Cheap, Highly Efficient New EV Motor Uses No Magnets (newatlas.com) 159
"An EV motor has been developed that uses no magnets, thus lessening the United States' reliance on Chinese magnets (which make up 97% of the world's supply)," writes Slashdot reader nickwinlund77, adding: "I wonder what the motor's performance is like on high grade roads?" New Atlas reports: German company Mahle has just announced a new electric motor that sounds like it solves a lot of problems in a very tidy manner. The new Mahle design uses no magnets, instead using powered coils in its rotor. Unlike previous efforts, it transfers power to the spinning rotor using contactless induction -- so there are basically no wear surfaces. This should make it extremely durable -- not that electric motors have a reputation for needing much maintenance. The lack of expensive metals should make it cheaper to manufacture than typical permanent-magnet motors. Mahle says the ability to tune and change the parameters of the rotor's magnetism instead of being stuck with what a permanent magnet offers has allowed its engineers to achieve efficiencies above 95 percent right through the range of operating speeds -- "a level that has only been achieved by Formula E racing cars." It's also particularly efficient at high speeds, so it could help squeeze a few extra miles out of a battery in normal use. The company says it'll scale nicely from sizes relevant to compact cars up to commercial vehicles.
"Our magnet-free motor can certainly be described as a breakthrough, because it provides several advantages that have not yet been combined in a product of this type," says Dr. Martin Berger, Mahle's VP of Corporate Research and Advanced Engineering. "As a result, we can offer our customers a product with outstanding efficiency at a comparatively low cost." Mass production is about two and a half years away, according to IEEE Spectrum, and Mahle has not yet nominated which auto manufacturers it's dealing with, but test samples are already starting to circulate.
"Our magnet-free motor can certainly be described as a breakthrough, because it provides several advantages that have not yet been combined in a product of this type," says Dr. Martin Berger, Mahle's VP of Corporate Research and Advanced Engineering. "As a result, we can offer our customers a product with outstanding efficiency at a comparatively low cost." Mass production is about two and a half years away, according to IEEE Spectrum, and Mahle has not yet nominated which auto manufacturers it's dealing with, but test samples are already starting to circulate.
Yo dawg (Score:4, Funny)
Yo dawg. I heard you liked electromagnets, so we used electromagnets to power your electromagnets so you can repel while you repel?
Re:Yo dawg (Score:5, Informative)
Re: (Score:3, Informative)
Yes, basically.
Though this may work more like a PM motor in practice if it's feeding the rotor via an AC magnetic field, then rectifying the current on the rotor, and using it to feed DC to electromagnets.
Re: (Score:2)
Re:Yo dawg (Score:5, Interesting)
If they can put nigh-unto indestructible bearings in the thing then it'll probably outlive the rest of the car.
Re:Yo dawg (Score:5, Insightful)
If they can put nigh-unto indestructible bearings in the thing then it'll probably outlive the rest of the car.
Science Fiction (n): Companies putting parts that never need to be replaced into a product.
Re: (Score:3, Insightful)
He didn't suggest that the bearings would last forever, just longer than the rest of the car. That's not unreasonable.
Re: Yo dawg (Score:3)
You didnâ(TM)t understand the joke, mate.
Re: (Score:2)
Re: (Score:2)
That would be reasonable, but won't happen. They'll "value engineer" it to death so the bearings start squealing a couple months after the warranty expires. They'll happily cost you $1000 tomorrow to save themselves $1 today.
Re:Yo dawg (Score:4)
We had something like that. Westinghouse dishwasher in the mid-1960s. They sold you a service contract, and you needed it - EVERYTHING broke in the first year or 2. But the replacements never broke, over the following 20 years. But after the first couple of years they had you on the hook, because something *might* break...
Re: (Score:2)
Re: (Score:3)
Or make sure the bearings are replaceable, I'm no mechanical expert but I know bicycle bearings need to be placed once they've worn out.
Re: (Score:2)
Re: Yo dawg (Score:2)
Re: (Score:3)
Ah well that explains the condom industry business model. Lot's of breakage, buy more.
Re: (Score:2)
Ah well that explains the condom industry business model. Lot's of breakage, buy more.
No, that model is "Lots of breakage, buy stuff for your kids."
Re:Yo dawg (Score:4, Interesting)
Electric motors are pretty reliable already, and generally outlast the car.
EVs in general are changing the used market because even when the bodywork is worn out or damaged there are still many valuable parts that can be re-used with minimal refurbishment, if any. The motors are one example, the battery packs usually have a lot of life left in them too.
