Improved H∞ repetitive controller for current harmonics suppression of PMSM control system

Abstract

The inverter owns nonlinearity characteristic, leading to high amount current harmonics in the Permanent Magnet Synchronous Motor (PMSM) control system. Hence, the operation performance of the PMSM control system will be affected. To suppress the current harmonics, the repetitive controller in the current loop is optimized through H∞ control theory, and an improved H∞ repetitive controller is proposed in this paper. Firstly, the state equation of the PMSM in dq reference frames is studied. To obtain the feedback compensator, estimated signals and auxiliary input signal are introduced into the control system. And then the transfer function matrix of the generalized controlled plant is established. Finally, the operation performances of the PMSM control system are carried out through Matlab/Simulink software, and the simulation results can verify the effectiveness and the superiority of the improved H∞ repetitive controller.

Keywords

• Permanent magnet synchronous motor
• Current harmonics
• Repetitive controller
• H∞