14 ms·
Electric motors with no rare earths
- latentframe 4mo agoOne of the most interesting thing about commodity bottlenecks is that they often accelerate substitution ; scarcity can end up by making a material being less important
- numpad0 4mo agoWeren'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.
- dmitrygr 4mo agoSeems to be: replace permanent Nd magnet with an electromagnet.
- dyauspitr 4mo agoSo does it consume significantly more electricity?
- cyberax 4mo agoNot 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.
- cyberax 4mo agoThey 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 https://www.youtube.com/watch?v=BFmp9ODkCA8
- somat 4mo agoThere 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 4mo agoPermanent 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 4mo agoAC 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.
- Onavo 4mo agoThe 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 4mo agoThey are electronically commutated. The stator field is more or less variable AC.
- Onavo 4mo agoThe inductance ones yes, not these ones.
- sinaa 4mo agoI iiiioiooo iko to keep up ok it iiiioiooo the same i
- bgarbiak 4mo agoBMW also makes rare-earths-free motors for their EVs and - at this very moment - theirs are far more advanced. They offer almost twice the power (up to 300kW vs 160kW) and are on a 800v architecture.
- PedroBatista 4mo agoThe cheapest EV model Renault sells is around €20K, the cheapest BMW EV is around €65K. It's safe to say the companies are not in the market bracket, no?
- alephnerd 4mo agoThey share the same OEMs, and both are following the same ex-China automotive strategy. Renault has also been thumbing China recently for undermining EU manufacturing as well [0] while China has returned to using Wolf Warrior diplomacy against Europe [1][2][3][4] using the same rhetoric that the Trump admin uses. Of course, under the Xi admin China's foreign policy has always viewed the EU as inferior and a has-been [5] and has become an active participant in the Ukraine War [6][7]. Europe might not be able to trust the US, but it can't trust China either. [0] - https://www.reuters.com/world/china/renault-ceo-asks-eu-encourage-chinese-car-makers-source-parts-europe-2026-06-10/ https://www.reuters.com/world/china/renault-ceo-asks-eu-enco... [1] - https://www.globaltimes.cn/page/202605/1361926.shtml https://www.globaltimes.cn/page/202605/1361926.shtml [2] - https://www.chinausfocus.com/finance-economy/dear-brussels-dont-blame-beijing https://www.chinausfocus.com/finance-economy/dear-brussels-d... [3] - https://www.globaltimes.cn/page/202605/1362161.shtml https://www.globaltimes.cn/page/202605/1362161.shtml [4] - http://news.china.com.cn/2026-06/10/content_118541873.shtml http://news.china.com.cn/2026-06/10/content_118541873.shtml [5] - https://fddi.fudan.edu.cn/_t2515/57/f8/c21257a743416/page.htm https://fddi.fudan.edu.cn/_t2515/57/f8/c21257a743416/page.ht... [6] - https://www.reuters.com/business/aerospace-defense/russians-covertly-trained-by-china-return-fight-ukraine-sources-say-2026-05-19/ https://www.reuters.com/business/aerospace-defense/russians-... [7] - https://www.pravda.com.ua/eng/news/2026/06/12/8039041/ https://www.pravda.com.ua/eng/news/2026/06/12/8039041/
- 4mo ago
- alephnerd 4mo agoMentioned 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 https://news.ycombinator.com/item?id=48510402 [1] - https://leandesign.com/nissan-ariya-magnet-free-motor-teardown/ https://leandesign.com/nissan-ariya-magnet-free-motor-teardo... [2] - https://www.bmwblog.com/2025/02/20/bmw-gen6-electric-motors-neue-klasse-powertrain/ https://www.bmwblog.com/2025/02/20/bmw-gen6-electric-motors-... [3] - https://www.reuters.com/world/china/india-revs-up-alternate-ev-motor-tests-china-curbs-rare-earths-exports-2025-09-09/ 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-fta-renault-eyes-india-as-launchpad-for-european-exports/amp_articleshow/127669635.cms https://m.economictimes.com/industry/auto/auto-news/india-eu... [1] - https://www.valeo.com/en/valeo-inaugurates-new-electric-powertrain-manufacturing-line-in-pune/ https://www.valeo.com/en/valeo-inaugurates-new-electric-powe... [2] - https://auto.economictimes.indiatimes.com/news/auto-technology/mahle-india-opens-new-rd-facility-for-electrification-in-coimbatore-tn/104884856 https://auto.economictimes.indiatimes.com/news/auto-technolo... [3] - https://press.zf.com/press/en/releases/release_66050.html https://press.zf.com/press/en/releases/release_66050.html [4] - https://www.basispointinsight.com/Story/schaeffler-india-opens-fifth-plant-in-tamil-nadu-for-powertrain--ev-tech_41b2ce5ffc61.html https://www.basispointinsight.com/Story/schaeffler-india-ope... [5] - https://newsroom.toyota.eu/the-all-new-toyota-urban-cruiser/ https://newsroom.toyota.eu/the-all-new-toyota-urban-cruiser/
- delfugal 4mo agoHow soon to see rare-earth-free paired with CATL Sodium batteries? Seems a price war, range war is imminent.
