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Rare Earth Free e-Drives featuring low cost manufacturing

Periodic Reporting for period 2 - ReFreeDrive (Rare Earth Free e-Drives featuring low cost manufacturing)

Reporting period: 2019-04-01 to 2021-03-31

The ReFreeDrive project was focused on contributing to avoid the use of rare earth magnets through the development of a next generation of electric drivetrains, ensuring the industrial feasibility for mass production while focusing on the low cost of the manufacturing technologies.
The project has studied and developed simultaneously two solutions for the power traction system of electrical vehicles.
Both solutions are brushless AC electrical machines: induction machine with fabricated and copper die‐cast rotor (IM) and synchronous reluctance (SynRel) machine.
Through their configurations these machines not only are rare‐earth magnet free, but also share common features that can were exploited during the design step, as well as in the manufacturing process.
These common features lead to a complex synergy between the two technologies, which justified the development of different topologies of electric machines in just one project.
ReFreeDrive motor topologies have good room for cost reduction by off-setting permanent magnet use. One of the key avenues for cost reduction is the reduction of size through different techniques such as compact winding.
An optimized use of copper on the project provides technical design with a higher efficiency due to lower losses regards other alternatives, and more efficient heat management.
Beyond the motor design, ReFreeDrive also considered an integrated design of the power train that allows the optimization of the electric connections, the cooling systems and the housing.

As final conclusions:
₋ Given that by 2030 as latest we will have >25 Mio EVs per year produced globally and assuming that maybe 30% are an addressable market for our ReFreeDrive motor sizes (scalable between 75kW to 200kW), with the uptake of BEV & PHEV sales beyond 2025 and the need to substitute critical rare earths, both technologies Induction Motor with copper rotor and Synchronous Reluctance Motor (with/ or without non-critical Ferrites) promise to have a solid market opportunity.
₋ The know-how generated during the project development has been of great relevance for all the partners involved, beyond the specific performance achieved to be further exploited (on academic and commercial levels).
₋ ReFreeDrive drivetrain solutions promise excellent performance vs cost ratio for mass production.
₋ Plus, all e-machines from the ReFreeDrive project show a significant lower environmental impact compared to NdFeB permanent magnet motors.
The main results of the ReFreeDrive project are:
₋ Two rare-earth‐free motor technologies (copper rotor induction machines and synchronous reluctance machines) have been designed, optimized and compared. In the case of the induction machines two different types of motor were studied (fabricated and die casted copper rotors) for comparison and optimization purposes. Similarly, another two different avenues were developed for the synchronous reluctance machines (pure and ferrite permanent magnet assisted). As a result, four designs have being obtained for each of the two power range settings under study in this project: 75kW and 200kW.
₋ To achieve a design that meets the economic requirements, both traction technologies share the same power electronics and the same control algorithms for each use case (medium power range, high power range).
₋ Experimental testing of the developed motor technologies has been carried out, validating the proposed design methodologies and testing the performance of the motors with a series of test campaigns that added powertrain components until full integration into a vehicle.
₋ The techno-economic evaluation of each technology route in different manufacturing scenarios showed that all RFD motors achieve the cost saving targets in mass production. From an environmental point of view, the LCA of the developed motors shows a significantly lower environmental impact linked to their manufacturing process (Cradle-to-Gate approach).
₋ A Final Exploitation Plan was developed. This plan provides, among other things: (1) a comprehensive Market Analysis, covering the evolution and prospects of the electric vehicle (EV) market for the next decade, with a particular focus on reviewing the availability of critical raw materials from a European perspective; and (2) a Commercialisation Strategy that seeks the best avenues for market access after the project by enabling ReFreeDrive partners to compete for the development of new electric motors.
₋ The dissemination of the project results are satisfactory and have been mainly tracked through the website visits, papers statistics and LinkedIn statistics. More than 4700 users and 17000 sessions have been collected in the period October 2017 - March 2021 on the website.
In light of the aforementioned results and outcomes of the project, it is clear that it contributes to fostering the already ongoing uptake of electric powertrain technologies in the automotive sector; hence this project is fully in line with the objectives set in the Paris Agreement. The progress beyond current technologies is demonstrated at both technical and economic levels. From a technological point of view the motors improve the performance of the benchmark motors that have been used in the automotive sector in the last years. From an economic point of view, these superior performances do not entail a cost increase: taking into account the economic dimension of the challenge since the very beginning of the project has allowed the Consortium to establish synergies between the different motor technologies, and at the same time to ensure that all solutions are scalable to take advantage of economies of scale. As a result, all Key Performance Indicators that were set prior to the beginning of the project have been accomplished. Needless to say, the materialization of the manufacturing scenarios envisioned in the project’s exploitation plan (either 30k or 100k units/year) would mean significant job creation.

Furthermore, the implications of the motor technologies developed within the project are not merely technological or economical. All motor technologies are rare-earth free, hence from an environmental perspective they are much cleaner that the current prevailing technologies, which are based on the use of rare earth magnets, as demonstrated in the Life Cycle Assessment. Similarly, all components and materials included in the motors are relatively easy to recycle or reuse, which contributes to the circularity of the motors by easing the dismantling and disposal stages.

Finally, it is considered that this project is fully aligned with the vision and the industrial strategy of the European manufacturing sector, as it generated new knowledge and capabilities ready to be used by industrial stakeholders. Besides, the variety of technologies developed should support the creation and/or growth of the e-drive value chains in Europe. And finally, the absence of rare earths in the motors clearly reduces the dependence of the European electric motors value chains on external material imports, avoiding the price volatility and supply threats associated to this kind of materials, therefore contributing to the long-term stability of the European e-drive market.
ReFreeDrive Synchronous Reluctance motors
ReFreeDrive Vehicle integrated testing
ReFreeDrive Induction motors