Research on Measurement Technology of Ship Leakage Current by All-Fiber Optic Current Sensor

In this study, all-fiber optic current sensor is adapted to measure the leakage current of ships. The analytical model is built in a two-dimensional (2D) cartesian coordinate system. The magnetic field distribution of the weak current of a single long straight wire and the leakage current formed by two wires are modeled and simulated, respectively. In addition, the correctness of the analytical model is verified with the finite element method. An investigation is conducted on the conditions of the formula application of the all-fiber current sensor. According to the result, no magnetic field mutation, sensing fiber coil closure, transmission fiber insensitive to the magnetic field, and stable operation of the Verdet constant are demonstrated as the prerequisites for the combination of the Faraday effect and Ampere loop theorem. Lastly, the experiments are performed to verify the feasibility of the method proposed in this study. The sensor exhibits an accuracy of 1% and high linearity when the leakage current ranges from 1mA to 99mA.