PVPower PVCurrent PVVolt - correlation.

[v1lad]

Hi All !
As everyone has known since school :
PVPower = PVVolt x PVCurrent
Now let's take a look at the chart. I have 20 panels, but the strings connections were not made identically.
Why at high enough voltage from solar panels, the current is still 0, and therefore the power is also 0 ?
Is the threshold of the invertor high enough ?
P.S. I added another chart from which you can see when the current is not 0.

[Dave Foster]

It’s difficult to tell from just this information, the inverter runs a maximum power point tracker on each string and attempts to optimise the best voltage / current performance from the panels to get maximum power.

But the inverter must have a consumer for every watt of power that it produces, either house load, battery charge or export - if there are no consumers it will derate the MPPT to reduce the generation to match the demand.

So at the times you are seeing zero power, is the inverter running normally? , no error conditions? (10 minute average volt faults etc..)

Do you have battery storage attached, was it at maximum soc when the power was at zero?.

Do you export excess power to the grid, or has the inverter got an export limit set?

[v1lad]

Hi Dave!
Thank you very much for your answer. The inverter is running without any errors in the log. The battery is attached, and the state of charge is at 13-14% (the settings specify a minimum of 15% on the grid and 10% without the grid). There are no limits for export, and during this time, the house consumes about 0.2 kW from the grid. I encounter the same situation every morning and evening. I'm wondering if the inverter settings could include options such as a minimum threshold voltage for startup or something similar. I also have the idea that the inverter can use all the power generated by the solar panels for its own needs. However, I still expected to see non-zero values in the raw data for PVPower or PVCurrent at this time.

[Dave Foster]

Ahhh ok, if it’s happening at dawn and dusk then it is likely the MPPT has worked out there’s no power point that would get enough power to start up - in effect what you are seeing is the open circuit voltage of your strings.

The inverter has a specified start-up voltage which you are well over (the threshold cannot be changed) but i’ve been told by Foxess it’s not just the voltage, it also needs enough current to be able to start-up and mantain the inverter trackers as well - so it’s very likely that.

Worth checking your firmware versions are up to date just in case

[LSJPC02]

any one help
i keep getting on my inverter display..10 min volt fault...stays on there for about 10 mins then the display shows checking for a minute then shows normal in the display window ??

[Dave Foster]

any one help
i keep getting on my inverter display..10 min volt fault...stays on there for about 10 mins then the display shows checking for a minute then shows normal in the display window ??

Your grid voltage is too high when you are exporting, the alarm limit can be adjusted - check this post viewtopic.php?p=668#p668

[LSJPC02]

any one help
i keep getting on my inverter display..10 min volt fault...stays on there for about 10 mins then the display shows checking for a minute then shows normal in the display window ??

Your grid voltage is too high when you are exporting, the alarm limit can be adjusted - check this post viewtopic.php?p=668#p668

thanks david
just a quick one.if i do this what should the volts be set at.

[Dave Foster]

any one help
i keep getting on my inverter display..10 min volt fault...stays on there for about 10 mins then the display shows checking for a minute then shows normal in the display window ??

Your grid voltage is too high when you are exporting, the alarm limit can be adjusted - check this post viewtopic.php?p=668#p668

thanks david
just a quick one.if i do this what should the volts be set at.

You have to work that out, as it will be different for each install - the best way to do this is to go on the Foxcloud website and on the Inverter Details page (that shows energy flow) at the bottom is a blank graph - select the item RVolt and it will show you the voltage your system records as it goes through the day including the high and low marked - whatever the high is, set the voltage to 2V above it.

[LSJPC02]

thanks dave