Fault current suppression method of MMC-HVDC DC side based on edge devices

Based on the analysis of various factors affecting the DC fault current, this paper proposes a current-limiting control strategy suitable for HB-MMC DC power grid, which utilizes the high controllability of the flexible DC power grid and presets the limit through the outer loop control command. The two links of the current and the adaptive current limiting based on the DC voltage change realize the current limiting of the DC side fault. The simulation results show that the current-limiting control strategy proposed in this paper can reduce the voltage fluctuation after the fault is removed, and can also ensure better current-limiting effect of DC current, AC current and bridge arm current. This research can be applied to a large number of edge computing devices to avoid equipment damage caused by abnormal current.