The half-bridge modular multilevel converter(MMC)used in existing flexible high voltage direct current(HVDC)projects has high economic benefits

but no ability of DC fault clearance. This paper introduces a kind of arm damping fault recovery system with the ability of DC fault clearance. A strategy of the fault recovery system is proposed

which uses a mono-polar and bipolar fault line selection strategy to select the fault line. And arm damping and resonance-switch is adopted to achieve fault current fast inhibition and fault line isolation

respectively. By using the proposed strategy

the healthy system can resume operation in the shortest possible time. To verify the effectiveness of the fault recovery strategy

a five terminal flexible HVDC model is built using PSCAD/EMTDC. Simulation results show the feasibility and effectiveness of the proposed fault recovery scheme. This work is supported by State Grid Corporation of China.