Re: Charging/Amp question

[Rich Rudman <rmanzan@tscnet.com>]

Tony McCormick wrote:
> 
> I'm curious, I have a PFC20 charger and I was wondering:   if my emeter
> reads 19.7 amps, I assume that means going into the battery pack, what's it
> pulling from the AC side?
> 
> - Tony
> ---------------------------------------------------------------
> My Web: http://www.notebene.net/ - EV Web: http://www.oeva.org/
> ---------------------------------------------------------------
> "Nobody made a greater mistake than he who did nothing because
> he could do only a little" - Edmund Burke


About 16.7 from 240 VAC 

The charger can't make 19.7 amps from a 120 VAC feed at 132 and higher.
At 175 VDC it makes about 14.3 with just over 25 amps of 120VAC.

19.7amps is hanging on the 20 amp output current limit. Just about where
I want it for a stocker PFC20.

The whole concept of the Buck enhancer options is, the charger is NOT
drawing even 20 amp at this point, from 240 VAC. The BeF will allow you
to draw 20 amps of line current Even if the output current goes up
beyond 20 amps. 
	Also I have been having to turn up the peak line currents to get decent
currents at 120 to 190 VDC. This has pushed the AC line draws up to 25
amps, just so I can get 20 amps output. This is a quirk of the control
loops. Adding a AC line current sensor, and then turning up the DC
limits will allow us to pull just 20 amps of line but make 25 plus while
bucking from 240 VAC to 144.  
	I will set the output limits to 30 amps, and the input to more than 20
but less than 25. You will get more amps down under 200 volts, and I
will get 5 amps of overhead.
	In theroy I get to claim that if you have a battery voltage of 166VDC
or higher you will get a full 5000 watts of charge power. If you have
less battery voltage you get 30 amp of current. All from less than 25
amps of 240 VAC.(more like 22 amps).
	Without the Buck enhancer you can only get 5000 watts if your battery
pack is 350 volts and higher. This gives lots of real power improvements
to most of us EVers who are in the 96 to 156 range. This is about %95 of
all home buildt EVs.

Oh yea.... we got the Buck enhancer running on the PFC50 this weekend...
and we did get 73amps of 80 from 120VAC. This is the low voltage version
of what I am promising Bruce P. We tried 75 amps of 150 from 240, and
had some problems. Like 100 plus amps of current in the Windloader, and
it was chattering, and we got close but I have more testing to do. Also
it's very noisey, Joe has some control loop engineering to do, and we
are testing a new circuit, that should quite things down a bit.  This
new circuit is going into all the new PCB sets, and has me in a holding
pattern on releasing them. This is holding up the PFC20s right now. I
have 3 rev 2 Board sets left, 2 will ship within few days. I am outta
Boards. 

	It really works, but adds a lot of heat to things. We are also nearing
the design edge of our test gear, and Well it can get very exciting.....

Rich Rudman
Manzanita Micro