New GE advanced traction motor

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hal2000

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Sep 20, 2012
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Yesterday I heard the news about GE announcing the developing a new traction motor with almost double the power and improved efficiency. The future is coming I just wish the little guys could open source it instead of GE owning it. The move into low carbon alternatives has to happen faster than the corporate circle your patent wagons mentality is going to allow! A little trolling found this milestone roadmap of progress which reveled a little more than the generic press release from G.E. I would love to hear what more tecky members of this list think As to how the Advances are being achieved, I.E. whats a 3x sintered permanent magnet with ultra low resistivity and eddy currents , in normal speak!.


http://www.google.com/url?sa=t&rct=j&q=3x%20permenant%20magnets&source=web&cd=2&cad=rja&ved=0CCgQFjAB&url=http%3A%2F%2Fwww1.eere.energy.gov%2Fvehiclesandfuels%2Fpdfs%2Fmerit_review_2009%2Fadvanced_power_electronics%2Fape_08_elrefaie.pdf&ei=aGpdUM3dBLHmiwLL04HIAQ&usg=AFQjCNG3MDjiw2jknitdBogeUvF8BXt9qw
 
Electric motors had reached the point of diminishing returns long before we were born. For most purposes, a motor that's 95% efficient is not really any better than one that's 90% efficient-- and way worse if it costs ten times as much. Shaving down losses so LFP can stuff 100kW through a bicycle hub is good for LFP, but irrelevant for just about everyone else. Our motors are all great in comparison to our lousy batteries.

If folks were interested in small efficiency improvements to things that are already close to optimal, there would be a lot more 40+ mpg cars on the streets of America. But once you get in the 30-something mpg ballpark, folks become more interested in crap like what paint colors are available.

There may well be a killer app for ultra efficient electric traction motors, but I sure don't know what it is.

Chalo
 
Chalo said:
Electric motors had reached the point of diminishing returns long before we were born. For most purposes, a motor that's 95% efficient is not really any better than one that's 90% efficient.........
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Oh, come off it. Halving the losses would allow a significant reduction in weight.....not to mention materials.
 
What does that matter when the battery dominates the whole physical package? It's like obsessing about the weight and energy dissipation of your shock absorbers-- sure, that makes a measurable difference, but in the big picture it's not worth spending much time and money on.

Running an e-motor at such a high specific power that it burns up if anything goes awry is not really good design or suitable for most uses. And that's the only place where there would be a practical difference between a 90% and a 95% efficient motor.
 
Chalo said:
What does that matter when the battery dominates the whole physical package? It's like obsessing about the weight and energy dissipation of your shock absorbers-- sure, that makes a measurable difference, but in the big picture it's not worth spending much time and money on.
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In what way does it dominate? By weight? What is the weight ratio between hub motor and battery pack for the average build?

Chalo said:
Running an e-motor at such a high specific power that it burns up if anything goes awry is not really good design or suitable for most uses. And that's the only place where there would be a practical difference between a 90% and a 95% efficient motor.
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The power level you run it at, relative to maximum, is a neutral. The difference between 90% and 95% efficiency is 50% less heat generated.
 
I felt That the real advance was heat tolerance, and power output, not the small gain in efficency. Most of the motor testing I see going on amomg members of this site is temperature limited and ends in a puff of smoke straight out of the wizard of oz. (live for phisics) A Motor with less stringent cooling demands is going to lend it's self to a simpler and more affordable package.

Ok you E.E. nerds now that you know it is possible. check out the goals and implied hints in the PDF I linked to,
Pretend you were part of this GE brain trust that achieved these advances, and tell us how you did it.
 
Miles said:
Chalo said:
What does that matter when the battery dominates the whole physical package?
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In what way does it dominate? By weight?
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Weight, size, mounting, maintenance, reliability, longevity... and when we get outside physical issues, cost and availability too.

If we had good batteries, the bicycle hub motors we had fifteen years ago would be thoroughly adequate for most folks. Non-hub motors have been up to the task, as I said before, for longer than our lifetimes. But because we don't have good batteries yet, e-bikes still kinda suck even though motors are quite good.

Chalo
 
Chalo. This is the motor technology section. We discuss improvements to motors not the inadequacy of batteries. If you don't think there's any point in developing better motors, that's fine but, in that case, I'd suggest you go and suck your thumb in the battery technology section... :)
 
A $5.8 million or probably more motor will never be open sourced when it's done. GE will seek to recover it's $2.2 million or probably more, eventually it'll leak out into the hands of others. The idea there can be a big, expensive step forward open sourced is ridiculous. If the government didn't pay for more than half the technology would never be developed at all. Only way it'll work.

