Design Analysis of High Power Density Additively Manufactured Induction Motor

Induction machines (IM) are considered work horse for industrial applications due to their rugged, reliable and inexpensive nature; however, their low power density restricts their use in volume and weight limited environments such as an aerospace, traction and propulsion applications. Given recent advancements in additive manufacturing technologies, this paper presents opportunity to improve power density of induction machines by taking advantage of higher slot fill factor (SFF) (defined as ratio of bare copper area to slot area) is explored. Increase in SFF is achieved by deposition of copper in much more compact way than conventional manufacturing methods of winding in electrical machines. Thus a design tradeoff study for an induction motor with improved SFF is essential to identify and highlight the potentials of IM for high power density applications and is elaborated in this paper. A traction/propulsion motor application is considered due to its demanding requirements on power density, constant power to speed ratio and efficiency. The motor design space explores different number of poles, slots-per-pole-per-phase and slot fill factors while satisfying the stringent requirements. Then the total weight reduction of active materials in the proposed design is compared with traditional manufacturing methods. The analysis and proposed design validates the power density and efficiency improvement given the increased SFF availed due to additive manufacturing method.