18kpv inconsistent solar unless in off-grid mode

[FurryAlpaca]

Anyone experience inconsistent solar unless their 18kpv is in off-grid mode? I get multiple "drop outs" even when there's no change in cloud coverage. Today was an example of the behavior when on grid all day:




And a few days ago when in off-grid mode:


Note that above was on-grid until 11:00AM (last big "drop out"), as soon I I switched to off-grid the output was much more consistent.

I have grid sell back disabled and fast zero export enabled. Is the PV just more sensitive because it has to adjust to not export?

 

[Ampster]

Is the PV just more sensitive because it has to adjust to not export?

It would seem that way from what you have plotted. Is all the solar DC coupled?

 

[FurryAlpaca]

Setup is all standard, I replaced two 6500EXs so running in a similar configuration, no AC Coupling or anything like that. I've got the CTs facing the inverter in the 18k itself. Wanted to see if this was "just the way it worked" or if something else might be going on?

 

[Quattrohead]

Can you tell us the layout of your PV array, particularly interested in the voltage being generated.

 

[FurryAlpaca]

Can you tell us the layout of your PV array, particularly interested in the voltage being generated.

Sure! Using these panels:

4pcs 320 Watt Monocrystalline Solar Panel

Primarily used for residential and commercial purposes, rooftop solar power systems are the perfect way to decrease an electric bill. Also great for large off-grid systems, the 320W Monocrystalline Panel can be used in multi-panel solar arrays for cabins and sheds.

www.renogy.com

On PV1 I have 10 in series pointing solar south, PV2 I have 6 in series pointing east-ish. Below is both my voltage and current for today (bad/on-grid):



And below are graphs that correlate to the "good" day (on grid until 11AM, off grid after that) from my initial post:


It almost seems like something is throttling the solar? I've played around with some of the settings a bit but couldn't really find anything that made a difference except for the "off-grid" setting.

I also have 3 LifePower4 batteries.

 

[Quattrohead]

You say you have three rack batteries, are they closed or open loop to the inverter? I am thinking that the PV is being so-called regulated because you just don't have enough battery or load to absorb all the possible generated PV. It would be interesting to see your battery charge status and AC loads too.

 

[1201]

Anyone experience inconsistent solar unless their 18kpv is in off-grid mode? I get multiple "drop outs" even when there's no change in cloud coverage. Today was an example of the behavior when on grid all day:

View attachment 206386


And a few days ago when in off-grid mode:
View attachment 206387

Note that above was on-grid until 11:00AM (last big "drop out"), as soon I I switched to off-grid the output was much more consistent.

I have grid sell back disabled and fast zero export enabled. Is the PV just more sensitive because it has to adjust to not export?

It seems like it's varying the pv DC input to ensure "zero export "

 

[EG4_Jared]

If you could DM your serial number for the inverter, I can take a look.