全光纤电流互感器白噪声特性及对测试的影响研究

Research of character and influence on testing of white noise in FOCT

白噪声是全光纤电流互感器(FOCT)的一种固有特性,使小电流下FOCT的即时电流波形显示较多毛刺的视觉效果。文中分析了FOCT白噪声来源和表征方法,研究FOCT在零输入电流下的白噪声统计特性,分析其在不同一次电流下的数据时域及频域特性,表明FOCT白噪声符合均值为零的正态分布,噪声大小与一次侧输入电流大小无关。在此基础上,深入研究白噪声对FOCT测量结果造成的影响并给出减小该影响的方法。

White noise is one of the inherent characters of FOCT,thus the real-time sensing waveform of a small current FOCT current displays many glitches. This paper analyzes the source and the characterization method of white noise in FOCT,and researches on the statistical properties of white noise in FOCT while the equipment is in a zero-input current environment. Data in time-domain and frequency-domain is analyzed and compared under different primary input current. The result indicates that white noise in FOCT accords with a normal distribution with mean zero,and the noise magnitude is independent of the primary current value. On that basis,we study how the white noise affects test result of FOCT,and also provide an effective method of how to reduce the impact.