Proterial and FEV Simulate Amorphous-Alloy EV Motor Without Heavy Rare Earths
Simulations indicate potential for 300 kW peak power and a 27% weight reduction compared to a 230 kW reference unit.
Materials manufacturer Proterial and engineering services firm FEV have utilized simulation technology to evaluate a new electric vehicle traction motor concept. The design combines Proterial’s amorphous alloy core material with its heavy-rare-earth-free neodymium sintered magnets to enhance performance while addressing supply chain constraints.
What Happened
FEV constructed a reference model of a 230 kW drive unit, typical of modern passenger-car BEVs, using a silicon steel motor core. They then evaluated the impact of substituting the core with Proterial’s amorphous alloy through electromagnetic simulation. Amorphous alloy is a metal with no crystalline structure, created by rapidly cooling molten alloy, which exhibits lower iron loss than standard electrical steel sheets. Proterial has developed a continuous lamination and bonding process to make the amorphous alloy ribbon suitable for punching into motor cores.
The simulated concept motor operates at a higher maximum speed of 20,000 rpm, compared to 14,900 rpm for the reference unit. To maintain equivalent maximum torque and speed during vehicle operation, the reduction ratio was increased from 10.8 to 14.4. The new design features 12 poles instead of eight, maintains the same 72 slots and 200 mm stator outer diameter, but reduces the active length to 77.1% of the reference motor’s length.
Why It Matters
The integration of heavy-rare-earth-free neodymium sintered magnets addresses critical resource constraints and procurement risks associated with materials like terbium and dysprosium. Proterial states these magnets combine high remanence flux density with high coercivity. The simulations suggest significant efficiency gains, with motor efficiency rising from 95.5% to 97.9% on the WLTP Class 3 cycle and from 95.3% to 97.4% on the ARTEMIS MW 150 drive cycle. Additionally, the potential for peak power to increase from 230 kW to 300 kW and for motor weight to be reduced by 27% could offer substantial advantages in vehicle range and performance metrics.
The Bottom Line
Proterial and FEV’s simulations indicate that combining amorphous alloy cores with HRE-free magnets can significantly improve EV traction motor efficiency and power density while mitigating rare earth supply risks. These findings remain at the simulation stage, pending further development and real-world validation.
