光源调制全光纤电流互感器的研究

Fiber Optical Current Transformers Based on Modulated Light Source

介绍了全光纤电流互感器的结构,分析了系统输出信号的特点,指出工频干扰及线性双折射效应是影响系统稳定性的主要问题.提出并实现了基于光源调制的抑制工频干扰方法.该方法利用2000 Hz的方波光源作为互感器的光驱动,系统的输出信息由原来的一路变成了两路,通过两路信息的融合有效地抑制了电路工频干扰.理论分析及实验结果表明,在不增加系统复杂性和硬件投入的条件下,该方法不仅抑制了电路中的低频干扰,还有效地抑制了工频干扰,提高了系统的信噪比,为提高全光纤电流互感器系统的稳定性和可靠性提供了新的方法.

A structure of an optical current transformer is presented. The output of the system is analyzed theoretically and experimentally. The power-line interference and the linear birefringence effect are pointed out as the key barriers for getting the useful signal from the system, and a way based on modulated light source for depressing the power-line interference is verified,where 2 000 Hz square-wave light is considered as the optic supply. For amelioration, the different information is got from two channels to depress the power-line interference by information fusion. The theoretical analysis and experimental results demonstrate that by the improved method the powerline interference is depressed more efficiently, while the signal-to-noise ratio is enhanced obviously.