A New Control Method for Rectifier Converter Station Suitable for Renewable Energy Access

The large-scale renewable energy generation sent through modular multilevel converter-high voltage direct current (MMC-HVDC) is one of the important development directions to help China build a new-typed power system with stronger renewable energy consumption capacity and reach the grand strategic objective of “carbon peaking, carbon neutralization”. However, a partial short-circuit fault of DC lines can easily influence the stable operation of the whole MMC-HVDC system, which severely hinder the development and engineering applications of the MMC-HVDC technology. One of the main reason for this is that, based on existing control strategies, the MMC is unable to provide feedback control for the DC current flowing through its DC output. In this regard, this paper breaks through the barriers of existing control strategies for MMC-HVDC systems and proposes a new control strategy, which enables feedback control of the MMC's DC output current, significantly improving MMC's ability to respond to DC faults, guaranteeing the safty and stability of MMC-HVDC system operation.