Petri net control strategy for series multilevel converters using a state observer

Abstract

Multilevel converters are a special type of power converters, which can be classified as hybrid systems. This means that their model contains both continuous and discrete variables, which pose a challenge for the controller. However, this type of power converter has certain advantages, such as improved switching frequency, reduced output ripple and modularity. Petri nets are ideal for representing hybrid systems. In this paper, a Petri net controller will be developed for a series flying capacitor converter. The proposed control strategy will use a state observer in order to estimate the flying capacitor voltages.