Re: what is the max bus voltage, 300V?

[Lee Hart <leeahart@earthlink.net>]

Dave Davidson wrote:
> My TEVan uses SEPEX at 180 volts... Chrysler really kept the power
> down and the van is really slow.

Yes; something is wrong with GE's motor design. GE certainly knows (or
used to know) how to design large DC motors to work reliably, but they
bungled this one somehow.

> I believe series DC came about for hobbyists because the industrial
> EVs have historically been series DC. It was a simple matter to adapt
> to a car and then they started increasing the voltage and power.
> A series DC system can be made very simple and relatively inexpensive.

Agreed (see, I *can* say it, Victor :-)

> I believe the reason high voltage AC systems were chosen was because
> the engineers were familiar with industrial drives, which are at
> least 208 volts three phase. It was probably not difficult to adapt
> an industrial drive to a vehicle.

Again I agree. This is a good description of what I meant by
"fashionable" designs; picking a design based what is already available
and what everyone else is doing.

> If you designed a DC system to have all the whistles and bells that
> current AC systems have, it would likely be just as expensive but
> without the advantages of AC.

I don't think this is true. Most of the cost in a motor controller is in
the power semiconductors and cooling. AC drives have a lot more silicon,
and so are a lot more expensive. The control electronics cost very
littl, and with microcomputers, you can have a very large feature set at
low cost.
-- 
Lee A. Hart                Ring the bells that still can ring
814 8th Ave. N.            Forget your perfect offering
Sartell, MN 56377 USA      There is a crack in everything
leeahart_at_earthlink.net  That's how the light gets in - Leonard Cohen