- alephnerd 4mo agoUnlikely. EESMs are primarily manufactured by European OEMs (ZF, MAHLE, Schaffler, AEM) and their Indian JV partners (Sona Comstar, Sterling, and the India branches of the OEMs listed). Both have been blocked via export controls from accessing battery tech from China over the past few years, and a major reason for the push for EESMs was for an ex-China supply chain, especially after China began export controlling rare earths to the EU [6]. Additonally, Chinese and American EVs tend to use PMSMs unlike European and now Indian EVs. Also, the EU is cracking down on automotive exports (cars and OEMs) from non-FTA states as part of the EU Industrial Accelerator Act (which btw has made China go ballistic [2][3][4][5]). On the other hand, they will most likely use Japanese or Korean solid-state batteries as Idemetsu Kosan is in the process of mass producing them [0][1] as is LG [7], and both Japan+SK are FTA partners with the EU. [0] - https://www.chiyodacorp.com/en/projects/solidelectrolytefacility.html https://www.chiyodacorp.com/en/projects/solidelectrolytefaci... [1] - https://battery-tech.net/battery-markets-news/idemitsu-kosan-opens-new-solid-electrolyte-pilot-plant/ https://battery-tech.net/battery-markets-news/idemitsu-kosan... [2] - https://www.globaltimes.cn/page/202605/1361926.shtml https://www.globaltimes.cn/page/202605/1361926.shtml [3] - https://www.globaltimes.cn/page/202605/1362200.shtml https://www.globaltimes.cn/page/202605/1362200.shtml [4] - https://www.globaltimes.cn/page/202605/1362161.shtml https://www.globaltimes.cn/page/202605/1362161.shtml [5] - https://www.ft.com/content/5903318c-319b-426e-b05d-062f7620f799?syn-25a6b1a6=1 https://www.ft.com/content/5903318c-319b-426e-b05d-062f7620f... [6] - https://www.reuters.com/world/china/eu-lawmakers-rebuke-china-over-rare-earth-curbs-before-summit-2025-07-10/ https://www.reuters.com/world/china/eu-lawmakers-rebuke-chin... [7] - https://blog.lgchem.com/en/2026/03/25_solid_state_battery/ https://blog.lgchem.com/en/2026/03/25_solid_state_battery/
- cogman10 4mo agoCould be wrong, but AFAIK the CATL Sodium batteries haven't yet hit LFP pricing. You are unlikely to see a vehicle with sodium batteries until after that happens, and it needs to be significantly less than LFPs as you Na batteries have more weight per Wh. I believe they also have a shorter lifespan (but not NMC short). Edit correction, looks like CATL is promising 15000 cycles, which is much longer than LFPs which usually come in at 7000 to 10000. It seems far more likely to me that if the Na prices tank, you'll probably first see them deployed as grid and home battery solutions.
- willXare 4mo ago[flagged]
- pfannl 4mo agoAlso known as: “we removed the rare earths and added software.”
- Jblx2 4mo agoSynchronous motors: running on software since the 1880s. Nikola really was ahead of his time!
- hnav 4mo agoHe invented the induction motor which runs right off the grid.
- regularfry 4mo agoOther way round. He invented the induction motor (1887) which the three-phase grid was then demonstrated to drive (1891). That's how influential it was. There are other reasons a three-phase grid is handy but being able to drive these brushless contraptions must have seemed utterly wild at the time.
- adrian_b 4mo agoA three-phase grid cannot drive a two-phase induction motor, like that invented by Tesla. In 1891, the three-phase induction motor was invented by Mikhail Dolivo-Dobrovolsky, combining the principles of the three-phase synchronous motor previously invented by Mikhail Dolivo-Dobrovolsky with the principle of the induction motors invented by Nikola Tesla and Galileo Ferraris. Like any inventions, the induction motors of Nikola Tesla and Galileo Ferraris had not sprung out of nothing, but they were based on the experimental observation that had been known for many decades that if you rotate some magnets around a disk of copper, the disk will rotate, even if the magnets do not have any action on the disk when stationary. Because of the symmetry, it is easier to generate electromechanically three-phase currents than two-phase currents where the phase difference must be precisely of one right angle.
- derac 4mo agohttps://youtu.be/FHufjrP0xDI?is=xmFQrXGa1dBHM67I https://youtu.be/FHufjrP0xDI?is=xmFQrXGa1dBHM67I This is a helpful explanation of what this technology is and looks like. (Munro)
- lowbloodsugar 4mo agoIt 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.
- hijinks 4mo agolet me guess.. but its 2x the price?
- hnav 4mo agono, but requires introduces brushes (slip-rings really) which is a wear item
- themafia 4mo agoCars 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.
- hnav 4mo agoso apparently on the BMW i4s it requires a rear subframe drop which isn't going to be cheap (10s of hours).
- drnick1 4mo 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 4mo agoYet they still charge me the same price as my ICE to service! What a scam.
- jillesvangurp 4mo agoI 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.
- giobox 4mo agoIt's interesting that this is a brushed design. In the RC car community, brushless motors are generally regarded as superior, but those of course have the rare earth magnet problem. Technically the brushes can wear out, although there are claims they are good for 150,000-250,000 miles it seems.
- hnav 4mo agoIt's technically not a brush but a slip-ring. The design of these motors is very similar to automotive alternators, just scaled up 100x (in terms of power).
- dheera 4mo agoSlip rings have brushes.
- raverbashing 4mo agoYes but they wear less than DC brushed motors exactly because it's a slip ring and not a commutator
- ahartmetz 4mo agoBecause it's the discontinuities in the commutator where the sparks fly (with much help from self-induction of the motor's coils) and erode the ring and brushes.
- genter 4mo agoI've probably taken apart 10 automotive alternators. Every single one had brushes.
- hnav 4mo agoyeah I misspoke, I meant to say that it's a brush riding on a slip-ring (continuous contact, no arcing, lasts long) rather than a bunch of contacts in a cylinder (commutator, arcing, wears out).
- ipbrown 4mo agoElectrically excited synchronous machines (EESMs), also known as wound field synchronous machines (WFSMs) have a number of potential advantages and disadvantages compared to interior permanent magnet synchronous machines (IPMSMs). IPMSMs are the dominant motor topology currently in use for North American electric vehicles. Advantages: - Not subject to the price and supply chain volatility of rare earth permanent magnets. - For highway dominant drive cycles, the cycle efficiency of EESMs can be higher than state of the art IPMSMs. EESMs tend to have their best efficiency at moderate torques and high speeds because of their excellent field weakening characteristics. I tend to think that they would be a good fit for application in class 8 trucks or as auxiliary motors in automobiles with two powered axles. - The output torque doesn't necessarily decrease with rotor temperature. In IPMSMs the permanent magnet flux linkage decreases with rotor temperature. - At least theoretically, with proper control, it is possible to operate EESMs with unity power factor and decrease the kVA rating of the stator inverter. - If there is a stator inverter fault, there are schemes to denergize the rotor which have some safety implications. Disadvantages: - DC current needs to be transferred to the rotating field winding. For automotive applications this tends to be done either with brushes and slip rings or brushlessly using a high frequency transformer with a rotating rectifier. In either case additional power electronics and other components are needed for the field power transfer and control which reduces some of the potential cost savings of the elimination of the permanent magnets. If brushes and slip rings are used with oil spray/oil jet cooling of the rotor they need to be sealed in a separate compartment. I am a little surprised that Renault has stuck with brushes and slip rings versus an inductive high frequency transformer solution. I think this has limited their power density. - For very torque dense machines, cooling the rotor field winding is challenging, and in my opinion is best accomplished by oil spray/oil jet cooling. - It is difficult to reach the same maximum speeds as IPMSMs in an automotive package size. The rotor field winding retention system to keep the field turns from moving into the airgap at high speeds needs considerable attention during the design. - The overall axial length of the non-active region of EESMs is typically longer than IPMSMs because of the field winding end turns and field excitation system. - EESM efficiency is dominated by the manufacturable slot fill of the field winding. - High performance current/torque regulation is considerably more difficult. High performance EESMs have been used in aerospace generator applications for decades, albeit with a different rotor excitation system than what is used in automotive applications. Renault (and their supplier Continental) really led the commercialization of EESMs into automotive mass production. Now BMW has followed suit and multiple suppliers have EESM designs (Mahle, ZF, etc.) GM had a really nice EESM design and high frequency transformer excitation which they published back in 2014. My colleagues and I built several generations of EESMs as part of U.S. Dept. of Energy projects (https://www.osti.gov/servlets/purl/1837809 https://www.osti.gov/servlets/purl/1837809) and I think they have their place as EV traction motors for certain applications.
