View Single Post
Old 09-25-2011, 05:22 PM   #7 (permalink)
IamIan
Master EcoModder
 
IamIan's Avatar
 
Join Date: Dec 2010
Location: RI
Posts: 692
Thanks: 371
Thanked 227 Times in 140 Posts
Quote:
Originally Posted by thingstodo View Post
The off-the-shelf DC to AC inverter I've tried takes 12V in and puts out 150- 155VDC. With 85% efficiency, that would be 12V in at 170A continuous, 340A peak. Output would be just over 11A continuous at 150VDC.

I need about 30A at 900VDC. That should give me 35 HP, about what I expect that 'SalvageS10' will need to make highway speed.

I've read about all of the AC conversions that I can find. No one seems to be using this method. I expect there are one or more reasons for that. I'm trying to figure out what the issues are and work around them.
I think that is the reason people don't use this method.

If you manage to get ~85% efficiency ... getting 30A @ 900V from 12V looks like about ~2,650 Amps from the battery side

That is some serious current ... need huge connectors and cabling... be careful with those huge cables or you will also be generating some serious size magnetic fields from that electromagnet.

For continuous operation of ~30A @ 900V ... from that type of inverter you're looking at about ~18 of those inverters.... 6 in series to Voltage 3 in parralel for current.

That is a lot of places to something to go wrong ... and a good size investment in time , money , space , and weight , in inverters ... plus the question of how the battery will take ~2,650 Amp discharge rates... so before you go out and buy ~20 inverters I would look into comparing to other options ... such as more batteries to make up the voltage instead of inverters ... or a different motor controller / motor that doesn't need 900V... the other options might not work for you ... but I would still recommend looking into them before seriously investing in this path.

Last edited by IamIan; 09-25-2011 at 05:29 PM.. Reason: correction
  Reply With Quote