Ultra-Compact Design of Additively Manufactured Variable Cross Section Profile Bar Winding for Traction Motor

Due to advancements in additive manufacturing of pure copper, previously unavailable opportunities are becoming possible for ultra-compact windings in electric machines. In this paper a conductor design featuring constant cross section with variable profile is introduced, resulting in a reduction of 22% of the end turn volume. A demonstration prototype was built using a conventional laminated stator stack, winding conductors created by Additive Drives GmbH (ADD) via selective laser melting, and subsequently insulated with PEEK coating. Thanks to an ADD proprietary technique, the entire winding was created and assembled into the stator without the need for additional welding. The motor performance and efficiency were measured on a dynamometer and are included in the paper.