Re: (Score:3)
Re: (Score:2)
Re:Yo dawg (Score:5, Informative)
Yeah, was just thinking the same thing.
The problem with all these "pop sci" articles is that they try to dumb things down and make them relatable by latching onto the part of the invention that may actually not be novel at all.
So the entire article is about geopolitical issues with permanent magnets, acting as if somehow the concept of an induction motor is what's new and interesting here. But yeah, Tesla invented those a long time ago. So whatever is novel, its something else.
Re: (Score:3)
Well having 97 percent of a market, and china no less is VERY VERY important. People grumble about the CPU/GPU shortages, but imagine the grumbling if china controlled the supply of those two. At least with miners there's a chance any restrictions will eventually ease.
Re: (Score:2)
Re:Yo dawg (Score:5, Funny)
These were "invented" long before tesla was incorporated.
Are you sure? Tesla was incorporated in 1856. (Well, actually he was conceived, but it amounts to the same thing)
Re: (Score:2)
Re: (Score:3)
The theory of an induction motor is from 1824, according to wikipedia.
Nikola Tesla was the first person to figure out how to make it work well enough to be practical. He was granted a patent for it in 1896.
Re:Yo dawg (Score:4, Funny)
Re:Yo dawg (Score:4, Funny)
Nicola Tesla is still alive?
Wait. Tesla is dead? I didn't even know he was sick.
Re:Yo dawg (Score:4)
Re: (Score:3)
Re:Yo dawg (Score:4, Informative)
Re:Yo dawg (Score:5, Funny)
As I'm pretty sure Nicola Tesla has been dead for a long time and isn't using anything.
Perhaps he uses them to spin in his grave...
Re: (Score:3)
Re: (Score:2)
Re: (Score:2)
Re: (Score:2)
Re: Yo dawg (Score:2)
What this sounds like is a classic brush motor without the actual brush contact (the
Re: Yo dawg (Score:5, Informative)
Induced current is energy lost as heat.
In a pm motor the induced current is almost zero because the magnetic field is synchronous with the rotor and thus does not change (no changing field thus no current thus no heat loss).
In an induction motor the rotor shaft speed must be a little slower than the field rotation frequency. The torque produced is monotonic to this difference. No torque at matched speed, maximum torque and maximum losses with stationary rotor.
In a pm rotor, torque is proportional to the angle between the field and the rotor, at any speed. And the only losses are in the stator coils.
Further, the max speed of the field is limited by the time constant of the stator coils in both types. Thus you can't generate more torque at high speed with an induction motor because you can't make the field rotate any more. In a pm motor you can have torque with a constant slip angle even at the maximum speed of the field provided you have enough voltage to overcome the back emf.
Having an electromagnetic rotor can allow you to back off on the back emf at high speeds, which is an advantage in that you no longer necessarily need to operate at as high a voltage.
Re: (Score:2)
Re: (Score:2)
Are Tesla's motors 95% efficient? Every single percentage of extra efficiency can equal several miles extra distance the car can go on 1 charge. A quick yahoo says Tesla motors are 93% efficient.
Re: (Score:2)
It sounds like a reluctance motor. There was another story pitching them as wundertech a few months ago.
Re:Yo dawg (Score:5, Informative)
Nope. They invented a _brushless_ AC induction motor. In motors before you needed magnets if you wanted the high reliability that comes with a brushless motor. Now you can have both brushless and no-magnets and still the same effectiveness. And that is definitely new and quite an engineering accomplishment.
Incidentally, your referenced article nicely explains that decision that had to be taken up to now. Seems you have not read your reference.
Re: (Score:2)
My six year old Tesla has an AC induction motor with NO Magnets.
Did these folks just reinvent the wheel?
Re:Yo dawg (Score:4, Funny)
Re: (Score:3)
They work very well. Which is important, because modern technology would be SOL without them.
Re:Yo dawg (Score:4, Funny)
I'd prefer motors without magnets.
Magnets have mental issues, they are all bipolar.
Re: (Score:3, Funny)
I'm sure you're a chick magnet
The repelling type
Just when you think you have rare earths locked up (Score:3)
Just when you think you have rare earths locked up the Germans come along and develop and electric motor that doesn't use magnets.
I wonder how this motor will perform in my zero point energy over unity device that makes unlimited free power, after a couple of tweaks I still need to make.
