Sliding Mode Variable Structure I/o Feedback Linearization Design for the Speed Control of Pmsm with Load Torque Observer

Based on the mathematical model of the permanent magnet synchronous motor (PMSM), a novel sliding mode variable structure input-output feedback linearization controller is proposed. A precision linearization method is employed to achieve input-output linearization and decoupling control of the motor, which is decoupled into a second-order linear speed subsystem and a first-order linear d-axis current subsystem. Sliding mode variable structure is simple, and easy to combine with other intelligent methods, especially it has robustness to external disturbances. So the combination of sliding mode variable structure and feedback linearization could make the design method robust and quick dynamic. At the same time, an observer based on extended state observer is designed to evaluate the load torque of the system online. Theoretical analysis and matlab simulation results prove the effectiveness of the proposed method.