Comparison of sensorless FOC and SVM-DTFC of PMSM for low-speed applications

This article presents the performance analysis of Field Oriented Control (FOC) and Space Vector Modulation (SVM) Direct Torque and Flux Control (DTFC) of a Non-Salient Permanent Magnet Synchronous Machine (PMSM) under sensorless control within low speed region. The high-frequency alternating voltage signal injection method has been chosen for sensorless control design. PMSM is modelled at high frequencies, and a rotor speed and position estimation algorithm is proposed. The proposed estimator is designed and implemented using MATLAB/Simulink^® and is tested under several operating conditions with a commercially available PMSM machine. Both controllers show satisfactory sensorless performance. FOC provides smoother and more accurate response while SVM-DTFC has the advantage of faster control.