Distributed earth fault detection method for low voltage distribution networks using phase voltage synchronization

This is the authors' abstract. We don't add key points for this paper.

The existing earth fault detection methods for low-voltage distribution networks demonstrate poor adaptability to faults with fault resistance. To address this problem, the composition of residual current during non-fault states and its impact on earth fault detection are analysed. A distributed earth fault detection method is then proposed. This method divides a low-voltage distribution network into multiple protection zones and uses the differential residual current of each protection zone to identify earth faults, effectively reducing the impact of residual current during non-fault states. Furthermore, a time synchronization technique using phase voltage as a reference is proposed, which achieves low-cost time synchronization without relying on external clocks. The effectiveness of the proposed method is verified by simulations and field tests in an actual low-voltage platform. Compared with conventional approaches, the proposed method exhibits significant enhancements in both sensitivity and reliability.