Re: (Score:3)
Substitute "patents" for "rare metals" and you can see how saying "no" can be a powerful motivator towards progress instead of the drag some think it might be. In other words would this motor have been developed if there hadn't been a rare earth monopoly?
Re: (Score:2)
Considering the reluctance motor was developed in 1838, yes?
Re: (Score:2)
Well, saying it doesn't use magnets is just PR speak, but it uses magnets based around induction coils rather than permanent magnets. Different advantages and disadvantages. It *may* be very important, but I'm not sure one can count on that. Wireless charging normally comes with efficiency costs.
Freeing them up for other uses (Score:4, Funny)
Re: (Score:2)
I guess you could use them to stick messages on refrigerators.
AC induction motors (Score:4, Insightful)
AC induction motors aren't exactly a new invention -- they've been around since the 1880s, and cheap/small inverters to run them at variable speeds have been common since the 1980s.
This one probably uses some electronics on the rotor itself to modulate the rotor's magnetic field more effectively.
Re:AC induction motors (Score:5, Informative)
This is a pretty clever solution.
Re:AC induction motors (Score:4)
It IS an AC induction motor with some fancy electronics on the rotor. BTW, even DC motors typically run on AC internally.
The only true DC motor is a homopolar motor, which isn't very efficient nor practical.
Re: (Score:2)
Re: (Score:3)
Re: (Score:2)
Re:AC induction motors (Score:5, Informative)
It IS an AC induction motor with some fancy electronics on the rotor. BTW, even DC motors typically run on AC internally.
No. In an AC induction motor, the current induced in the rotor is AC, and the resulting AC magnetic field interacts with the rotating stator magnetic field. In the motor in the article, AC current is induced into rotor coils, and is then rectified, to produce a DC current in the rotor coils. The motor is then much more like a conventional DC motor, with field and armature coils. The innovation is in getting DC current into the rotor coils, without needing brushes, that wear out.
The performance characteristics of DC motors are completely different to AC induction motors. As far as I know, AC induction motors are not used for traction, because of their unsuitable torque-speed characteristics.
Re: (Score:2)
Re: (Score:3)
So an improved synchronous motor. They found a way to power the rotor without going through slip rings and brushes.
Re: (Score:2)
Re: (Score:2)
usually done with an electronic motor controller that adjust the frequency going to the motor in a frequency locked loop
Maybe there is something new here, but its not obvious from the article what it is.
It is quite obvious what is new but you need to understand motor technology. Up to now you had to either use AC induction tech or you could go brushless but needed to use magnets. You could not have both. This thing is a _brushless_ AC induction motor with comparable efficiency and that is quite an accomplishment. No brushes to wear down, no magnets.
Re: (Score:2)
Contact less induction also means they can have a sealed design with friction-less bearings.
Re: (Score:2)
Got it. Actually described, vaguely, in Wiki: https://en.wikipedia.org/wiki/... [wikipedia.org]. So even the "wireless" rotor might not be completely novel. Undoubtedly, though, something new is added otherwise the lawyers (who want to patent things) wouldn't be happy.
Re: (Score:2)
The new thing is to get it to work with efficiency comparable to a conventional electric car motor and at the same power-ratings. And they have actually working engineering samples, only mass-production is missing.
Re: (Score:3)
Exactly. They get best of both worlds, being brushless and magnet-less. As they do not compromise efficiency, this is quite an accomplishment and it is a first.
Re: (Score:2)
*cough*
Re: (Score:3)
It is an AC induction motor. The impressive part is getting rid of the brushes without compromising efficiency. Nobody has accomplished that before.
Re: (Score:2)
AC induction motors aren't exactly a new invention -- they've been around since the 1880s, and cheap/small inverters to run them at variable speeds have been common since the 1980s.
This one probably uses some electronics on the rotor itself to modulate the rotor's magnetic field more effectively.
Jeez even the TFS explains how it works, no assumptions necessary. It's not an AC induction motor. It's some sort of AC motor with a wound armature and the armature field excited via a wireless coupling instead of brushes. What you are alluding to is more akin to a brushless DC motor. Which this is definitely not.
Re: (Score:2)
Re: (Score:2, Interesting)
You can tune the current in both the stator and rotor. With permanent magnets you can only tune one side. Apparently they've managed to gain some efficiency with this affordance, which seems plausible.
Seems to require more iron and more mass, and more wires.
The point of all of this is that none of the more iron and more mass and more wires have to come from China. And if you omit the more mass factor and define 'efficiency' as mechanical power out vs electric power in then, for the purposes of PR, the more mass doesn't matter.
