光纤传输表面电流探头的设计与校准

Design and calibration of optical fiber transmission surface current probe

本文介绍了一种在强电磁场环境中用于检测表面电流强度的光纤传输表面电流探头。采用光纤代替传统的电缆传输,对强电磁场有很好的抗干扰作用,同时也大大减少了对周围空间场的扰乱。其核心的信号处理环节采用直接强度调制式光纤通信,即采用射频晶体管做前级放大,将电压信号转换为电流信号,对光电器件进行直接光强调制。该系统动态范围大,非线性失真小,带宽达到5～120 MHz,最大可测试电流为4 A。文中给出了光纤传输表面电流探头的校准测试实例以及传输阻抗曲线。

A surface current probe based on optical fiber transmission is introduced. It is made to measure surface current under strong electromagnetic field. Compared to traditional electric cable, optical fiber benefits from high immunity to strong electromagnetic interference and makes little disturbance to its surrounding area. By converting voltage to current with RF transistor, and modulating photo-electric component, the signal process is primary important. The system has wide dynamic range, little nonlinear distortion, wide pass band from 5 MHz to 120 MHz, and maximum measurable current of 4 A. The transfer impedance and calibration test of optical fiber transmission surface current probe are presented.