数字滤波器滤除电子测量系统中工频及其谐波干扰的研究

在电子测量中工频是主要的噪声干扰源之一，若不滤除将大大影响测量精度。而传统的模拟电路滤波器在精度方面无法与数字滤波器相比；另外对多阻带滤波器的设计摸拟电路更是无法实现。本设计用FIR(Finite Impulse Response)数字滤波原理设计了阻带范围分别为48～52Hz，98～102Hz，148～152Hz的三阻带数字滤波器，经仿真实验证明其对电子测量系统中的工频50Hz及其二次谐波和三次谐波干扰将衰减30dB。对去噪后的信号进行分析，大大提高了测试系统的精度，整个过程分为多阻带滤波器的数学建模和滤波算法实现，并分析比较了不同窗函数和阶数的变化对滤波性能的影响。

Digital Filter Application for Squelch on Industrial Frequency Noise and Its Harmonic Waves Interference

Industrial frequency and its harmonious waves are one of the main interferences in electronic measurement,which will cause severe influence on test accuracy.Digital filter is better than analog filter at resolution,furthermore multiband stop filter design is unrealizable for analog filter design method.This paper designs an FIR(Finite Impulse Response) multiband stop digital filter to reject the noise of 50 Hz and its harmonic waves from power network,whose stop bands are respectively as 48~52 Hz,98~102 Hz and 148~152 Hz.Simulation results prove that the noise can be depressed to 30 dB.To analyze the filtered signal can improve accuracy of the test system. The whole course includes two parts,which are filter mathematical modeling and filter algorithm implementation on worksite dada.