Design of Robust Controller for PMSM Drivers

Generally, because of the temperature rise, the ageing, the saturation, etc. the resistance value and inductance value of the machine windings and the magnetic flux will be changed. The control performance of the permanent magnetic synchronous motors (PMSM) can be influenced by the plant parameter variation and external disturbance. This paper presents a robust H∞ control for PMSM drivers. Firstly, the state equations of the system was built based on the mathematical model of the PMSM, and appropriate weighting functions was selected to meet the requirement of the robust control system. The Riccati inequality was solved to derive the H∞ controller. Simulation results demonstrate that the designed control system has faster response and better load disturbance rejection capability compared with the conventional PI controller. And the robust H∞ control system can still work very well when the parameters of the PMSM have been changed.