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Turning individual PV inverters on & off

Hi all,

It would be useful if I could disable PV inverters individually via VenusOS. This is particularly useful in off grid system when the batteries are (nearly) full and there is not much load. When a sufficiently significant load would appear, the PV inverter(s) can be turned back on, of course with some hysteresis applied. The idea is that the PV inverters are responsible for the bulk of the charging but, as charging via a Multi is a bit "clunky" (not my words, but Victron's :-) ).

It is possible to disable/enable all PV inverters via com.victronenergy.vebus.ttyUSB0/PvInverter/Disable. I assume VenusOS achieves this by telling the Multi to raise the frequency to the value as specified in the PV assistant parameter "The PV inverter will disconnect when the frequency is higher than".

There is also com.victronenergy.settings/Settings/Fronius/Inverters/<serial>/IsActive for each individual PV inverter but as expected this disconnects the PV inverter from VenusOS but doesn't stop it generating power.

Is it possible to turn individual PV inverters on & off via VenusOS using dbus or MQTT?

Jan


MultiPlus Quattro Inverter ChargeroffgridAC PV Coupling
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jbakuwel answered ·

Hi all,

Answering my own question.

I have found a better way to solve my issue, not by turning the PV inverters off, but to vary the WMax (currently set active power limit) and VAMax (currently set apparent power limit) parameters.

You'll need the Python pysunspec package. The following Python script does the trick:

#!/bin/python3

IP='192.168.1.1'
ID=126 # ID for SMA PV inverters

import sunspec.core.client as client
d = client.SunSpecClientDevice (client.TCP, ID, ipaddr=IP, ipport=502)
print ("Models: ", d.models)
d.settings.read()
print (d.settings)
d.settings.WMax = 3150
d.settings.VAMax = 3150
d.settings.write ()
d.close ()

cheers,
Jan

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