New Generation of Electrical Machines Enabled by Additive Manufacturing

Project Information

EMByAM

Grant agreement ID: 101073250

DOI

10.3030/101073250

EC signature date 12 July 2022

Start date 1 September 2022

End date 31 August 2026

Funded under

• Marie Skłodowska-Curie Actions (MSCA)

Total cost

No data

EU contribution

€ 1 520 395,20

Coordinated by

GOTTFRIED WILHELM LEIBNIZ UNIVERSITAET HANNOVER
Germany

Periodic Reporting for period 1 - EMByAM (New Generation of Electrical Machines Enabled by Additive Manufacturing)

Reporting period: 2022-09-01 to 2024-08-31

Summary of the context and overall objectives of the project

Additive manufacturing (AM) is a term used to describe various manufacturing processes in which a three-dimensional body is produced layer-by-layer by adding material. Process-related special features and the associated potentials open up new design possibilities and at the same time bring new challenges. The potential of additive processing of soft magnetic materials and windings in the manufacturing of rotating electrical machines (EM) and the free constructive design in all three spatial directions distinguishes it from conventional manufacturing, which is usually based on two-dimensional iron sheet lamellas. Solid materials can be replaced by lightweight lattice structures or by cavities in places where it is not needed from an electromagnetic, mechanical or thermal (multi-physics) point of view. In addition, additive manufacturing eliminates the need for component-specific tools, which is particularly relevant for the production of prototypes and niche applications, hence accelerating the development cycle of innovative drive solutions. Despite the promising prospects of 3D-printed electrical machines, there is no commercially additively manufactured EM yet and the state-of-the-art of application of AM in EM is solely limited to some diverse research projects. The time-consuming process of 3D printing and the higher costs of AM EMs are not yet balanced with the evidence to date of the improvements in functionality provided by 3D-printed electrical machines. The break-through technology is the multi-material additive manufacturing of electrical machines. In this case, not only considerable, multi-physics modifications can be achieved, but also AM makes the ground-breaking progress to reach a new generation of high-performance electrical machines for diverse applications. Concrete examples are extremely high gravimetric power density EM for electrical aircrafts with AM, direct cooled, transposed stator windings for very high current densities or the additive manufacturing of hairpin windings for electrical vehicles. The impact of these technologies in the context of climate change and decarbonisation is obvious.
It is therefore essential to study not only the potential of this technology to achieve a new-generation of electrical machines, but also to prepare the required tools and methods for design, calculation and construction of these machines. Only then new AM EM can reach the required performance, which cannot be achieved by conventionally manufactured EMs and, in the longer term, can become a cost-effective competitor to established manufacturing techniques. To summarise, the main objectives of the project are:
- Conceiving new concepts of electrical machines that benefit from the 3D geometrical freedom of AM
- Studying the potential and laying the foundations of multi-material additive manufacturing to enhance the EM performance
- Establishing a network for educating qualified engineers with deep knowledge on both additive manufacturing processes and electrical machines
- Establishing a founded knowledge-based group of experts from academic and industry to represent a solid European innovation and to maintain the pioneering role of the EU in this field
- Reducing the stringent material requirements, particularly focusing on rare-earth magnets, in the light of raw materials shortages.
The goal of the EMByAM project is to establish a consortium of renowned institutes and industry partners in the field of electrical machines and additive manufacturing for a comprehensive, multi-disciplinary development of these objectives.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

At the current stage of the project the review of the state-of-the-art literature and technology is finished and the development of new electrical machine designs enabled through additive manufacturing is underway. On the one hand various simulations to optimize key parameters of different types of electrical machines through changes in the machine design and the possibilities of additive manufacturing have been completed. Currently, the main focus is on the winding geometry and layout as well as the rotor design. The two machine types that are examined at the moment are the synchronous reluctance machine (with and without permanent magnet assistance) and the permanent magnet synchronous machine. Where possible, standard simulation software and algorithms are applied but also new tools for the project specific requirements have been developed and are being used. For testing of these new machine designs the development of new test setups has already started.
The additive manufacturing side of the project heavily relies upon the 3D-printing of small samples of different materials (mainly copper, aluminium and iron), geometries and printer settings to find optimal parameters for the machine windings, housing, stator core and rotor. So far over 40 sample structures from AlSi10Mg (planned for the machine housing) were printed for mechanical and thermal testing. Additionally, some thick-walled cylinders as an approximation for the EM stator and housing were printed to study vibrations as well as three spoke-type ferrite permanent magnet rotors for validating previous simulation results.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

The works on topology optimization on magnetic actuators will open new designs for electric machines that can leverage benefits of the freedom in manufacturing using additive manufacturing. Several journal articles beyond the state of the art were published. For example, design considerations of a new IPM rotor with efficient utilization of PMs enabled by additive manufacturing was published in IEEE Access. Several articles are also under review where novel ideas of using additive manufacturing to improve the performance of electric machines were investigated. Furthermore, several prototypes were additively manufacturing by different printers, and they are ready to be tested and compared with those produced by conventional manufacturing techniques. This will allow a demonstration of using additive manufacturing of electric machines in both theoretical and experimental aspects.
The results of the project also cover a wide range of winding optimization methods for reduction of additional losses caused by the skin effect. This includes new construction solutions for a hair-pin winding such as optimal choice of conductors arrangement in a slot, twisting conductors in the winding overhang and using Roebel bar concept. The key need to ensure further success in development of the skin-effect-optimized hair-pin winding is to find a technical opportunity to produce the full winding with these construction solutions.
The thermal analysis simulation of electrical machine frames using a gyroid structure shows better results than the conventional frame. These results will impact the scientific community by advancing the knowledge of electrical machine frames and enabling further research in the design of new frames. Current solutions are limited by the unavailability of multi-material diffused printing and the higher costs of the overall printing process. In contrast, the proposed solution will enable lightweight, vibration-damped, and thermally efficient electrical machine frames, representing a significant leap forward in scientific, technological, and industrial terms.