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

Abstract

The all-fiber optic current sensor is applied to realize the measurement of the leakage current of ships. The analytical model is established in a two-dimensional 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. The correctness of the analytical model is verified by the finite element method. The conditions of the formula application of the all-fiber current sensor are studied. It is determined that no magnetic field mutation, sensing fiber coil closure, transmission fiber insensitive to the magnetic field, and stable operation of the Verdet constant are the prerequisites for the combination of the Faraday effect and Ampere loop theorem. Finally, the experiments are conducted to prove the feasibility of the proposed method. The sensor achieves an accuracy of 1% and good linearity when the leakage current is from 1mA to 99mA.

Research on the Dual Modulation of All-Fiber Optic Current Sensor

“…In a particular case, when the frequency multiplication factor is equal to the duty cycle of AOM while the frequency multiplication factor is an integer multiple of 0.1, the sensitivity and the resolution of AFOCS are 0.01063 mV/mA and 3 mA, respectively. The ratio error is less than 0.3%, which can meet the requirement of microcurrent measurement applications, such as partial discharge detection [13] and leakage detection [14].…”

Influence of Imperfect Faraday Rotation Mirror on All-Fiber Optic Current Sensor

“…As a potential substitute for the traditional electromagnetic current transformer in power industry, the all-fiber optic current sensor (AFOCS) has many advantages, e.g., immunity against electromagnetic interference, high sensitivity, wide dynamic range, measuring AC and DC simultaneous, light weight, and small size [6,7]. Due to these intrinsic advantages, AFOCS has been widely used in many electric current measurement fields, such as the electrolytic aluminium industry [8], high voltage direct current transmission system [9], international thermonuclear experimental reactor [10], and ship leakage current measurement [11].…”