线性测量法拉第旋转角的新型OCT设计  

New Design of OCT with Faraday Rotation Angle Linear Measurement

作　　者：李超[1] 林韩[2] 徐启峰[1] 

机构地区：[1]福州大学电气工程与自动化学院,福州350108 [2]国网福建省电力有限公司,福州350003

出　　处：《电工技术学报》2015年第24期46-54,共9页Transactions of China Electrotechnical Society

基　　金：国家自然科学基金(51177016);国家电网公司科技项目(闽电发展[2012]88)资助

摘　　要：传统的光学电流传感器(OCT)基于法拉第磁光效应、马吕斯定律和偏振光光强解调模式,存在动态测量范围受到限制、非线性测量、易受线双折射和温漂等问题。通过提出一种基于会聚偏光干涉原理的新型OCT,将法拉第旋转角转换为干涉条纹的线性位移,用线阵CCD像机采集位移图样并由图像处理算法计算位移量,得到电流信号的实时数字量。采用磁光薄膜代替传统的磁光玻璃或磁光晶体,以降低线双折射对测量结果的影响。通过实验验证,新型OCT能够测量的法拉第旋转角达到±64.51°,线性度良好,并有效降低了线双折射和温漂的影响。Traditional optical current transducer is based on Faraday Magneto-Optic effect and Malus law. Its light intensity detection mode has some defects of small dynamic measurement range, big temperature drift, and linear birefringence. This paper presents a new type of optical current transducer based on convergent polarized light interference. It converts Faraday rotation angle to interference fringe’s displacement, and uses linear CCD camera to capture the image and calculate the displacement. Magneto-optical film is also used to reduce the impact of linear birefringence. The experiments show the new OCT is capable of measuring Faraday rotation angle up to ±64.51° with good linearity, and reduces the effects of linear birefringence and temperature drift.

关 键 词：光学电流传感器 法拉第旋转角 会聚偏光干涉 磁光薄膜 温漂 线双折射 

分 类 号：TM452[电气工程—电器]