Dual three-phase system based on four neutral-point-clamped inverters with synchronized space-vector modulation

Algorithms of synchronized pulsewidth modulation (PWM), based on special space-vector control scheme (with utilization of minimal number of voltage space vectors), have been applied for synchronous control of four neutral-point-clamped (NPC) inverters feeding six-phase (dual three-phase) drive on the base of asymmetrical open-end windings induction motor. It allows providing continuous synchronization and symmetry of the phase voltage of system during the whole control range for any ratio of voltage magnitudes of DC-sources, and for any configuration of DC-sources. Also, in this case four inverters of the system can be supplied by reduced number of insulated DC-sources (by one/two/three DC-sources instead of four DC-sources for standard system topology based on four two-level inverters.