I don't think EVERYONE is experimenting with motors by blowing them up. Even Mr. Physics must have things that never explode, he just has fun telling us about what DOES go Krakatoa.

For once Chalo was discussing this calmly and without flinging insults, so you stick your knife between his ribs and give him an excuse to stab back? Nice work. And he's right about how new motor technology pales in comparison to the need for battery work. I agree ebikes are not seriously in need of new motors.

What little I know about traction motors is that they must be developing something a long way from a transportation drive. Are you sure they're not just plugging in existing motor advances in an area where they haven't put that kind of work in up to now? I'd compare to the lawnmower engine, much the same as in the 1930's even as they can build a Sachs Madass with that displacement of engine that is smaller and higher performing, to say nothing of cleaner. There's the real question for the experts: Are they advancing these motors, or merely modernizing them?
 
I took no offense.

And I still think that spending to improve something that's already 90% of the way to theoretically perfect is a waste or resources when there's related stuff that hasn't even reached OK yet.

Chalo
 
Chalo said:
And I still think that spending to improve something that's already 90% of the way to theoretically perfect is a waste or resources when there's related stuff that hasn't even reached OK yet.

Chalo
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I see your point, but apparently small improvements in motor efficiency do have a large impact on system design.

Take a big EV, for example, such as might use this 30kW (55kW peak) motor. If a 90% efficient motor was used, then the vehicle has to be able to deal with cooling losses of around 3 kW. If the motor is made just 5% more efficient, taking it to 95%, then the losses are halved, so halving the cooling requirement to just 1.5 kW. Such a saving in system costs makes even small motor efficiency improvements very well worth pursuing, even though in overall terms it may not, at first glance, seem to be something worth doing.
 
Simplified stator windings will reduce end-turn length and losses, together with motor mass and volume and manufacturing cost.
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GM like solid bar oil sprayed stators?? Reduced end turn losses,etc,etc as above.

Chalo wrote:What does that matter when the battery dominates the whole physical package?
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I disagree Chalo.
Here is good example of a bad power density electric motor and is pretty typical (give or take a bit) of what a lot of people are using. My wife's bamboo commuter bike has a Cro hub motor which weighs a whopping 11kg without rim, spokes, freewheel tube and tyre and can only maintain 4kw output 100% duty cycle. The motors CG is up high (340mm above ground) and contributes the most to a heavy less responsive
physical package
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.
The bikes rear unsuspended weight to suspended weight ratio on rear axle also means rear suspension would be a lot less effective hence grip and ride quality suffers because poor design/material.
In comparison the batteries weigh only 8kg (1000W/hr of A123 prismatics). They are down low and centralized in the bike, and give enough power for over 50km range without breaking a sweat. Enough range for most bikes.
Peak efficiency is very important but a lot of motor waste in the real world goes when motors are operating to often in the death zone, pouring amps in and going hardly anywhere, grinding up hill or doing a lot of accelerating from stop or low speed.
A 4kw %100 duty cycle motor should weigh about 2kg operate above %90 and have a flexible enough power band to operate without multispeed gearboxes.
Wait a minute thats what Miles is drawing. :roll:

Zappy
 
Chalo said:
Shaving down losses so LFP can stuff 100kW through a bicycle hub is good for LFP, but irrelevant for just about everyone else.
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I run a non-hub motor that gets a mere 85kw stuffed down it's throat kicking and screaming. lol The motor I've been using for the last 3 events has taken a hell of a beating and not suffered any failures, doesn't even smell like hot windings inside, it survives where the previous ones failed because it's more efficient.


That's not what matters a bit though.

What matters a bit, is that in my feather-weight 700c road bicycle build I'm doing, if my motor could leverage things like high electrical resistance magnets(to lower magnet surface eddy currents) with N50SH strength/temp range, and steel alloys with ultra high permeability, and windings using hairpin welded square copper bars rather than enameled round wire, I can get the performance of a 10lbs hubmotor at the weight of a 3-4lbs hubmotor (because efficiency increased from ~85% to 95%, meaning only 1/3rd the waste heat to shed for a given power level). Or perhaps even the power of a 6lbs cute motor in a package of only a 2-3lbs, not much heavier than a non-ebike hub.

