Deadbeat predictive current control for non-salient PMAC machine drives at very low switching-to-fundamental frequency ratios

This paper focuses on current control techniques employed in non-salient permanent magnet alternating current (AC) machines, particularly at extremely low switching-to-fundamental frequency ratios (SFFR). To address this issue, a discrete deadbeat predictive control method is proposed, leveraging a precise discrete model and a complex-valued adaptive observer. Through frequency analysis, simulations, and experimental results, the stability and dynamic characteristics of the proposed method are validated even at SFFR as low as 3.