【作者】 张玲；

【导师】 鲍丙豪；

【作者基本信息】 江苏大学 ， 测试计量技术及仪器， 2009， 硕士

【摘要】 随着工业、农业、交通、国防事业的发展,用电量越来越大,电力工业在人民生活中起着越来越重要的作用,但是随着用电负荷越来越多,对电流检测提出了更高的要求,传统的电流传感器已经不能很好的满足当今工业技术发展的需要,导致电力故障频频出现。新型的光学电流传感器能够很好的弥补传统电流传感器的不足,因此被广泛的研究,成为未来电流测量的一个热点领域。光纤光栅是近年来飞速发展的一种新型光纤无源器件,具有成本低、重量轻、体积小、抗电磁干扰、易于实现分布式测量等特点而被广泛地应用于通信和传感领域,尤其是在电流传感领域中,各种结构的光纤光栅电流传感器不断涌现出来。本文回顾了近年来出现的各种光纤光栅电流传感器,比较和分析了它们的发展和存在的问题,在此基础上提出了一种将光纤布拉格光栅与超磁致伸缩材料Terfenol-D结合起来构成的光学电流传感器。Terfenol-D棒材在磁场中随待测电流的增加产生伸长,从而带动沿轴向粘贴在材料上的光纤布拉格光栅的光学参数发生变化,其中心波长发生偏移。在一定磁场范围内,中心波长偏移量与待测电流成较好的线性关系。因此可以通过测量光纤布拉格光栅的波长偏移量,来获得产生磁场的待测直流电流的大小。主要研究工作如下:1、研究了光纤布拉格光栅的光学特性和传感原理,建立了光纤布拉格光栅的应力和温度测量模型。2、研究了磁致伸缩效应的现象、产生的机理和磁致伸缩材料的特性,通过比较稀土超磁致伸缩材料和普通磁致伸缩材料的优缺点,选择稀土超磁致伸缩材料Terfenol-D作为光纤光栅电流传感器的传感媒介,确定了整个基于超磁致伸缩材料的光纤光栅电流传感器的研究方案。3、采用电阻应变法对超磁致伸缩材料的磁致伸缩系数进行测量,并且根据磁致伸缩材料的特性设计了预应力施加装置,从理论和实验上分析了施加应力对磁致伸缩材料性能的影响。4、设计并制作了将被测电流转换成对应磁场的硅钢磁芯线圈和产生偏置磁场的偏置磁芯线圈,实现了用多匝小电流产生的磁场模拟单根大电流直导线产生的磁场。5、设计了光纤光栅电流传感系统,包括传感头设计、磁回路设计、测量光路设计、偏置磁场设计和优化。6、完成光纤光栅电流传感器的数据测量,并对数据进行分析。更多还原

【Abstract】 With the fast developments of the industry,agriculture,transportation,and national defense,the power industry plays an increasingly important role in people’s living.However,higher requests are put forward to electric detection.The traditional current sensors can’t meet the requirements of recent industrial technology development and the power failures are appearing frequently with the increase of the electricity consumption.The optical current sensor can make up for the shortcomings of the traditional current sensors,and this field has been extensive researched.The optical current sensors have become a hot research field of current measurement.Fiber Bragg grating(FBG) is one of the most rapidly developed optical passive devices in recent years.FBG has the features of low cost,light weight,small size, anti-electromagnetic interference and can realize the distributed measured,so it has been widely applied in communication and sensing fields,especially in the field of current sensing.Various structures of fiber Bragg grating current sensors are emerging constantly.This essay reviewed the present situation of FBG current sensors,compared and analyzed their developments and existing problems.Based on this research,this paper proposed a new optical current sensor composed by combining FBG with the giant magnetostrictive material(GMM) Terfenol-D.The Terfenol-D rod was elongated in the magnetic field,and the strain caused the change of the optical parameters of FBG, which was stuck on the material along the axial direction.Thereby the center wavelength of FBG was shift.In certain biased magnetic field,the relationship between the measured current and the wavelength shift is linear.So the value of the current which produced the magnetic field can be got through measuring the center wavelength shift.The main research works are as following:1.The optical properties and sensing principles of FBG was studied,and the FBG temperature and stress model was established.2.The magnetostrictive phenomena,mechanism and material characteristics of the magnetostrictive material was studied.Compared the GMM Terfenol-D with other magnetostrictive material,Terfenol-D was chosen as sensor medium.The whole scheme of FBG current sensor based on GMM was designed on this basis.3.The magnetostriction coefficient of GMM was measured by the resistance strain gauges.The prestressed device was designed according to the characteristics of magnetostrictive materials.The effect of prestress impact on the properties of magnetostrictive materials was analyzed from the theory and the experiments.4.The silicon plate magnetic core coils which were used to change the measured current into magnetic field were designed and made.The magnetic field generated by one circle of great electric current was simulated by many circles of little current.5.The FBG current sensing system,including the sensing head,magnetic circuit, light path was designed and the bias magnetic field was designed and optimized.6.The data measurement of FBG current sensor was completed and analyzed.更多还原