Re: (Score:2)
It is an AC induction motor. But it is a _brushless_ AC induction motor. Also works in the same efficiency and power range as normal motors used in electric cars.
Re: (Score:3)
This is a _brushless_ AC induction motor with the same efficiency as a conventional one, and that is definitely new. Brushless motors are far more reliable and need less or no maintenance. AC induction motors up to now always needed to used brushes.
Exciter generator (Score:5, Interesting)
Old technology.
Basically an "inside-out" synchronous generator on the same shaft as the main motor (or generator) rotor. The exciter field is on the outside (fixed) and induces AC voltage on the stator windings, which are actually on the shaft. A rotating rectifier converts this to DC and passes it to the main device field windings, also on the shaft. So, no slip rings.
This works well at synchronous shaft speeds. To produce torque from zero RPM the exciter field can be driven by a solid state switched supply (much like a variable speed drive) to "get the exciter going" at zero speed.
Already invented? (Score:3)
Re: Already invented? (Score:5, Informative)
Switched reluctance is nothing new, their innovation lies in fine-grained software control, and optional telemetry directly from the controller.
Re: Already invented? (Score:2)
Re: (Score:2)
Translation (Score:5, Funny)
Mass production is about two and a half years away
Translation: "Well, we can pretty much almost kinda sorta make it work in the lab slightly more than half the time."
Re: (Score:2)
Mass production is about two and a half years away
Translation: "Well, we can pretty much almost kinda sorta make it work in the lab slightly more than half the time."
Nope. You are confusing this with software. In actual engineering this means "we have engineering samples that are fully functional and equivalent to the final product, there is just a lot of manual manufacturing involved at the moment".
What about (Score:5, Funny)
What about smaller applications like drones or electric chainsaws or drones with electric chainsaws?
Re: (Score:2)
> drones with electric chainsaws
Well there goes my investment in bucket truck companies.
Re: (Score:2)
You are a genius! Elon Musk sold flamethrowers to raise money so I bet he could sell chainsaw drones too.
Re: (Score:2)
Do the drones all have hockey masks covering the front?
Copper (Score:4, Interesting)
It might not use rare earth metals, but sill needs large amouts of copper for the windings. The price of copper is rising rapidly just now and may be another bottleneck for production.
Re: (Score:2)
The world has plenty of copper so it's unlikely there would be a bottleneck, just slightly higher prices for the usual short period of time.
Re: (Score:2)
It might not use rare earth metals, but sill needs large amouts of copper for the windings.
No, they can use Aluminum. It results in a larger motor, but not much heavier, and modern motors are so small that a larger motor is not a big problem for many designs.
Re: (Score:2)
If only... (Score:2, Troll)
Squirrel Cage Induction Motor (Score:2)
Re: Squirrel Cage Induction Motor (Score:3)
They have high starting current of you go from 0 to 60hz instantly by throwing a switch or contactor.
With VFD control you can control the motor in a way that Is extremely similar to what the summary said..
Heck, these days a lot of servo drives are actually squirrel cage induction motors on the inside, controlled by an advanced variable frequency drive, and able to accurately control the magnetic fluxes of the rotor and stator to produce just the right amount of torque to, for example keep anà lifting d
Obligatory Insane Clown Posse reference. . . (Score:2)
. . . f*cking magnets, how do they work ?
(grin)
Re:BFD (Score:5, Informative)
It's not like a normal induction motor. A normal induction motor has to have slip to work. That is, it rotates at less than synchronous speed in order to get current induced in the squirrel cage on the rotor.
This new motor is a synchronous motor where the current that magnetizes the rotor is applied externally and is not dependent upon slip. This allows better speed control, higher efficiency and higher power density.
Re: (Score:2)
There's no way inducing the magnetic field in the rotor instead of using permanent magnets would make it more efficient. I'll bet either the designers or the article is quoting some other efficiency number that is not comparable to what most motors are measured on.
Re: (Score:2)
Re: (Score:2)
So it's like a new type of switched reluctance motor?
Re: (Score:2)
It's just a variant of the AC induction motor, which was invented by Nikola Tesla in the 1880s.
Then why aren't we already driving cars powered by them?
Maybe it is a BFD ...
Re: BFD (Score:2)
Every AWD Tesla still uses them. The original Model S and Roadster both exclusively used them.
The cost of buying rare earth magnets from China is offset by the increased efficiency which means a smaller cheaper battery. Car makers use induction motors where power is needed with minimal cost and permanent magnet motors where they need efficiency.