Selective Harmonics Elimination for Nine Level Inverter Based on Linear System Solution

An analytical method for elimination of low order harmonics has been setup for a 9-level, single phase cascaded H-bridge inverter. The method requires the solution of a linear system and returns a set of four switching angles capable to delete some predetermined low order harmonics and their multiples, thus improving the quality of the output voltage. In this paper, after a description of the proposed method some simulaiton results and analysis are reported in order to demonstrate the quality of achievable results.