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Posted by bestouff 13 hours ago

Electric motors with no rare earths(www.renaultgroup.com)
506 points | 145 commentspage 2
numpad0 9 hours ago|
Weren't Tesla ACIM drive unit motors before Model 3 also magnet-free? I thought they used passive isolated bundles of copper wires and their reluctance as magnets.
derac 12 hours ago||
https://youtu.be/FHufjrP0xDI?is=xmFQrXGa1dBHM67I

This is a helpful explanation of what this technology is and looks like. (Munro)

lowbloodsugar 11 hours ago|
It was a dude with motors on a table with a flip board. No animations. No diagrams. When it got to the point about having one of each motor, and using the best, he then said that you use the permanent motor even when the other makes sense. Ok, well then why have the two different kinds of motors? No answer. Just handwaved. If you can't use the induction motor when its most efficient, because thats when the permanent motor is causing spin loss, why have the induction motor at all? No answer.

So. Analog presentation. Actual motors on a desk with a flip chart. No animations. No internal visualizations. One page had diagrams that would have been better super-imposed (or hey, animated). Then one page the begs questions with no answers given.

PowerElectronix 4 hours ago||
Rare earth magnets are just too good for electric motors to go this way. Europe and the US just need to get the rare earth manufacturing going and stop being reliant on china for this stuff.
general_error 4 hours ago||
I own a Zoe for that reason
bestouff 2 hours ago|
I also have a Zoé (an R135). Wonderful little machine.
MrDrMcCoy 9 hours ago||
It's a bummer they are not really available in the US.
alephnerd 9 hours ago|
EVs in the US and China tend to use PMSMs, though GM, Stellantis, the DoE, and the DoD are funding an EESM startup [0]

[0] - https://nironmagnetics.com/

alephnerd 12 hours ago||
Mentioned in another HN thread [0]:

They're also used by Nissan [1], BMW [2], and Indian EVs [3].

European firms like ZF, Valeo, MAHLE, and Schaffler along with British firms like AEM have been working with their Indian JVs as well as Indian players like Sona Comstar and Sterling for a couple years now to integrate supply chains for mass-producing EESMs.

EESMs as well as the larger OEM story played a role in helping land the EU-India and the UK-India FTAs because the supply chains for French+Italian (Renault, Stellantis), Japanese (Toyota, Honda, Suzuki), Korean (Hyundai-Kia), and Indian automotive manufacturers merged.

On the other hand, EESM EVs aren't a thing here in North America nor China yet as both primarily use PMSMs (edited typo).

[0] - https://news.ycombinator.com/item?id=48510402

[1] - https://leandesign.com/nissan-ariya-magnet-free-motor-teardo...

[2] - https://www.bmwblog.com/2025/02/20/bmw-gen6-electric-motors-...

[3] - https://www.reuters.com/world/china/india-revs-up-alternate-...

---

Edit: can't reply

> does Nissan still use these motors, the car in the linked article has been discontinued

Yes. The Ariya was discontinued in North America (EDIT: USA, TIL still sold in Canada) but is still manufactured and sold in Asia.

> European and Indian manufacturers/engineering are definitely not in the same category though

It's the same manufacturers and supply chain now.

Renault and their OEMs are the biggest driver for EESM, and Renault's largest markets and manufacturing hubs are France, India, and Romania. Heck, Renault is now going to start exporting it's Made in India cars and parts back to the EU [0] becuase of the EU-India FTA.

And the European OEMs have transferred the IP for EESMs to Indian JVs as I mentioned. It's the same style of tech transfer as Samsung did for BYD and TDK for CATL for battery chemistry in the 2000s. Heck, Valeo [1], MAHLE [2], ZF [3], and Schaffler [4] are opening and expanding factories and R&D hubs dedicated to EV transmission manufacturing in India for domestic and export usecases.

Also, if you've ever driven a Japanese (Toyota, Honda, Suzuki) or Korean (Hyundai, Kia) make care in the EU, Australia, Middle East, Africa, or Asia outside of their home countries their parts sourcing and even the entire manufactured car would have come from India, such as the Toyota Urban Cruiser EV [5].

[0] - https://m.economictimes.com/industry/auto/auto-news/india-eu...

[1] - https://www.valeo.com/en/valeo-inaugurates-new-electric-powe...

[2] - https://auto.economictimes.indiatimes.com/news/auto-technolo...

[3] - https://press.zf.com/press/en/releases/release_66050.html

[4] - https://www.basispointinsight.com/Story/schaeffler-india-ope...

[5] - https://newsroom.toyota.eu/the-all-new-toyota-urban-cruiser/

IlikeMadison 9 hours ago||
No, and it was mentioned by the consortium of European cars manufacturers after the joint press release with Der Leyen herself: the implementation of factories and research centers in India is solely to be able to sell on that market. It is the exact same process that happened with China in the past. The exact same also happened with Airbus.

You are also wrong on the market importance for Renault. For 2024, France was the biggest, followed by Italy, Turkey, Spain, Germany, Brazil, UK, Morocco, BENELUX, Romania, Poland, Netherlands and... #13 India with 0.9% market share...

Supply chains didn't change at all, in fact it did the opposite, and Europeans won't rely on anything Indian made for the near future, as local re-industrialization is already acted on and even accelerated since the pandemic.

Production numbers across all manufacturers even Volkswagen (which was unexpected) show the number of cars manufactured in Europe increased in the past 2 years.

