On Sat, 16 Apr 2011 11:29:27 -0700 (PDT), harry wrote:
On Apr 16, 3:36*pm, Jim Wilkins wrote:
On Apr 16, 9:42*am, Home Guy wrote:
harry wrote:
So what you're saying is this:
Connect 2 batteries of the same voltage together in parallel to
the same load and each battey will supply half the current to
the load.
That sounds like a really good bargain. *Just by matching the
power companies voltage at my service input, my PV system will
supply half the current - always! *
No. You match the voltage and then turn it up until the full load
current of your array is flowing in practical terms.
There. Do you understand that?
That's exactly what I've been saying - that you "turn it up" (the
inverter's voltage output) to maximize the PV's current (I) supply into
the grid. *
But everyone else (or most everyone else) is saying no - that simply
matching the grid voltage (as measured at your service connection) is
all that happens (and is all that needs to happen) for the entire PV
current (I) capacity of the PV system to be "injected" into the grid.
...
You can only guess at what the inverter is forcing and sensing without
looking at the schematic and uP code or a technical explanation of it.
The Wiki type explanations are oversimplified for general readers,
engineers have better sources.
I was hired to decipher and troubleshoot several lead-acid and lithium
battery charging circuits after the designers quit, and found a couple
of different approaches in use. Generally they compared voltage and
current measurements to a model and used the result to pulse-width-
modulate the output control.
Power factor control is similar to the design issues of a grid-tie
inverter, with a large enough market to support custom ICs:http://focus.ti.com/lit/an/slua144/slua144.pdf
*jsw- Hide quoted text -
- Show quoted text -
An unneccessary complication. Far easier and better to mount PF
correction capacitors on individual motors.
Motors aren't the only things that need PF correction. Capacitors aren't the
only, or often the, way of doing it.