Digital field oriented control for dual three-phase induction motor drives

A direct rotor field oriented control (DRFOC) of a dual-three phase induction motor drive is described in this paper. The induction machine has two sets of stator three-phase windings spatially shifted by 30 electrical degrees. The stator windings are fed by a current controlled PWM (CRPWM) six-phase voltage source inverter (VSI). Three key issues are discussed: (1) the machine dynamic model is based on the vector space decomposition theory; (2) the PWM strategy uses the double zero-sequence injection modulation technique which gives good results with low computational and hardware requirements; and (3) to eliminate the inherent asymmetries of the drive power section, a new current control scheme is proposed. Experimental results are presented for a 10 kW dual three-phase induction motor drive prototype.