The circulating current existing in modular multilevel converter（MMC） affects MMC’s stable operation and increases the loss simultaneously. For suppressing circulating current

the relationship between the voltage drop of arm inductance and circulating current is analyzed firstly. On this basis

MMC circulating suppression method based on hysteresis control is proposed. This method can be able to control independently the circulating current of each phase without additional hardware

change variation direction of circulating current by increasing or decreasing the number of inserted sub-modules to limit the circulating current within the permitted range and acting as suppressing the circulating current. Three phase MMC simulation model is set up in Simulink and the circulating current suppression method proposed in this paper is verified. It is shown by the result that the method can suppress effectively the internal circulating current of MMC.