基于FFT算法的低频信号失真度测量装置优化设计  

Optimal design of low frequency signal distortion measuring device based on FFT algorithm

作　　者：俞达 陈冬英[1,2] 安南 谢孔亮 YU Da;CHEN Dongying;AN Nan;XIE Kongliang(School of Electronic Information Science,Fujian Jiangxia University,Fuzhou 350108,China;Smart Home Information Collection and Processing on Internet of Things Laboratory of Digital Fujian,Fujian Jiangxia University,Fuzhou 350108,China)

机构地区：[1]福建江夏学院电子信息科学学院,福建福州350108 [2]福建江夏学院数字福建智能家居信息采集及处理物联网实验室,福建福州350108

出　　处：《高师理科学刊》2022年第11期47-52,共6页Journal of Science of Teachers＇College and University

基　　金：福建江夏学院2022年大学生创新创业训练计划项目(202213763157);2022年大学生创新创业训练国家级计划项目(202213763023);福建省教育厅中青年教师教育科研项目(JAT210359);福建江夏学院校级科研人才培育项目(JXZ2021011)。

摘　　要：总谐波失真(THD)是运算放大器、功率放大器等器件的主要衡量参数之一.设计以TMDSSK3358开发板为硬件基础,以FFT算法为核心的高精度快速信号失真度测量装置.传统的模拟测量法不仅硬件设计复杂,且性能受限于滤波器.该设计利用AD转换实现模拟信号与单片机可接收的数字信号转换,采用FFT(快速傅里叶变换)实现信号的时频转换,通过获得幅频信息进而得到各个谐波的功率,最后所测的THD值通过TMDSSK3358开发板上的液晶屏模块显示.测量结果表明,该设计在频率为1 kHz时测量精度误差小于0.05%,失真度测量与显示用时不超过10 s.与传统的信号失真度测量装置对比,在简化硬件复杂度时,速度更快、精度更高,为FFT算法应用于失真度测量提高新的研究思路.Total Harmonic Distortion(THD)is one of the main measuring parameters of operational amplifiers,power amplifiers and other devices.This design is a high-precision signal distortion measuring device based on the TMDSSK3358 development board and FFT algorithm.The hardware design of traditional analog measurement method is complex,and its performance is limited by the filter.First of all,the design uses AD conversion to realize the conversion between analog signals and digital signals that can be received by the microcontroller.Secondly,FFT(Fast Fourier Transform)is used to realize the time-frequency conversion of the signal,and the power of each harmonic is obtained by obtaining the amplitude frequency information.Finally,the measured THD value is displayed by the LCD module on the TMDSSK3358 development board.The measurement results show that the measurement accuracy error of this design is less than 0.05%when the frequency is 1 kHz,and the measurement and display time of distortion is not more than 10 s.Compared with the traditional signal distortion measurement transpose,it is faster and more accurate when simplifying the hardware complexityalgorithm applied to distortion measurement.

关 键 词：信号失真度测量 FFT算法 AD转换:总谐波失真 

分 类 号：TH77[机械工程—仪器科学与技术]