张伟超 来永宝 赵洪 张立永 施云波

关键词：光纤传感;电流传感器;温度特性;校正函数;灵敏度分析

DOI：10.15938/j.emc.2019.06.000

中图分类号文献标志码：A 文章编号：1007 -449X（2019）06 -0000 -00

Abstract：To solve the problem that the sensitivity and accuracy of GMMFBG current sensor are affected by temperature influencing center wavelength of FBG and magnetostriction coefficient of GMM， the GMMFBG sensing model with temperature parameter is presented to calibrate current values. According to Faraday electromagnetic theory， the magnetic structure is designed to increase the magnetic coupling efficiency and homogenize magnetic distribution using finite element method （FEM）. Then， the experimental platform is constructed by using the wavelength demodulation system. At the temperature of 20 to 70 degrees Celsius， wavelength response amplitudes of the sensor are tested under different current value. The experimental results show that the sensitivity of GMMFBG current sensor decreases with the increase of temperature， and it is positive correlation to the target current. Analyzing the law of sensor response versus temperature， a GMMFBG sensing mathematical model with temperature compensation coefficient is established based on mathematical fitting method. Then， according to the modal， the current detecting accuracy is increased by 4.8% during measuring 60A current at the temperature of 40 ℃.

Keywords：optical fiber sensor; fiber current sensor; temperature characteristic; correction function; sensitivity analysing

0 引 言

隨着我国电力工业的高速发展，电流传感器在电能计量和监测领域起到了越来越重要的作用[1-2]，然而传统的电磁式电流传感器暴露出许多严重的缺点，难以满足当代高电压、大电流和强功率的电力系统需求[3-4]。因此，人们一直在寻找一种新型电流传感器以满足当前电力系统在线监测、故障高精确度诊断、电力数字网等发展的需要。光学电流传感器（optical current transducer，OCT）[5-6]因其本征绝缘，抗电磁干扰性能优异，更适于电力系统的电流量的计量和在线监测而受到关注。

目前文献报道的光学电流传感器主要有法拉第磁光效应方式，罗氏线圈光电混合方式和磁致伸缩效应结合光纤方式。法拉第磁光效应电流传感器光纤中的线性双折射、温度引起的精确度问题以及传感头老化问题一直是此类电流传感器实用化的最大障碍[7-8];罗氏线圈光电混合式的电流互感器在实际应用中仍受到环境电磁场、高压端电路电流供电等因素的影响[9];磁致伸缩式电流传感器主要采用超磁致伸缩材料（giant magnetostrictive material，GMM）做为磁应变敏感单元，通过在GMM上集成光纤布拉格光栅（fiber Bragg gratings，FBG）将磁场强度加载到调制光波中[10]，该种方式电流响应频带宽，灵敏度高，且在解调仪器配合下可以实现分布式测量，用于多点电流量同步监测成本相对较低，具有较好的工业应用前景。……