Permanent Magnet Synchronous Motor Direct Torque Control Based on Stator Resistance Online Estimation

Permanent magnet synchronous motor direct torque control system is characterized by its fast, automatic control and so on. Based on the actual value and reference value of the motor control system, this article analysis the effect of the stator resistance variation on the performance of the system.A method to track stator resistance variation is proposed according to the effect of stator resistance deviation on stator flux and current vector.Based on the optimal reference value of the stator current vector, the stator resistance value is estimated on-line by using the angle between the electromagnetic torque and the stator flux; and the simulation studies results using Matlab/Simulink shows that the control method is very effective to improve the low-speed performance of the system, reduced torque ripple and improve system robustness.