Design of High Power Permanent Magnet Motor With Segment Rectangular Copper Wire and Closed Slot Opening on Electric Vehicles*

Brushless permanent magnet DC motors are being manufactured and used increasingly in everything from home appliances to automobiles due to their inherent advantages. The merits of these motors could be enhanced further according to another design approach method which alters the typically used winding parts for low to medium power range motors. This paper deals with the high power brushless DC motor used for traction in a 48 V golf cart system. The stator is designed with segment rectangular copper winding to maximize output power within its limited dimensions. In the design process, the closed slot opening and slot-pole combination are investigated and compared in terms of efficiency and input current density. The developed motor obtained about 120% greater power density per volume compared to a commercial motor with round winding coils at similar efficiency and variable speed range.