Is this kind of technique desirable here?

what is it? a generator?

what is it? a time machine?

>>60959490
>>60959505
Intel Core i9 cooler.

>>60959490
>>60959505
>>could be a particle accelerator...

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>>60959490
No. Both are 3*400-AC (asynch)motors.

>>60959539
are you building one?

>>60959539
Aren't all motors also generators?

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>>60959584
I repair. Rarely we build machines, and usually only DC motors.

>>60959633
No. The asynchronous short-circuit motor is definitely not a generator. But there are many kinds which are either, or can be.

>>60959648
what is your job title? how much do one of those cost? what are you asking?

>>60959704
electrician

Motor 2,2 kW-3*230/400V .....brand-new € 130,--

>what are you asking?
? I'm bored

>>60959633
motors use electrical energy and convert it into mechanical while generators turn mechanical energy into electrical

>>60959539
Why can I not bolt that into my shitbox of a car to convert it into an electric car. Why aren't there any conversion kits for doing just that?

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>>60959807
Basically you can do that. But there are other engines. But it would be stupid to change the internal combustion engine to an electric motor. This is not the way to do it. You do not need a manual gearbox with an electric motor, and most of the time there are 4 engines directly on the wheels.

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I made these motor controllers recently.

This is a nice thread, we should have more of these threads.

>>60959648
bump for OP,
please post this shit to
>>>/diy/ we will appreciate you more there.

>>60960997
are these homemade ESCs ?

>>60961093
yeah, this its real technology.
How ever in my country this kind of motors its called "squirrel cage" and they are not capable on electrical generation like they come when you buy it, but you can modded to work as an generator.
Does OP make some money doing the maintance? the re-coaling of thos bad boys you could have as low as 300$ dollars for and 10 hp one.

>>60959633
In theory yes, but some machines are much more efficient as motor than as generators.

>>60959686

Couldn't you put a capacitor in parallel to the rotor winding to use the asynchronous motor as a generator.Without a capacitor it would work as a generator but with very low power output because the magnetic field would only be the remnant left on the rotor.

>>60959883
Do electric cars use AC or DC motors?

>>60960997
How does this work and what kind of motor are they controlling?

>>60961624
Any PM 3 phase motor within reason. They have enough sensors to detect motor properties and run them using sinusoidal field orientated control.

>>60961602
AC. Most of them at least. The Tesla name comes from the Tesla AC motor that drives them.

>>60961948
Why is that?

Wouldn't it be more efficient to use DC since batteries are always DC?

>>60962755
Induction drives are more efficient, especially when needing high torque across a wide RPM range. Also permanent magnets are also heavy, expensive, and brushless DC drives don't scale well.

https://www.tesla.com/blog/induction-versus-dc-brushless-motors

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>>60961590
>asynchronous Motor
>No. The asynchronous short-circuit motor is definitely not a Generator
>short-circuit Motor!!!

A short-circuited rotor winding can not provide excitation current (In generator mode), which is not possible.
Theoretically it is possible with the three-phase slip ring rotor (pic3). (Theoretically)

>>60961602
All different types, but designed for vehicles. DC-permanent is common in commercial vehicles, but even reluctance, disks or synchronous three-phase motors are used.

And these engines can also brake in generator mode and return energy.

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>>60961590
Forgot the picture with the short-circuit rotor.

>>60963624

DC-permanent are basically AC, but replace the solenoids usually used for voltage conversion with the coils of the motor. Hell, you can even buy "sine wave" controllers that run the with AC.

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>>60959450
A fellow motor rewinder? On /g/? It must opposite day where we post decent threads.

>>60959450
Oh hey, something relevant to what I do for a living.

I welcome electric motors anytime.

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>>60963676
I meant a rotor winding that not is short-circuited.In the second type of rotor of pic related you could put a capacitor in parallel to the winding(the inductance), and while turning it you would cause a variable flux on the stator.At the start it would be really small, only dependent on the remnant magnetic field on the rotor, but as time passes the capacitor will inject current to the inductance;hence, producing a stronger field.

Has anyone built their own frequency variator for speed control?

>>60959807
A lot of /diy/nosaurs do just that to old motorcycles. Just about any light frame, an AC motor, big ass battery, AC adapters, and PWM is needed. Use a Buell Blast because their single cylinder engine is so shit it drives the price down but everything else about them is bliss.

>>60965443
>but as time passes the capacitor will inject current
Where's the power coming from?

>>60965456
/diy/ing a vfd has been on my bucket list for a while now. ive got this 2hp 3-phase induction motor standing on the floor in storage, and ive been wanting to put it to good use, but life always gets in the way

>>60962941
>Induction drives are more efficient, especially when needing high torque across a wide RPM range. Also permanent magnets are also heavy, expensive, and brushless DC drives don't scale well.
Not really, induction motors are the least efficient and have lower power densities. They are however robust and easy to mass produce.

