The permanent-magnet synchronous motor is the kind of motor most regularly utilized in EVs, however it’s primarily based on magnets that require uncommon earth supplies, which supplies automakers an incentive to hunt options. As readers of Jeffrey Jenkins’s common articles know, there are numerous different choices, every with its personal execs and cons relating to use in EVs.

Now Tier 1 provider ZF has developed an electrical motor which requires no magnets. In distinction to the at the moment out there magnet-free Individually Excited Synchronous Motor (SESM), ZF’s In-Rotor Inductive-Excited Synchronous Motor (I2SM) transmits the power for the magnetic area through an inductive exciter contained in the rotor shaft. ZF says this makes the motor uniquely compact, with most energy and torque density.

In line with ZF, in comparison with widespread SESM methods, the inductive exciter can cut back losses for power transmission into the rotor by 15 p.c. Additionally, the CO₂ footprint of productioncan be lowered by as much as 50 p.c in comparison with PSM motors that use uncommon earth supplies.

“This uniquely compact electrical motor with out magnets is spectacular proof of our technique to make e-drives extra resource-efficient and sustainable, primarily by means of effectivity enhancements,” stated Stephan von Schuckmann, Member of the Board of Administration of the ZF Group.

ZF says its I2SM eliminates the drag losses created in conventional PSM e-motors. This permits higher effectivity at sure working factors corresponding to lengthy freeway journeys at excessive pace.

To make sure that the magnetic area within the rotor is constructed up by present as an alternative of magnets, present SESM ideas nonetheless require sliding or brush components normally, ZF explains. The I2SM doesn’t require any brush components or slip rings. As with a completely magnetized synchronous motor, the rotor is effectively cooled by circulating oil. In comparison with a typical individually excited synchronous motor, ZF says its I2SM requires as much as 90 millimeters much less axial set up house. When it comes to energy and torque density, nonetheless, it operates on the degree of a PSM.

ZF plans to develop the I2SM expertise to manufacturing maturity and provide it as an possibility inside its personal e-drive platform, in each 400-volt and 800-volt variants.

“With this magnet-free e-motor with out uncommon earth supplies, we now have one other innovation with which we’re persistently bettering our electrical drive portfolio to create much more sustainable, environment friendly and resource-saving mobility,” stated Dr. Holger Klein, CEO of ZF.

Supply: ZF