Assessment of Predictive Current Control of Six-Phase Induction Motor With Different Winding Configurations

Asymmetrical six-phase (A6P) induction motor-based drives can be considered as a well-established employed technology in high-power safety-critical industry sectors. Of the different control techniques proposed for multiphase machines, model predictive control (MPC) has recently been favored thanks to its simplicity, rapid dynamic response, and flexibility to define new control objectives. One of the main operating challenges when employing MPC to A6P induction machine is the poor quality of the phase current waveform due to the relatively low impedance of the secondary <inline-formula> <tex-math notation="LaTeX">$xy$ </tex-math></inline-formula> subspace. Although different controller structures have been introduced in the available literature to mitigate this problem, most of the available proposals, if not affecting the dc-link voltage utilization, will likely add to the control complexity. From the stator winding layout perspective, this paper attempts to investigate the effect of different winding configurations of six-phase stators with isolated neutral arrangements on the performance of predictive current control (PCC). This study shows that the winding configuration affect the mapping of the 64 available voltage vectors to the <inline-formula> <tex-math notation="LaTeX">$\alpha \beta $ </tex-math></inline-formula> and <inline-formula> <tex-math notation="LaTeX">$xy$ </tex-math></inline-formula> subspaces, the induced current ripples, and the required weighting factor employed in PCC. The theoretical findings have experimentally been validated using a 1kW twelve-phase machine that can externally be reconnected to form any of the three available six-phase winding configurations.