Model 3 Motors on the Tesla Parts Catalog

[mongo]

I don't believe there is any difference in the motors or electronics. Any performance difference is most likely software controlled. If there was a difference there would be unique part numbers for the different model cars.

See post 15 and 18 which list and show the new different rear motor part numbers. (or go to https://epc.teslamotors.com/#/systemGroups/47412 yourself)

My guess is the LC version is Low Cost for SR.

Edit: not SR since it has AWD in the description. (I reserve the right to hedge the possiblity on the SR not existing yet...)
Thanks @MP3Mike for the clue by 4

 

[Kirby64]

It's pretty clear there's new part numbers now... the question is whether there's actually different part numbers for older models. If older PAWD vehicles have the same hardware/drive units, it seems to be extremely unlikely that they are actually different hardware or receive a different burn-in/assembly procedure. If that's the case, swapping parts should be relatively straightforward.

 

[AlanSubie4Life]

I don't believe there is any difference in the motors or electronics. Any performance difference is most likely software controlled. If there was a difference there would be unique part numbers for the different model cars.

Ha! A comedian!

This seems like an odd conclusion given the part details right there in the part description. I mean it is right there! There are three parts listed.

Do you also believe all batteries are the same size (even though there is a part for 75kWh and another for ~62kWh)?

 

[MP3Mike]

My guess is the LC version is Low Cost for SR.

But the part description specifically says AWD in it, so not SR/MR. And AWD is listed as having a less powerful motor than the RWD and Performance version.

 

[mongo]

But the part number specifically says AWD in it. And AWD is listed as having a less powerful motor than the RWD and Performance version.

There you go, throwing facts at me again...

 

[Kirby64]

But the part description specifically says AWD in it, so not SR/MR. And AWD is listed as having a less powerful motor than the RWD and Performance version.

My guess is this is a new AWD inverter (but not PAWD) for a reduced cost for rear drive in AWD.

I'd guess it's mapped like this:
MOSFET -> RWD, all PAWD, and older AWD
IGBT -> SR/MR only
AWD,MOSFET-LC -> newer AWD

Assuming I'm correct... that means older (original production) AWD models are purely software mods to get to the PAWD performance. Which makes sense given the reports that some people didn't get their PAWD performance until they asked nicely, and it just took a short time in the service center (i.e. not nearly enough time to swap drivetrains).

 

[DrDabbles]

My guess is this is a new AWD inverter (but not PAWD) for a reduced cost for rear drive in AWD.

I'd guess it's mapped like this:
MOSFET -> RWD, all PAWD, and older AWD
IGBT -> SR/MR only
AWD,MOSFET-LC -> newer AWD

Assuming I'm correct... that means older (original production) AWD models are purely software mods to get to the PAWD performance. Which makes sense given the reports that some people didn't get their PAWD performance until they asked nicely, and it just took a short time in the service center (i.e. not nearly enough time to swap drivetrains).

I'd actually guess it's more like this:

1120960: Front induction motor
1120970 (IGBT): LR RWD, PAWD
1120980 (MOSFET): MR, SR
1120990 (MOSFET-LC): LR AWD, SR AWD?

This is a guess. I know the IGBT motors are better for high power applications because of the better performance of IGBT over MOSFET. But I do remember a few teardown videos noting that the rear motor was MOSFET at some point, so this is likely another production change.

The -LC designation on 1120990 could be short for nearly anything. Left connector, low (profile) connector, etc. I doubt they'd code low cost into their part nomenclature. But either way, having three parts and two known major motors (high power RWD, lower power for AWD), means they're likely making changes as production happens.

 

[Saghost]

I'd actually guess it's more like this:

1120960: Front induction motor
1120970 (IGBT): LR RWD, PAWD
1120980 (MOSFET): MR, SR
1120990 (MOSFET-LC): LR AWD, SR AWD?

This is a guess. I know the IGBT motors are better for high power applications because of the better performance of IGBT over MOSFET. But I do remember a few teardown videos noting that the rear motor was MOSFET at some point, so this is likely another production change.

The -LC designation on 1120990 could be short for nearly anything. Left connector, low (profile) connector, etc. I doubt they'd code low cost into their part nomenclature. But either way, having three parts and two known major motors (high power RWD, lower power for AWD), means they're likely making changes as production happens.