IPM motors are the best for cars at the moment, you basically get a permanent magnet motor and a reluctance motor in one device. Axial flux permanent magnet motors usually win when it comes to extreme power to weight ratios.

>>60959788
Generally if you spin the end of a DC motor while it's not powered, you generate some power as well.

>>60959450
I have designed and hand-wound a motor before - ~20kW, for an electric car. 24/28, so the winding was much simpler than for a classic induction motor.

>>60959883
>and most of the time there are 4 engines directly on the wheels.
Actually no, most conversions mount the motor where the engine was, it's too difficult to do anything else.

Factory-made electric cars also don't mount the motors on the wheels, because they would be a large unsprung mass. The Leaf mounts it in a rather normal position, and the Tesla mounts it lower, but it's still sprung.

>>60961590
Yes, you totally can. This has achieved some popularity with homebrew wind farms. Startup is sorta complicated, you need to charge the capacitors with DC to produce enough reactive power to start it.

If it's grid-tied, startup is way simpler as the grid can supply reactive power (but you usually still have caps because you don't want it too).

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>>60960997
Very nice!

I recently got a VESC and am a huge fan. It's an open source design that has a really nice autosensing and configuration UI. I think if I later build a bigger motor controller, I'll base it on the VESC.

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>>60969229
I'm using the same software on mine, waiting on the new version to be released as mine is closer to the VESC 6 and the current firmware doesn't make full use of it.

I wish I could find people interested in working on open source motor controllers, I have built about 5 motor controller designs and can make hardware for almost any design but have no luck finding anyone to help with software. Even when I try to hire people on freelancer or locally finding any with motor controller experience is impossible and paying them to learn how motorcontrollers work becomes expensive.

>>60970282
Yeah, it's a super niche thing and there aren't very many people interested (and most of them are okay with chinese ESCs).

I previously built much larger motor controllers (160V, 200A). I'd be interested in building a copy of yours and playing with it - hit me up on #vedder or at this email: [email protected]

Looks like it was designed with KiCad?

>>60970392
I built them all in kicad, the ones with removable MCUs have the same pin layout as Ti instaspin boards. I like instaspin but their motor detection software is awful and blows up inverters.

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>>60965443
And this is how you do it in reality!
(Synchronous brushless- 3 * 400 V - 520 kVA)

synchronous!

>>60959522
it's obviously an solar panel

>>60959490
>>60959505
>>60959522
>>60959528
Nuclear machine bomb reactor

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>>60964793
>A fellow motor rewinder?

Ego sum lux mundi!

>>60972949
What kind of efficiency do these huge motors get?

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>>60974227
This (IMG_2353.jpg) is an old synchronous generator, coupled to a double Francis turbine. We have recalculated and the stator winding renewed.

AEG, ano1907, 3*5000 V, 540 kVA

n before repair = 0,75 , n after repair = 0,79

>>60974227
But new engines / generators are available up to n = 0.97

>>60975449
What kind of designs do they use for those? On the smaller motors I'm familiar with 95+ is possible but requires less conventional designs such as coreless axial flux motors with halbach array magnets.

>>60972877
Synchronous generator with rectifier on-shaft to power the field windings of the main generator? Neat!

I rarely see this used in practice, is there a reason it's not as popular? Or is this more common for smaller machines?

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>>60975731
I think it's mostly tons of copper and relatively low frequency and field. Core loss on little motors is way higher because they usually run at higher frequencies (for universal motors) or because they run at a higher field because they are trying to be small and cheap. Also windage losses are going to be less on big motors because less surface area per volume.

Dumping pictures of generators. Here's a hundred-year-old hydro generator. IIRC it was attached to a Francis turbine.

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>>60976557
Much bigger hydro generator with exciter.

>>60959648
I wouldnt be that close to it if I were him.

If the wrong cable snaps hes looking at crushed legs and more than likely death from blood loss.

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>>60976666
There's no "cable to snap", and that rotor is constrained with huge bearings. It's been spinning there for 100 years. I think it's fine.

>japan

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>>60975731
>What kind of designs do they use for those?
I mean big synchronous generators of pumped storage plants* or large hydroelectric power stations.
Here, special and very thin dynamo plates are used. Very small air gap and hydrogen-gas cooling.

*In this case, the generators also operate as motors, and for phase shifting (cosPhi);

For medium motors, n = 0.95 is quite good.

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>>60976381
Medium generators are built in such a way that no abrasive rings or brushes are necessary. The excitation current control is more complex, but it is more efficient (carbon brushes have ohmic resistance) and without frequent maintenance.