Based on their successful joint development with a European OEM on magnet-free electric motor technology, top-tier automotive supplier Valeo is now extending its portfolio of the externally excited synchronous motors (EESM) towards upper segment vehicles together with Mahle. Magnet-free motors still employ strong magnetic fields to generate their power but, instead of relying on rare earth permanent magnets, they use an inductive system to create the rotating magnetic field necessary for operation.
The two companies have joined forces to develop an innovative magnet-free electric axle system, targeting upper segment electric vehicles with peak power ranging from 220 kW to 350 kW. Based on a system of inner brushless electrical excitation (iBEE), the technology aims to revolutionize performance and efficiency of magnet free electric motors.
Valeo, based in France, and Mahle, headquartered in Germany, recently 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 rotor with its contactless transmitter technology known as MCT. Engineers with the companies 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.
“This cooperation with MAHLE is a perfect match. MAHLE develops the EESM rotor and their brushless excitation system,” stated Xavier Dupont, Valeo Power Division CEO. “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”, said Martin Wellhoeffer, member of the Mahle Group management board.
Valeo”s first EESM development came from 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 was 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. Second was to shrink its carbon footprint by 30% versus an electric motor equipped with permanent magnets. A validation phase for more than 6 months was successfully ended with results level over the initial expectations in terms of power and efficiency especially thanks to Valeo inverter expertise. The performances match the level of permanent magnet electric motors for B/C segment vehicles without the use of rare earth permanent magnets.
