应用于电网谐波补偿的MMC多重准谐振控制

MMC Multiple Quasi-resonant Control Strategy for Harmonic Compensation in Power Grid

为改善中压配网的电能质量,提出了一种基于超级电容储能的模块化串联型多电平变流器(S-MMC-SC),通过在直流母线配置超级电容器作为储能单元,结合串联型多电平变换器实现对中压配网电能质量治理。此处详细讨论了S-MMC-SC整体控制流程,以及基于多重准比例谐振(PR)控制的谐波补偿分量跟踪方法,给出了S-MMC-SC超级电容相间均压与各相各模块均压控制策略。最后分别通过系统仿真与原理样机实验表明,含超级电容的串联型模块换变流器兼具补偿系统电压暂降、补偿负载谐波和无功电流的功能。该研究成果可为在中压侧进行电能质量综合治理提供一种有效的技术途径。

In order to improve the power quality of medium voltage distribution network,a modular shunt multi-level converter based on super capacitor energy storage(S-MMC-SC)is proposed,which can control the power quality of medium voltage distribution network by configuring super capacitor as energy storage unit in DC bus and combining with shunt multi-level converter.The overall control flow of S-MMC-SC is discussed in detail,As well as the harmonic compensation component tracking method based on multiple quasi-proportional resonance(PR)control,and the control strategy of voltage equalized between phases of S-MMC-SC super-capacitor and voltage equalized in each phase and module of each phase is given.Finally,the system simulation and principle prototype experiments show that the converter with super capacitor can compensate the voltage sag of the system and the harmonic and reactive current of the load.The research results can provide an effective technical approach for comprehensive power quality management in medium voltage side.