COMPARISONS OF THE EXECUTION TIMES AND MEMORY REQUIREMENTS FOR HIGH-SPEED DISCRETE FOURIER TRANSFORMS AND FAST FOURIER TRANSFORMS, FOR THE MEASUREMENT OF AC POWER HARMONICS

A. J. Roscoe, G. M. Burt

Abstract

Conventional wisdom dictates that a Fast Fourier Transform (FFT) will be a more computationally effective method for measuring multiple harmonics than a Discrete Fourier Transform (DFT) approach. However, in this paper it is shown that carefully coded discrete transforms which distribute their computational load over many frames can be made to produce results in shorter execution times than the FFT approach, even for large number of harmonic measurement frequencies. This is because the execution time of the presented DFT actually rises with N and not the classical N² value, while the execution time of the FFT rises with Nlog₂N.

Keywords

power system harmonics, harmonic analysis, Fourier transforms, power quality

Download

IMEKO-TC20-2011-11.pdf

DOI

-

IMEKO TC

TC20 - Measurements of Energy and Related Quantities

Back to the proceedings