Enhanced switching function matrix calculation in the interharmonic domain

This paper presents an alternative for the calculation of the switching function matrix in periodic steady state computations including harmonics/interharmonics. The basis of the methodology is the decomposition of the signals under interest through the discrete Fourier transform (DFT). This permits to include both harmonics and interharmonics simultaneously. Additionally, the DFT allows calculating the switching function directly from its time domain counterpart. This represents a computational advantage over traditional methods that compute the switching function matrix through perturbations or by using local iterations. Two illustrative examples, including basic power electronic devices, one with lumped parameters and the other with distributed parameters, are provided in this paper.