Study On The Application Technology Ofoptical Fiber Current Sensor Based Onmagneto-optic Crystal

It is very difficult for the traditional current sensor to cope with the ever-increasing demands as the voltage,current,and capacity increase,as well as smart grid UHV transmission and other major projects.Optical fiber current sensor with its unique advantages has attracted great attention.This thesis summarizes the advantages and disadvantages of various current sensors,discusses and provides solution to some problems encountered in the practical application of fiber-optic current sensors based on Faraday magneto-optic effect.First of all,the underlying principle of fiber optic current sensor and its practical usage are discussed,particularly,a novel design of the optic current sensor is proposed to solve the inherent measurement inaccuracy associated with physical installation.Our novel optic current sensor design consists of two parallel or orthogonal optic current sensor heads,which can eliminate the inherent measurement inaccuracy associated with the physical alignment of the optic current sensor,including distance and angle.The experimental results show that this novel design can effectively eliminate the measurement inaccuracy caused by the uncertainty of the distance between the sensor head and the conductor to be measured.In addition,this thesis also studies the magnetic crosstalk effect between multi-conductor in the current measurement using optical fiber current sensor.To minimize magnetic crosstalk effect,the optimal solution of the sensor head and the magnetic shielding method are suggested.Theoretical analysis and experimental verification show that the reasonable adjustment of the distance between the sensor head and the wire and angle,so that it is in the best place to place the magnetic crosstalk error can be very good to improve the current measurement accuracy.In addition,the shielding ring on the magnetic crosstalk also has a certain weakening effect.In summary,this thesis provides a novel solution to the inherent measurement inaccuracy associated with the physical alignment of optic current sensor and magnetic crosstalk effect,which not only improves the measurement accuracy,but also makes it easier to install and use.The results are of great value to the application of fiber current sensor.