The Electrical Machine Works: Exploring Metal Additive Manufacturing for Next Generation High Performance Electrical Machines and Wound Components

Step changes in electrical machine (e-machine) performance are central to the success of future More-Electric and All-Electric transport initiatives and play a vital role in meeting the UK's Net Zero Emission target by 2050. E-machine technology roadmaps from the Advanced Propulsion Centre (APC) and Aerospace Technology Institute (ATI) seek continuous power-density of between 9 and 25 kW/kg by 2035, in stark contrast to the 2-5 kW/kg available today.

E-machine power-density is ultimately limited by the ability to dissipate internally generated losses, which manifest as heat, and the temperature rating of the electrical insulation system. The electrical conductors, referred to as windings, are often the dominant loss source and are conventionally formed from electrically insulated copper or aluminium conductors. Such conductors are manufactured using a drawing and insulation technique, which aside from improvements in materials, has seen little change in the past century. Exploring alternative manufacturing methods could allow reduction in losses, enhanced heat extraction and facilitate increased temperature ratings, ushering the necessary step changes in power-density and e-machine performance.

Metal Additive Manufacturing (AM) is a process in which material is selectively bonded layer by layer to ultimately form a 3D part, enabling complex parts to be produced which may not be feasible using conventional methods. The design freedom offered by AM provides much sought-after opportunities to simultaneously reduce winding losses and packaging volume, improve thermal management and enable the use of high-temperature electrical insulation coatings.

The design of such windings requires the development of new multi-physics design tools accounting for electromagnetic, thermo- and fluid- dynamics, mechanical and Design for AM (DfAM) aspects. It is important to have an understanding of the AM process, including the resulting material properties of parts and limitations on feature sizes and geometry in order to fully exploit the design freedoms whilst ensuring manufacturing feasibility. Establishing how to use build-supports and post-processes to improve component surface quality and facilitate application of electrical insulation coatings is another important aspect. To this end, I conducted initial studies in collaboration with academic and industrial partners focusing on shaped profile windings which have demonstrated the potential benefits of metal AM in e-machines and the drastic expansion of design possibilities to be explored.

I intend to expand on this initial work through this fellowship which will provide me with flexible funding over a 4 + 3 year term to support The Electrical Machine Works, an ambitious and comprehensive research programme reminiscent of a Skunk Works project which draws together UK industry and academic expertise in AM, material science and multi-physics e-machine design to establish an internationally leading platform in this important emerging field.

It is envisaged that the fellowship and associated platform, The Electrical Machine Works, will facilitate interdisciplinary collaboration with both industry and academia, catalysing high quality academic outputs disseminated through appropriate conference and journal publications, and the generation of Intellectual Property (IP), helping to keep the UK competitive in Power Electronics Machines and Drives (PEMD) and at the forefront of this area. If successful, in time The Electrical Machine Works will become a centre of excellence for AM in e-machines, contributing to a future skills and people pipeline and aiding in the raising of Technology Readiness Levels (TRL) in line with national priorities as expressed by the UK's Industrial Strategy, Advanced Propulsion Centre (APC), Aerospace Technology Institute (ATI) and Industrial Strategy Challenge Fund (ISCF) Driving the Electric Revolution (DER) and Future Flight (FF) initiatives.