Open AccessDevelopment of interharmonics identification using enhanced‐FFT algorithm
Author(s) -
Lin Hsiung Cheng
Publication year - 2017
Publication title -
the journal of engineering
Language(s) - English
Resource type - Journals
ISSN - 2051-3305
DOI - 10.1049/joe.2017.0133
Subject(s) - fast fourier transform , harmonics , spectral leakage , computer science , leakage (economics) , algorithm , electronic engineering , power (physics) , energy (signal processing) , mathematics , engineering , electrical engineering , statistics , voltage , physics , quantum mechanics , economics , macroeconomics
The fast Fourier transform (FFT) is a mostly used tool to measure power system harmonics. FFT, however, is not applicable to analyse interharmonics due to spectral leakage effect. Although International Electrotechnical Commission (IEC) standard is recommended for interharmonic measurement, the individual interharmonic frequency and respective amplitude cannot be worked out under this framework. For this reason, this paper proposes an enhanced‐FFT model to build up the relationship between interharmonic frequency and dispersed leakage energy. The mathematical equation is thus established to find actual value of interharmonic frequency. Moreover, the true interharmonic amplitude can be retrieved from the dispersed energy collection. In other words, the sampling window length is no longer required to match the interharmonic period and the correct measurement results can be achieved. The proposed model is developed using a simple arithmetic equation so that it is feasible for more efficient calculation for interharmonic analysis. Performance results verify that the proposed scheme can achieve accurate, rapid and reliable outcomes.