Research on high-impedance fault diagnosis and location method for mesh topology constant current remote power supply system in cabled underwater information networks

Cabled underwater information networks (CUINs) have evolved over the last decade to provide abundant power and broad bandwidth communication to enable marine science. To ensure reliable operation of the CUINs, the technology for high-impedance fault diagnosis and isolation with high reliability and accuracy is essential. In this paper, we review diagnosis and location methods as applied to a constant voltage ring and the tree topology network. A high-impedance fault diagnosis method based on the variation of the sampling voltage in the primary nodes (PNs) for a constant current remote power supply system is proposed. The methods for analyzing the fault voltage with using power monitoring and control system (PMACS) and communications monitoring, control system (CMACS), and hybrid detection with alternating current and direct current are used for research the high-impedance fault location based on the designed fault isolation circuit. In particular, a verification scheme for high-impedance fault location is designed for the CUINs based on the classical mesh topology. Furthermore, high-impedance faults of nodes and submarine cable sections in the trunk cable are simulated, and the variations of leakage voltage are analyzed. By researching the change of leakage voltage before and after the fault occurs, the feasibility and practicability of the diagnosis and location scheme are verified.