PMAC vs induction motor for model 3

[stopcrazypp]

Which kind of Motor/Generator/Units do they use on the 2016 Audi R18? If my information is correct, it's PM.

They pay >$10,000 to lose a pound of weight. Everything possible is carbon fiber, even the transmission case. Titanium bolts are hollow. All parts are hand benched to reduced weight. 476HP of electric motors + 5xx horsepower of diesel power gives you over 1,000 hp in a 900kg (2000lb) package including the lithium battery and enclosed armored safety cockpit.

If induction motors are so light in the 400+ HP arena, why didn't they used them?

Or check the Porsche 918, Ferrari LaFerrari, or McLaren P1.

Do you have the weights of the mentioned motors? Easier to have that than to guess the density. I should say however racing equipment tends to skew things differently because they are designed to last drastically shorter in life, so you can get power ratings far higher than if the exact same part was used in a consumer application.

918 uses 115 kW and 92 kW motors, fairly wimpy
LaFerrari 120kW, again wimpy
McLaren P1, 131 kW, again wimpy

Already pointed out, but in track applications the temperature performance requirements may be a bigger consideration (induction motors poor for this purpose because of rotor heat which is hard to remove).

Is there a PMAC for consumer applications that is in the same power range as Tesla's motor and weighs less? Or at least with better power density.

 

[JeffK]

Do you have the weights of the mentioned motors? Easier to have that than to guess the density. I should say however racing equipment tends to skew things differently because they are designed to last drastically shorter in life, so you can get power ratings far higher than if the exact same part was used in a consumer application.

918 uses 115 kW and 92 kW motors, fairly wimpy
LaFerrari 120kW, again wimpy
McLaren P1, 131 kW, again wimpy

Already pointed out, but in track applications the temperature performance requirements may be a bigger consideration (induction motors poor for this purpose because of rotor heat which is hard to remove).

Is there a PMAC for consumer applications that is in the same power range as Tesla's motor and weighs less? Or at least with better power density.

The Rimac uses PM. It uses four separate motors and the total output of all motors is 913 kW.

The rear two have 600 kW peak and the front two have 500 kW peak.
Concept_One | Rimac Automobili
Rimac Automobili Enters Electric Vehicle Powertrain Market With True Authority; Will Sell All of Its Highly Specialized Components | Inside EVs

 

[Saghost]

The Rimac uses PM. It uses four separate motors and the total output of all motors is 913 kW.

The rear two have 600 kW peak and the front two have 500 kW peak.
Concept_One | Rimac Automobili
Rimac Automobili Enters Electric Vehicle Powertrain Market With True Authority; Will Sell All of Its Highly Specialized Components | Inside EVs

Clearly a case where the need for sustained high performance dominates most other concerns. Do you have any information about the weight of their motors?

It'd be interesting if we had any data on the Nio, too - another car that needs (and has) serious track credibility.

 

[JeffK]

Clearly a case where the need for sustained high performance dominates most other concerns. Do you have any information about the weight of their motors?

It'd be interesting if we had any data on the Nio, too - another car that needs (and has) serious track credibility.

115 kg for the rear two and 95 kg for the front two. Both in a dual motor setup so the weights are for two motors together

See the spec sheet. http://www.rimac-automobili.com/media/2211/ra-motors-data-sheet.pdf

 

[Saghost]

115 kg for the rear two and 95 kg for the front two. Both in a dual motor setup so the weights are for two motors each.

See the spec sheet. http://www.rimac-automobili.com/media/2211/ra-motors-data-sheet.pdf

Impressive stuff. Are there similar datasheets for their reduction gears and inverters so we can try to compare at a system level?

(Though now the shoe is one the other foot - that's a whole lot more peak power than Tesla's original solution.)

I know Rimac uses a two speed dual clutch setup on the rear wheels for more low speed acceleration, which will add some extra weight that would have to be accounted for somehow.

You know, if you could get that power train for less than a king's ransom, I can think of a few cars that even the smaller one would make a lot of fun...

 

[JRP3]

No. But, I suspect Telsa doesn't want to take another S/X owner and give them yet another reason to feel the M3 did something better....

Since the S will still outperform the 3 I don't see how that's "better", and the X is a completely different animal, (SUV vs medium sedan), I don't see any cannibalizing happening because of the motor choice.

 

[JeffK]

Impressive stuff. Are there similar datasheets for their reduction gears and inverters so we can try to compare at a system level?

(Though now the shoe is one the other foot - that's a whole lot more peak power than Tesla's original solution.)

I know Rimac uses a two speed dual clutch setup on the rear wheels for more low speed acceleration, which will add some extra weight that would have to be accounted for somehow.

You know, if you could get that power train for less than a king's ransom, I can think of a few cars that even the smaller one would make a lot of fun...

Everything I can find and datasheets are located here: Technology | Rimac Automobili
(Their website is horrible from a usability standpoint.)

