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kellerza / pysma

Async library for SMA Solar's WebConnect interface
MIT License
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Wrong id used for retrieving PV power #31

Closed eelcohn closed 3 years ago

eelcohn commented 4 years ago

I've found that the key used to retrieve the pv_power value should be 6380_40251E00 instead of 6100_0046C200. The 6100_0046C200 key indicates the power generated by the converter, whereas the 6380_40251E00 key indicates the power generated by the solar panels. Since converters are never 100% efficient, there's a slight difference between the two values.

kellerza commented 4 years ago

If 6100_0046C200 is usable power, that seems more correct than some measurement before it is converted, or not?

How are these two affected when you limit the setup not to feed any power into the grid?

eelcohn commented 4 years ago

Hi, thanks for responding.

If 6100_0046C200 is usable power, that seems more correct than some measurement before it is converted, or not?

6100_0046C200 is indeed the usable power returned to the grid, but that value is always the same as 6100_40263F00, which makes it pretty useless IMHO to have two variables which have the same value (at least in the setups that I've seen).

The pv_ prefix in pv_power would suggest that it's value is about the solar panels, not about the converter or the power grid. If one would need the usable power, you could use the grid_power variable, or not?

On a sidenote, in the SMA management console there are actually six(!) power values available: 6380_40251E00 which is the power generated by the solar panels 6100_40464000 which is the power returned to the grid via phase L1 6100_40464100 which is the power returned to the grid via phase L2 6100_40464200 which is the power returned to the grid via phase L3 6100_40263F00 which is the total power returned to the grid (L1+L2+L3) 6100_0046C200 which is the power generated by the converter (which is always the same as 6100_40263F00)

How are these two affected when you limit the setup not to feed any power into the grid?

I'd have to do some tests on that one, I'll get back to you.

eelcohn commented 4 years ago

How are these two affected when you limit the setup not to feed any power into the grid?

I've done some testing and all values return 0 when the converter is switched off grid.

kellerza commented 3 years ago

Removed pv_power from the code as pv_power_a already uses the correct key today. Also added some notes to the sensors. Thanks!