基于Allan方差的磁光玻璃型光学电流互感器噪声分析

为了更有效地提高光学电流互感器(OCT)的信噪比,针对OCT的噪声特性,提出一种基于Allan方差的噪声分析方法。应用所提方法结合光电探测器结构以及实验采集得到的噪声性质将噪声分为6类:量化噪声、高斯白噪声、1/f噪声、指数相关噪声、温度相关噪声以及正弦噪声。进一步得到含有6类噪声项的OCT随机噪声模型。针对实测数据,计算辨识了磁光玻璃型OCT随机噪声模型中各主噪声源的噪声系数。实验结果表明所提方法能有效地辨识出磁光玻璃型OCT的各个噪声项系数。通过该方法得到的噪声模型能够提高输出信噪比,为OCT应用实时滤波算法提高测量精度奠定了基础。

Analysis on Noise of Magneto-optical Glass Type Optical Current Transformer Based on Allan Variance

In order to more effectively improve the optical current transformer (OCT) signal noise ratio, with focus on the noise characteristics of OCT, a method of OCT noise analysis based on Allan variance is proposed. With this method and by referring to the structure of noise and noise properties of OCT, noise can be divided into six types: quantized noise, white Gaussian noise, 1/f noise, index related noise, temperature noise and sinusoidal noise. Thus an OCT random noise model containing six type noise terms is obtained. Calculate and identify the noise factor of all the main noise sources in the OCT random noise model from the measured data of OCT for laboratory. Experiments show that this method is able to effectively identify each noise coefficient of OCT, laying a foundation for OCT using the real-time filtering algorithm to improve measuring precision. This work is supported by National Natural Science Foundation of China (No. 51277066).