Performance Comparison of Different Control Schemes from the Electromagnetic Interference View for Single-Phase Multilevel Inverter

When connecting a multilevel inverter to a load or the utility grid, two major factors must be considered: total harmonic distortion and electromagnetic disturbance due to the fast switching of the semiconductor devices. This paper focuses on these electromagnetic interference aspects of a multilevel inverter. The change in the inverter's control scheme and the change in the operating frequency on the conducted electromagnetic interference are investigated. This paper addresses carrier-based level-shifted pulse width modulation as a pulse width modulation control for the multilevel inverter. Three different level-shifted control schemes were compared at different switching frequencies to determine the effect of the control scheme and switching frequency on the electromagnetic interference. As an example of multilevel topology, a reduced-device single-phase multilevel inverter is presented in this paper.