A DOB based robust current control of Permanent Magnet Synchronous Motor

Abstract

This paper presents a novel current-control method for a Permanent Magnet Synchronous Motor(PMSM) with a disturbance observer (DOB). 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 and others 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. This algorithm is especially effective when mechanical motion makes sharp back-EMF changes and some frequency modes of disturbance suffer from torque ripples.