A new 5-level topology allowing the balancing of the DC bus capacitors voltages

Overview & Synopsis

Multilevel structures are becoming more and more common in the industry because they can convert a DC voltage into an AC voltage for high-power and medium voltage condition. However there are limitations in some topologies where the DC Bus is divided by capacitors. With 3 or more DC bus capacitors, it is difficult to ensure the voltages balance across each capacitor. This paper proposes a 5-level structure based on the SMC converter (Stacked Multicell Converter). The study of this structure is focused on the DC-AC conversion and the balance of the capacitors voltages. The way used to accomplish these objectives are based on the transfer of energy from one to another capacitor through an inductive storage element.