Modulator for 4-level flying capacitor converter with active voltage balancing control with P controllers

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