Application of Filter Capacitor Dynamics Based Short-Circuit Fault Detection Method in Ring-Type DC Microgrid

A healthy grid always needs precise and fast isolation because this makes the system reliable and improve the power quality. To achieve this, a short-circuit fault detection method is presented for low-voltage ring-type dc microgrid. This method uses the current dynamics of filter capacitors to identify the faulty zone. Along with fault identification, a fault isolation process is also explained decently. In the considered ring- type architecture, active sources, such as ac grid, battery, and solar photovoltaic, are connected to a common dc link via power converters. The proposed method considers an averaged capacitor current as a detection parameter. Additionally, a criterion for thresholds selection is also given in detail. The presented work is validated through both digital simulation and experimental studies. All the results assure that the proposed concept can detect and isolate the fault cable within 1.98 ms.