DC system fault monitoring device and method

The embodiment of the invention discloses a DC system fault monitoring device and method. The DC system fault monitoring device comprises a leakage current acquisition system used for acquiring leakage current original data of each loop in a DC system; a voltage-to-ground acquisition system, used for acquiring original voltage-to-ground data of a bus in the direct-current system; a data processingsystem, used for carrying out real-time processing on the leakage current original data and the ground voltage original data to generate leakage current data and ground voltage data and storing the leakage current data and the ground voltage data; and the data processing module being also used for determining a DC system fault and outputting leakage current data and voltage-to-ground data in a time period in which a fault occurrence time point is located after the DC system fault is determined. According to the embodiment of the invention, the problem that the existing fault monitoring devicecannot record the fault process data and thus the fault analysis is difficult is solved, the related data in the fault occurrence process can be provided, and the analysis of the fault point and thefault reason is facilitated.