Modulator for 4-level Flying Capacitor Converter with Balancing Control in the Closed Loop

This paper presents a modulator with an active voltage balancing control for the three-phase four-level FLC converter based electric motor drive for applications supplied directly from a 6 kV ac-grid. It describes a modulation algorithm of the FLC converter by using the phase shifted PWM modulation with balancing voltage of the flying capacitor by using P controllers in the closed loop. The proposed control was verified by experiments carried out on the down-scale drive prototype of the rated power of 35 kVA