A Non-Cascaded Control Method Based on Composite Extended State Observer for Permanent Magnet Synchronous Motor

The traditional vector control method for permanent magnet synchronous motor (PMSM) typically adopts a cascaded control structure, with an inner current loop and an outer speed loop. With advancements in technology, the control period difference between the inner and outer loops has become negligible. As an alternative approach, a non-cascaded structure offers a more straightforward control design and simpler parameter tuning, while still fulfilling the system's dynamic performance requirements. In this paper, a composite extended state observer-based sliding-mode control (SMC) method is proposed. Firstly, two extended state observers (ESO) are designed, one is the composite extended state observer to estimate the mismatched disturbances in the PMSM system, and the other is the extended state observer to estimate the matched disturbances. Based on this, a non-cascaded sliding-mode controller considering current constraint is designed, integrating disturbance estimation to enhance the anti-disturbance capability of the PMSM system. Finally, simulation results are provided to validate the effectiveness of the proposed method.