Novel deadbeat direct torque and flux control for interior permanent magnet synchronous motor

In response to the significant torque and flux pulsation and slow dynamic response speed in traditional direct torque flux control of interior permanent magnet synchronous motors (IPMSM), a new deadbeat direct torque and flux control (DB-DTFC) scheme is proposed. Firstly, a mathematical model is established based on the M-T axis coordinate system, simplifying the complex calculation process of traditional direct torque flux control. Secondly, a new composite convergence rate is proposed to design a novel nonsingular fast terminal sliding mode speed controller, replacing the traditional PI regulator, and significantly enhancing the system's dynamic performance. Finally, a new control framework is designed by introducing the maximum torque per ampere (MTPA) algorithm. This approach allows the stator flux to change with the motor's operational state adaptively, leveraging the convex pole effect to generate greater torque with less current, thus improving the motor's efficiency. The results indicate that the proposed method improves dynamic performance by 70%, reduces torque ripple by 34.4% and flux linkage ripple by 57.6%, and enhances efficiency by 34.3%.