With the vigorous development of offshore wind power, submarine cables have become the core infrastructure for international communication and cross-ocean power transmission. However, frequent human activities in the near-sea area and the erosion of ocean currents can easily cause submarine cable faults and route deviations. The repair of submarine cable faults is difficult and time-consuming, and it relies on precise route data. To address the challenge of accurate route positioning, this paper conducts research on the detection and calculation of submarine cable routes based on magnetic field sensors. The research object of this paper is a 35kV XLPE submarine cable. Through theoretical derivation, two mathematical models for electromagnetic calculation of submarine cables are established. Based on high-precision three-axis magnetic field sensors, an active magnetic detection method and fault judgment method are proposed. An experimental scheme is designed, and an experimental test system is built. Under DC conditions, the spatial magnetic field distribution of the submarine cable is tested at fixed points and scanned along the trajectory. An empirical tangent method for data processing is proposed. The experimental test results verify the formula model, achieving route positioning and fault detection. It is indicated that the route points and fault points of submarine cables have obvious magnetic anomaly characteristics, providing certain practical application value for route positioning and fault detection in submarine cable engineering.

Submarine cables,weak magnetic detection,route detection,electromagnetic calculation