A novel disturbance observer based robust current-control for a PMSM drive system

This paper presents a robust current-control method for a PMSM with a novel disturbance observer (DOB). The proposed DOB adopts a new method to treat inverse stability issues that the conventional DOB method had difficulties in actual applications. As the proposed DOB has a semi-deterministic feature, the method is simple to be adopted in a microprocessor based control logic. The frequency domain analysis shows control performance of the proposed algorithm more practically. This control method improves gain and phase margins of the conventional robust current control methods when uncertainties exist on motor parameters and motor speed.