Speed Ripples Reduction of PMSM Drives under Low-Speed Working Conditions

The present work deal with the undesired speed ripples caused by parasitic torques at low-speed conditions of Permanent Magnet Synchronous Machine (PMSM) based drives. The proposed speed ripples reduction technique is based on a power harmonic compensator where the damping signals are superposed to the reference current in a Field Oriented Control (FOC) scheme. The design procedure of the torque ripple compensator takes into account the local stability of the system. The practical feasibility and effectiveness of the proposed approach are verified under a small-scale laboratory test bench. Furthermore, the impact of the proposed method on the machine vibration is measured.