But that's the exact opposite of the notes that Tesla had given us back when - the IGBT version was specifically identified as being for the 62 kWh and 50 kWh versions, the MOSFET for 75 kWh...

 

[DrDabbles]

But that's the exact opposite of the notes that Tesla had given us back when - the IGBT version was specifically identified as being for the 62 kWh and 50 kWh versions, the MOSFET for 75 kWh...

Yeah, like I said, I know I remember some information coming out, but I don't remember the very specifics. Why you would use the IGBT for the lower power vehicles, I have absolutely no idea. Again, the major reason for using IGBTs is that they handle higher power applications better than traditional MOSFETs. MOSFETs are more efficient at low power levels, but SiC IGBTs have very high signalling rates and can handle fairly extreme levels of heat and output.

 

[MP3Mike]

MOSFETs are more efficient at low power levels, but SiC IGBTs have very high signalling rates and can handle fairly extreme levels of heat and output.

But what about SiC MOSFETs? Since that is what was used. We don't know if the IGBTs are SiC or not.

 

[DrDabbles]

But what about SiC MOSFETs? Since that is what was used. We don't know if the IGBTs are SiC or not.

Yeah, that's a good point.

 

[Saghost]

Yeah, like I said, I know I remember some information coming out, but I don't remember the very specifics. Why you would use the IGBT for the lower power vehicles, I have absolutely no idea. Again, the major reason for using IGBTs is that they handle higher power applications better than traditional MOSFETs. MOSFETs are more efficient at low power levels, but SiC IGBTs have very high signalling rates and can handle fairly extreme levels of heat and output.

My speculation is that the type of transistors in the inverter isn't actually the important part of the two motor types - that the IGBT inverter is controlling an induction motor like all of Tesla's previous vehicles with IGBT inverters and induction motors, while the MOSFET inverter drives the fancy new switched reluctant motor.

Under this theory they'd be switching to the IGBT motor for the smaller battery cars as a cost saving measure...

 

[AlanSubie4Life]

But what about SiC MOSFETs? Since that is what was used. We don't know if the IGBTs are SiC or not.

Front Drive Unit

ASY,3DU, Front DU, IGBT-HC

For all AWD M3 cars. Only to use as Front DU

Part # 1120960-00-E

Elon Musk on Twitter

With these two pieces of information, we can make a small leap and assume that SiC IGBTs are used, for the rear as well.

It is not certain with the information at our disposal thus far, but what is certain is:

=> The front motor drive unit is an IGBT-HC unit with the IGBTs fabricated in a SiC process (as per Elon's tweet & early part catalog info).

As far as the REAR IGBT unit (whichever model that is used in), I think it's probably pretty reasonable that it will also be SiC. SiC (rather than straight silicon) is the semiconductor of choice in these high power applications due to high temperature performance and high voltage performance, and perhaps other properties. I'm certainly not an expert on the power electronics side of things, and the relatively exotic SiC processes, but I think that a Si IGBT (rather than SiC) would not be as good for this application.

In addition I think it's reasonable that they'd want to use similar semiconductor devices for front motor & rear motor (even if the control is different) just to minimize sourcing issues for the components. So probably SiC IGBT for the rear unit (1120970 part #).

 

[AlanSubie4Life]

that the IGBT inverter is controlling an induction motor like all of Tesla's previous vehicles with IGBT inverters and induction motors

I think that the large efficiency hit of using a rear induction motor would be evident in the EPA range numbers for the MR, and we're not seeing that so far.

After I did my reading, my conclusion was that due to technology advances over the last several years, SiC MOSFETs are actually now superior to SiC IGBTs. However, not certain of that. It's definitely just guessing/speculation on my part, but I suspect the SiC IGBTs are generally more commoditized and cheaper at this point, but I don't think they do as well (specifically in terms of their efficiency) in the highest power applications, as compared to modern SiC MOSFETs. Hence their use (in my proposed assignment) in the higher power LR RWD application (80) and the Performance AWD application (90) (which is also the normal AWD application unless a magical new part number appears at some point).

Since the losses within the devices in a simplistic model are I^2*R type losses, the higher the peak current being applied to the motor, the more important it is that the most efficient device is used.

I do need to follow through on my commitment to get a part number off of my rear motor. We should ask one of the people with a hole in their rear aero shield to get a flashlight up in there and spare me the trouble.

