Stability Analysis for Direct Torque Control of Permanent Magnet Synchronous Motors

Direct torque control (DTC) is an effective control strategy for permanent magnet synchronous motor (PMSM). However, the asynchronization between stator flux linkage vector and rotor flux linkage vector may happen and this may result in unstable operation or serious vibration. This paper describes several principles that should be taken into account when we design the DTC system for PMSM. For instance, the choice of stator flux linkage, the effect of zero-voltage vector, the limitation for torque reference, and so on. The simulation results confirm the correctness of the stability analysis