Periodic Reporting for period 1 - CliMAFlux (Circular design and manufacturing techniques for next-generation highly-efficient integrated axial flux motor drives for electric vehicles)
Okres sprawozdawczy: 2024-01-01 do 2025-06-30
Electric powertrains are at the heart of the transition towards a zero tailpipe emission road mobility landscape, with their performance and cost directly impacting the attainable market penetration of electric vehicles. To accelerate the transition, next-generation electric motors need to push the existing boundaries in terms of efficiency, power density, manufacturability, cost, and environmental sustainability. A reduced and more circular use of rare earth resources is critical to reinforce Europe’s strategic autonomy and establish a more economically sustainable value chain. Recently developed axial flux motor technology based on a yokeless and segmented armature topology yields promising prospects in all these areas, significantly reducing the required amount of rare earth magnet material by design, and combining this with unmatched power density compared to state-of-the-art radial flux machines.
CliMAFlux will develop novel concepts(e.g. in terms of excitation and cooling) for more performant (e.g. >35% energy loss decrease in driving cycles) axial flux motors, thus reducing the need for rare earth materials by 60%, leveraging high-fidelity multiphysics models (e.g. electromagnetic, thermal, mechanical, and at the system level) and digital twins. Innovative designs and manufacturing processes will be proposed to: (i) increase the power density to >23 kW/l, through novel materials and improved thermal behaviour; (ii) enhance circularity over the lifetime (including >70% recyclability at the end of life); and (iii) ensure cost competitiveness (50% cost reduction) at mass production level (reaching ~€5/kW). The CliMAFlux on-board motors are integrated with the power electronics and mechanical transmission systems. The resulting electric drives will be managed by robust predictive controllers based on the CliMAFlux digital twins, including artificial intelligence (AI) prediction models, which will also facilitate novel functionalities in vehicle (sub)systems, hereby exploiting the full capability of the complete electrified drivetrain. The individual motor and integrated drive system will be benchmarked over a wider range of vehicles, in terms of both performance and environmental impact, on virtual (X-in-the-Loop with digital twin) and hardware test platforms up to TRL7, i.e. on a research electric vehicle already available at the consortium participants. To achieve these ambitious targets, CliMAFlux brings together the competences of 4 academic partners, 1 industry-oriented RTO, 3 SMEs and 1 LE with dedicated R&D and production facilities in the fields of motor and transmission development, power electronics integration, electrified vehicle systems, automotive design, and life cycle assessment and costing aspects.
CliMAFlux will develop novel concepts(e.g. in terms of excitation and cooling) for more performant (e.g. >35% energy loss decrease in driving cycles) axial flux motors, thus reducing the need for rare earth materials by 60%, leveraging high-fidelity multiphysics models (e.g. electromagnetic, thermal, mechanical, and at the system level) and digital twins. Innovative designs and manufacturing processes will be proposed to: (i) increase the power density to >23 kW/l, through novel materials and improved thermal behaviour; (ii) enhance circularity over the lifetime (including >70% recyclability at the end of life); and (iii) ensure cost competitiveness (50% cost reduction) at mass production level (reaching ~€5/kW). The CliMAFlux on-board motors are integrated with the power electronics and mechanical transmission systems. The resulting electric drives will be managed by robust predictive controllers based on the CliMAFlux digital twins, including artificial intelligence (AI) prediction models, which will also facilitate novel functionalities in vehicle (sub)systems, hereby exploiting the full capability of the complete electrified drivetrain. The individual motor and integrated drive system will be benchmarked over a wider range of vehicles, in terms of both performance and environmental impact, on virtual (X-in-the-Loop with digital twin) and hardware test platforms up to TRL7, i.e. on a research electric vehicle already available at the consortium participants. To achieve these ambitious targets, CliMAFlux brings together the competences of 4 academic partners, 1 industry-oriented RTO, 3 SMEs and 1 LE with dedicated R&D and production facilities in the fields of motor and transmission development, power electronics integration, electrified vehicle systems, automotive design, and life cycle assessment and costing aspects.
During the first 18 months of the CliMAFlux project, significant progress was made across all work packages toward the development of a next-generation, sustainable axial flux motor based integrated drive unit for battery electric vehicles (EVs). A major focus was on the co-design and integration of high-performance axial flux motors and power electronics into a compact, modular Integrated Drive Unit. The design emphasizes recyclability, reduced rare earth material usage, and improved energy efficiency, achieving substantial gains in power density and thermal management.
In addition to the main Integrated Drive Unit (IDU), axial flux motors were also studied for use in vehicle subsystems, with specific applications including active suspension, active steering, and active toe and camber control. Multi-physics digital twin frameworks were implemented to optimize the behavior of these subsystems and to accurately predict their performance under real-world operating conditions.
To enhance the sustainability of axial flux motors, a hybrid-excited rotor was investigated, in which a limited amount of permanent magnets is combined with an excitation winding. In parallel, research was conducted into the design adaptations required to enable the use of aluminum instead of copper in the stator windings. This included an analysis of how such material substitutions impact the key performance indicators of the motor system.
