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Maverick:
Thanks for responding. You've been very helpful in the past with
my battery based solution questions.
Daily load demand from the Protected Loads Panel is about 10kWh.
With 5 average daily peak sun hours, and 75% charging efficiency,
the battery bank will receive about 13kWh of solar charging per
day. The battery bank will be sized for 2 days of autonomy to 80%
DoD (2 or 3 strings of 200RE batteries). A 6kW generator, which
will be manually controlled, will provide charging assistance if
the solar charging alone is not sufficient.
The 10kW (ac) SE inverter and associated 10.7kWp PV array, using
the "Power Reduction Control" function, would be limited to about
3.5kW (ac).
Sizing the inverter and battery bank is not my issue - cranking
back the output power of the SE grid-tied inverter is what I need
help on.
The "standard" Outback GSLC solution uses one "Power Reduction
Control" relay (100% to 0%). I want to use two Outback activated
relays, and the SE inverter's "Power Reduction Control" function
to:
(1) reduce the SE inverter power from 100% to 30% when the grid
is down (relay #1)
(2) reduce the SE inverter power from 30% to 0% when the Radian
wants to totally shut down the SE inverter (relay #2)
If this two-relay solution is possible, I do not have to kluge up
a way to disconnect 70% of the PV array when the grid is down to
keep the SE10000A-US inverter from overloading the 4kW Radian
inverter and its battery bank.
Regards,
Gary Willett
Icarus Engineering / Solar Services LLC
On 10/18/16 9:23 AM, Maverick Brown
wrote:
How many kWh are you shooting for?
Esteemed
Wrenches:
Anyone have experience setting up AC coupling with
SolarEdge and the Outback Radian?
I have a client with a SolarEdge SE10000A-US inverter,
equipped with 31 SunPower X21-345 modules (10.7kWp) and
associated SolarEdge P400 DC optimizers. The DC
optimizers are arranged into two strings of series
connected optimizers: #1 = 16; #2 = 15.
The client wants to add a limited battery backup
solution, and a 4kW inverter will serve the needs of the
requisite protected loads panel.
I am considering using the Outback Radian GS4048A
inverter in conjunction with the GSLC175-AC-120/240
AC-Coupling Center.
I want to make a slight change to the PRI programming on
the SolarEdge inverter, and add another relay contact to
the Radian, to accommodate a 4kW Outback inverter AC
coupled to a 10kW SolarEdge inverter.
This is my first AC coupling project with these systems.
The analysis below is based solely on review of
available documents on the Outback and SolarEdge web
sites.
Any help or guidance will be greatly appreciated.
Regards,
Gary Willett
Icarus Engineering / Solar Services LLC
References:
(1) Outback
Application Note "AC
Coupling OutBack Power Radian Inverters with
SolarEdge N. American Inverters"
http://www.outbackpower.com/downloads/documents/technotes/ac_coupling_tech_note.pdf
(2) Outback Application Note "Adding the battery back-up
power option to existing grid-tied PV/solar
systems"
http://www.outbackpower.com/downloads/documents/flexcoupled/app_note_acc_new.pdf
(3) SolarEdge Application Note "SolarEdge Inverters, Power
Control Options"
http://www.solaredge.com/sites/default/files/application_note_power_control_configuration.pdf
REF (2); Page 9 of 14 -
Outback's AC Coupling Guideline Number Two:
The OutBack inverter power rating
should be 1.25% of the GT inverter power rating. This
guideline ensures that the GT inverter does not
overwhelm the charging circuitry in the OutBack
inverter if the load demand goes to zero and all
available GT inverter power is flowing to the OutBack
inverter.
With the 4kW GS4048A inverter, the PV power rating is
therefore limited to 3.2kW. This is 30% of the
nameplate rating of the PV array (3.2/10.7).
REF (3); Page 4 of 5 - SolarEdge/OutBack Radian Wiring Diagram:
On the male connector that fits
into the PRI connector on the SolarEdge PCB, two wires
are connected from the OutBack GSLC load center 12V
relay (OBR-16-DIN).
When activated, a normally open
contact (NO) of the Outback OBR-16-DIN 12V relay
supplies +5V from "pin 8" to "pin 6" of the SolarEdge
inverter's "Power Reduction Interface (PRI) port".
REF (1); Page 3 of 5 - SolarEdge Setup / Programming:
Per the App Note, when the Radian
wants to shut down the SolarEdge, the OBR-16-DIN 12V
relay is activated and a "1" is applied to bit 1 of
the PRI. This takes the SolarEdge output power, in a
gradual manner, from 100% to 0%.
"DEFAULT" SolarEdge
Programming
0000 <100,1,00,Y> ----meaning = 100% power,
1.00 power factor, point is active
0001 <0,1.00,Y> ----meaning = 0% power, 1.00
power factor, point is active
For my project, when the grid is down, the SolarEdge
inverter must be limited to 30% power. I want to use
the second NO/NC contact on the OBR-16-DIN 12V relay
to accomplish this. Not yet sure exactly how to
accomplish this in the Radian programming, but here's
how I want it to function:
(a) when the grid is down, the
second OBR contact, connected to bit 2 of the PRI,
is activated and a "1" is applied to bit 2. This
takes the SolarEdge output power, in a gradual
manner, from 100% to 30%.
(b) when the Radian wants to shut down the
SolarEdge, a "1" is applied to bit 1. This takes the
SolarEdge output power, in a gradual manner, from
30% to 0%.
"PROPOSED" SolarEdge
Programming
0000 <100,1,00,Y> ----meaning = 100% power,
1.00 power factor, point is active
0001 <0,1.00,Y> ----meaning = 0% power, 1.00
power factor, point is active
0010 <30,1.00,Y> ----meaning = 30% power, 1.00
power factor, point is active
0011 <0,1.00,Y> ----meaning = 0% power, 1.00
power factor, point is active
Is this doable?
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