应用于MMC环流抑制的准PR控制器参数设计

Designing of parameters for quasi proportional-resonance controller applying to MMC circulation suppression

模块化多电平变流器(Modular Multilevel Converter,MMC)相间电压不平衡会导致其内部产生三相环流。为了抑制环流,文章首先建立MMC环流等效模型,并在静止坐标系下设计准PR控制器参数,分析准PR控制器参数对MMC环流抑制特性的影响。为了验证提出的MMC环流抑制策略,搭建了PSCAD/EMTDC仿真模型,并在35 k V·A五电平MMC样机上进行实验。结果表明,设计的准PR控制器能够有效地抑制MMC内部环流。

Modular Multilevel C onverter（MMC）phase-to-phase voltage imbalance results in internal generation of three-phase current. To restrain the circulation, an equivalent model of MMC circulation is firstly established, and the parameters of quasi PR controller are designed in the stationary coordinate system, and the influence of the parameters of quasi PR controller on the restraining characteristics of the MMC circulation is analyzed. In order to verify the proposed strategy, a PSCAD/ EMTDC simulation model is built and tested on the 35 kV-A five-level MMC prototype.The results show that the designed quasi PR controller can suppress the internal circulation of MMC effectively.