[Spoiler Alert + Mild Speculation] Tesla has created a monster!

[FlatSix911]

Interesting data ... Can someone help interpret the key conclusions from pages 6-7

 

[hacer]

Page 3 of that report says th motor is AC 3 Phase Permanent Magnet. I don't believe the old motors were permanent magnet.

Indeed if this is a PM motor, then it is unlike other Teslas. The report incorrectly spelled the word permanent which, with the PM motor change and various factors a bit better then Tesla published specs colors me a bit skeptical of the document authenticity.

Edit: finishing the thread, I see it is available from epa.gov, so it probably is real. I'm surprised that Tesla shifted to PM motors.

 

[omgwtfbyobbq]

Where's the battery capacity in this report?

There ain't.
There is average voltage of 351V during testing and integrated AmpHours of 222Ah.
222 x 351 = 77,9 kWh used during the test.

I'm guessing (could be wrong) it's total voltage times energy capacity on page 3.

Are there documents for Model S, Model X or Roadster?
If they state the same, we would not it does not mean anything, on the other hand if ...

Here's the certification records for Tesla's other test groups from this year.

https://www3.epa.gov/otaq/datafiles/CSI-HTSLV00.0L1S.PDF
https://www3.epa.gov/otaq/datafiles/CSI-HTSLV00.0L2SV2.PDF
https://www3.epa.gov/otaq/datafiles/CSI-HTSLV00.0L2XV3.PDF

Indeed if this is a PM motor, then it is unlike other Tesla's. The report incorrectly spelled the word Permanent which, with the PM motor change and various factors a bit better then Tesla published specs colors me a bit skeptical of the document authenticity.

It could be a fake, but that means someone managed to fool the EPA into thinking they were Tesla.

 

[omgwtfbyobbq]

Oh wow, the Model 3 LR has slightly better overall range than the Model S 100D, at least on the test results. No wonder Musk is anti-selling the 3.

 

[WarpedOne]

@omgwtfbyobbq
Thank you!
For Roadster, Model S and Model X there is:

AC Induction

I guess this is a smoking gun or one very incompetent clerk.

 

[Swampgator]

Could also be some new hybrid type motor. Most PM motors are DC (Bolt).
This clearly says 3 phase PM which implies A/C

 

[CarlitoDoc]

Ok.....what's going on here?? English please, no hablo "electric engineering".

 

[WarpedOne]

Most PM motors are DC (Bolt).

No.
Actually ALL electric motors are AC, magnetic fields must switch or there is no rotation.
There is only one type of electrics motor called DC motors that take direct DC current. They can do that because they have internal mechanical inverter (called commutator) that switches the poles as rotor rotates.
No such DC motors in a production EVs. Where EV motors differ is how they "generate the opposing" magnetic field. AC induction uses induced current that opposes the 'primary' stator field, PM AC motors have permanent magnets.

This goes against scarcity of rare earths... interesting.

 

[22522]

Ok.....what's going on here?? English please, no hablo "electric engineering".

The motor technology in the Model 3 is like nothing else Tesla has done.

And it is very good (efficient).

This is consistent with what the designer said on the Motor Trend test drive (to fill up the conversation as the journalist was speechless - did not know what to say as his senses discovered gold)

 

[SageBrush]

This is the most informative document ever, and here is the mother lode:

Explanation and use courtesy of a Bob Wilson post at PriusChat

The EPA requires a set of roll-down tests that are reduced to three coefficients. There is a simple formula that converts them into the power required at any given speed:

• Target Coef A (lbf)
• Target Coef B (lbf/mph)
• Target Coef C (lbf/mph**2)
• v - mph
• Drag_HP = (v*(Coef_A+(v*Coef_B)+(v*v*Coef_C)))/375

The vehicle drag is the sum of aerodynamic, linear, and a static drag force which is why getting them from the USA "Test Car Database" is so useful. All of the forces must be accounted for and the roll-down coefficients have been very useful in predicting vehicle efficiency.

 

[Matias]

Wouldn't this mean, that Model 3 is not Tesla, since Nikolai Tesla invented the induction motor, not the permanent magnet motor

 

[JRP3]

This goes against scarcity of rare earths... interesting.

Unless it's a new rare earth free permanent magnet, I know there is work being done on them. I must say this is surprising that Tesla has switched to a PM motor if this does turn out to be true. There were signs of this possibility but nothing really credible.

 

[SageBrush]

Using the Dyno Coefficients, we get the efficiency data:

Keep in mind that this does not include accessory use like A/C; it includes car on, inverter, road, motor, transmission and air frictions.

 

[Matias]

Comparison Permanent magnet vs induction motor in electric cars

Induction Versus DC Brushless Motors

 

[SageBrush]

In case you were wondering how the Bolt compares ?
(Graph derived from roll-down Coefficient data used by EPA for cycle testing)

I find the 220 Wh/mile point the most interesting and impressive: The Bolt at 60 mph has the same consumption as the Model 3 at 70 mph.

 

[SageBrush]

There ain't.

The EPA sheet reports energy used from the wall to fill the battery from empty.
From there, IIRC EPA presumes 12% charging losses

Tesla reported 78.27 kWh consumption from the battery in a comment at the bottom of page #7. That works out to a 12.5% charging loss to get to the EPA number. Close enough for government work ;-)

 

[geoffreak]

Something interesting discovered in the reddit thread by Bob042:

On Page 3, for the RWD S it says Regenerative Braking Source: Rear Wheels.

For the AWD S and RWD 3, it says Regenerative Braking Source: Both

I don't know how you get regen from the front axle without a motor there, though, so I wonder if that's actually right? Or maybe Tesla has some tricks up their sleeve for the 3 still...

So is there a secret front motor/generator in RWD cars, or a typo?

 

[SageBrush]

I can now take a better guess at the SR Model 3 range at 70 mph
No more than 220 Wh at 70 mph (since it will be a tad better than the LR)
A bit less than 78*220/330 Usable battery, say 54 kWh

Then range at 70 mph w/o AC is 54/0.22 = 245 miles.

As OP stated, Tesla hit it out of the park.
Since my 257 mile drive is at 6000 feet elevation (80% air density of sea level), I'm increasingly confident the SR Model 3 can make the drive on a nice day without head-wind without any SC use. Damn

 

[powertoold]

Holy smokes, it's difficult to believe this information is true, but it comes directly from the EPA.

Tesla outdid themselves with the 3, lol.

 

[stopcrazypp]

Page 3 of that report says th motor is AC 3 Phase Permanent Magnet. I don't believe the old motors were permanent magnet.

That stuck out to me too. If so, this is a pretty big change. How much rare earths would this motor use?