Direct control strategy for a flying capacitor converter

In this paper, a direct control of a flying capacitor inverter is proposed. This control allows to limit the number of commutations in a switching period with the use of a pre-calculated output voltage profile. A predictive control is made for the 3 phases 4 levels inverter in a active filtering operation. The advantages of this direct control is to reduce the switching frequency of the IGBTs, to use only a threshold voltage detector for flying capacitor voltages and to define offline pre-calculated switching tables. Experimental results for an active power filter application validate the performances of this control for static and dynamic conditions.