Detection of high impedance faults on compensated distribution networks

Compensated distribution networks (CDNs) reduce the magnitude of fault current for single phase-to-ground (SPG) faults. Under SPG fault conditions, CDNs boast the advantages of improved reliability and a reduction in the risk of these faults igniting bushfires. Despite these benefits, the main challenge of detecting and localizing SPG faults with high impedance persists on these networks. This paper offers a new algorithm for detecting SPG high-impedance faults (HIFs) on CDNs. The algorithm utilizes both the neutral voltage (VN) displacement and negative sequence currents (I2) present during the network unbalance introduced by SPG faults. The proposed algorithm is capable of detecting HIFs on the system and localizing the fault at the feeder level, an alternative to the lengthy line patrols currently required to locate and isolate HIFs, thereby reducing the contribution of faulted electrical infrastructure in bushfire ignition. The algorithm is designed specifically for HIFs with a fault impedance exceeding 20k and has been tested and evaluated on a simulated CDN. Simulation results demonstrate the capability of the proposed algorithm to detect and localize transient and permanent SPG HIFs.