Ground Fault Location Using the Low-Voltage-Side Recorded Data in Distribution Systems

Ground fault location and isolation are challenging in compensated distribution systems due to the fact that the fault current is too small to be measured. Considering that massive intelligent electronic devices and "smart meter" are installed in the distribution networks with the development of the "smart grid," this paper proposes a fault location method using the low-voltage-side smart metering unit recorded data. The developed method uses the faulted negative-sequence voltage and locates the faulted sections by applying the relationship between fault distance and the clustered measurement groups. The method is tested using multibranched distribution systems, and results show that it is suitable for systems with both passive loads and distributed generations and not influenced by the system harmonic distortions, measurement noises, and loss of communication from one or even more of the metering units. The proposed method uses the wide-area measured data but does not require any synchronization. Accompanied with the low-cost contactors, the method can locate and isolate the fault sections without interrupting the healthy system operations, and this makes it feasible for industry application.