Estimação de Harmônicas e Inter-harmônicas em Tempo Real Utilizando a Transformada de Fourier Recursiva de Janela Deslizante

Abstract

The estimation of harmonic and inter-harmonic components is very important in Electrical Power Systems (EPS) because it can provide relevant information for solving Power Quality (PQ) problems. This work proposes a sample by sample harmonic and inter-harmonic estimator robust to noise and signal variations. The proposal was based on three main pillars: a first stage of frequency estimation based on zero crossing, an intermediate stage of resampling to guarantee sample synchronization, and a last stage composed of spectral decomposition cores based on the Discrete Fourier Transform in its recursive and sliding window form (SWRDFT). Tests using signals containing noise, subjected to magnitude variations and frequency deviation, showed that the estimator was able to accurately estimate the magnitudes of the spectral components, with normalized errors below 10−4.