Logging Dynamic Power Control

Hey folks.

Have a Fronius Primo with Smart Meter which has been setup to push to pvo for several months now and no drama. Previously limited to zero export (Thanks Ausnet) but recently been included in new trial for flexible exports. Ausnet have partnered with Switchdin for the trial and installed one of thier droplets into my home which dynamically controls the power output of the inverter via modbus based on control data that ausnet pushes down, I guess in a virtual power plant type setup.

This becomes more of a question of what the fronius push service can output rather than what PVO can consume but has anyone seen this parameter anywhere and been able to log it to PVO ? There is a “AC Active Power Limit” parameter that shows up in the Switchdin portal under the Inverter readings which operates as a variable percentage of the inverter power eg 33% of 5KW so this sets the total power generation of 1650W which is the current 1.5KW export limit plus 150w of consumption.

I can see some value in trying to log this so I can be clear of the dynamic limit versus just any poor generation for the day. It appears in the graphs in the switchdin portal but would be nice to overlay it all together in PVO.

The Fronius Push fields available from the meter push are -

Any one of these may be logged to the Extended Data graph e.g. v7=Current_AC_Sum

But ‘AC Active Power Limit’ does not appear to be supported.

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It looks like the Fronius inverter API can supply details of ‘Power_Limitation’ via the GetArchiveData.cgi call.

I have run it against my own inverter but there are not ‘events’ and I am not export limited.

You may be able to extract this field and export it to PVO using some simple scripting.

p. 58 of ‘Fronius Solar API V1’ shows some sample output.

The ‘GetArchiveData.cgi’ API is very fussy when it comes to the accepted date formats for the START_DATA and END_DATE.


After digging into this a little more it appears the Active Power Limit value I can see in the switchDin dashboard is the realtime dynamic export control value being SENT via modbus to the inverter rather than a value that is being queried out of the inverter. Pushes the WMaxLimPct param to set the %. Makes sense now I’ve looked at at it some more.

switchDin allows data download to CSV so worst case I can upload data to extended to get it on the overlay. Would be nice to see the set limit versus generation, if the limit is 100% (eg no limit) but not seeing full production on a perfect day then could be a good way to identify any system issues.

Thanks for that, I had a poke around on mine and don’t see any events like that logged anywhere and later found the value I was seeing is what is SENT to the inverter for export control rather than something in there I can query. Its possible its still stashed away in there somewhere and able to be queried and I have more of an understanding of how it all fits together now so may or may not help find it :smile: