Additive Manufacturing for Next Generation Functional Integration of Windings and Thermal Management in Future Electrical Machines
Step changes in electrical machine (e-machine) performance in terms of efficiency, power-density and torque-density are central to the success of future More-Electric and All-Electric transport initiatives. These changes play a vital role in decarbonisation eﬀorts and in meeting the UK’s Net Zero Emissions target by 2050.
The performance of an electrical machine is ultimately limited by the ability to dissipate internally generated losses, manifesting as heat, and the temperature rating of the electrical insulation system. At present, the electrical windings are a major performance bottleneck, hence, improvement in their design and functionality could unlock these step changes.
Why is it important?
The Aerospace Technology Institute (ATI) and Advanced Propulsion Centre (APC) technology roadmaps envisage future elimination of conventional winding processes and functional integration as key to removing the bottleneck and achieving the necessary performance goals toward 2035.
A promising approach is to adopt metal Additive Manufacturing (AM), in which feedstock or powdered material is selectively bonded in a succession of 2D layers to incrementally form a 3D part and produce windings with unmatched geometric freedom. The design flexibility on offer has great potential in realising high-performance, high-value, customisable, low-volume windings applicable to vehicle traction, aerospace and eVTOL systems among others.
What will the project demonstrate?
This project aims to demonstrate the design flexibility and close functional integration possibilities afforded by metal AM through the realisation of a low Technology Readiness Level (TRL) 3-phase concentrated winding and integrated cooled star-point concept, as illustrated in Fig. 1. The coils will be manufactured in copper or copper alloy by a Powder Bed Fusion (PBF) technique in collaboration with two industrial partners.
Fig. 1: 3-phase set of AM coils mounted on a stator section. Note: concept illustration – star point, detailed connections and fluid channels not shown
The viability of cooing coils through an integrated star-point will be assessed alongside a 3-phase set of coils, each of which will showcase a different set of integrated design features including:
- Shaped profile windings (non-uniform conductors)
- Sculpted, minimal volume end-windings
- Through conductor fluid cooling
- Splayed end-windings to enhance heat extraction (via natural convection or impingement cooling)
- Integrated terminals/fluid couplings
- Integrated sensors (thermocouples, current shunt)
If successful, the demonstrator will encourage conversation between manufacturers and electrical machine designers across the FEMM Hub and beyond, and could spur innovation in highly integrated traction drive solutions for low-volume, high-value markets such as performance automotive, future aerospace and eVTOL.