Robust nonlinear observer design for permanent magnet synchronous motors

This paper is devoted to the application of a recently proposed globally convergent adaptive position observer to non-salient permanent magnet synchronous motors. Following the Dynamic Regressor Extension and Mixing Based Adaptive Observer (DREMBAO) approach, a new finite-time robust observer is presented that allows to track adaptively the rotor position by measuring only the currents and voltages and without knowledge of mechanical, electrical and magnetic parameters. A numerical example for the case with different rotor speeds and time-varying load torque is considered to reveal the advantages of the proposed approach in comparison with other existing methods. Experimental studies of the proposed robust nonlinear observer implementation are presented to illustrate the efficiency of the new design technique in different speed modes together with adaptive estimation of unknown parameters.