- userbinator 4mo agoA historical pioneer in the complex technology of electric motors without magnets Those who know the history of electric machines will find the title and verbiage very amusing. Motors with no permanent magnets were the first practical ones, and at this point wound-rotor motors are over a century old. It's worth noting that some of the biggest motors have always been designed this way, because the size of magnets required would make them both too expensive and dangerous, and still not powerful enough for their size; a field coil can generate a field that's only limited by the current and resistive heating of the winding, but rare earth magnets have fixed limits on field strength.
- XorNot 4mo agoNot quite true: you're also limited by the mechanical strength of your windings and core (this is the upper limit on superconducting magnets like at CERN and in fusion plants).
- Jblx2 4mo agoAnd if you also ignore iron saturation.
- butWhathuh 4mo ago[flagged]
- deleted 4mo ago[deleted]
- xeonmc 4mo agoWhat advantage do permanent magnets provide that it isn't the case that all motors are made without them?
- sitharus 4mo agoA lack of wear components. A permanent magnet motor uses permanent magnets on the rotor, but an electrically excited synchronous motor has an electromagnet on the rotor. This requires a rotating electrical contact which has normally been made with slip rings and carbon brushes. These wear over time and need replacement. Most large electric generators are externally excited synchronous generators using carbon slip rings, so it's a well understood field. This can be made contactless using inductive coupling and a rectifier - since inductive coupling needs AC but the excitation coil needs DC - at the expense of some efficiency. You can see the efficiency difference - Renault claim 92% efficiency but permanent magnet motor EVs have touted efficiency over 95% in the motor.
- GreenSalem 4mo ago[flagged]
- teiji-tango 4mo ago[flagged]
- isopede 4mo agoDoes regenerative braking work with a motor like this?
- ahartmetz 4mo agoAfter 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 4mo agoThere are electromagnets in the rotor, it is directly energized.
- cwillu 4mo agoYes: IIRC some large generators work exactly like this, as the energized rotor gives a lot more flexibility in managing frequency and power output.
- fc417fc802 4mo agoNot 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 https://en.wikipedia.org/wiki/Black_start
- tlb 4mo ago
- MrDrMcCoy 4mo agoIt's a bummer they are not really available in the US.
- alephnerd 4mo agoEVs 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/ https://nironmagnetics.com/
- ipbrown 4mo agoNiron is not developing an EESM. They are developing Iron Nitride permanent magnets. These magnets can be used in a variable flux permanent magnet synchronous machine (VFPMSM). Variable flux machines have some similar characteristics to EESMs in terms of their ability to change the field excitation, but they are fundamentally different than EESM in terms of how they do so. EESM change their field excitation and VFPMSMs change the magnetization state through stator current pulses. Their current/torque regulation control is also quite different. There are other startup companies developing EESMs but not Niron to my knowledge.
- letmutt 4mo ago[flagged]
- aaron695 4mo ago[dead]
- E-Reverance 4mo ago"At the same time, China is also the world's leading producer of electric cars..." Kind of interesting for a professionally branded company to use "..." like that
- PowerElectronix 4mo agoRare 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 4mo agoI own a Zoe for that reason
- bestouff 4mo agoI also have a Zoé (an R135). Wonderful little machine.
- dcanelhas 4mo agoClearly making a motor with induced magnetic fields both for the stator and rotor isn't the innovation here, since a large fraction of industrial motors do not have permanent magnets. I would assume the innovation here would need to be making it small and efficient for any meaningful torque output? Usually when you see claims of a 93% efficient electrical motor its the result of taking an absolute beast of a 2kW machine and operating it at 400W. Does anyone have insights into what Renault are doing here?
- rbanffy 4mo agoThe real innovation is in making them brushless and essentially maintenance free while still being efficient enough.
- adrian_b 4mo agoUnfortunately, their Web page does not say a single word about the important problems of their motors. The electrically excited synchronous motors have been known forever, but they had not been used in EVs because of 2 disadvantages. The first is that traditional EESMs require brushes, i.e. sliding electrical contacts, which are worn out by friction, so such motors require frequent maintenance for changing the brushes. It is possible to make brushless EESMs, but they require a rotating transformer and a semiconductor rectifier inside the rotor. The second disadvantage is a lower efficiency than with permanent magnets, which cannot be improved so much as to match PM motors, because the electrical currents that circulate through the rotor windings must generate heat. The lower efficiency also makes cooling more difficult. Renault says that their EESMs have an efficiency of 92%. This is a good efficiency, even if not as good as attainable with permanent magnets. Losing a few percents in efficiency is an acceptable compromise for avoiding the use of expensive and supply-constrained chemical elements. What I wonder is whether Renault reaches this 92% efficiency with EESMs having brushes, or with brushless EESMs, and this is what I would have liked to read on the parent Web page. Brushless EESMs usually had a lower efficiency, so 92% would be impressive for them, while it would look normal for EESMs with brushes. If Renault has succeeded to make a brushless EESM (i.e. maintenance-free) with an efficiency of 92%, that is something worth to brag about. Otherwise, making a traditional EESM would not be great news, because everybody has avoided those because of the maintenance problem.
