Magnet-free electric motor technology expands

Valeo and MAHLE have joined forces to develop an innovative magnet-free electric axle system, targeting upper segment electric vehicles with peak power ranging from 220kW to 350kW. The iBEE system (inner Brushless Electrical Excitation) aims to revolutionize performance and efficiency of magnet-free electric motors. Valeo and MAHLE signed a Joint Development Agreement to combine both Valeo’s expertise in electric motors, highly efficient inverters, and associated motor control laws and the expertise of MAHLE on magnet-free rotors with its MAHLE Contactless Transmitter (MCT) technology. Valeo and MAHLE are working on an innovative cooling concept in order to achieve an outstanding continuous to peak power ratio. Moreover, the carbon footprint is expected to be reduced by more than 40% versus a permanent magnet electric motor of equivalent power. The testing of the first prototypes will be completed by the end of 2024.

“This cooperation with MAHLE is a perfect match,” says Xavier Dupont, Valeo Power Division CEO. “MAHLE develops the EESM rotor and their brushless excitation system. Based on our power electronics know-how, Valeo provides a dedicated control of this electric motor and brushless system embedded in our inverter. This partnership allows Valeo to complete its EESM portfolio towards upper segment and is key to support the evolution of the automotive industry towards more innovative sustainable solutions.”

“In this project two front runners of electrification are joining forces. The new e-axle will benefit from MAHLE’s expertise in contactless transmitter technology. Together we will be setting a new benchmark in packaging and efficiency for EESM based e-axles and taking the next step for our customers towards future mobility,” says Martin Wellhoeffer, member of the MAHLE Group Management Board.

Valeo’s first EESM development is based on a cooperation with a European OEM launched in 2022 in order to create a new magnet-free electric motor generation. The initial targets of the project were double; first, to get an all-in-one architecture with a new stator and cooling technology in order to increase by 30% the power density compared to the current motors equipping the current OEM’s vehicles on the road, and second, to shrink its carbon footprint by 30% vs. an electric motor equipped with magnets (PMSM). A validation phase for more than six months was successfully ended with results level over the initial expectations in terms of power and efficiency. The performances are matching the level of permanent magnet electric motors for B/C segment vehicles with all of the benefits of a magnet-free technology.

As part of its electrification strategy MAHLE has been focusing on developing electric drive systems. Its contactless transmitter technology for magnet-free electric motors is testament to the company’s strong expertise in this field. Thanks to its high maturity level it is a key enabler for the next evolution of EESM based eAxles. Avoiding the use of rare earth materials does not only positively contribute to the sustainability of e-mobility, but is also advantageous in terms of costs and resource security. The key feature is the inductive and thus contactless and wear-free power transmission allowing motor operation at benchmark efficiency level.