 

[Kirby64]

I'd actually guess it's more like this:

1120960: Front induction motor
1120970 (IGBT): LR RWD, PAWD
1120980 (MOSFET): MR, SR
1120990 (MOSFET-LC): LR AWD, SR AWD?

This is a guess. I know the IGBT motors are better for high power applications because of the better performance of IGBT over MOSFET. But I do remember a few teardown videos noting that the rear motor was MOSFET at some point, so this is likely another production change.

The -LC designation on 1120990 could be short for nearly anything. Left connector, low (profile) connector, etc. I doubt they'd code low cost into their part nomenclature. But either way, having three parts and two known major motors (high power RWD, lower power for AWD), means they're likely making changes as production happens.

See, thing is I'm not sure there actually are 2 separate motors (unless you mean front vs. rear motor), only inverter changes. Until proven otherwise, it seems the difference across all rear motors is strictly the inverter hardware. Probably cheaper from Tesla perspective as well.

Obviously it makes sense they'll do production changes... which is why I think actual hardware changes to make the AWD (non-P) inverter to use lower power tech makes the most sense. That's the cheapest way to lower cost; redesigning the motor is a pretty crazy task.

 

[DrDabbles]

My speculation is that the type of transistors in the inverter isn't actually the important part of the two motor types - that the IGBT inverter is controlling an induction motor like all of Tesla's previous vehicles with IGBT inverters and induction motors, while the MOSFET inverter drives the fancy new switched reluctant motor.

Under this theory they'd be switching to the IGBT motor for the smaller battery cars as a cost saving measure...

We know that only the front motor on the 3 is an induction motor. The rear motor is a switched reluctance motor.

See, thing is I'm not sure there actually are 2 separate motors (unless you mean front vs. rear motor), only inverter changes. Until proven otherwise, it seems the difference across all rear motors is strictly the inverter hardware. Probably cheaper from Tesla perspective as well.

Obviously it makes sense they'll do production changes... which is why I think actual hardware changes to make the AWD (non-P) inverter to use lower power tech makes the most sense. That's the cheapest way to lower cost; redesigning the motor is a pretty crazy task.

I believe the stator, rotor, bearings, etc. would all the same, yes. I agree with the sentiment that the difference between AWD and P is likely to only be software. But if they aren't, then it would seem reasonable to use the higher power motor assembly from the RWD in the Performance car, but a lesser assembly in the AWD, MR, and SR RWD.

 

[adaptabl]

Ha! A comedian!

This seems like an odd conclusion given the part details right there in the part description. I mean it is right there! There are three parts listed.

Do you also believe all batteries are the same size (even though there is a part for 75kWh and another for ~62kWh)?

Or just production changes that have occurred over the production cycle.

 

[Kirby64]

I believe the stator, rotor, bearings, etc. would all the same, yes. I agree with the sentiment that the difference between AWD and P is likely to only be software. But if they aren't, then it would seem reasonable to use the higher power motor assembly from the RWD in the Performance car, but a lesser assembly in the AWD, MR, and SR RWD.

There's three assemblies for the rear drive unit by the part number, so it can't be that simple. I think we have clarity that the SR/MR use the IGBT unit (Elon noted that on Twitter?).

The only question is whether MOSFET-LC is for AWD only, PAWD only, or AWD and PAWD. The RWD part has to be the -980, but it may also be shared with either the PAWD or the regular AWD... once we have someone actually peek at part numbers I'm sure this can be resolved rather quickly.

 

[AlanSubie4Life]

Sadly not so simple. Couldn’t find a match to the numbers in question! So many part numbers. Did not have time to get my mirror out to look on top of motor.

Part numbers next to the orange connector, may be interesting since I believe behind that is the inverter/converter electronics. But who knows, part might just refer to the metal plate.

Would still be nice to see similar pics from someone with RWD or AWD (and MR) to compare.

 

[GregRF]

Sadly not so simple. Couldn’t find a match to the numbers in question! So many part numbers. Did not have time to get my mirror out to look on top of motor.

Part numbers next to the orange connector, may be interesting since I believe behind that is the inverter/converter electronics. But who knows, part might just refer to the metal plate.

Would still be nice to see similar pics from someone with RWD or AWD (and MR) to compare.

My part number is stamped on that big shiny piece that looks blank on yours.

1120980-00-C (looks like I'm a rev behind, wonder what changed)
LR RWD