Go Back   EcoModder Forum > EcoModding > Fossil Fuel Free
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 08-02-2009, 10:23 PM   #1 (permalink)
Master EcoModder
 
Join Date: Sep 2008
Location: Texas
Posts: 632
Thanks: 0
Thanked 25 Times in 23 Posts
Another DIY EV controller

Circuit Cellar - The Magazine for Computer Applications
The main advantage is that a common industrial 3 phase motor can be used.

__________________
If America manages to eliminate obesity, we would save as much fuel as if every American were to stop driving for three days every year. To be slender like Tiffany Yep is to be a real hypermiler...

Allie Moore and I have a combined carbon footprint much smaller than that of one average American...
  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 08-03-2009, 03:44 AM   #2 (permalink)
PaulH
 
MPaulHolmes's Avatar
 
Join Date: Feb 2008
Location: Maricopa, AZ (sort of. Actually outside of town)
Posts: 3,831

Michael's Electric Beetle - '71 Volkswagen Superbeetle 500000
Thanks: 1,367
Thanked 1,119 Times in 734 Posts
Those little buggers! They even did field oriented control! That has good behavior at low rpm and high rpm. It needs to do a few trig transformations, so you need something a little better than an ATMega8. I really want to try one of these.
__________________
kits and boards
  Reply With Quote
Old 08-03-2009, 09:14 AM   #3 (permalink)
bjn
EcoModding Lurker
 
Join Date: Jul 2009
Location: Sweden
Posts: 10
Thanks: 1
Thanked 0 Times in 0 Posts
Common industrial AC induction motors have a pretty bad power to weight ratio compared to commen DC motors, I think. However, if it's possible to drive them with a higher frequency than 50/60 Hz then maybe they can produce more power (if the torque doesn't decrease too much with RPM).

How high much can you overrev a typical 3-phase AC induction motor before it breaks apart? at which RPM does the power curve start to decrease due to the torque curve falling too fast?
  Reply With Quote
Old 08-03-2009, 12:10 PM   #4 (permalink)
Master EcoModder
 
Join Date: Sep 2008
Location: Texas
Posts: 632
Thanks: 0
Thanked 25 Times in 23 Posts
Industrial motors are rated to operate continuously at their rating plus plenty of margin for overload. So in an EV, the motor would actually be much more powerful than its rating would indicate. As little as 7.5HP might be enough for an EV.

Maybe it's possible to make a small 2 phase version to allow the use of large appliance motors for something like power steering? Or to allow a common window A/C compressor be used for an EV heat pump?
__________________
If America manages to eliminate obesity, we would save as much fuel as if every American were to stop driving for three days every year. To be slender like Tiffany Yep is to be a real hypermiler...

Allie Moore and I have a combined carbon footprint much smaller than that of one average American...
  Reply With Quote
Old 08-03-2009, 03:30 PM   #5 (permalink)
Master EcoModder
 
Join Date: Jun 2008
Location: London, Ontario
Posts: 1,096

2k2Prot5 - '02 Mazda Protege5
90 day: 33.82 mpg (US)
Thanks: 0
Thanked 12 Times in 9 Posts
He's still sayin 2500 dollars in components? Paul, what's your cost?
  Reply With Quote
Old 08-11-2009, 03:28 AM   #6 (permalink)
PaulH
 
MPaulHolmes's Avatar
 
Join Date: Feb 2008
Location: Maricopa, AZ (sort of. Actually outside of town)
Posts: 3,831

Michael's Electric Beetle - '71 Volkswagen Superbeetle 500000
Thanks: 1,367
Thanked 1,119 Times in 734 Posts
Hey Matt! Well, for the DC controller, for 1 offs, it's about $300. In bulk about $230 or so.
__________________
kits and boards
  Reply With Quote
Old 08-11-2009, 09:26 AM   #7 (permalink)
Master EcoModder
 
