Sensorless Control of PMSM using DTC Strategy Based on PI-ILC Law and MRAS Observer

This article presents the sensorless control system of a PMSM (Permanent Magnet Synchronous Motor) based on the DTC (Direct Torque Control) control strategy, where the speed controller is of ILC (Iterative Learning Control) type. This control system is recommended in case of the repetitive tasks performed by the PMSM control system. Also, the superiority of the ILC controller leads to good performance if the load torque (considered as a disturbing signal for the speed control system) has an oscillating variation. In order to increase the reliability of the control system, the speed sensor is replaced with a MRAS (Model Reference Adaptive System) speed observer. The article presents the equations of the PMSM, of the control system, of the observer and the implementation in Matlab/Simulink. The results obtained are presented comparatively for PI, PI-ILC law speed controllers. The superior performance and the parametric robustness are noted for the PI-ILC law speed controller. Based on the results obtained through numerical simulations, the implementation in embedded systems is recommended, in future papers.