Coordinated Control Strategy for Power Imbalance in Bipolar MMC-HVDC

With the rapid development of MMC-HVDC technology, bipolar MMC-HVDC system will receive more and more attention. The types of power imbalance problems are more diverse in bipolar islanded large-scale renewable energy transmission system, which puts forward higher requirements for fault ride-through under AC and DC faults. Therefore, this paper considers these three kinds of power imbalance problems the fault ride-through problem of non-fault pole MMC over-current, DC overvoltage and DC overcurrent of bipolar system, and considers the cooperation of AC Chopper and bipolar converter control strategy to achieve the fault ride-through (FRT) of these three kinds of power imbalance problems.