配电网电压不平衡时MMC控制策略研究

Research on MMC Control Strategy When the Distribution Network Voltage is Unbalanced

基于柔直技术的交直流混合配电网在促进配电网低碳化转型、提升供电可靠性等方面具有显著优势。模块化多电平变换器(MMC)具有扩展能力强、输出电压等级高等优势,为构建多电压等级、多层次、交直流混联的配电网提供有效的解决方案。结合我国配电网70%以上的故障是由电压不平衡所导致的现状,展开配电网电压不平衡时MMC控制策略的研究有广阔的学术研究意义和工程应用价值。因此,在理论分析的基础上利用PSCAD仿真软件和RTDS半实物平台搭建电网电压不平衡时的仿真模型,验证了所研究的电压不平衡时MMC控制策略的有效性。

The AC/DC hybrid distribution network based on the VSC-HVDC has significant advantages in promoting the low-carbon transformation and improving the reliability of power supply.Modular multi-level converter(MMC)has the advantages of strong expandability and high output voltage level,and provides an effective solution for building a multi-voltage level,multi-level,AC/DC hybrid distribution network.Combining with the current situation that more than70%of the faults in distribution network are caused by voltage imbalance,the research on the MMC control strategy when the distribution network voltage is unbalanced has broad academic research significance and engineering application value.Therefore,based on the theoretical analysis,PSCAD simulation software and RTDS semi-physical platform are used to build a simulation model when the network voltage is unbalanced to verify the effectiveness of the MMC control strategy when the voltage is unbalanced.