Hybrid traction drive with symmetrical split-phase motor controlled by synchronized PWM

This paper presents results of application of a new method of synchronized pulsewidth modulation (PWM) for control of symmetrical six-phase traction drives with two DC sources. The six-phase (dual three-phase) drive system includes in this case a symmetrical induction motor which has two sets of windings spatially shifted by 60 electrical degrees. Analysis of operation of the symmetrical six-phase system with synchronized PWM, providing balanced control of the system, has been performed. Simulation results are given for basic continuous and discontinuous versions of synchronized pulsewidth modulation. The spectra of the phase voltage of the six-phase vehicle drives with algorithms of synchronized PWM do not contain even harmonics and sub-harmonics, which is especially important for the high power/current applications.