Fault Ride Through in DC Microgrid with Faster Recovery

Breaking of fault current in dc microgrid has been a challenge due to lack of dc current zero crossing. The fault current in case of pole to pole fault is high and even higher in the presence of multiple generators as all the generators feed current to the fault. This results in very high current in the faulted line. Clearing such high fault current is difficult. Many methods have been proposed in literature to maintain low current during fault for ease of fault clearing. This paper presents a fault ride through (FRT) techniques for the generator to limit the current fed during fault. The proposed FRT scheme limits the fault current to a minimum value by feeding a minimum current into the network. The minimum current is derived based on the characteristics of the source and operating strategies of converter. The proposed FRT scheme ensures fast recovery of the network voltage. The proposed FRT scheme is verified through detailed simulations in Simulink.