Estimation of short circuit currents in mesh DC networks

DC power systems, such as DC microgrids, DC datacenters, and HVDC systems, are emerging technologies in recent years. Short circuit current calculation is essential to study the protection and safety issues for DC systems. The time domain simulation for detailed fault analysis contains detail dynamic system models with controllers and thus requires high modeling efforts and computational complexity for fault analysis. This paper extends the short circuit current approximation method in IEC61660 to mesh DC systems with improvements. The accuracy of the proposed method is verified by comparing with fault simulation results of a LVDC system. This DC short circuit current calculation can also be implemented to conservatively estimate arc flash incident energy for DC safety study.