Design Studies on a Permanent Magnet Synchronous Machine With Y- and $\Delta$-Connected Stator Winding

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 presents finite element analyses of a such a machine in terms of a comparison of both Y- and Δ-connected stator windings. Thereby, the unknown zero sequence current with the Δ-connected stator winding has to be determined iteratively for each angular rotor position with all operating conditions. The most important design parameters such as electromagnetic torque and phase voltages are compared against both connections of the stator winding.