Analysis of harmonic and inter-harmonic signals through generalized-Fourier series

A harmonic and inter-harmonic signal analysis technique is presented in this paper. The technique consists in the use of The Fourier Theory for synthesizing harmonic signals and the use of two generalized-Fourier approximations based in different orthogonal basis for inter-harmonic signals. A numerical example yields that polynomial Chebyshev and Legendre function approximations can be very efficient to analyze inter-harmonic signals in a very short running time.