Novel Selective Harmonic Mitigation Algorithm for Seven-level Three-phase Cascaded H-Bridge Inverters

This paper presents a novel Selective Harmonic Mitigation algorithm for three-phase seven-level Cascaded H-Bridge inverters. The proposed algorithm overcomes the main issues of these modulation strategies by identifying control angle trends through a graphical-numerical approach using a four-dimensional space, without solving nonlinear equations. Moreover, polynomial equations have been defined for real-time implementation using the least-squares approximation method, considering various solutions to reduce computational costs. Through simulation analysis in the MATLAB environment, the effectiveness of the proposed algorithm has been demonstrated by comparing the Total Harmonic Distortion and voltage harmonic amplitudes among the theoretical and approximated control angles.