配电网混合型 MMC 双极短路故障后快速恢复策略

The rapid recovery technology after fault clearing based on modular multilevel converter is an important research content of flexible DC power distribution technology. For the sub⁃module hybrid MMC,a bridge arm overcurrent suppression strategy is proposed to avoid the occurrence of secondary overcurrent of the bridge arm,so that the unlocking process could be carried out stably and reliably;at the same time,a fast sub⁃module capacitor voltage equalization method based on bridge arm current feedforward is studied. The recovery control could also ensure that the capacitor voltage of the sub⁃module of the bridge arm is quickly stabilized to the rated value when the converter is unlocked,which greatly improves the recovery speed of the converter. Finally,a single⁃ended hybrid MMC simulation model is built in MATLAB/ Simulink to verify the effectiveness and feasibility of the proposed control method.