A novel multilevel inverter topology with no clamping diodes and flying capacitors

To decrease the number of clamping diodes and flying capacitors in multilevel inverters, a novel multilevel inverter topology with no clamping diodes and flying capacitors is proposed in the paper. The topology structure, operating principle, balance of the DC link capacitor voltages, and comparisons with the conventional multilevel topologies will be discussed. The number of power switching devices needed is same as the conventional multilevel inverters, i.e. 2(M-1) for an M-level single-phase inverter. With no clamping diodes and flying capacitors, the reliability is improved and the costs are saved. But two of the switching devices will block double of one DC link capacitor voltages at some voltage levels. So this novel topology is more suitable for medium voltage applications with low THD requirements. By using the method of hybrid clamped, the DC link capacitors can be balanced with easy control. Its validity is confirmed by simulations and experiments based on a five level inverter.