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Functionally Integrated E-axle Ready for Mass Market Third GENeration Electric Vehicles

Periodic Reporting for period 1 - FITGEN (Functionally Integrated E-axle Ready for Mass Market Third GENeration Electric Vehicles)

Reporting period: 2019-01-01 to 2020-06-30

The ongoing activities in the electrification of vehicle technologies are key contributions to the protection of the environment by reducing anthropogenic CO2 emissions. In this context, FITGEN aims at developing a functionally highly integrated e-axle ready for implementation in third-generation electric vehicles (entering the market in the year 2023) by exploiting the potential of a portfolio of electric drivetrain technologies and components delivered at the end of the project at TRL and MRL of 7.

In FITGEN, these technologies are organized into three areas: power electronics and charger (area I), electric motor and transmission (area II), and cooling and control (area III). Together, these areas cover all the technical challenges addressed under the LC-GV-01-2018 call with innovative and highly integrated solutions. The advances under these areas are reported below:

• AREA I (WP2), power electronics, and charger: performance density of inverter will be increased by 50 % compared to the current State of the Art (SotA), with peak efficiency of 99 % and full optimization in WLTP conditions, with full adoption of wide bandgap SiC-modules. Charging capability is ensured, with increased capability from fast-charge to super-fast-charge, by decreasing magnetic losses and reducing the weight of the components. AC/DC onboard charging is also investigated in different possible configurations;
• AREA II (WP3), electric motor, and transmission: 40 % increased gravimetric power density compared to the current SotA by using a high-speed Buried Permanent Magnet-Synchronous Machine (BPM-SM) with high-speed operation. The motor is integrated with a very compact single-speed transmission;
• AREA III (WP4), cooling and control: design and optimization of the liquid cooling system of the machine, the power electronics and oil cooling of the high-speed transmission, with investigation of the functional integration of the liquid/oil cooling systems; development of joint control strategy for the power electronics, enabling the DC/DC-converter and SiC-inverter for the high-voltage operation of the e-motor in traction and enabling super-fast charging.
FITGEN has reached in June 2020 it's midterm status, delivering many of the expected results, despite the encountered technical difficulties and the Covid-19 pandemic which did not facilitate the work and technical progress of the involved partners.

Hereunder a concise overview of FITGEN’s progress in the period from January 2019 to June 2020:

The FITGEN project maintains in full its scope and ambition. The technical solutions identified at a proposal level under the inverter, motor, transmission have been all maintained, and the e-axle architecture conserves the original ideas which gave birth to the project. The relevance of the work is also ensured by the persistent interest of the reference OEM in integrating the FITGEN e-axle architecture in the demonstrator and in bringing the proposed solutions to the market. Preliminary results show that FITGEN is also over-performing on some KPIs. In particular:

- FITGEN motor power density is expected to exceed the initial target of 5.0 kW/kg by 4%, realizing 5.2 kW/kg and 24.5 kW/l;
- FITGEN motor speed is expected to exceed the initial target of 18,000 rpm by 28%, realizing 23,000 rpm of max. speed and sustaining 27,600 rpm in the overspeed test;
- FITGEN inverter power density is expected to exceed the initial target of 25 kW/l by more than 4%, realizing above 26 kW/l.

Hereunder a breakdown of the project progress per WP:

- WP1 has been completed, delivering the technical specification relevant to the definition of the architecture of the e-axle. The delivered elements enabled to undertake the design choices in the inverter, motor, and transmission domains;

- WP2 is in progress and in scope, running with an approximate delay of 4 months. The delay is mainly due to the difficulties encountered in the inverter design combined with the non-optimal working conditions imposed by the Covid-19 pandemic between March and July 2020. However, the two main innovative elements of the inverter design (6-phase architecture and the adoption of Si-C technology) are fully maintained. The risk associated with this delay has been managed by issuing a recovery plan (see WP8-T8.3 description) and a dedicated evaluation of the progress against the recovery plan (i.e. May 2020 Checkpoint). The other WP2 activities, i.e. on-board charger, DC/DC, and E/E interfaces among components, are progressing, minorly affected by the delays of the inverter design. This delay is critical, in the sense that it does have a cascade effect on the subsequent WPs (i.e. WP5/WP6); however, at the moment, the consortium is working to recover it, therefore the project does not need an amendment as per midterm status;

- WP3 is in progress and in scope, running with an approximate delay of 8 weeks. The delay is mainly due to difficulties encountered in converging the mechanical designs of the motor-inverter groups, as well as to several minor, yet relevant, details in designing ancillary components such as stub/link-shaft, bearing, brackets, mounting points, etc. This delay is non-critical, and it does not cumulate with the delay of WP2;

- WP4 is in progress and in scope, running with an approximate delay of 8 weeks. Here the activities on the cooling system design are proceeding in parallel with the progress of WP2/WP3, thus adopting the same delay on the schedule but without generating extra delays. This delay is also non-critical, and it does not cumulate with the delay of WP2;

- WP5/WP6 are not yet started in RP1, and only minor preparatory activities are reported;

- WP7 (dissemination) and WP8 (management) are in progress and in scope. So far, the project performed well in dissemination, publishing three scientific papers in RP1 and with four more in preparation for the second half of 2020.

At the moment of compiling the present report, FITGEN achieved 2 out of 2 milestones planned for RP1 and submitted 10 out of 11 deliverables planned for RP1.
The attached table reports a summary of the progress beyond the SotA (i.e. Progress beyond the SotA - FITGEN Midterm.jpg).

Concerning the expected results until the end of the project, FITGEN will deliver all the components of the e-axle (i.e. e-motor, inverter, transmission, DC/DC converter, and charger), assemble them, test and characterize the e-axle and demonstrate it on a demonstrator vehicle at TRL and MRL 7. The expected results are fully in line with the KPIs indicated in the DoA exceeding, where possible, a part of them.

Concerning the impact, FITGEN will address in full the impact categories addressed in the H2020-LC-GV-01-2018. Specifically, the FITGEN e-axle:

• realize significant improvements in the e-powertrain technological area, integrating new components (e.g. SiC modules) and functionalities (e.g. super-fast charging);
• provide an affordable e-axle fit for the automotive market of 2020-2030 decade, whose cost is expected to be 2,000 EUR by 2030 (considering production at scale);
• demonstrate the developed technologies at the vehicle level.

Ultimately, FITGEN will strengthen the competitiveness of the European industry contributing to unlocking the societal, environmental, and economical benefits associated with the roll-out of the third-generation electric vehicles.