Electric cars in Europe mostly come from China, the US and European brands. Nothing Indian-made, not even parts.

analogpixel 11 hours ago|||
Not sure why this was voted down, it was the most useful comment here.

does Nissan still use these motors, the car in the linked article has been discontinued, and then only real info I can find on their site about the leaf is about their ROCKIN' bose sound system/s

IlikeMadison 9 hours ago||
Because it's grossly untrue and backed with propaganda slop articles. I suspect this is a bot.
IlikeMadison 11 hours ago|||
European and Indian manufacturers/engineering are definitely not in the same category though.
heresie-dabord 11 hours ago|||
> The Ariya was discontinued in North America but is still manufactured and sold in Asia.

The Nissan Ariya is NOT discontinued in North America. Nissan no longer sells it in the USA because of Trump's tariff war.

The Nissan Ariya is still sold in Canada.

AtlasBarfed 11 hours ago||
what is a prsm? Do you mean pmsm?
isopede 11 hours ago||
Does regenerative braking work with a motor like this?
cwillu 10 hours ago||
Yes: IIRC some large generators work exactly like this, as the energized rotor gives a lot more flexibility in managing frequency and power output.
fc417fc802 8 hours ago||
Not just some, approximately all of them. It greatly complicates the logistics of a black start. † Of course that situation has additional complexity due to the need for substantial additional power in order for the various fuel supply systems to operate but I digress.

† https://en.wikipedia.org/wiki/Black_start

tlb 2 hours ago||
Generator excitation is not the hard part of a black start. You have to run coal feeders, blowers, and water pumps for an hour before you can spin the generator. Then you get power instantly upon applying power to the field windings.
ahartmetz 10 hours ago||
After watching a Munro video about it, I see your point. In the motor shown, the rotor gets its magnetic field simply by inducing a current and a field in it in reaction to the stator's field. There are no electromagnets in the rotor like I expected. In that case, I'm not sure either... I'd say more likely than not but it's complicated since the stator basically needs to induce a field and at the same time recover energy from the field that comes back from the rotor. I would further guess that the phase shift between the two components makes it possible to treat them separately.

Previous comment: Don't see why not - the "field" coils (the ones that replace the permanent magnets) need to be energized, which can initially come from the batteries if necessary.

maxerickson 8 hours ago||
There are electromagnets in the rotor, it is directly energized.
dmitrygr 12 hours ago||
Seems to be: replace permanent Nd magnet with an electromagnet.
somat 11 hours ago||
There is something... weird about this. this tech has existed.... a long time. And I am not familiar with what is common in electric cars so may be missing something obvious but thought this was already how it was done. let me explain my limited understanding.

With ac motors electromagnets can be used in the rotor. there is even a super clever way to do it where the electromagnet in the rotor is driven wirelessly via induction. there are some downsides but having no physical sliding electrical connection to the rotor is a huge upside. The ac can be dynamically formed from DC via high speed switching(transistors, in industry often called a VFD).

Due to the upsides of ac induction motors I sort of assumed this was already what was found in cars. I am a bit surprised to find out there were rare earth magnets in the first place.

userbinator 11 hours ago|||
Permanent magnet motors are simpler and cheaper to make, at least in the small (yes, small --- there are electric motors in the MW range in industrial applications, which are themselves larger than an average car) sizes found in EVs.
cyberax 8 hours ago|||
AC motors are not magic. The core is essentially just a coil with one turn, so it can generate only a very limited magnetic field. So they have to be bulkier for a given power density and generally slightly less efficient.
cyberax 12 hours ago|||
They even use regular carbon brushes to supply power to the magnet. Munro has a teardown video for a similar motor for Nissan: https://www.youtube.com/watch?v=BFmp9ODkCA8
dyauspitr 12 hours ago||
So does it consume significantly more electricity?
cyberax 12 hours ago||
Not really. The excitation power is a small fraction of the total.

The problem is that it makes the rotor far less mechanically robust and also heavier. That's why these motors are less powerful.

hijinks 11 hours ago||
let me guess.. but its 2x the price?
hnav 11 hours ago|
no, but requires introduces brushes (slip-rings really) which is a wear item
jillesvangurp 5 hours ago|||
I don't think car owners have to worry about this the first half million miles or so with these motors. Electrical motors last a long time. We'll know for sure in a few decades, I guess. That's how long it will take for a significant number of their cars to actually drive that far.

Also, compare this to ICE engines which experience continuous explosions, lots of mechanical parts, extreme temperature swings, etc. and still manage pretty decent durability. There's simply no base for assuming that parts like this wearing out and needing to be replaced is going to be a common thing.

theodric 5 hours ago||
The Continental and Renault motors like those in my Kangoo ZE and Zoe have so far proven fairly reliable, with the occasional exception being shaft bearings. The Q210 is particularly robust. I'm not aware of anybody having brush/slip ring issues yet.
themafia 10 hours ago|||
Cars already have lots of wear items and a mature service industry for them. If I can reliably get at least 50k miles out of it, then I wouldn't be all that bothered, as this is not likely to be an expensive part or service.
drnick1 10 hours ago|||
> mature service industry for them

The car service industry is a scam, and I am glad that EVs require minimal to no servicing that cannot be easily DIY like tires and brakes.

stavros 2 hours ago||
Yet they still charge me the same price as my ICE to service! What a scam.
hnav 10 hours ago|||
so apparently on the BMW i4s it requires a rear subframe drop which isn't going to be cheap (10s of hours).
Onavo 12 hours ago|
The main difference between this and your typical AC induction motors (also magnet free) is that this is a DC motor so you need a commutator. Your AC induction magnet free motors are very similar to drone motors in that you don't have any electrically active moving parts like slip rings and commutators. But for AC induction there will be a slight lag (known as slip).
maxerickson 12 hours ago|
They are electronically commutated. The stator field is more or less variable AC.
Onavo 6 hours ago||
The inductance ones yes, not these ones.
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