Multilevel Dual Inverter-Fed Drives with Algorithms of Synchronized PWM

Novel method of direct synchronized pulsewidth modulation has been disseminated for control of a dual inverter-fed open-end winding induction motor drive with separate dc-link sources with both equal and different voltages. Special attention has been given to analysis of processes in drive system in the zone of overmodulation. Simulations results are given for continuous and discontinuous versions of synchronized PWM. Novel strategy and new techniques of synchronized pulsewidth modulation (PWM) provide quarter-wave symmetry of the multilevel actual phase voltage of the system during the whole control range including the zone of overmodulation. Spectra of the actual phase voltage do not contain even harmonics and sub-harmonics, which is especially important for the drive systems with increased power rating