基于锁相放大器的光纤电流互感器研究

为了测试光纤电流互感器中由于Faraday效应引起的旋转量，提出了采用锁相放大器处理信号的方法，改进了传统的将交流成分与直流成分相除的方法。系统将采集信号做单端电压输入测试和差分电压输入测试，并比较了单端输入与差分输入的测试效果，定性分析了输出幅值与被测电流的关系。测试结果表明，锁相放大器输出幅值与被测电流具有线l陛关系，且差分输入较单端输入幅值大、线性度好、对外界干扰抑制性强。其成果为进一步研究基于旋光效应的光纤电流互感器的应用奠定了基础。

Fiber-optical Current Transducer Based on the Lock-in Amplifier

In order to test the rotation amount caused by the Faraday effect in the fiber-optic current transformer,a method using the lock-in amplifier for DC signal processing is proposed.This method improves the traditional method of dividing the AC component by the DC component.The acquired signal is used for single-ended voltage input testing and differential voltage input testing respectively,the testing results are compared,and the relationship between the output amplitude and the measured current is analyzed qualitatively.The testing results show that the relationship between the output amplitude and the measured current is linear.Compared with the single-ended voltage input,the differential voltage input has a larger amplitude and better linearity and suppression against outside interference.This work provides a foundation for further study of the fiber-optic current transformer based on the rotation effect.