Solar Edge major unresolved problem

[Treepmeyer]

Update - problem appears solved, but its not clear how. On or about Oct. 10 the performance changed dramatically. See the screen shots attached typical for before and after. The power company did set the local regulator voltage down 2 volts and my solar edge installer thinks that is what did it. I'm not so sure. Both the installer and the power company had been working with Solar Edge because I wasn't the only one having problems. Solar Edge support said that they made no changes to my inverter's power management settings, but I rather suspect that Solar Edge did make changes the the country default power management settings. The results were dramatic. Keeping in mind that the changes were effective about 10 days into October, here are the power outputs for October over the last four years:
2019 0.99 MwH
2020 0.88
2021 0.46
2022 1.04
The fall-off in 2021 was not an anomaly. Starting in March 2021 output had dropped off consistently 25-50% compared to the same month over 2019 and 2020.
I strongly suspect that Solar Edge's power management default settings for the US were sub-optimal from the beginning. Something (maybe the power co. regulator voltage) made it worse in March, 2021 and that Solar Edge and the power company have finally focused sufficiently on the issue to get everything properly sorted out. It's been quite a slog.

Thanks very much to everyone on this forum who contributed.

Tom Reepmeyer

[Treepmeyer]

Yes, I have to get the customer service rep to give me a password, then I will be able to see the power management settings and, I think, a log of changes.

[oregon_phil]

Do you have a log to view for events and/or firmware updates? Even if SE did something remotely, I would hope it would be logged for either you or your installer to view.

[Treepmeyer]

All of a sudden, on Monday the inverter started acting normally, or nearly so. The head electrician at MI Solar told me last week that he and his people were going to have a discussion with Solar Edge techs because I wasn't the only installation having these problems. I don't know if SE did anything but something definitely changed. Only one shutdown for the entire week versus 41 the previous week. Voltage levels off at 260v. I strongly suspect that SE finally realized that the power management settings were incorrect. I'll let you know if I find out more.

[SunEagle]

Thanks for reminding me about how the did that. I forgot the details but now remember.

Sad I know that because I use to work with POCO's as an EE.

[Ampster]

I use to see a voltage change on the grid every Monday and Friday. It seems the POCO would use capacitors to adjust the voltage based on industrial usage and then industry not being used due to the weekend. .........

Thanks for reminding me about how they did that. I forgot the details but now remember.

[SunEagle]

This may not help your issue but years ago I had an old Xantrex inverter go offline because of higher grid voltage. When I called SCE about the issue they fixed it quickly and the field guy explained that they routinely adjust things at the substation. In this case they had upped the voltage because of summer loads and did not ramp them down in the Fall which created higher voltage than they intended.

I use to see a voltage change on the grid every Monday and Friday. It seems the POCO would use capacitors to adjust the voltage based on industrial usage and then industry not being used due to the weekend. I am glad I did not have a sensitive inverter at that time.

[Ampster]

This may not help your issue but years ago I had an old Xantrex inverter go offline because of higher grid voltage. When I called SCE about the issue they fixed it quickly and the field guy explained that they routinely adjust things at the substation. In this case they had upped the voltage because of summer loads and did not ramp them down in the Fall which created higher voltage than they intended.

[Mike 134]

I have a hunch when the solution it found it will be multiple causes adding up to create your troubles. "Normal voltage" 250v but on the high side.......acceptable voltage drop but also at the upper limit, perhaps a connection that's loosen just a tad, just enough to be the provable straw that broke the camel's back.

[Treepmeyer]

I just checked my frequency over the last two days. 60 Hz, +/- 0.02 Hz.

[Grabcon]

Okay first off I am not an electric guy but everyone seems to be talking voltage fluctuations in this thread. If you look at the parameters that Oregon_Phil posted there is a very narrow margin for the frequency threshold. Could the problem be unstable frequency causing the issues? I ask because I just saw a YouTube on this but I can't remember where and the topic.

[bcroe]

The line is not a perfect lab clean sine wave. There are bumps as
things cycle, it could easily bobble a few volts and shut down the
quick reacting inverter electronics. Cross that line and my inverters
were off 5 minutes. Look for a significant operational improvment,
a small one may not cure it, just reduce the shutdowns. Bruce Roe

[oregon_phil]

I just analyzed the data on inverter shutdowns over the last week and I'd appreciate your comments on it.

There were 41 shutdowns for excess voltage (plus 3 for hitting the inverter 10kw limit). That's about 6 per day. The range was 1 to 13.

Average voltage at shutdown was 260.1v, but the range was 251.0v to 262.5. Fully 22 of 41 shutdowns were at less than 260.0v.

Shutdown time averaged 20 minutes but, again, the range was large: 5 minutes to 3:35 hours. Three shutdowns were for more than 1:50 hours.

Does this sound like appropriate inverter functioning? Why would it be shutting down at 251.0v? Or for that matter anything less than 260? And why would it shut down for such extended periods?

I'm not an expert in power line monitoring, but regarding the power line monitor the power company left on site, was it a calibrated device (regular certification)?

How was the device set up? Trigger on event or continuously monitor the entire test period at a xx microsecond sampling rate?

My SMA inverter follow UL 1741 rules for frequency and voltage ride through requirements. Some of these parameters are distilled in the attachment SMA thresholds.

Previously, peakbagger brough up the point that sometimes inverters have internal parameters tighter than standard voltage range. As stated previously, my SMA inverter has separate settings for grid reconnection limits vs grid connection limits. Once a fault happens, the inverter goes through an unknown set of boot up processes that checks and tests the grid. One of those variables exposed to me in my parameters menu is reconnection upper voltage limit, 127vac per leg or 254vac between legs.

It is entirely possible that SolarEdge's grid checking routine compares the grid to a set of internal inverter variables that you have zero visibility to seeing.

[nerdralph]

Average voltage at shutdown was 260.1v, but the range was 251.0v to 262.5. Fully 22 of 41 shutdowns were at less than 260.0v.

Shutdown time averaged 20 minutes but, again, the range was large: 5 minutes to 3:35 hours. Three shutdowns were for more than 1:50 hours.

Does this sound like appropriate inverter functioning? Why would it be shutting down at 251.0v? Or for that matter anything less than 260? And why would it shut down for such extended periods?

Sounds like a **** inverter. On a sunny day my Solis 6 kW inverter rarely sees below 250V, and sometimes gets as high as 255. If I understand the manual correctly, at 264V it doesn't shut down, it just starts de-rating the output.

[Treepmeyer]

I just analyzed the data on inverter shutdowns over the last week and I'd appreciate your comments on it.

There were 41 shutdowns for excess voltage (plus 3 for hitting the inverter 10kw limit). That's about 6 per day. The range was 1 to 13.

Average voltage at shutdown was 260.1v, but the range was 251.0v to 262.5. Fully 22 of 41 shutdowns were at less than 260.0v.

Shutdown time averaged 20 minutes but, again, the range was large: 5 minutes to 3:35 hours. Three shutdowns were for more than 1:50 hours.

Does this sound like appropriate inverter functioning? Why would it be shutting down at 251.0v? Or for that matter anything less than 260? And why would it shut down for such extended periods?