Comparison of stator flux linkage estimators for PWM-based direct torque controlled PMSM drives

Direct torque control can be applied to any AC motor drive and requires an estimation of the stator flux linkage. Many kinds of estimation schemes have been proposed. However, there are few reports that compare them. This paper compares the estimation schemes in PWM-based direct torque controlled PMSM drives and discusses a suitable estimator for PMSM drive systems with simulations and experiments.