基于二阶前向差分的低压电弧辐射电磁噪声频域分析

Frequency Domain Analysis of Electromagnetic Noise Produced by Low Voltage Arc Based on Second Order Forward Difference

针对干扰接收机测量的低压电弧辐射电磁噪声波形,利用二阶前向差分对电磁噪声波形不同频点的幅值进行处理,并对差分进行求和作为评估频点变化的指标。在每组试验条件下将差分和降序排列的前10个频点进行统计分析,获得了不同试验条件下低压电弧辐射电磁噪声频域波形的变化规律。磁场噪声低频和高频变化剧烈的频点主要分布在20~100 k Hz附近,电场噪声低频和高频变化剧烈的频点以200 MHz为分界线。随着接触电流、测量距离的增加,磁场噪声频域波形的低频部分变化剧烈,电场噪声频域波形的高频部分变化剧烈。

Considering the waveforms of electromagnetic noise produced by low voltage arc received by interference receiver,second order forward difference was used to deal with the value of different frequency points of the waveforms of electromagnetic noise,and the sum of difference was used to evaluate the change of frequency points. The top 10 frequency points of the sum of difference in descending order were statistically analyzed under different groups,and the change rule of the waveforms of electromagnetic noise produced by low voltage arc under different experimental conditions was obtained. Drastic changes of the low frequency and high frequency parts of magnetic field noise are distributed mainly near 20 k Hz and 100 k Hz respectively,and that of electric field noise are bounded approximately by 200 MHz. With the increase of contact current and measure distance,the magnetic field noise’s low frequency parts and the electric field noise’s high frequency parts change dramatically.