A NEW DESIGN METHOD FOR LOW-SPEED TORUS TYPE AFPM MACHINE FOR HEV APPLICATIONS

Axial flux permanent magnet (AFPM) machine type has some advantages such as compressed packaging, easy handling, and safety operation. In this paper the proper structure selec tion of AFPM machine for hybrid electric vehicle (H EV) application is one of the aims. To reduce the losses and the total volume of machine, the coreless TORUS-NS type machine is sele cted. Designing of this machine, to obtain a wide speed range with high eff iciency, low cogging torque and high torque value, as in-wheel direct-drive AFPM machine for HEV, is investigated. The operation per formance in low and medium speed ranges is studied. A new design method based on multi speed design (MSD) strategy is proposed. U sing this method with a coreless type of stators, t he total AFPM machine efficiency at the HEV operation cycles could be imp roved. Performance analysis of this in-wheel AFPM m achine is done using finiteelement method (FEM). FEM analysis of the single-sp eed design (SSD) method is also done. MSD and SSD d esigned machines are applied in HEV and simulated using urban and highwa y cycles. The obtained results show the better perf ormance of HEV, using the MSD based designed machine in all operation cycles. The experimental results obtained from sample prac tical prototype, confirm the analytical method.