Research on hybrid controller utilizing proportional and repetitive control scheme for Permanent Magnet Servo System

Abstract

Due to the existence of high amount stator current harmonics caused by the inverter nonlinearity, the operation performance of Permanent Magnet Servo System (PMSS) used Proportional–Integral (PI) controller will be affected. To suppress the current harmonics in the PMSS, a hybrid controller utilizing proportional and repetitive control scheme for the current loop is proposed. Firstly, the phase-frequency characteristic and the magnitude–frequency characteristic for the hybrid controller bode diagrams are analysed. To improve the open-loop gain in the frequency band of high-proportion harmonics and compensate the phase lag, the hybrid controller parameter setting method is also studied. Furthermore, the stability and the anti-interference ability of the PMSS used hybrid controller are analysed through Lyapunov theory. Finally, the PMSS model is established through Matlab/Simulink software, and the operation performances of the PMSS utilizing different current loop controllers are studied. The simulation results show that the proposed hybrid controller can suppress the current harmonics and the output torque ripple effectively.