Sensorless Control of PMSM using FOC Strategy based on LADRC Speed Controller

This article presents the study of the control system of a Permanent Magnet Synchronous Motor (PMSM) based on the Field Oriented Control (FOC) strategy, where the mathematical model of the PMSM may include uncertainties on parameter values, and the external disturbance represented by the load torque may be characterized by significant sudden variation. In this case, the PMSM control system is based on a Linear Adaptive Disturbance Rejection Controller (LADRC) speed controller. The LADRC type controller is based on an Extended State Observer (ESO), which performs the estimation of the rotor speed and of an extended state which includes the uncertainty of the system parameters and the external disturbance. The article presents the operating principle, the equations, and the structures of implementation in Matlab/Simulink of the main blocks of the control system based on the FOC strategy and the LADRC speed controller. Numerical simulations are presented comparatively for PI-type and respectively LADRC-type speed controller. The superior quality performance, the robustness, as well as a good dynamic and stationary response are noted for the LADRC controller. Future papers propose the approach of using the LADRC-type controller in the DTC strategy, as well as the implementation in embedded systems.