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Electric motor design claims remarkable improvements

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Re: Electric motor design claims remarkable improvements

#111

Post by dstroot »

corodra wrote: post #53

Don't get me wrong, I saw the title and was excited. I want this to be real. I want to believe. But way too many keyword drops. Disruptive is what red flagged me the most. Way too many promises. Only lab results and "experts" commenting that it should work in theory. But no prototype? Even though it's a different motor they don't "believe" it's going to cost more to make than traditional motors? Only 3d renders? I th…

If what they say is 5% true they would have raised $50m seed rather than $4.5m.

Re: Electric motor design claims remarkable improvements

#112

Post by djddjdjd »

hedora wrote: post #94
RickJWagner wrote: post #57

Earlier quoted context omitted.

I had the same reaction. Reminds me of old claims for a 50 mpg carburtor (on cars circa 1970). There's definitely a fishy smell about it.

Yeah; my old GMC had a carburetor and the fuel economy is the same as the current replacement, which is the same size, runs half the cylinders (unless it needs all 8) re-levels into aerodynamic mode at speed, and has shutters that close the radiator grill when possible. (The new one is fuel injected, etc). I’m not sure what fuel injectors and electronic ignition got the industry, but it wasn’t real world fuel economy…

“I’m not sure what fuel injectors and electronic ignition got the industry, but it wasn’t real world fuel economy.”

Actually it is fuel economy. Your old truck [0] doesn’t have a bunch of mpg sapping emissions rules to deal with.

The fuel injector allow for more power for the same amount of fuel giving the engineer the power budget to spend on reducing non carbon emissions and increasing weight (ie safety)

[0] your truck appears to be tuned slightly lean, or at stoichiometry. Otherwise there’s no way you’d get similar mph.

Re: Electric motor design claims remarkable improvements

#113

Post by davidgould »

adammunich wrote: post #107
corodra wrote: post #53

Don't get me wrong, I saw the title and was excited. I want this to be real. I want to believe. But way too many keyword drops. Disruptive is what red flagged me the most. Way too many promises. Only lab results and "experts" commenting that it should work in theory. But no prototype? Even though it's a different motor they don't "believe" it's going to cost more to make than traditional motors? Only 3d renders? I th…

I've learned a great deal about motors over the years. I don't doubt what they have here is real, as, these principles have been known for a long time. The reason we don't use permanent-magnet synchronous motors like this in cars though, is because rare earth magnets are much more expensive, and more fragile, than using synchronous reluctance motors which are mostly iron. The auto companies aren't dumb --if they thou…

The car makers with any volume are using asynchronous AC motors (Leaf, Tesla) or PM DC synchronous motors (GM). Tesla got a lot of publicity when there was speculation about the Model 3 using a reluctance motor, which suggests it would have been a new thing. But it turns out to be a hybrid of PM and reluctance. Possibly Chinese vendors are doing something different for cars, but the e-bike and scooter motors are all PM.

I don't believe the company in the article have anything at the level they are claiming.

Re: Electric motor design claims remarkable improvements

#114

Post by davidgould »

magicalhippo wrote: post #83
throwawaycanada wrote: post #77

Earlier quoted context omitted.

Electric motors are already well over 90% efficient. I don't see what they could do to improve this. Maybe weight/power ratio? Even then, Tesla pretty much nailed it with his three phase "squirrel cage" motor. That's why even today that is what a Tesla car uses and it's what quadricopters use.

In the Fully Charged episode[1] linked in a recent thread here about some guy in Amsterdam making electric cars and boats, the guy mentions that the motors have brushes. I was mildly surprised as I just assumed they'd be brushless DC motors. Are they just efficient enough that the cost/simplicity outweighs going brusless? Or are there other advantages to using brushed motors for electric vehicles? [1]: https://www.yo…

Brushed motors are readily available in the appropriate sizes in small quantities and used. Brushless motors not so much yet. Then you also have to use the OEM inverter which will take some reverse engineering or bring your own inverter. People are doing this with car conversions, but it's early days and anyone can wire up a brushed motor.

Re: Electric motor design claims remarkable improvements

#115

Post by moogly »

xxpor wrote: post #90
mikeash wrote: post #86

Earlier quoted context omitted.

