An On-line Fault Location Technique for DC Microgrid Using Transient Measurements

Locating faults in meshed dc microgrids poses challenges due to low impedance offered by the de network. In this paper, an on-line fault location scheme which can he implemented as an additional feature in a relay is proposed. The algorithm is developed to determine fault location based on voltage and current transients. Both line to line and monopole ground faults are analysed separately and algorithms are developed based on the rate of change of current. Direct short circuit faults are located using transient measurements captured locally, while communication based technique is utilized to locate the impedance faults. The developed fault location technique is also capable of estimating the fault resistance accurately. The algorithm is validated on a +/- 600 V meshed dc grid, for both the types of faults under wide range of fault impedance at different fault locations.