Harmonics and interharmonics analysis of power signals using Gaussian filter banks

The paper presents a method based on the Fast Fourier Transform and Gauss Window combined with a recursive algorithm for the estimation of the voltages and currents harmonics and interharmonics. The proposed method uses pairs of band-pass filters to obtain the frequency domain components of the power signals. The band-pass filters emerge from the grouping made between the Gauss Window and the Fourier Transform. The outputs of these filters are attenuated copies of the input distorted signals and they are utilized to calculate the characteristics of the harmonic and interharmonic components present in the spectrum of the power signals. The analysis is performed on a time interval equivalent with 10 cycles of the fundamental frequency as the standard literature recommends. The proposed algorithm was implemented in a virtual instrument used to process synthetic and field data. The obtained results showed high precision in harmonics and interharmonics detection, with no leakage effect even in the case of fundamental frequency deviation.