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tractor conversion

Posted: Thu, 24 Oct 2019, 05:58
by pirpy
Hello
I want to convert small tractor to EV
IMT-542.jpg
IMT-542.jpg (460 KiB) Viewed 675 times
I have 16 x lifepo4 200 Ah for the project.
I want the conversion to be as cheap as possible, so Im looking to rewind industrial 4 pole 400 V AC motor 7.5 kWh to 22V .
original diesel engine in this tractor is 31 kW peak at 2250 rpm and 149 nM torque at 1400 rpm.
what peak torque can I expect from this motor?
As I understand I need to add an encoder to the motor, where can i get one that would work with let's say Kelly KAC-8080I

or would 10kW bldc be a better option ?

Thank you

Re: tractor conversion

Posted: Thu, 24 Oct 2019, 08:18
by jonescg
What kind of work will it be doing? Will it be doing any serious cultivation or mainly towing things? Because the motor need not be too amazing. A re-wound industrial AC motor would certainly fit the cheap requirements, but it might need some kind of cooling added.

4 pole is ideal for most applications, and any VFD will make it spin, you just need to find a reasonably efficient one.

Re: tractor conversion

Posted: Thu, 24 Oct 2019, 08:51
by antiscab
An encoder is only needed it you want fine torque control. On a tractor you could probably get away with either speed control only, or course torque control that running open loop without an encoder would offer

Re: tractor conversion

Posted: Thu, 24 Oct 2019, 12:35
by Richo
pirpy wrote:
Thu, 24 Oct 2019, 05:58
...rewind industrial 4 pole 400 V AC motor 7.5 kWh to 22V .
Although the specifications match your tractor I'm skeptical that someone would rewind it to 22Vac.
When you think about 400Vac/22Vac this is 18:1.
I'd think this would mean you'd only have 3 or 4 conductors per slot.
Or many in parallel.

This would add perhaps AUD$1,000 to the cost of the conversion.

Re: tractor conversion

Posted: Thu, 24 Oct 2019, 12:50
by Richo
Possible alternatives are a series DC motor:
A00-4009
203-06-4001
ME1002

Re: tractor conversion

Posted: Thu, 24 Oct 2019, 12:53
by Richo
Possible alternatives for Magnet motor:
ME1302
ME1616
ME1507

Re: tractor conversion

Posted: Thu, 24 Oct 2019, 15:48
by pirpy
antiscab wrote:
Thu, 24 Oct 2019, 08:51
An encoder is only needed it you want fine torque control. On a tractor you could probably get away with either speed control only, or course torque control that running open loop without an encoder would offer
thank you !


It will be doing light work, for heavy work I have this one
[tube]https://youtu.be/e2CAHfJqlFM[/tube]

The speed controll would be the best for tractor as it is the case with diesel engine.

The rewinding will not be the problem I would use the same wire but meny of them in paralel, the problem I'm expecting is with 3 or 4 wounds per coil I will not be able to make the motor 22 V but hope close to that .
I could lift the battery voltage but I'm planning to simply put my power wall 48 V lifepo4 cells to tractor and then use it for both aplications :)
Local rewind shop would charge me 300 € for rewinding 7.5 kW motor to lower woltage , and I already have a suitable motor in my junk bin :
7.5kW 4 pole 400 V
7.5kW 4 pole 400 V
7.5kw.jpg (907.15 KiB) Viewed 642 times
I also have a DC motor in my junk bin:
72 V 80 A series DC  motor
72 V 80 A series DC motor
6 kW DC.jpg (662.12 KiB) Viewed 642 times
I gues I could rewind the stator coils to lower voltage but this one does not have shaft that would allow me to mount a flywheel, ....

Comments appreciated

Re: tractor conversion

Posted: Mon, 28 Oct 2019, 12:48
by Richo
pirpy wrote:
Thu, 24 Oct 2019, 05:58
As I understand I need to add an encoder to the motor, where can i get one that would work with let's say Kelly KAC-8080I
antiscab wrote:
Thu, 24 Oct 2019, 08:51
An encoder is only needed it you want fine torque control.
The Kelly controllers do seem to be the cheapest option for an Induction motor.
KAC72601-8080I USD$700
KAC72701-8080I USD$800

They require a "Dual channel A/B encoder" to work.
I'm assuming they mean a quadrature encoder.

Re: tractor conversion

Posted: Mon, 28 Oct 2019, 12:52
by Richo
Please don't buy this it's only an example
https://www.aliexpress.com/item/893080068.html

Re: tractor conversion

Posted: Mon, 28 Oct 2019, 13:02
by Richo
A curtis controller might work too:
1234SE-452X
1234SE-562X
But I expect they'll be harder to get and cost more.

Re: tractor conversion

Posted: Mon, 28 Oct 2019, 16:39
by pirpy
So kelly or slider will not work without encoder ?
in speed mode?
slider:
https://www.alibaba.com/product-detail/ ... 3e5fw0fNC3

Re: tractor conversion

Posted: Mon, 28 Oct 2019, 20:04
by antiscab
likely the best answer is we won't know until someone tries it.
There may be a setting to run straight v/hz

It would be worth contacting kelly controls and asking

Re: tractor conversion

Posted: Tue, 29 Oct 2019, 12:25
by Richo
I did scan over the kelly manual yesterday and I was under the assumption it is required.
Someone must have already done it - its a case of finding it.
When I have more time...