Detection of Fault Inception in a Low Voltage DC Microgrid using Current Differential Protection Method

DC microgrids have gained more attention over the last few years as they have several advantages compared to AC microgrids as it is more reliable, efficient, easy control structure, interconnection of Renewable Energy Sources (RES) and DC loads. In spite of the numerous advantages, designing and implementing an efficient and effective protection scheme for DC microgrids is still an obstacle. The challenge comes from the rapidly rising fault current within few microseconds (upto 17 A/μsec) which has to be quenched off in the non-existence of naturally occurring zero crossing, time constant for control and protection operation are very close and lack of existing guidelines and standards in DC protection. In this paper a LV DC microgrid (DCMG) of 600 V is developed and current differential protection method is implemented to detect the fault and provide operating signal to Solid State Circuit Breaker (SSCB) to isolate the faulty section. The simulation is carried out in MATLAB/SIMULINK environment.