Finite element analysis of an external rotor permanent magnet synchronous machine with star- and delta-connected tooth coil windings

The permanent magnet synchronous machine with an external rotor is the most important device for high performance electrical drive systems in particular for hybrid electric vehicles. The paper discusses finite element analyses of such a machine with concentrated tooth coils in terms of a comparison of both Y- and Δ-connected stator windings. As the evolved electromagnetic torque is one of the most important design parameter, various ratios of tooth width and slot pitch are analyzed with the two connections of the stator winding. On the other hand, the phase voltages for various operating conditions are compared between both Y- and Δ-connected stator windings.