Fuzzy Logic Control of the Cross Connected Intermediate Level (CCIL) Voltage Source Inverter

The Cross Connected Intermediate Level (CCIL) Voltage Source Inverter Topology was first introduced in 2007 [1]. The idea behind this novel multilevel topology is to explore the area of reduced number of component topologies producing large number of voltage levels. Mathematical modeling of the electrical circuit for the understanding and the control of the capacitor voltage has proven to be less intuitive and rather complex. A model based on graphical representation of the currents, modulation index and voltage levels was developed. It allowed having a good intuitive understanding on how to control the capacitor voltage. In this paper, a regulation scheme for the voltage control of the unsupplied phase capacitor voltage of the topology is proposed, based on a graphical model and using a fuzzy logic control strategy.