Ground Fault Analysis and Grounding Design Considerations in DC Microgrids

Low voltage DC microgrids (DCMGs) are future power systems to meet the increasing energy demand and solve problems caused by conventional power systems. Although DCMGs have some clear advantages over AC microgrids, several DCMG issues are still open for study. DCMG system grounding is such an issue, and realizing a suitable grounding scheme would accelerate the integration of DCMGs to the utility network. To design suitable grounding and protection scheme for DCMGs, it is important to determine transient and steady state ground fault characteristics of the system. In this paper ground faults with different grounding configurations are simulated (PSCAD/EMTDC) and results are analyzed to identify grounding configurations and ground fault detection schemes, which enables reliable fault detection and uninterrupted supply to the loads.