Additive Manufacturing of High Performance Shaped-Profile Electrical Machine Windings

Lead Research Organisation: University of Bristol
Department Name: Electrical and Electronic Engineering

Abstract

Performance improvement of electrical machines in terms of power-density and efficiency is central to the success of hybrid- and electric- vehicles and more- or all- electric aircraft, as indicated by the UK Advanced Propulsion Centre and the Aerospace Technology Institute. Efficiency and packaging volume of conventional electrical machines are limited by the method used to manufacture electrical windings, i.e. using pre-insulated conductors of uniform cross-section wound around the teeth of the stator. Here, we propose the use of metal additive manufacturing (3d printing), in which feedstock or powdered material is selectively bonded in a succession of 2D layers to incrementally form a compact 3D winding. The geometric freedom offered by additive manufacturing allows the simultaneous minimisation of end-winding volume and individual shaping of conductor profiles to optimise efficiency all while acting as a substrate for high performance inorganic electrical insulation materials. The technology could address the increasing drive to low batch size, flexibility and customisation in design for high integrity and high value electrical machines for the aerospace, energy and high value automotive sectors while enabling CO2 reductions demanded by legislation and market sentiment.

Specifically, I will lead this multidisciplinary project exploring the potential benefits of Additive Manufacturing of High Performance Shaped Profile Electrical Machine windings leveraging expertise from industrial and academic partners Renishaw, 3TAM, Motor Design Ltd and Teesside University. The partners represent leading electrical machine design (Motor Design Ltd, University of Bristol), electrical insulation materials (Teesside University), UK additive manufacturing supply chain (Renishaw) and end-use additive manufacturing part production (3TAM). This range of partners cover the necessary skills and capability to go from theoretical winding design to manufactured, insulated prototype windings. As such, the project will result in a significant growth in the UK's knowledge and skills base in this area and develop a technology demonstrator to illustrate the quantitative benefit of such windings to industry and academia. This will allow new cross-sector relationships and collaborations to be cultivated with a view to perpetuate the research beyond the project period, ultimately leading to industrial adoption and further poising the UK as a centre for excellence in high value electrical machine technologies.

Planned Impact

The research undertaken in the project is expected to provide direct, short- to medium-term impact for the partners involved, however, greater benefits are expected for the broader community in the longer-term.

BENEFITS TO INDUSTRY
The project aims to develop underpinning knowledge and capability to produce state-of-art additively manufactured shaped profile windings from theoretical design to prototype parts. This project will orchestrate knowledge transfer between industrial additive manufacturers, electrical machine designers and material scientists to communicate with each other respective requirements and needs, enabling each party to develop their technologies converging on solutions which provide short- and long-term competitive advantage in high value electrical machines. The project will contribute to a growth in the UK's knowledge and skills base, helping to incubate new supply chain capabilities and step toward meeting the electrical machine performance targets set out by the Advanced Propulsion Centre and Aerospace Technology Institute.

BENEFITS TO POLICY MAKERS
The development of high performance shaped profile electrical machine windings can enable electrical machine efficiency and power-density improvements necessary to accelerate the timeline of, for instance, future low-carbon electric transport technologies. This will benefit policy makers in a timely positive impact on worldwide governments' plans to reduce reliance on imported oil and, commensurate with a growth in renewable electricity production, lower global C02 emissions and local pollution.

BENEFITS TO SOCIETY AND THE ENVIRONMENT
Faster introduction of electric vehicles has significant benefits to local society and the environment, these include reduction in local air and noise pollution. Furthermore, if UK academia and industry can take the lead in the development of this technology then additional jobs both in manufacturing and the knowledge economy can be expected. To this end, the project aims to develop a people pipeline of appropriately skilled individuals rooted in the Electrical Energy Management Group at the University of Bristol. On a global scale, faster introduction of pure electric vehicles, assuming production of electricity by renewables or nuclear, will enable faster reduction in transport related CO2 emissions and other airborne pollutants resulting from use of internal combustion vehicles.

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