Design studies on an external rotor permanent magnet synchronous machine for a position sensorless control — Comparison of Y- and Δ-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. With such an application, the machine will operate in a wide speed range and on the other hand with very fast changing loads in both motor and generator operational modes. The paper discusses finite element analyses for the optimization of a permanent magnet machine with an external rotor in terms of a comparison of a Y- and Δ-connected stator winding and the influence on the electromagnetic torque as one of the most important design parameter.