Torque Improvement of Dual Three-phase YASA Machine Based on Current Harmonics Injection

The method for enhancing the torque capability of the dual three-phase yokeless and segmented armature (YASA) axial flux permanent magnet machine by injecting the 5th and 7th current harmonics is proposed in this paper. The mathematical model of the dual three-phase YASA machine considering the 5th and 7th harmonics of the open-circuit flux-linkage is established based on vector space decomposition method. The parametric model and vector control systems with and without the 5th and 7th current harmonics injection of the dual three-phase YASA machine are built to verify the effectiveness of torque enhancement by current harmonics injection. The simulation results show that the torque per peak current of the analyzed YASA machine can be improved by 8.74% by injecting 5th and 7th current harmonics.