Shaving off 6-7lbs off the wheel of an electric roadbike would make it feel a hell of a lot better to ride. My battery is only 4lbs and 6fet controller is less than 1lbs. I see wheel sets that cost many thousands of dollars to shave off less than 1lbs from the wheelset my bike runs (which are pretty light). I would happily pay say 5x the price of a cutemotor (~$600) for a cutemotor performing motor at half or 1/3rd the weight.
 
It's the same motivation that drives roadie cyclists to shell out $10 per saved gram (or more) for ever lighter components, and it faces you with analogous knife-edged consequences. An overlight bike component can snap off and leave you injured, but an overlight e-motor can reach a fault condition and go up in smoke before you have time to realize anything is wrong--perhaps even before a thermal sensor can get the news. How much more sudden and vicious would thermal runaway be in a 2 pound hub than in a 14 pound hub?

If the Chinese could make you a reliable ceiling fan with a motor that weighed two pounds instead of twenty pounds, you can bet your bottom dollar they'd do it-- the savings in materials and shipping would dramatically improve their bottom line. So why don't they? Those things are only pulling 80W or so at full tilt.

I reckon it's because they don't want to make ceiling fans that burn down and take your house with them.

Chalo
 
Chalo said:
How much more sudden and vicious would thermal runaway be in a 2 pound hub than in a 14 pound hub?
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Whar a pathetic reason for not increasing specific torque........ given that the batteries still dominate the safety aspect.... :p
 
Miles said:
Chalo said:
How much more sudden and vicious would thermal runaway be in a 2 pound hub than in a 14 pound hub?
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Whar a pathetic reason for not increasing specific torque........ given that the batteries dominate the safety aspect.... :p
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I remember saying [about e-bike batteries] that they dominate

Weight, size, mounting, maintenance, reliability, longevity... and when we get outside physical issues, cost and availability too.
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but nothing about safety one way or another.

Chalo
 
I don't think there is a major safety issue in burning up a motor; it's just expensive and inconvenient.
 
liveforphysics said:
I would happily pay say 5x the price of a cutemotor (~$600) for a cutemotor performing motor at half or 1/3rd the weight.
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After using hubmotors with well over 90% peak efficiency for much of the last 9 months I agree with your sentiments, but why are you eager to pay so much? For essentially that price I can put a motor in your hands weighs only 5-6 times as much as the cutemotor, is capable of 10-12 times the continuous power in stock form, and with simple modifications 20-25 times the power.

John
 
John in CR said:
liveforphysics said:
I would happily pay say 5x the price of a cutemotor (~$600) for a cutemotor performing motor at half or 1/3rd the weight.
Click to expand...

After using hubmotors with well over 90% peak efficiency for much of the last 9 months I agree with your sentiments, but why are you eager to pay so much? For essentially that price I can put a motor in your hands weighs only 5-6 times as much as the cutemotor, is capable of 10-12 times the continuous power in stock form, and with simple modifications 20-25 times the power.

John
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Nice plug! And I have been eyeing up that motor BTW. But what LFP is talking about is the weight! There is a certain niche out there that like very light / high quality bikes.

Go in a bike shop and lift up an ebike. They are stupid heavy and don't perform. Pain to get on a bike rack, pain to get up some stairs. They don't handle like a real bike.

We need something the weight of a commuter booster but in a hub motor w/ cassette. MAC/BMC are OK, but are by no means as good as it could get. I know a lot of roadies that aren't getting any younger. And they are used to spending *lots* on bikes. :lol:
 
John in CR said:
liveforphysics said:
I would happily pay say 5x the price of a cutemotor (~$600) for a cutemotor performing motor at half or 1/3rd the weight.
Click to expand...

After using hubmotors with well over 90% peak efficiency for much of the last 9 months I agree with your sentiments, but why are you eager to pay so much? For essentially that price I can put a motor in your hands weighs only 5-6 times as much as the cutemotor, is capable of 10-12 times the continuous power in stock form, and with simple modifications 20-25 times the power.

John
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Because I've got deathbike when I'm feeling like a peppy ride. I want to just supplement what I can pedal a bit on this bike, but still keep it feeling like a blissfully light pleasure to pedal around on.

I'm also going to be doing cyclocross events with it, which often involves carrying the bike while running up stairs or over logs and things (yes I know deathbike can just torque up stairs effortlessly, but I want to participate for fun without anyone even noticing that I'm electric assisted).

Here is a bit of video from my local cyclocross group in Santa Cruz.

http://vimeo.com/31392079#
 
i dont know whether to laugh or cry, LPF is now buying cute motors and wearing lycra????
 
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