Some interesting results from AC coupled IQ7+ and Outback Skybox during 200A meter upgrade

[goldserve]

I took on the project to upgrade my meter to a new meter + main panel with my existing 100A main as a sub panel. I have 4.7kw DC coupled system with 7.5kw IQ7+ AC coupled system and 30KWh batteries. The Outback Skybox took over the backup loads panel which basically covers all my servers, cameras, fridge and lights around the house. Total loads around 600-700w on backup loads. I'll post more interesting observations as I dig through the my data set in the coming days. For now, this is what happened on the enphase.



What's up with two panels?

 

[zanydroid]

Do you have hourly Wh or W data on those sorry looking panels? That might figure out what is going on.

It almost looks like you are rolling up data for a 2 hour period of time, judging by the total Wh

If those panels are on the receiving end of the shadow from that roof vent, you can expect some pretty sharp drops from time to time.

Looks like you have this overlaid on a fuzzy roof picture from Google maps, maybe find a neighbor with a drone to get you better pics. I bought a drone to support my solar DIY stuff…

I would probably use the hourly production graph on those panels to see when the dips are and fly the drone to see what the shadow is (or set up a ladder if it’s close and I didn’t have a drone). If you get full sun and the production is that low the panel might be busted. Or maybe the PLC comms to get telemetry is busted (weird to have only part of a circuit affected)

 

[goldserve]

On a normal day, the production of those two panels are OK. It's when they are running off-grid and frequency-watt is coming into play. Maybe I need to check if the correct grid profile is set for these two panels but I am using: Off-Grid FW100 HI (1.2.1). It says it should be used when AC coupled with third party battery inverters that shift frequency to curtail. Anti-islanding is disabled to allow off-grid operation.

 

[zanydroid]

Hope you can find some help with the settings, I don't own that system / have practical experience with AC coupling, only sniffed at it and done some basic system design.

Doesn't PG&E want you to have anti-islanding on for the times when you are on-grid and passing through the microinverters to grid?

frequency watt-var

I think you mean frequency-watt -- WattsOutAdjustment = Fn(ACFreq). When you start saying Var it sounds like the Volt-Var curve from 1741SA -- VarsOutAdjustment = Fn(ACVoltage)

 

[goldserve]

Hope you can find some help with the settings, I don't own that system / have practical experience with AC coupling, only sniffed at it and done some basic system design.

Doesn't PG&E want you to have anti-islanding on for the times when you are on-grid and passing through the microinverters to grid?



I think you mean frequency-watt -- WattsOutAdjustment = Fn(ACFreq). When you start saying Var it sounds like the Volt-Var curve from 1741SA -- VarsOutAdjustment = Fn(ACVoltage)

the Enphase profile says explicitly it is for AC coupling behind a third party battery inverter. The Skybox will do the anti-island checks and disconnect the grid relay once the grid connection is out of range. Enphase micros will still be connected to critical loads panel so it will see a solid grid input but the AI detection messes up lights and will drop off too easily even though the hybrid inverter is outputting a valid grid voltage and frequency. That's what I read so it made sense to choose that profile.

You are correct with the frequency-watt adjustment.

 

[zanydroid]

the Enphase profile says explicitly it is for AC coupling behind a third party battery inverter. The Skybox will do the anti-island checks and disconnect the grid relay once the grid connection is out of range.

Got it, this seems OK as long as the only way the Enphase inverters can see the grid is through this automatic relay.

If there is a service or emergency bypass around the Skybox then this is more problematic but it's OK most of the time.

 

[goldserve]

Oh you are right, I do have a skybox bypass via an interlocked feed-in breaker so I should change back the profile to the recommended CA Rule21 201902 VV VW FW (1.2.8) profile and run another off-grid test for the day. The last one was so successful, it was very satisfying.