The article states another benefit of the motor is that it doesn’t require rare earth elements, so presumably they’re trying to solve the ecological and supply problems presented by rare earth mining.
Yeah, it sounds like they're saying they get the efficiency of a permanent magnet motor (which can be around 95% or so) without using magnets. Induction motors I think tend to be in the high 80's.
I don't entirely buy the rare earths thing. You can buy permanent magnet EV motors without rare earths, like the Netgain Hyper9 [1] (which I'm using in a conversion I've been working on for awhile). The hyper9 is kind of heavy for its power density, though, so maybe that's the advantage of rare earth magnets. If this company can get the efficiency of a permanent magnet motor but without rare earths and at a high power density, maybe they've got something new and interesting.
edit: another advantage of avoiding magnets is that they tend to demagnetize if they get too hot. Not having magnets means you might be able to run the motor hotter without damage. Though, a 95% efficient motor should be pretty easy to keep cool.
I don't entirely buy the rare earths thing. You can buy permanent magnet EV motors without rare earths, like the Netgain Hyper9 [1] (which I'm using in a conversion I've been working on for awhile). The hyper9 is kind of heavy for its power density, though, so maybe that's the advantage of rare earth magnets. If this company can get the efficiency of a permanent magnet motor but without rare earths and at a high power density, maybe they've got something new and interesting.
[1] https://www.evwest.com/catalog/product_info.php?products_id=...
edit: another advantage of avoiding magnets is that they tend to demagnetize if they get too hot. Not having magnets means you might be able to run the motor hotter without damage. Though, a 95% efficient motor should be pretty easy to keep cool.