Estimation of harmonics and interharmonics based on Single Channel Independent Component Analysis

The Discrete Fourier Transform (DFT) is one of the most used tools for spectral analysis. However, the DFT-based harmonic estimation is inaccurate when the power system frequency deviates from its nominal value. Also, an interharmonic may be not distinguishable when the DFT frequency resolution does not match the interharmonic frequency. This paper proposes the application of Single Channel Independent Component Analysis (SCICA) to blindly estimate harmonics and interharmonics of a power system signal. The SCICA operation is equivalent to an adaptive linear filter bank which can blindly separate the harmonics and interharmonics of the signal. It will be shown that the SCICA algorithm obtains more accurate results for estimation of arbitrary harmonic and interharmonic frequencies than the DFT.