Axial-flux permanent-magnet brushless-dc (AFPMBLDC) machines with concentrated windings are very attractive choices for direct-driven applications due to their high torque-density, high efficiency, and extreme compact construction. This paper presents comparison of AFPMBLDC machines having either conventional slot and pole numbers, i.e. slot number to pole number ratio of 3 to 2; or similar slot and pole numbers. To estimate the required torque of the axial-flux motors, a simple vehicle model load is considered which includes rolling resistance, aerodynamic drag, and climbing resistance. In this research cogging torque, flux linkage, back-electromotive force (back-EMF), winding inductance, and electromagnetic torque are obtained for the two AFPMBLDC motors using high precision three-dimensional finite-element (3-D FE) method. It provides useful results to be considered in design of AFPMBLDC machines.

Full text: IJEIR-2178-FINAL.pdf