RE: ACRX goes down to 27 Optimas

["Roger Stockton" <rstockton@delta-q.com>]

> -----Original Message-----
> From: Victor Tikhonov [mailto:vtikhono@lsil.com] 
> Sent: April 29, 2002 11:45 AM
> To: ev@listproc.sjsu.edu
> Subject: Re: ACRX goes down to 27 Optimas

> The point was - if regen is off you waste your kinetic evergy for the 
> first few electric miles. With 27 batts I can start recovering most
> of it right away.
> 
> You can automate regen off function by having it off by the battery 
> management system, but as you know, Siemens inverter already 
> takes care of that - reducing regen current (to 0 if nesessary) not
> to let the pack voltage to exceed the level you specify.

Victor, could you explain this a bit more?  What I'm wondering is how
dropping your pack voltage by one battery lets you recover most of the
available regen energy right away at the start of the trip, especially
since the inverter is programmed to reduce regen current as required to
keep the pack voltage below a set threshold.

I think that what you've found is that with the full 28 module pack, you
can't set the regen voltage limit high enough to permit recapturing much
energy when the pack is nearly full, and that dropping back to 27
modules avoids this problem, however, isn't the max regen voltage limit
going to be set at X volts/cell times the number of cells in the string
anyway, so when the pack is nearly full (i.e. the first few miles) you
still won't be able to recover much energy through regen unless you
allow the inverter to over-voltage the cells?

Thanks,

Roger.