A fault detection method for low-voltage DC distribution networks based on magnetic ring boundaries

In low-voltage DC (LVDC) distribution networks, the rapid current rise following line faults presents a significant technical challenge that impedes the widespread deployment of these networks, thereby necessitating fast and reliable fault detection methodologies. Equipping lines with magnetic ring boundaries to enable fault identification across the entire line using single-ended electrical measurements is a promising approach. This paper proposes a protection method based on the synchrosqueezed transform (SSST) through a comprehensive analysis of the distinctive characteristics exhibited by internal and external faults under the influence of magnetic ring boundaries. The proposed method achieves fault identification utilizing exclusively the summation of high-frequency voltage amplitudes. Extensive numerical simulations demonstrate that the proposed methodology reliably differentiates between internal and external faults while exhibiting robust tolerance to varying transition resistances.