Right, look at the size of the motor versus the size of the batteries in an electric car. Efficiency is already well over 90%, too. If you managed to create an idealized electric motor that was 100% efficient, had no limits on power, torque, or RPM, weighed nothing, took up no space, and cost nothing, it would be a nice improvement but I don't think even this would revolutionize electric cars. Batteries are the key.

According to people on the TMC forums (so take with a grain of salt) Tesla's motors only cost $350-400. If that's true, they're basically perfect already. It's the batteries which drive cost and weight.

Is that the Model 3 motors? I've heard that the Model S motors had a surprisingly high failure rate, many owners of the earlier models having had 5+ drive unit replacements. I'm guessing the Model 3 drive units are more reliable?

Re: Electric motor design claims remarkable improvements

#116

Post by mikeash »

moogly wrote: post #115
xxpor wrote: post #90

Earlier quoted context omitted.

According to people on the TMC forums (so take with a grain of salt) Tesla's motors only cost $350-400. If that's true, they're basically perfect already. It's the batteries which drive cost and weight.

Is that the Model 3 motors? I've heard that the Model S motors had a surprisingly high failure rate, many owners of the earlier models having had 5+ drive unit replacements. I'm guessing the Model 3 drive units are more reliable?

The early Model S motors had problems like that. They got a lot better over the years. The Model 3's is great, and the Model S/X front motors are now the same as the Model 3's, while the rear motors are something else that's still a lot better.

Re: Electric motor design claims remarkable improvements

#117

Post by mrfusion »

blattimwind wrote: post #51
mrfusion wrote: post #47

Earlier quoted context omitted.

How much of that is just a matter of more R&D though? I don’t see why any of that is inherent to electrostatic?

It's mostly Coulomb's law; electrostatic force is proportional to the involved charges divided by their separation. You don't have that problem in electromagnetic motors because strong magnetic fields don't break down the rotor/stator air gap. You might turn the air gap into a dielectric oil gap, but now you have fluid friction losses which again limit how narrow that gap can be. You'll note that this is a recurring…

Good explanation. So it makes me wonder if we could improve on the capacitor if we could find its magnetic counterpart. Does that even make sense?

Re: Electric motor design claims remarkable improvements

#118

Post by londons_explore »

mikeash wrote: post #102
dzhiurgis wrote: post #100

Earlier quoted context omitted.

While motor efficiency is 90%, drivetrain is less than that because of gearbox. This motor claims to remove this inefficiency.

Tesla claims that their drive unit (which includes the motor, inverter, and gearbox) efficiency on their latest models is 93%.

Average or peak?

Making something that performs well at freeway speeds, yet also is efficient when manuvering round a parking lot is hard.

Most companies just hope you don't care about only getting 5% efficiency round the parking lot, because that isn't a large fraction of your energy budget, even when it's so inefficient.

Re: Electric motor design claims remarkable improvements

#119

Post by londons_explore »

mikeash wrote: post #116
moogly wrote: post #115

Earlier quoted context omitted.

Is that the Model 3 motors? I've heard that the Model S motors had a surprisingly high failure rate, many owners of the earlier models having had 5+ drive unit replacements. I'm guessing the Model 3 drive units are more reliable?

The early Model S motors had problems like that. They got a lot better over the years. The Model 3's is great, and the Model S/X front motors are now the same as the Model 3's, while the rear motors are something else that's still a lot better.

Any clues what exactly within the motors fails?

Re: Electric motor design claims remarkable improvements

#120

Post by londons_explore »

marcosdumay wrote: post #87
throwawaycanada wrote: post #77

Earlier quoted context omitted.

Electric motors are already well over 90% efficient. I don't see what they could do to improve this. Maybe weight/power ratio? Even then, Tesla pretty much nailed it with his three phase "squirrel cage" motor. That's why even today that is what a Tesla car uses and it's what quadricopters use.

If you go distillate the actual claims from the fluff, the article is saying it has a larger torque to weight, smoother operation at low speeds, and larger efficiency at very high speeds. And well, three is much to improve on the last two, so I'm willing to believe they got something for those, while I do expect the first claim to get completely lost once they actually produce the motor.

Cogging (non-smooth operation at low speeds) is pretty much a solved problem already. You simply program the cogging torques into the controller as a function of shaft angle, and tell it to compensate.

Final result: motor that behaves as if it had no cogging.

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