Research on speed sensorless backstepping control of permanent magnet synchronous motor

An nonlinear adaptive sliding mode speed/position observer was proposed for sensorless control of permanent magnet synchronous motors (PMSM) in this paper. The sliding surface was defined on the errors between the actual and estimated currents. The estimated back-EMF was observed to calculate the position of the rotor. A novel nonlinear control strategy, backstepping, is used to design speed tracking and current controllers. The system can achieve fast speed tracking and torque response. This paper gives the proof of system stabilization. Matlab simulation is carried out to prove the efficiency and feasibility of system design.