Field-weakening in vector controlled and DTC PMSM drives, a comparative analysis

The present paper gives a comparative analysis of field-weakening in vector controlled and direct torque control (DTC) permanent magnet synchronous motor drives. For this purpose, the fundamentals of these drives are discussed. The results of extensive simulations and a comprehensive set of experiments are given. The possibility of unstable operation in the high-speed region using DTC has been shown. Important differences between the compared drives have also been emphasised, such as quickness of response, ripple content and implementation aspects