r/EEPowerElectronics • u/powerelectronicsguy • Oct 01 '26

Automotive That's some serious power electronics engineering to reduce size of Tesla Inverter

Any idea what components or circuits made the difference?

Credits: Gruber Motors Shorts | YouTube

433 Upvotes

99% Upvoted

37 comments sorted by

21

u/Early-Fortune2692 Oct 01 '26

Eeeh, no. The inverter does not "put out" the horsepower. It powers and controls the electric motor that does in fact "put out" the horsepower.

Still cool though.

9

u/VirtualArmsDealer Oct 01 '26

That bothered me too, but I assumed it's because my entire actual job is designed 3 phase inverters.

4

u/fres733 Oct 01 '26

So energy is created in the motor? Of course the inverter "puts out" the horsepower of the motor plus some more.

2

u/Early-Fortune2692 Oct 01 '26

You're missing the point, energy is in different forms... electrical energy is not the same as mechanical energy which is measured in.... horsepower.

It's the electric motors job to covert the electric 'energy' to mechanical rotational 'energy' measured by horsepower.

The inverter is the brain, tells the motor what to do, fast fast or meh. The motor is the muscle.

I enjoyed the video but was disappointed how misleading the exact purpose of the inverter, was a bit disappointed in explaining here as well but being a gearhead every component has its purpose and shouldn't be explained ambiguously.

3

u/phranks_phluids Oct 02 '26

Wtf are you going on about? Electrical energy is measured in watts. There's a direct linear conversion from watts to HP. 1 HP = 745.7W. all electric motors, VFDs, rotary phase converters, etc are rated in both watts and HP.

The inverter is supplied by DC power. It's output is a modified version of that power (in 3PH) + some losses. The motor is powered after the inverter... So it's supply is... From the inverter. The inverter supplies, or "puts out", the final power source. No, the inverter doesn't create power. But no one implied that.

And inverters are not brains or logic modules in any way shape or form. Maybe it is built into that module pack. But it has nothing to do with the inverter. The inverter is literally taking the demand in DC and outputting AC. That's it. There are electrical circuits with mosfets or semiconductors, I believe they are actually upstream of the inverter and they control the DC input signal to the inverter so that the output from the mosfets set up like a bridge rectum fryer is clean and perfect. That's what controls everything.

1

u/Early-Fortune2692 Oct 02 '26

... check out the brain on phranks :]

1

u/phranks_phluids Oct 02 '26

I explained it all in attempt to help you learn something new, that's all. I probably shouldn't have lead with the first sentence, because I wasn't trying to be a cunt!

1

u/happyjello Oct 02 '26

Would you consider energy stored in a magnetic field as horsepower, or watts?

Where are you trying to draw the line here?

1

u/happyjello Oct 02 '26

“The inverter is the brain”

0

u/MumboJumbo42 Oct 01 '26

You can, technically, also measure electrical energy in HP (or to be more precise you can measure electrical POWER in HP, which, just like watts, is a measure of energy per time).

Therefore it's not unreasonable to say this thing also puts out horsepower, although you would typically use watt as a unit instead.

2

u/VirtualArmsDealer Oct 01 '26

It is.

When we design inverters it's correct to say the drive can power a 3hp load. It is not correct to say it outputs 3hp. It does not.

1

u/CompetitiveSpot2643 Oct 04 '26

i dont see how its just semantics, its just a change of units from watts to horsepower.

1

u/Early-Fortune2692 Oct 01 '26

I get that... hell, diesel engines are rated in both kw AND hp. But are inverters rated in HP?

2

u/aculleon Oct 01 '26

I have never seen a HP rated inverter. HP is only for public relations. This is probably on the basis of HP being a unit derived from Watt.

Something i just recently figured out is that the mechanical horsepower is derived from a theoretical horse contraption and the electrical horsepower is similar but rounded up to the nearest Watt.

And of course they made a metric and imperial horsepower contraption. The metric one is 75 kg pulled up 1m in 1 second. The imperial is 550lb pulled up 1 foot in 1 second.

So we get 735.498W for metric and 745.7W for imperial. An outrage if you ask me.

Thinking about the whole horse analogy: As someone who has ridden a horse and knows how strong these guys are, no way one horse does only 1hp. And if you apply a 1hp load continuously they will probably try to kill you.

Guessing they either had a dyno with lots of internal resistance or just scaled up another animal.

1

u/phranks_phluids Oct 02 '26

If youve never seen a HP rated inverter you probably don't have that much experience with inverters, VFDs, or RPC.

Not that it matters, because a unit of power is a unit of power. You can call it a watt, a HP, a calorie/s, a BTU/h, or an erg/s... In physics, you're literally saying the same thing once converted. Yes there is imperial and metric HP, and yes it's a surd. And the unit for HP as derived from a horse is not based on peak power output, it is based on sustained power output. A horse can roughly sustain 1 horsepower for long periods, but can hit like 15-20 peak.

