全光纤电流互感器研究

Research on All Fiber-optical Current Transducer

介绍了全光纤电流互感器工作原理,分析了光电探测器输出信号的特点,提出了在正弦调制下的数字相关检测方法,消除了光强、调制深度变化的影响,并阐述了测量原理、处理方法以及相关处理电路和软件的设计思路,将数据处理引入的延时缩短到小于300μs的范围,提高了响应速度。实验结果表明,最大比差为0.04998%,线性度达到0.9999824,达到了0.2级准确度的要求。

The principle of All Fiber-Optical Current Transducer （AFOCT） is introduced. By analyzing the characteristics of photo-detector output signal, a digital correlative detection scheme based on sine wave modulation and demodulation is put forward, which eliminates the influence of light intensity change and modulation depth change. The measurement principle, processing method and the design ideas of related circuits and software are also discussed. The delay caused by data processing is reduced to less than 300us, which improves the response speed of the total system. Experimental data show that the maximum ratio error is 0. 04998% and the linearity is up to 0. 9999824, which meets the precision requirement of 0.2 class.