Space Vector-Based Hysteresis Current Controller of Asymmetrical Six-Phase Induction Motor

Abstract

This article proposes hysteresis current controller (HCC) for an asymmetrical six-phase induction motor (A6P-IM). Space vector-based HCC (SV-HCC) is utilized to maintain the current vector error within a specified band. For A6P-IM, not only $ \alpha \beta $ current components need to be controlled, but also the $ xy$ components must be minimized to achieve high current quality and reduce stator copper loss. Therefore, instead of actual voltage vector, virtual voltage vectors ($ VVV$ s) are adopted in the proposed controller. The error between the reference and the one step prediction of actual currents in $ \alpha \beta $ subspace is calculated and is fed to a five levels HCC. Then, the optimal $ VVV$ is selected based on a novel lookup table. The proposed procedure avoids cost function calculation and several iterations required for optimization process of the conventional predictive current controller (PCC). The performance of the proposed controller is compared to state of art PCCs and $ VVV$ based PCC ($ VVV$-PCC). The results indicate that the proposed controller has improved current total harmonic distortion (THD) compared to conventional PCC. On the other hand, it has less average switching frequency compared to $ VVV$-PCC.