半全桥子模块混合型柔性直流换流阀的充电策略研究与样机实验验证

Charging Strategy for Hybrid-MMC Valve Composed of HBSM and FBSM with Experimental Verification

介绍了基于半桥和全桥子模块构建的混合型柔性直流输电换流阀的拓扑结构特点和在不控充电阶段中的子模块电压分布;分析了半桥子模块存在充电电压较低导致的取能失败及充电不成功的问题;提出了一种用于混合型柔直换流阀的充电策略,并搭建了±10kV/60MW半全桥混合型模块化多电平换流阀样机对该策略进行验证。实验结果表明,该充电策略可以有效解决基于半桥和全桥子模块构建的混合型柔直换流阀充电过程中半桥子模块自取能失败问题。

The topology and the voltage distribution of hybrid modular multilevel converter( MMC ) composed of fullbridge sub-module( FBSM) and half-bridge sub-module ( HBSM) in uncontrollable charging stage are introduced, and the charging failure phenomenon of the hybrid-MMC valve is analyzed. A new charging strategy is proposed for the hybrid- MMC valve. And a±10 kV/60 MW hybrid-MMC system is built for verifying the charging strategy. Experimental results show that the charging failure problem of the hybrid-MMC valve could be solved by the new charging strategy.