了所提出方法的正确性和有效性。

Voltage difference between full bridge and half bridge submodules in hybrid topology based converter is critical during AC non-controlled charging process. The working principle of full bridge and half bridge module in hybrid topology converter and the process of AC non-controlled charging are analyzed. A controllable AC side charging method for modular multi-level converter based on full and half bridge hybrid topology is proposed which can improve the average voltage of the modules by controllable charging strategy, maintaining the voltage balance of all the modules in the arm. Finally, PSCAD simulation model based on cell-hybrid MMC-HVDC was set up, and the simulation results prove the correctness and effectiveness of the proposed strategy.