便携式光纤电流互感器传感头设计

针对电解铝工业中大电流测量现场环境复杂的难题,在传统光纤电流互感器的基础上提出一种便携式光纤电流互感器.对设计安装过程中由于柔性传感头光路不闭合和导体偏心引起的法拉第相移误差进行分析和有限元仿真计算,结果表明:法拉第相移相对误差随传感头不闭合度角度线性增加,随导体到非闭合点的距离增大而减小,且增加传感头匝数能减小法拉第相移误差.由于便携式光纤电流互感器准确度随导体到非闭合点的距离增大而提高,设计了一种使传感头非闭合点向一端延伸且易拆装的结构,实验测试得到该便携式光纤电流互感器的全温准确度为0.86%,满足电解铝厂准确度1%的使用要求.

Design of a Sensing Coil in Portable Fiber Optic Current Transformer

To deal with the problem of complex large current measurement site in electrolytic aluminum industry,a portable fiberoptic current transformer was proposed on the basis of the traditional fiber opticcurrent transformerin.The Faraday phase shift error which caused by the flexible sensing coil nonclosed optical path and current conductor eccentric position in the process of design and installation was analyzed and calculated by finite element method.It has been obtained that the Faraday phase shift relative error increases linearly with the non-closed angle of sensing coil and decreases with the increasing distance between conductor and the non-closed point,and the Faraday phase shift relative error can be decreased by increasing number of turns.Based the accuracy of portable fiberoptic current transformer increases with the distance between conductor and the non-closed point,a sensor head structure with the extending non-closed point and easy accessibility was designed,it has been obtained that the full temperature accuracy is 0.86％ of portable fiberoptic current transformer by experimental test,which meets the required accuracy 1％ in smelter.