全相位时移相位差法在电力谐波检测中的应用

摘要

分析了传统FFT和全相位FFT(apFFT)谱分析的原理和区别,说明了全相位FFT谱分析方法在电力系统谐波检测方面的优势.根据apFFT谱分析方法的相位不变特性可以精确地得到各个谐波的相位,再利用全相位时移相位差校正法获取各个谐波的频率和幅值.文中详细说明了采用目前在电力系统比较流行的基于CortexM3内核的STM32芯片对该算法进行设计与实现,测量所得结果准确度较高.该方案对电力系统谐波检测有一定参考价值.%This article analyzes principles and differences between traditional FFT and all-phase FFT (apFFT) spectrum analysis,and illustrates the advantage of all -phase FFT spectrum analysis method in power system harmonic detection.According to its characteristics of phase invariance,apFFT spectrum analysis method could calculate the phase of each harmonic accurately.Then it applies all-phase time-shift phase difference method to obtain the frequency and amplitude of each harmonic.This paper introduces how to use the STM32 chip which is based on the Cortex-M3 kernel and is popularly used in the current power system to implement this algorithm.The results are high accuracy and this program has some practical value reference in power system harmonic detection.