Ferrstron Road-Tests Rare Earth-Free Ferrite-Magnet Motor

Indian electric powertrain developer Ferrstron Powertrains has successfully road-tested a prototype 150 kW, 400 Nm powertrain in a 2.3-ton multi-utility vehicle. The system’s motor utilizes ferrite magnets instead of rare earth magnets.

Ferrstron develops electric powertrains tailored for heavy-duty trucks, buses, high-speed trains, marine vessels, direct-drive wind turbines, and gensets. According to the company, its motor designs achieve 98 percent efficiency, driven by proprietary electromagnetic physics simulation technology.

The motors feature an axial-flux, dual-airgap layout, windings equipped with in-coil cooling, and a multi-phase flux control algorithm. This on-road test of the fully integrated system advances the core technology to Technology Readiness Level 6 (TRL 6).

While ferrite magnets are abundant, they traditionally trail rare earth magnets in magnetic strength and resistance to demagnetization. Ferrstron combats these limitations through four design strategies: generating higher overall magnetic flux, increasing armature reaction to decrease the required magnet flux, minimizing the demagnetizing impact of armature reaction, and applying multi-phase flux control to move the internal operating point away from the demagnetization limit.

Vishal Sharma, founder and CEO of Ferrstron, explained that this electromagnetic balance stems from combined innovations in magnetic circuit architecture, key element geometry and placement, in-coil cooled windings, and a proprietary multi-phase flux control algorithm. Looking ahead, Ferrstron plans to assemble its product lineup using stackable motor cartridges.

Validated simulation concepts include a 400 Nm cartridge intended for passenger and light commercial vehicles, deployable individually or in pairs to reach up to 800 Nm. Additionally, a larger 1,100 Nm cartridge can be stacked up to five times to deliver between 1,100 and 5,500 Nm for medium and heavy-duty trucks, buses, and distributed-traction high-speed trains.

Randolph Toom, Head of Global Strategic Partnerships at Ferrstron, noted strong market interest from global Tier 1 suppliers and OEMs aiming to phase out rare earth materials. The company is currently seeking investment for its next funding round to reach TRL 8 and launch production. Source: Ferrstron Powertrains.