Direct torque control can utilize M-T coordinates and has been proposed for high-efficiency permanent magnet synchronous motor control that is robust against motor parameter variations. However, direct torque control becomes unstable when operating at the maximum torque per flux (MTPF) condition. This paper proposes an MTPF control method that achieves stable operation with minimal design parameters. Simulation and experimental results demonstrate the effectiveness of the proposed method.
Inoue et al. (Sat,) studied this question.