Consumerbot3418
Fitting square pegs into round holes... for fun?
I'm writing to share my recent experience with trying to add AC coupled PV to my existing Sunny Island and Sunny Boy system, in case it proves useful to anyone. Ideas and suggestions welcome!
Backstory/set-up: I had a DC Solar trailer with 2kW on-board PV, DC coupled via Midnite Classic. No communication with the Sunny Islands means occasional conflicts with target charge voltage, but that's for another thread, lol! I added a Sunny Boy 7.7 via AC coupling, and everything worked pretty well (aside from inadequate battery). I then added a pair of 2000VA Victron Multiplus Compacts between the house and the DC Solar trailer, for redundancy, as well as a way to add some LFP battery storage. Using ESS, I can have the Victron either dump surplus power into the batteries, or even backfeed the Sunny Islands to keep the FLA batteries at float. Also added a Victron MPPT to DC couple some PV to the LFP batteries.
Although we did experience some dimmable LED flickering when running high-power inverter-based AC units (both window and mini split), everything worked pretty flawlessly.
I then added some Enphase IQ7 micros to the system. The Enphase grid profile listing is a bit overwhelming--there are lots of abbreviations, and naming isn't quite consistent. After reading descriptions of many different profiles, I finally settled on the "PANAM-60-120 off-grid FW VV (1.2.1)" profile. It seemed to work well with a 2 strings of 13 total units. I recently added another 5, and began to encounter major problems with power quality.
The first clue was that the UPS unit that powers our internet router began dropping the grid connection, reconnecting, then dropping again cyclicly. I also noticed that the Sunny Boy had curtailed its output drastically, derating the majority of its output. The UPS said "input frequency out of range", and the SB gave "frequency deviation" as the cause for derating, although it always indicated a steady 60.0Hz on the Instantaneous Values page. The Sunny Island hadn't raised the the frequency, either, so it wasn't the expected behavior that occurs when the batteries are approaching full charge--something was awry.
At the same time the UPS was clicking its relay, we also noted substantial flickering of a dimmable LED. Rather than minor, annoying variations in the light output, it would sometimes go completely out for a fraction of a second. We also got an error from our Frigidaire Induction range a few times--FS00.
I initially suspected a faulty appliance, or perhaps wiring in the house, but the issue persisted even with all appliances unplugged or switched off. Disconnecting the AC input to Victron cleared up the flickering, so I then realized it was likely the Sunny Islands, or AC coupled PV.
Eventually, I figured out that the Enphase IQ7s were the culprit. Today, I propagated a different grid profile, "Off-Grid FW60 FP98oe (1.1.1)", which is explicitly described as having a fixed power factor to alleviate flickering issues (although it does say it's only for use with Schneider XW+/XWpro inverters). It may be premature, since the previously described issue was somewhat intermittent, but so far it seems to have resolved the issue, and perhaps even improved the minor annoying flicker issues we were previously experiencing. Fingers crossed. Meanwhile, I'm hoping household appliances haven't been damaged or degraded by being subjected to such poor power quality!
Backstory/set-up: I had a DC Solar trailer with 2kW on-board PV, DC coupled via Midnite Classic. No communication with the Sunny Islands means occasional conflicts with target charge voltage, but that's for another thread, lol! I added a Sunny Boy 7.7 via AC coupling, and everything worked pretty well (aside from inadequate battery). I then added a pair of 2000VA Victron Multiplus Compacts between the house and the DC Solar trailer, for redundancy, as well as a way to add some LFP battery storage. Using ESS, I can have the Victron either dump surplus power into the batteries, or even backfeed the Sunny Islands to keep the FLA batteries at float. Also added a Victron MPPT to DC couple some PV to the LFP batteries.
Although we did experience some dimmable LED flickering when running high-power inverter-based AC units (both window and mini split), everything worked pretty flawlessly.
I then added some Enphase IQ7 micros to the system. The Enphase grid profile listing is a bit overwhelming--there are lots of abbreviations, and naming isn't quite consistent. After reading descriptions of many different profiles, I finally settled on the "PANAM-60-120 off-grid FW VV (1.2.1)" profile. It seemed to work well with a 2 strings of 13 total units. I recently added another 5, and began to encounter major problems with power quality.
The first clue was that the UPS unit that powers our internet router began dropping the grid connection, reconnecting, then dropping again cyclicly. I also noticed that the Sunny Boy had curtailed its output drastically, derating the majority of its output. The UPS said "input frequency out of range", and the SB gave "frequency deviation" as the cause for derating, although it always indicated a steady 60.0Hz on the Instantaneous Values page. The Sunny Island hadn't raised the the frequency, either, so it wasn't the expected behavior that occurs when the batteries are approaching full charge--something was awry.
At the same time the UPS was clicking its relay, we also noted substantial flickering of a dimmable LED. Rather than minor, annoying variations in the light output, it would sometimes go completely out for a fraction of a second. We also got an error from our Frigidaire Induction range a few times--FS00.
I initially suspected a faulty appliance, or perhaps wiring in the house, but the issue persisted even with all appliances unplugged or switched off. Disconnecting the AC input to Victron cleared up the flickering, so I then realized it was likely the Sunny Islands, or AC coupled PV.
Eventually, I figured out that the Enphase IQ7s were the culprit. Today, I propagated a different grid profile, "Off-Grid FW60 FP98oe (1.1.1)", which is explicitly described as having a fixed power factor to alleviate flickering issues (although it does say it's only for use with Schneider XW+/XWpro inverters). It may be premature, since the previously described issue was somewhat intermittent, but so far it seems to have resolved the issue, and perhaps even improved the minor annoying flicker issues we were previously experiencing. Fingers crossed. Meanwhile, I'm hoping household appliances haven't been damaged or degraded by being subjected to such poor power quality!
