Need clarification on v1 - v4 parameters


#1

Fiddling with a upload script for my Fronius Inverter and smart meter. I think I know what the v1 - v4 params are but would like confirmation on that :slight_smile:

  • v1 - Energy Generation
    This is the total Watt Hours generated so far for the current day, so this should start at 0 and steadily increase or stay the same during the day

  • v2 - Power Generation
    The current watts being generated. This will of course vary up/down from 0 to . Not really significant except for pretty graphs of your output.

  • v3 - Energy Consumption
    This is the total Watt Hours consumed so far for the current day, so this should start at 0 and steadily increase or stay the same during the day.

  • v4 - Power Consumption
    The current watts being consumed. This will of course vary up/down from 0 to .

Questions:
v2 & v4 - are they exclusive of each other? i.e v2 is the current generation before being consumed by the household? v4 is the current consumption before any generation is applied?

Same for v1 & v3 - are the the raw values before export/consumption?

Do I need to supply v2 & v4 at all? can they be extrapolated form v1 & v3? My inverter (Fronius) does supply them.

How about current and total export? how is that calculated?

Thanks


#2

v2 = Gross Generation
v4 = Gross Consumption

They are independent.

All data uploaded is gross by default.

v1 is supplied and v2 is missing, then v2 is calculated and vice versa.

You will need to provide current as an extended parameter v7-v12.

Net = Consumption - Generation

A positive value is import, a negative value is export.


#3

Thanks for the details bankstownbloke, much appreciated as still feeling my way through this :slight_smile:

Is there documentation for those extended values? the help doesn’t say what they should be.

Thanks.


#4

Or do you mean using custom rules and graphs? Only just noticed the help for that.


#5

Blackpaw,

As you know from WP, I recently wrote a push program for my Fronius to PVO and have the following comments.

Sending instantaneous values in v2 and v4 as the Fronius push service does, is silly if you think carefully about it. Those values are a single spot sample in a 5 min period. E.g. if you turn the microwave oven on for 30 secs over a 5 min period when the sample is taken then a high value will be sent but you could have had the microwave on for 4 of the next 5 mins and if the sample was done in that other min then the value sent will be low. The only sensible power which people should be considering is the average power over the 5 mins. But the average can be calculated completely by the difference in the current and preceding energy totals (x 60/5 to scale for time). The average value is the best representation of power use over the period. In fact, if you don’t send v2 and v4 then PVO will calculate the average powers for you.

There is only one little issue as I wrote about here at Cumulative flag and daily energy totals. PVO currently has a flaw that if you don’t send v2 and v4 then it will not calculate and display the peak and standby values at the top of the table. That is minor but since I didn’t want to compromise what I do is to calculate average v2 and v4 myself and then redundantly send them in the push.


#6

Thanks bulletmark, I was wondering that - makes sense and thanks for the heads up on the bug.

Currently implementing things from scratch with reference to other scripts as I find that the best way to actually understand what is going on.

My biggest problem is twofold - I only have a surface knowledge of PV systems, so a lot there are a lot off assumptions in pvoutput that I have to catch up on, getting there though.

The other is the complete lack of documentation of the meaning of the variables returned by fronius api, they probably mean a lot more to a electrician than myself :slight_smile: but its handy being able to compare them against my live system.