Fault Detection and Isolation in Low-Voltage DC-Bus Microgrid System

Rationale for the use of DC microgrids: feasibility, efficiency and protection analysis

“…Accordingly, different studies have designed effective methods to address the preceding problems. This study highlights current techniques and devices presented in Park and Candelaria [15]. Avoiding any protection system in the DC circuit and using protection devices (i.e., circuit breakers and fuses) in the AC side once the fault happens are the simplest and commonly used protection techniques.…”

“…The main problem associated with these methods is de-energizing the whole DC power system from fault detection to removal. Furthermore, these techniques are not appropriate for a purely DC-powered microgrid, where the DC is used in transmitting power from the AC generation units to the loads [15,16]. Another method of protecting the system from excessive fault current is by limiting the bus current under fault conditions.…”

“…The advantages of limiting the fault current include a ride through for temporary faults, safe operation of the switchgear, and low-cost system by switchgear capacity reduction. Several devices (e.g., superconductor saturated inductors and power electronic devices) have been utilized to limit the fault current [15,17,18].…”

“…The gate turn-off thyristor (GTO) block the high voltage in off state and has low voltage drop in on state. However, the deficiency of the GTO appears in high-frequency switching [15].…”

“…The drawback of fuses and MCCBs is that neither conducts an autonomous control, albeit this problem solved in MCCBs. Human intervention is required in the event of a fault to re-energize the system once the fault has been removed [15].…”