- whazor 4mo agoNot sure how familiar you are with Renault, but “maintenance problems” pretty much sums up a lot of older Renaults.
- ReptileMan 4mo agoAs the old saying goes - better a naughty French than boring German...
- mirsadm 4mo agoWhat does older mean in this context? Because some people still think the year 1996 wasn't that long ago. Modern Renault cars are fine and reliable enough. I've had 4 in my life time and had zero issues myself. I see a ton of them here in the UK and, again, they're fine.
- RobotToaster 4mo agoWhy not just use an induction motor with VFD?
- adrian_b 4mo agoAs said in the parent Web page, lower energy efficiency, thus shorter range with the same battery. Another poster has mentioned that BMW also uses EESMs instead of permanent-motor magnets. BMW uses EESMs as the main motors, on the rear axle, while they use induction motors as auxiliary motors on the front axle. Besides being cheaper, the induction motors have the advantage that if they are used only as auxiliary motors, you can cut the power supply to them at any time, in which case they will consume nothing. So their lower efficiency does not matter, because most of the time they are turned off.
- CarVac 4mo ago> Besides being cheaper, the induction motors have the advantage that if they are used only as auxiliary motors, you can cut the power supply to them at any time, in which case they will consume nothing. EESMs have this advantage too, you can simply cut power to the field winding.
- kopirgan 4mo agoBroader point is this: Middle East created oil crisis back in 70s. Since then US economy has grown enormously while it's still using pretty much same amount of oil, imported or otherwise. They shot themselves in their foot. Iran is doing this now, telling the world to avoid Hormuz. They will learn to do that. China is doing that by blackmailing countries with rare earth. Answers will be found. Especially as some of finest brains across 2 continents + Japan are very interested in doing it. In the past, China could flood market at right time to make alternatives unviable. But that trick has worn off. In this context, 92% or even 80% efficiency of permanent magnets is no big deal. It'll not be the answer to every use case but will satisfy many and limit demand.
- jfengel 4mo agoIn the long term solutions will be found, but in the short term they can gain an enormous bargaining chip. If food prices double because we've burnt the last drop from the Strategic Petroleum Reserve, the administration will give them just about anything they want to avoid utter political destruction. The game theoretic definition of a threat is something that harms you, but harms them so much that they will avoid forcing you to trigger the threat. It's a different matrix from the Prisoner's Dilemma, but still leaves you guessing about the personality of your opponent. The personality of Iran seems reasonably consistent. The US, less so.
- kopirgan 4mo agoYeah that is looking at it from US side. If you were Iranian, cutting nose to spite face looks like a bad deal, only as Iranian you have no say in it. As with virus, the ones that survive are the ones that dont cause too much damage and learn to live with adversary. Ebola will never spread as bad as COVID if it kills everyone it touches. Unless it too evolves into gentler version.
- coryrc 4mo agoI don't know. Europe had the opportunity to make themselves energy independent multiple times; instead they doubled down on Russian oil, and in response to the latest invasion, they instead doubled down on Qatar natural gas... Germany spent enough on solar to have nuclear power for winter heating and instead they get nearly nothing from it when energy (note I said Energy not Electricity) demand is the highest: winter heating. Now, if they had put that solar in North Africa and ran cables, sure, but they didn't. Or if they did Drake's landing solar storage, that would also work. But they spent a fortune only to still be completely dependent on fossil fuels and are destroying the economic base because of the cost.
- ZedZark 4mo agoSay all you want about the inferior efficiency and so on, but if nothing else they have proven that it's viable, even commercially. So the rare earths are really not as vital as they have been made out to be.
- Danox 4mo agoReally sounds promising. The question is will the French have the will to build it in bulk on shore in France or Europe? There’s no point if they want to sub it out to the world to build cheaper somewhere else? This technology does show that you should never give up on industry, research, development and building on shore.
- maxjackson92 4mo agoInteresting how Tesla went the other way with their magnet motors. Two different bets on supply chains, guess we'll see who was right.