Variable Turn Rectangular Wire Winding Permanent Magnet Machine

Abstract

Nowadays, the rectangular wire winding permanent magnet machines for electric vehicle application have drawn more and more attentions due to their high torque density and high efficiency. However, considering the conductors in the rectangular wire winding always have much higher cross section area than that of regular machines with stranded windings, the rectangular wire winding machines suffer big AC losses especially at the high speed condition due to severe proximity and skin effects. In this paper, a variable turn rectangular wire winding machine with 48-slot 8-pole 4/2-layer has been proposed to restrict the AC losses, where the conductors near the slot opening can be disconnected at designed operating speed according to the control of centrifugal switch. Especially, based on the unique process craft of rectangular wire winding, the corresponding 4/2-layer winding connection have been properly designed with little increase of the cost and process difficulty. What's more, the performance of proposed machine has been compared with the regular 4-layer rectangular wire winding machine, which indicated that the power density, torque density, efficiency and flux-weakening capability can be significantly improved.