Sensorless of integral sliding mode controlled PMSM at low speeds

As the variation of stator resistance may influence the speed estimation and tracking control of reference speed for the sensorless of permanent magnet synchronous motor(PMSM),so based on model reference adaptive strategy(MRAS),an observer is constructed,which provides the rotor speed and stator resistance estimation on the basis of the measured stator voltages and currents.The speed and stator resistance adaptive law was defined by Popov's hyperstability.And also a sliding-mode controller with an integral switching surface was designed,which was employed for speed tracking of the drive system.The closed-loop stability of the proposed controller was proved under parameter uncertainties and load disturbances using the Lyapunov stability theory.Theoretical analysis and simulation results have verified the feasibility and effectiveness of the proposed method at low speeds.