Join Date: Jun 2008
Location: London, Ontario
Posts: 1,096

2k2Prot5 - '02 Mazda Protege5
90 day: 33.82 mpg (US)
Thanks: 0
Thanked 12 Times in 9 Posts
Somebody ought to tell him he blew it. However, a 3-phase setup with IGBT's in the DIY realm is nice to see.
  Reply With Quote
Old 08-27-2009, 12:58 PM   #8 (permalink)
EcoModding Lurker
 
Join Date: Mar 2008
Location: portland, or
Posts: 41
Thanks: 0
Thanked 0 Times in 0 Posts
blew it? How so? because cost is $2500? He got a development kit, and had to pay full cost for parts.... you could cut that cost by 1/3-1/2 in bulk.

Its essentially 6 DC controllers (2 for each phase, one neg, one pos).... so its got 6 times the overhead on the microcontroller, 6 times the gate drive, 3 times the current control, 6 times the voltage sensing, vector or volts/hz control. 6 high power gate drivers, 3 IGBT dual packs....you get the idea). A DC controller is fairly easy to do, if you can get the FET's or IGBT's to gate at the same time. Its just pure PWM. An AC controller is PWM and PFM.

And not to mention, he can now use off the shelf AC motors, that don't have to be rewound, so that cuts cost quite a bit. Forklift motors are limited in voltage and RPM, induction motors can go quite a bit higher and are much more widely available. Just go look for an industrial 208V motor, they're everywhere.
__________________
Travis Gintz
1986 Honda Electric VFR
www.evfr.net

Last edited by frodus; 08-27-2009 at 05:03 PM..
  Reply With Quote
Old 08-27-2009, 04:57 PM   #9 (permalink)
Master EcoModder
 
Join Date: Sep 2008
Location: Texas
Posts: 632
Thanks: 0
Thanked 25 Times in 23 Posts
Quote:
Originally Posted by frodus View Post
And not to mention, he can now use off the shelf AC motors, that don't have to be rewound, so that cuts cost quite a bit. Forklift motors are limited in voltage and RPM, induction motors can go quite a bit higher and are much more widely available. Just go look for an industrial 240V motor, they're everywhere.
Actually, industrial motors in the sizes we are interested in are either 208v or 480v since those are the common 3 phase industrial voltages. (Some are designed so they can be used on either by rewiring.)
__________________
If America manages to eliminate obesity, we would save as much fuel as if every American were to stop driving for three days every year. To be slender like Tiffany Yep is to be a real hypermiler...

Allie Moore and I have a combined carbon footprint much smaller than that of one average American...
  Reply With Quote
Old 08-27-2009, 05:04 PM   #10 (permalink)
Master EcoModder
 
Join Date: Jun 2008
Location: London, Ontario
Posts: 1,096

2k2Prot5 - '02 Mazda Protege5
90 day: 33.82 mpg (US)
Thanks: 0
Thanked 12 Times in 9 Posts
I didn't think that his cost was rolling in development kits, and since we're talking DIY then "bulk" is not really a factor. DIY mean batch or single... else you're not exactly D'ing IY.

I'd love to know his "second time around" production cost. One MAJOR savings area would be the IGBT drivers. Build them from scratch and save major coin. Those things are a niche market electronic device with high standards of reliability - read: expensive.

  Reply With Quote
Reply  Post New Thread


Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Electric car conversion: Project ForkenSwift MetroMPG Fossil Fuel Free 1041 07-28-2014 10:19 AM
DIY Open Source EV Charger bennelson Fossil Fuel Free 385 12-27-2011 03:46 PM
DIY EV DC/DC converter? NiHaoMike Fossil Fuel Free 6 04-12-2010 09:13 AM
Home Brew Challenge for Electric Geniuses (make a DIY electric motor controller) WaxyChicken Off-Topic Tech 42 08-19-2008 02:05 AM
Fun with Voltage Controller Heatsinks Dradus Fossil Fuel Free 14 05-02-2008 04:16 PM



Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com