Optical Fiber Current Sensor Research

As the increase of the current and voltage, the traditional electromagnetic current transformer could not satisfy the requirements of the measurement. The fiber-optic current sensor was investigated for its unique advantages.The research achievements of the fiber-optic current sensor have been summarized in the paper. The reflective fiber-optic current sensor has been designed basing on the phase modulated type fiber-optic current sensor. The theory model of the reflective fiber-optic current sensor has been established using Jones matrix analyzing method and the proper devices have been chose.According to the characteristics of the sensor's output, signal processing circuits including photoelectric translating circuit, preamplifier, correlation detector, low-pass filter and ARM processor have been designed. The fundamental wave was changed into direct-current component through correlation detector, and then the direct-current component was separated by low-pass filter. At last, the AD conversion was completed by ARM processor to do signal processing and output displayThe simulation mode was established in the Matlab environment. The simulation analysis as well as the noise analysis was carried out. Finally, the analysis of the relationship between sensor's input and output was analyzed by using function-fitting method. The fitting coefficients and error were given and quadratic or quartic curve fitting was proposed.