Optimizing losses in multilevel inverters

Losses generation in a multilevel inverter leg are analyzed in this paper for N=2, 3, 4, and 5 levels. An N-level inverter is modeled as the superposition of N-1 elementary buck converters to simplify the losses analysis. The results of the analysis show that the efficiency of a multilevel inverter can increase when the number of levels increases if an appropriate device selection is made. SABER simulations and experimental results in a 500 W 5-level prototype confirm the analytic predictions.