A new single-phase five-level inverter with no problem of voltage balancing

In this paper, a new single-phase five-level inverter is presented using coupled inductors. This inverter can output five-level voltage with only one dc source and no split of the dc voltage capacitor is needed, totally avoiding the voltage balancing problem. What is more, as this inverter is based on the widely used three-arm power module, it is very easy to construct. Operation mechanism of this inverter is analyzed and the possible switching patterns are investigated. Based on these analyses, the rules for optimizing the modulation schemes are also presented. Following these rules, no dc component will exist in the inductor currents, which is very helpful for minimization of the inductors. Simulation and experimental results show validity of the proposed inverter together with the optimized modulation scheme.