[RE-wrenches] AC coupling SolarEdge

[Chris Mason]

I'll tell you exactly how to do this, if I understand the SolarEdge
documentation. I am working on a similar project, but using a contactor to
disconnect three 10KW String inverters.
Forget the Radio Ripple. The SolarEdge has a simple four line control
system. SMA has the same thing on it's Power Control Module that plugs into
TL inverters.
You can use a Raspberry Pi or Arduino microcontroller to switch those four
lines to get the inverter output control you want. Both controllers have
accessory relay boards, but I suspect the General Purpose Input Outputs
would also suffice.

So once you are switching those control lines, you have control of the
inverters.

Now, what is the criteria you are using?
In pseudo code, it would be

If Grid_Power is present
   //Switch Inverters to 100%
   Set GPIO1 = 0
   Set GPIO2 = 0
   Set GPIO3 = 0
   Set GPIO4 = 1
else
 //Switch Inverters to 30%
   Set GPIO1 = 0
   Set GPIO2 = 1
   Set GPIO3 = 0
   Set GPIO4 = 0


then the question is, how do you sense grid power?
You can also turn on and off an Outback Radian 4048A inverter using the
microcontroller as the Radian has a contact for this purpose.
Pretty easy project



On Wed, Dec 10, 2014 at 10:12 AM, Mac Lewis <maclewis1 at gmail.com> wrote:

> Hello wrenches,
>
> I have a request to design a modest battery backup system for a residence
> that has a 10 kW grid-tied Solar Edge system using a single SolarEdge
> Inverter SE10000A- US.  I'd like to try to utilize the solar potential that
> we have on site.  One idea that I had was to use DC relay(s) to cut out a
> couple strings when the grid was out, dropping the PV input down to about
> 3kW.  Has anyone ever tried this?
>
> I could easily get away with a ~4 kW battery-based inverter and would like
> to avoid stacking unnecessarily.
>
> Solar Edge also offers power output control through radio ripple control.
> I took a look at this paper on it
> http://www.solaredge.com/files/pdfs/power-reduction-control-application-note.pdf.
> Off-the shelf it looks like I would need a computer to control the power
> output dynamically.  Perhaps I could activate the 5V K2 relay with a simple
> control scheme and drop the power to 30%, but I hesitate to dive in too
> deep.  Anyone worked with radio ripple control?
>
> Thanks
>
> --
>
>
>
> Mac Lewis
>
> *"Yo solo sé que no sé nada." -Sócrates*
>
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-- 
Chris Mason
NABCEP Certified Solar PV Installer™
Solar Design Engineer
Generac Generators Industrial technician

www.cometsolar.com <http://www.cometenergysystems.com>
264.235.5670
869.662.5670
Skype: netconcepts
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