Technical specifications for the test vehicle and its components (motor, gearbox, inverter, suspension) were completed, enabling integration and validation testing. Various cooling strategies and structural optimizations were performed on the main IDU and AF-bas ed subsystems, including advanced casing designs using cast and machined aluminum components. In parallel, digital twins and AI-based models were developed to simulate and optimize motor control strategies.
The project also established a comprehensive sustainability framework that guides material selection, recyclability, and life-cycle assessments. Project management activities ensured effective coordination, risk monitoring, and compliance with data and IPR management protocols. Multiple consortium meetings and technical committee sessions facilitated collaboration across all partners. Two amendments were submitted and approved, including the addition of Vilnius Tech (Hop-on) and Universidad de Deusto as project partners to reinforce technical expertise.
In addition to the main Integrated Drive Unit (IDU), axial flux motors were also studied for use in vehicle subsystems, with specific applications including active suspension, active steering, and active toe and camber control. Multi-physics digital twin frameworks were implemented to optimize the behavior of these subsystems and to accurately predict their performance under real-world operating conditions.
To enhance the sustainability of axial flux motors, a hybrid-excited rotor was investigated, in which a limited amount of permanent magnets is combined with an excitation winding. In parallel, research was conducted into the design adaptations required to enable the use of aluminum instead of copper in the stator windings. This included an analysis of how such material substitutions impact the key performance indicators of the motor system.
Technical specifications for the test vehicle and its components (motor, gearbox, inverter, suspension) were completed, enabling integration and validation testing. Various cooling strategies and structural optimizations were performed on the main IDU and AF-bas ed subsystems, including advanced casing designs using cast and machined aluminum components. In parallel, digital twins and AI-based models were developed to simulate and optimize motor control strategies.
The project also established a comprehensive sustainability framework that guides material selection, recyclability, and life-cycle assessments. Project management activities ensured effective coordination, risk monitoring, and compliance with data and IPR management protocols. Multiple consortium meetings and technical committee sessions facilitated collaboration across all partners. Two amendments were submitted and approved, including the addition of Vilnius Tech (Hop-on) and Universidad de Deusto as project partners to reinforce technical expertise.
Although much attention has been devoted to improving the sustainability of electric motors, the use of aluminium stator windings remains limited to a few conceptual studies and research prototypes. This project has comprehensively demonstrated that the gravimetric power density of axial flux motors with YASA topology can be increased by 10–15% compared to equivalent designs using copper windings. This is a significant research finding, particularly relevant for applications where weight is a dominant constraint.
In addition to the performance benefits, aluminium also scores substantially better in both Life Cycle Cost (LCC) and Life Cycle Assessment (LCA). The reduced LCC makes this technology attractive for cost-sensitive applications, such as vehicle subsystems and even industrial electric drive systems.
Within the CliMAFlux project, the existing design toolchain for axial flux motors with YASA topology was extended to support the use of aluminium stator windings. In particular, detailed modelling of skin and proximity effects and revised thermal models were developed. These enhancements enable semi-automated motor designs based on customer specifications. Demand for feasibility and benchmarking studies for axial flux motors has steadily increased in recent years.
A second major innovation concerns the introduction of axial flux motors with hybrid excitation. In this concept, permanent magnets are combined with a field excitation winding. This allows for a significant reduction—up to 60%—in the amount of permanent magnet material used. Compared to designs relying solely on field excitation (currently under investigation by competing axial flux motor manufacturers and service providers), the hybrid concept offers superior key performance indicators in terms of power density and drive cycle efficiency.
As this specific series-parallel hybrid topology has not yet been proposed for either axial or radial flux machines, protection of the intellectual property is being pursued via a patent application. In addition to axial flux applications, a lightweight variant of the hybrid excitation concept could also be made suitable for standard radial flux motors.
In addition to the performance benefits, aluminium also scores substantially better in both Life Cycle Cost (LCC) and Life Cycle Assessment (LCA). The reduced LCC makes this technology attractive for cost-sensitive applications, such as vehicle subsystems and even industrial electric drive systems.
Within the CliMAFlux project, the existing design toolchain for axial flux motors with YASA topology was extended to support the use of aluminium stator windings. In particular, detailed modelling of skin and proximity effects and revised thermal models were developed. These enhancements enable semi-automated motor designs based on customer specifications. Demand for feasibility and benchmarking studies for axial flux motors has steadily increased in recent years.
A second major innovation concerns the introduction of axial flux motors with hybrid excitation. In this concept, permanent magnets are combined with a field excitation winding. This allows for a significant reduction—up to 60%—in the amount of permanent magnet material used. Compared to designs relying solely on field excitation (currently under investigation by competing axial flux motor manufacturers and service providers), the hybrid concept offers superior key performance indicators in terms of power density and drive cycle efficiency.
As this specific series-parallel hybrid topology has not yet been proposed for either axial or radial flux machines, protection of the intellectual property is being pursued via a patent application. In addition to axial flux applications, a lightweight variant of the hybrid excitation concept could also be made suitable for standard radial flux motors.