Modelling and evaluation of low voltage DC circuit breaker for the protection of DC microgrid

DC microgrid has become a preferred choice over AC microgrid, due to the growth of critical DC loads and higher efficiency during power distribution. However, the transient behavior of DC microgrid is more severe than AC microgrid, which makes the correct DC Circuit Breaker (DCCB) selection very important. In this research paper, we have proposed an evaluation method to select a commercially available DCCB by using simulation results of the stresses subjected to DCCB in low voltage DC microgrid (LVDCM). A LVDCM having AC utility grid, photovoltaic (PV) and battery-storage was modeled. A DCCB model using Schwarz's Black Box arc model was applied in the LVDCM, and its parameters were determined by using parameter sweep method. Voltage and current stresses subjected to DCCBs were analyzed and compared with DCCB's capability based on its datasheet. An appropriate DCCB was selected by comparing the voltage and current stresses with DCCB's datasheet limit.