Predictive Control of a 27-level Asymmetric Multilevel Current Source Inverter

In this work a study of a 27 -level asymmetric multilevel current source inverter is developed. The presented structure is composed by three current source inverters that together are in a 9:3:1 ratio to produce a current waveform with multiple levels. A model predictive control scheme is developed for tracking the references for the output AC voltages, and to keep the asymmetric ratio between the DC currents even during transient conditions. Furthermore, an extra control goal is included in order to reduce the commutations of the inverter, and therefore reduce the power losses. In order to apply the predictive controller, the equations of the model to be analyzed are obtained systematically for continuous and discrete time domains. Simulations are carried out to validate the proposal and the integrity of the predictive control strategy.