On winding design of a high performance ferrite motor for traction application

Design of low cost traction motors with ferrite magnets needs to meet challenges such as minimizing the risk of demagnetization, and maximizing the torque and power density, via a suitable choice of rotor and stator winding topology and parameters. With regards to the stator, distributed and concentrated windings may have both advantages and disadvantages when considering manufacturing cost, slot fill factor, the contribution factor of reluctance torque and parasitic effects. Furthermore, the trend toward high speed operation of the traction motors may increase the AC loss effects in the windings, contributing to motor deficiencies and risk of thermal failure. In this paper, the performance of a high speed ferrite motor with a distributed and concentrated wound stator, and with regards to torque and power performance as well AC loss effects is assessed. The dynamic performance of a full scale prototype design based on a distributed aluminum wound stator is presented.