Motor Stator With Thick Rectangular Wire Lap Winding for HEVs

A stator structure with a rectangular wire distributed winding that exhibited high levels of productivity and extremely flexible design was designed for hybrid electric vehicle motors. We devised a method of forming thick rectangular wire diamond coils and determined the best conditions for forming high-density coils. A structure for terminal connections was also devised to achieve a short coil end. The slot-fill rate of a prototype stator was 80.5%, and its total coil end was 42 mm, which is roughly the same motor performance of a stator with segmented coil wave winding. The key advantage here is that the proposed stator had fewer coils and welding points than a stator with segmented coil wave winding and that the possible number of conductors per slot was higher than four, which is the limit for the stator with segmented coil wave winding.