Got a free AC motor, it is strong enough for EV conversion?

Electric Motors and Controllers
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bigchief   100 mW

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Got a free AC motor, it is strong enough for EV conversion?

Post by bigchief » Mar 19 2011 12:38am

Hey guys, I've been into EV's ever since I got my electric bike working about a year ago, thanks in no small part to all of you. Since then I've been dreaming of an electric car conversion. Now, seemingly out of nowhere, my boss asked me to toss out an old motor in the basement of our building. I took a look at it, and surprise! It's actually a huge, powerful looking AC motor. At the same time, my brother offered me a decent donor that he was planning to scrap (Nissan Maxima). Seems like this is a sign to follow my dreams and take the plunge.

Anyways, would anyone here be able to look at these pics of the motor/faceplate and explain to me what I have on my hands? Is this thing powerful enough to run an average car? What would you suppose a top speed would be assuming I get good batteries/controller? Any general advice on making use of this? Thanks in advance for the help!
Attachments
faceplate.jpg
Faceplate
entireMotor.jpg
The whole thing

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fizzit   10 kW

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Re: Got a free AC motor, it is strong enough for EV conversi

Post by fizzit » Mar 19 2011 12:45am

Well you would need a huge inverter... and a 230v battery pack (I think)... and you would only get 15HP out of it, if the nameplate reading is correct. That's barely enough to run a small car.
-Colin

bigchief   100 mW

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Re: Got a free AC motor, it is strong enough for EV conversi

Post by bigchief » Mar 19 2011 12:57am

Some Googling seems to suggest that this is a discontinued "Belt Drive Condenser" from 1989, whatever that means. Could 15 Horsepower take a very light car (like a Geo Metro) to highway speeds? Or would this be more of an "around town" thing if it works? Is this a three phase AC?

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fizzit   10 kW

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Re: Got a free AC motor, it is strong enough for EV conversi

Post by fizzit » Mar 19 2011 1:09am

I'm pretty sure that 3PH on the label means that it is indeed 3-phase AC. I don't know about highway speeds, but I would guess that it could take a small car around town. Methods put a 4HP motor in his VW beetle. If you ran it over it's rated HP and installed some forced air cooling, it would go even faster!
-Colin

tostino   10 kW

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Re: Got a free AC motor, it is strong enough for EV conversi

Post by tostino » Mar 19 2011 11:26am

That motor is just not at all wound ideally for a car... At 230v its only spinning 1700 rpm... That's an issue. If you over volted it, and geared it down, that would work fine. But over volting something that's already at that high of a voltage is kinda hard.

Harold in CR   1 MW

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Re: Got a free AC motor, it is strong enough for EV conversi

Post by Harold in CR » Mar 19 2011 12:03pm

I would take it and sell it. Whatever you get will be more than you have now. Then, get a better suited motor.
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fechter   100 GW

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Re: Got a free AC motor, it is strong enough for EV conversi

Post by fechter » Mar 19 2011 1:57pm

The HP and rpm numbers only apply at 60Hz. If you use a VFD inverter, you can get a lot more out of it.
Sometimes you can find used VFD inverters on eBay. It would probably take a little modification to make one run off a battery, but probably not too hard.
"One test is worth a thousand opinions"

Harold in CR   1 MW

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Re: Got a free AC motor, it is strong enough for EV conversi

Post by Harold in CR » Mar 19 2011 3:23pm

Go to http://www.diyelectriccar.com.

There is a running thread about those AC motors and controllers. Might have to look around a little to find the thread.
Thanks to Justin, the forum is open source and NON-commercialized.

dbaker   100 kW

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Re: Got a free AC motor, it is strong enough for EV conversi

Post by dbaker » Mar 19 2011 3:54pm

You would need to get a 230V VFD rated for at least 15HP that can be fed DC. VFDs take 3 phase AC and convert it to DC then use an inverter to convert the DC back to AC at a variable frequency to vary the speed of the motor. There are plenty of people who have done this. Here is an example: http://www.evalbum.com/1687

When I looked into it several years ago I realized I could not afford a suitable lithium battery pack. For a 230 volt 3 phase AC motor you will need a 530 volt DC pack!

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fizzit   10 kW

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Re: Got a free AC motor, it is strong enough for EV conversi

Post by fizzit » Mar 19 2011 5:30pm

I wouldn't think that a pack of that voltage wouldn't be that much more expensive if you had the same WH as a similar, lower-voltage pack, but it would be a bitch to balance and charge!
-Colin

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fechter   100 GW

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Re: Got a free AC motor, it is strong enough for EV conversi

Post by fechter » Mar 19 2011 11:28pm

The guys running AC induction motors on motorcycles use a motor that's been re-wound for lower voltage. With the right winding, you could then use a Curtis or Sevcon controller at a reasonable (under 100v) voltage.
I don't know how much work it would be to rewind a motor like that, but there are places that specialize in that.
Here's the Curtis website: http://www.curtisinstruments.com/index. ... ontrollers
Sevcon: http://www.sevcon.com/pages/gen4.html
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voicecoils   10 MW

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Re: Got a free AC motor, it is strong enough for EV conversi

Post by voicecoils » Mar 20 2011 1:00am

Don't forget that the nameplate rating is often for continuous industrial use.

You might be able to get 5-10x the nameplate power out of the motor for short periods with some temperature monitoring and those periods of higher power can be extended with forced air cooling or even liquid cooling. It's worth also remembering that if you're generating lots of heat, you're wasting power.

REdiculous   10 kW

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Re: Got a free AC motor, it is strong enough for EV conversi

Post by REdiculous » Apr 05 2011 11:22am

The plate says 15HP but if you do the math it's 12HP (230v*39a=8970w=12.0289HP). :)

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