Research on AC transmission line fault ride-through control strategy of MMC-based unified power flow controller

In this paper, an AC transmission line fault ride-through control strategy is studied, which can quickly isolate the fault points and MMC-UPFC when an AC line fault occurs. After the fault is cleared, UPFC can also be re-put into normal operation quickly. Above all, the strategy can improve the reliability and the utilization of UPFC, and also can protect the security of UPFC.