低频微弱信号检测中工频噪声的零点消除法

Method of zero sample to remove power noise in weak low frequency signal detection

针对陷波器不能有效滤除工频及各高次谐波的情况,提出了一种在低频微弱信号检测中消除工频干扰的零点采样新方法,该方法通过跟踪工频信号产生间隔与工频周期相同的脉冲序列,对混合信号进行过零同步采样。理论分析和仿真实验表明有用信号在低频条件下,此方法可有效滤除工频及其整数倍谐波干扰噪声,对随机噪声也有一定的抑制能力。此方法可以推广到具有任意单频噪声干扰的信号检测系统中。

A novel method of zero sample to eliminate the power noise in the low frequency is presented. In the zero sample, pulses of half power noise period interval that synchronize with the power noise are used to sample the mixed signals when power noises pass zero. The theory analysis and simulation have verified that this method can remove the power noise and times frequency noise effectively in the low frequency, which restrain the random noise in the mean time. This method can be used in any weak low frequency signal detection with certain frequency noise and times of frequency.