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

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 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$ \alpha \beta $</tex-math></inline-formula> current components need to be controlled, but also the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$ xy$</tex-math></inline-formula> components must be minimized to achieve high current quality and reduce stator copper loss. Therefore, instead of actual voltage vector, virtual voltage vectors (<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$ VVV$</tex-math></inline-formula> s) are adopted in the proposed controller. The error between the reference and the one step prediction of actual currents in <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$ \alpha \beta $</tex-math></inline-formula> subspace is calculated and is fed to a five levels HCC. Then, the optimal <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$ VVV$</tex-math></inline-formula> is selected based on a novel lookup table. The proposed procedure avoids cost function calculation and several iterations required for optimization process of the conventional predictive current controller (PCC). The performance of the proposed controller is compared to state of art PCCs and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$ VVV$</tex-math></inline-formula> based PCC (<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$ VVV$</tex-math></inline-formula>-PCC). The results indicate that the proposed controller has improved current total harmonic distortion (THD) compared to conventional PCC. On the other hand, it has less average switching frequency compared to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$ VVV$</tex-math></inline-formula>-PCC.