Current harmonic suppression in the flux-weakening control based on resonant-2DOF PID controllers for permanent magnet synchronous linear motor

In this paper, the current harmonic suppression problem of permanent magnet synchronous linear motor (PMSLM) in the flux-weakening control is studied by using the proposed resonant two degree of freedom (2DOF) current PID controllers. First, the principle of the flux-weakening is analyzed based on the mathematical model and the current voltage constraints of PMSLM in the rotating reference coordinate system. Then a current leading angle flux-weakening control method is designed, which provides a wide velocity operation of PMSLM over based velocity. Subsequently, the resonant-2DOF PID controllers are adopted to effectively suppress the current harmonics induced by the non-ideal factors in the flux-weakening control. At last, the simulation studies and experiments are performed for PMSLM based on the control platform in comparison with the traditional PID controller. The contrast results indicate that the proposed method suppresses the current harmonics effectively, and achieves optimal tracking ability and optimal antidisturbance performance simultaneously.