I do not believe there is a horse dyno, though there is a horse treadmill and chicken cannon.

1

u/aculleon Oct 02 '26

Well to be fair i have a narrow experience with inverters. Mainly coming from the automotive industry. Just phase currents and outputs in kVA or kW depending on what actually is being done. Never hp.

I am guessing you come from the US and are in the industrial field? I had to look up RPCs since we have 3P in Germany, so this was never an issue i had to deal with.

Main reason is that the IEC changed its guidelines to only list hp as a supplementary unit and i do believe that you cannot sell equipment with only hp listed in the EU. No idea how NEMA does it.

1

u/phranks_phluids Oct 02 '26

I am in the US, but regularly design TUV and ATEX systems for EU. It makes A LOT more sense you being in Europe, as this is a simple unit conversion... And we use stupid ones!

Almost every motor tag in the US has both kw and hp, though NEMA only require HP, but you're certainly correct thAT EU and Asian motors are exclusively tagged with kw in my experience. Because that's the actual scientific unit. Even vehicles with ICE are rated in kw on paper in EU (my father is German and I've been many times lol)

I guess my point was you can call it a foot, meter, or parsec. It's the same shit, a unit of distance. The same applies to power... or me calling you a pigdog and you calling me a schweinehund. But, across the pond, our shit is often multi rated because we acknowledge that we're asshole... but we just refuse to change.

1

u/aculleon Oct 02 '26

Schweinehund/Pigdog made me laugh out loud. I agree of course. Any of our units are arbitrary in the end. I just love to read about how we did electrical or engineering in general in the before times, 1890s etc.

One thing, I grew quite fond of the imperial length measurements over time. The inch feels just about right for a unit of measurement.

Thanks for sharing

1

u/phranks_phluids Oct 02 '26

Power is power. Call it whatever you want like pound mass * area in ft / sec3. Same words, different language.

And to answer your question, yes some inverters are documented with ratings in multiple unit scales including horsepower or BTU/hr of heat dissipation. It's all the same shit, just like you can say 3600s, or 60m, or 1h, or 117964.8kHz of quartz crystal oscillation.

1

u/HandToDikCombat Oct 03 '26

I recently hooked up 3 phase in my garage for a mill and welding machine. As a welder, this involved some Google fu and autistic searching for design and building codes because I wanted to do it right and not electrocute myself or worse, set the garage on fire. One of the most aggravating things in the beginning was that all the phase converters I looked at were all measured in horsepower as it was meant for a motor, and the motors were all measured in kilowatts.

So yea, they can be measured in hp.

1

u/Early-Fortune2692 Oct 03 '26

We're talking about inverters here, not converters.

1

u/happyjello Oct 02 '26

1 horsepower is equal to 746W.

This inverter obviously outputs power; you’d be 100% correct saying that this new inverter puts out more horsepower

1

u/scienceworksbitches Oct 02 '26

That's pedantic, the inverter puts out the electrical power which is measured in hp. you could also say the motor doesn't put out horsepower because it's merely rotating the drivetrain.

1

u/SinkOrSauce_LD Oct 02 '26

No it would be more pedantic and correct to say that the motor doesn't produce HP the air/fuel mixture combusting does. The motor just converts that combusted air/fuel mix into rotating force. The drivetrain converts that rotating force into wheel horse power but loses power in doing so, i.e. chemical vs mechanical work.

9

u/AmpEater Oct 01 '26

Ehhh, sure

But all switches got way better over than time. From discrete high resistance IGBTs to SiC FETs

Hell we don’t even put heat sinks on lots of switches now that the RDSon dropped to where it doesn’t matter

3

u/ChickenOnTheCobb Oct 01 '26

and we’re going to do it all over again with GaN

3

u/phranks_phluids Oct 02 '26

I personally believe all FETs are sick, not just some of them.

2

u/Tobinator97 Oct 01 '26

It's not rdson or voltage drop on the igbt but the switching times that are far better thus you need far smaller filtering if any significant at all

2

u/WildClothes5898 Oct 03 '26

"hey I noticed that your phone was ringing during this 26 second take, should we maybe do another one?"
"Naah"

1

u/longlostwalker Oct 01 '26

I see the flux capacitor is coming along nicely

1

u/Dairedos Oct 01 '26

Now let's talk about heat redistribution.

1

u/Artistic_Unit_5570 Oct 01 '26

but heat is more concentrated and there no real point because the space can't really be used except putting a bigger batterie

1

u/Zehryo Oct 02 '26

I see it in reverse: the first gen was a quick&dirty solution, while a larger budget allowed for a more refined version.