Model predictive control for asymmetrical cascaded H-Bridge multilevel grid-connected inverter with flying capacitor

The main advantages of multilevel inverters are the improved power quality and higher efficiency. Cascaded H-Bridge (CHB) multilevel inverters are widely used in photovoltaic grid-connected generators, electric vehicles and motor drive systems. However, the CHB multilevel inverters require a large number of isolated dc power supplies, which make these inverters complicated to implement in industrial applications. This paper presents a model predictive control method to improve the mentioned drawbacks of CHB inverters by using a flying capacitor to replace a dc power supply. Simulation and experimental results of a seven-level asymmetrical CHB grid-connected inverter show that one can simultaneously maintain the inverters output voltage level and can also keep the flying capacitors voltage balance.