Nonlinear control of a permanent magnet synchronous motor with disturbancetorque estimation

This paper introduces a sensorless nonlinear control scheme for controlling the speed of a permanent magnet synchronous motor (PNSM) driving an unknow n load torque. The states of the motor and disturbance torque are estimated via an extended nonlinear observer avoiding the use of mechanical sensors. The control strategy is an exact feedback linearization law, with trajecto ry tracking evaluated on estimated values of the PMSM states and the distur bance torque. The system performance is evaluated by simulations.