A protection scheme for MMC–HVDC grid based on blocking time of converter station

•This paper proposes a local protection scheme based on the blocking time of the converter station for the flexible DC grid. Only the local fault data information is used in the scheme, and no communication is required.•This paper proposes a fault current processing method for inverter station and defines the virtual blocking time, which can well reflect the fault severity and is beneficial to the cooperation of protections.•This paper proposes a prediction method of bridge arm fault current based on moving data window, which can predict the current based on real-time updated fault data with high precision. The blocking time of the converter station can be accurately calculated in accordance with the blocking condition of converter station.•The scheme fully considers the cooperation between the protection action and the blocking of converter station, and realizes the removal of the fault line before the blocking of the converter station, which is conducive to the rapid recovery of the grid after the fault is cleared.