 

[insaneoctane]

Since the S will still outperform the 3 I don't see how that's "better", and the X is a completely different animal, (SUV vs medium sedan), I don't see any cannibalizing happening because of the motor choice.

That depends on your metric for performance. Acceleration? Yes. Energy efficiency? No. Range? Hmmm.

 

[JRP3]

Even with an AC induction motor the smaller, lighter Model 3 would be more efficient than the S and X, so that differentiation has nothing to do with the use of a PMAC motor.

 

[gregd]

Even with an AC induction motor the smaller, lighter Model 3 would be more efficient than the S and X, so that differentiation has nothing to do with the use of a PMAC motor.

Perhaps the use of the same motor in the long-haul truck was the lever? I wouldn't be surprised if in a truck application, the Achilles heel of rotor cooling would be a problem. By using a PMAC motor in both applications, they heavy duty resiliency (as well as volume / cost reduction) for the truck, and efficiency for the Model 3.

 

[int32_t]

Siemens has been able to squeeze 5 kW/kg out of their aircraft motor, but I can't find anywhere whether it's a permanent magnet or induction motor. Obviously this is designed first for weight, and performance and efficiency are close seconds.

Siemens Unveils 260 KW Electric Engine

 

[R.S]

Siemens has been able to squeeze 5 kW/kg out of their aircraft motor, but I can't find anywhere whether it's a permanent magnet or induction motor. Obviously this is designed first for weight, and performance and efficiency are close seconds.

Siemens Unveils 260 KW Electric Engine

It's a six phase PMAC and the impressive thing is that the 5kW/kg aren't peak, but continuous power. Peak power should be even higher.

 

[McRat]

...
Is there a PMAC for consumer applications that is in the same power range as Tesla's motor and weighs less? Or at least with better power density.

Sort of a loaded question. Tesla is the only mass produced high performance EV. So no matter what design, they win. Weight and size do not matter at all. If the motor weighed 4000lb and produced 250hp, they win.

The ideal system for a premium affordable 400hp electric would be 4 PMAC motors. Like the Audi, it could regen at full HP or higher on paper, that is 300kW of regen. Pragmatically, without huge downforce, you'd be limited to no higher than ~150 kW due to street tires, intense weight transfer, and battery life expectancy. Hence why you need the 150kW of MGU up front. The MGU controller also does the task of the wheel resolvers, differentials, transfer case, traction control, and stability control. The motors know what rpm they are at, the accelerometers know the rotational inertia compared to the steering wheel input. With the right battery, this could still be a 200 mile EV at 3800lb at $45k or less with world class handling. Purchase a proven low cost Body In White, like a Camaro or Mustang, fit the EV drivetrain.

 

[stopcrazypp]

Sort of a loaded question. Tesla is the only mass produced high performance EV. So no matter what design, they win. Weight and size do not matter at all. If the motor weighed 4000lb and produced 250hp, they win.

The ideal system for a premium affordable 400hp electric would be 4 PMAC motors. Like the Audi, it could regen at full HP or higher on paper, that is 300kW of regen. Pragmatically, without huge downforce, you'd be limited to no higher than ~150 kW due to street tires, intense weight transfer, and battery life expectancy. Hence why you need the 150kW of MGU up front. The MGU controller also does the task of the wheel resolvers, differentials, transfer case, traction control, and stability control. The motors know what rpm they are at, the accelerometers know the rotational inertia compared to the steering wheel input. With the right battery, this could still be a 200 mile EV at 3800lb at $45k or less with world class handling. Purchase a proven low cost Body In White, like a Camaro or Mustang, fit the EV drivetrain.

Nope, not a loaded question. Someone just posted a Rimac and even the Siemens might qualify (although it is an aircraft motor, so probably some slight differences in design, it at least is not a racing motor). There's also the R8 e-tron, SLS electric, Lightning GT, Nio EP9 (although this is not built to be street so kind of stretching it). Tesla is not the only one who has built a performance EV.

For reference, Elon said the original 270 kW motor in the Model S weighed around 70 lbs (32 kg). 8.4 kW/kg.

Original Roadster was 185 kW at around the same weight, 5.6 kW/kg.

 

[gambit48]

After 12 pages, am I the only who's still thoroughly confused as to whether the M3 motor is a good or bad thing?

 

[ruby110]

Either way, I would like the DU warranty to be 8 years. FWIW, I tweeted Elon about the duration. So far, no response.

 

[JeffK]

I tweeted Elon about the duration. So far, no response.

I tweet Elon probably every other day... I've yet to receive a response from the almighty Elon.

 

[JeffK]

After 12 pages, am I the only who's still thoroughly confused as to whether the M3 motor is a good or bad thing?

If it's really PMAC it's likely a good thing, especially for range. If it's not PMAC and its range is still that good, then that's great too.

 

[SageBrush]

I tweet Elon probably every other day... I've yet to receive a response from the almighty Elon.

Try at 2am

 

[James Anders]

I tweet Elon probably every other day... I've yet to receive a response from the almighty Elon.

That's probably why.