Adamas: 93% of all xEVs sold in 2018 used permanent magnet traction motors
08 March 2019
In 2018, 93% of all passenger BEVs, PHEVs and HEVs sold globally used permanent magnet (PM) traction motors, an increase of 1% over 2017 penetration rates, according to a model-by-model build-up using Adamas Intelligence’s “EV Motor Power and Motor Metals Tracker”.
A PM traction motor has NdFeB permanent magnets mounted on or embedded in its rotor, which cause the rotor to spin when exposed to a rotating magnetic field produced by windings in the stator.
Permanent magnets traction motors are up to 15% more efficient than induction motors and are the most power-dense type of traction motor available (in terms of kW/kg and kW/cm3).
Despite generally having a higher bill-of-materials than incumbent traction motor types, such as induction, use of a PM traction motor is substantially more economically attractive from an automaker’s perspective because its high efficiency enables thrifting of costly battery capacity without compromising vehicle range (distance driven per charge), Adamas observes.
For example, the cost of increasing the capacity of a 60-kWh battery pack by just 5% to compensate for use of an induction traction motor can increase powertrain costs by upwards of $300 (optimistically assuming an added cost of just $100 per kWh).
This is a resource tradeoff: using rare earths in the motor saves cobalt in the battery. Given the recent announcements of processes for recovery of heretofore-uneconomic rare earths from sources from phosphogypsum to acid mine drainage to kaolin mines, it looks like the motors are going to win in the short term.
Posted by: Engineer-Poet | 08 March 2019 at 03:44 AM
It should be no problem to build permanent magnet (PM) motors without rare earths in the PMs. Several hybrid materials have been discovered that are far cheaper and a more than adequate replacement for rare earths. E. g.:
https://aip.scitation.org/doi/abs/10.1063/1.333572
A very promising cell from Innolith is being produced that gets along without cobalt.
Posted by: yoatmon | 08 March 2019 at 07:19 AM
During the life time of an electrified vehicle, there is a price to pay for carrying too much death weight around. A few dollars more for lighter more efficient e-motors could be a worthwhile investment?
Secondly, who needs 1000 HP to drive around?
Posted by: HarveyD | 08 March 2019 at 08:00 AM
Okay, it's definitely Alzheimer's. Harvey is repeating what I wrote yesterday:
Time to give up the computer and go into assisted living, Harv.Posted by: Engineer-Poet | 08 March 2019 at 01:01 PM
Super SAEP is always as wrong and as nasty?
By the way, you previously maintained that the efficiency of e-motors did not mean much to increase the efficiency of EVs?
Of course you were wrong but you will never admit it?
Posted by: HarveyD | 08 March 2019 at 02:06 PM
Posted by: Engineer-Poet | 09 March 2019 at 03:32 AM
The recently announced BEV models: Mercedes-Benz EQC and Audi e-tron both have induction motors. Germans call them "asynchronous motors", it is the same thing. Both models are AWD, use two e-axles (2 motors per vehicle, both induction ones).
Posted by: Alex_C | 10 March 2019 at 03:00 AM
Insulting and criticizing is childish, the mentally ill do it anyway.
Posted by: SJC | 10 March 2019 at 01:10 PM
The GM EV1 also used twin induction motors (no differential).
Posted by: Engineer-Poet | 10 March 2019 at 01:59 PM