FBG电流互感器非线性校正系统研究

为了提高电流互感器的测量精度,减小相位误差 ,研究了基于现场可编程门阵列(FPGA)的光纤光栅(FBG)电流互感器非线性校正系统,分析 了超磁致伸缩材料GMM,giant magnetostrictive material)的 磁滞特性,采用参数可变曲线拟合法实现数据的非线性校正处理。通过FP GA完成数据采集、 滤波、缓存、分频、校正处理和数据转换等单元的设计,实现了对电流互感器输出信号的实 时非线性校正,减小了GMM的磁滞特性对FBG电流互感器的影响,使电流互感器的 相位误差由7°降为1°,幅度误差小于1%,提高了电流测试系统的测量精度。

Research on nonlinear correction system for FBG current transformer

The nonlinear correction system of the fiber Bragg grating (FBG) current transfo rmer based on field-p rogrammable gate array (FPGA) is studied in order to improve the measurement pre cision of the curren t transformer and reduce the phase error.This paper analyzes the hy steresis characteristics of the giant magnetostrictive material (GMM).Vari able parameter curve fitting method is adopted to realize the nonlinear correct ion of data processing.In order to rachieve the real-time nonlinear corre ction o f the current transformer output and reduce the hysteresis characteristics influ ence of GMM m aterials on FBG current transformer,data collecting,filtering,cachi ng,frequency division,correction processing and data conversion are all comp leted by FPGA.By use of the correction unit,the phase error of current transfo rmer is reduced from 7° to 1°,the amplitude error is less than 1%,so the measuring accuracy of the current test system is improved.