Recursive Selective Harmonic Elimination for Multilevel Inverters: Mathematical Formulation and Experimental Validation

Abstract

A recursive method that eliminates n+1 harmonics and their respective multiples from the output voltage of a cascaded H-bridge (CHB) multilevel inverters with s=2n dc sources (n=1,2,3,) is proposed. It solves 2 × 2 linear systems with no singular matrices and always gives an exact solution with very low computational effort. Simulated results in three-phase five-, nine-, 17-, and 33-level CHB inverters, and experimental results in a five-level inverter demonstrate the validity of the method.