适用于HVDC和HVAC高效稳定互联的MMC双端口电网形成控制

MMC Dual-port Grid-forming Control for Efficient and Stable Interconnection of HVDC and HVAC

针对不同类型电网互联时互联电力变换器IPC(interconnecting power converter)控制模式复杂、控制难度大等问题,提出一种用于互联多个高压直流和高压交流子电网的IPC新型电网形成GFM(grid-forming)控制方法。该方法利用模块化多电平变换器MMC(modular multilevel converter)同时控制其AC和DC端电压,并提出2个双端口GFM MMC控制策略。针对单端口GFM控制和所提双端口GFM控制进行仿真对比,结果表明,与单端口GFM控制相比,双端口GFM控制方法对突发事件(如线路和发电机停运等)的处理更具弹性,且不需为电网中的IPC端口选择GFM或电网跟随GFL(grid-following)的控制方式。

Aimed at the problem that the control modes of interconnecting power converters(IPCs)are complicated to assign and difficult to control when different types of power grids are connected,a novel grid-forming(GFM)control method for IPCs that interconnect high voltage direct current(HVDC)and high voltage alternating current(HVAC)sub-grids is proposed.This method uses modular multilevel converters(MMCs)to control AC and DC terminals simultaneously.In addition,two dual-port GFM MMC control strategies are put forward.Finally,a simulation comparison between single-port GFM control and the proposed two-port GFM control is performed.Results show that compared with the single-port GFM control,the two-port GFM control method is more flexible to emergencies(i.e.,line and generator outage),and there is no need to choose the control mode of GFM or grid-following(GFL)for IPC ports in the power grid.