An Accurate Noniterative Fault-Location Technique for Low-Voltage DC Microgrid

The least erroneous knowledge on fault location in distribution systems helps the restoration process, expedites maintenance, and reduces power outage duration. A fault-location method using the probe power unit (PPU) in dc microgrid assumes that the natural frequency of the system is equal to the damped resonant frequency of probe current. This assumption leads to prominent error in fault-location calculation. To estimate the location of fault in the low-voltage dc microgrid system, a noniterative fault-location technique using PPU is proposed in this paper. Considering damping frequency and attenuation of the probe current, which is a function of fault distance and damping coefficient, the fault location is obtained. The technique is tested for high-resistance fault as well as radial and looped topologies and is found to be more accurate.