Stationary frame digital current regulation for dual-three phase induction motor drives

A digital current regulation scheme in stationary reference frame for dual-three phase induction motor drives is discussed in the paper. The induction machine has two sets of three-phase stator windings spatially shifted by 30 electrical degrees. The stator windings are fed by a current controlled PWM (CRPWM) six-phase IGBT voltage source inverter (VSI). The basic issues are the current regulation scheme to cope with the inherent asymmetries of the drive and the digital implementation to have zero steady-state current error for the whole frequency range of the drive. Experimental tests are presented for a direct rotor field oriented control (DRFOC) of a 10 kW dual three-phase induction motor drive prototype; the results confirm the validity of the control scheme.