wheisenburg
Independent Solar Consultant
Well I have reliable power here. The few outages I have had tend to be of the 30 minutes to an hour. I would still like to get this working eventually, but it is not urgent.
How to AC couple Enphase IQ8 w/Battery Storage to Schneider XW Pro 6848 w/rack batteries, off-grid?
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wheisenburg
Independent Solar Consultant
I have tried Grid Codes that are supposed to have the Anti-Islanding turned off. They still don't work. The Schneider inverters appear to be working correctly. There is a "High Resolution" data section in the Enphase monitor that shows the Frequency and Volts appear to be stable and within the limits. There are no messages from the inverters indicating that voltage or frequency are out of range. So it must be something else.
Hedges
I See Electromagnetic Fields!
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Do like me and buy old-stock Sunny Boys. They are rock solid. At least the transformer-type 5000US series.
Playing with my TriPower, for which I need to use a step-up transformer, I was having issues with it disconnecting when seeing full 277V per phase. Backed off a bit with other turns ratios, I think it is working better. Haven't confirmed, may be voltage getting pushed higher.
Since Schneider has transformer output, may also behave that way backdriven. Can you set nominal line voltage a bit higher in the microinverters? Or buck the voltage they see down a bit with buck/boost transformer?
Easier, try dialing down voltage created by Schneider.
Playing with my TriPower, for which I need to use a step-up transformer, I was having issues with it disconnecting when seeing full 277V per phase. Backed off a bit with other turns ratios, I think it is working better. Haven't confirmed, may be voltage getting pushed higher.
Since Schneider has transformer output, may also behave that way backdriven. Can you set nominal line voltage a bit higher in the microinverters? Or buck the voltage they see down a bit with buck/boost transformer?
Easier, try dialing down voltage created by Schneider.
GXMnow
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It appears to me that Enphase is using a very aggressive grid stability test. Even when the grid is up here, I se some of my cheaper LED lights flickering a bit when the Enphase iQ7's are producing decent power. And when I go off grid the flicker is much more noticeable. And when the iQ7's go offline, they were reporting "Grid Instability" in the log. Bu the voltage and frequency from the Schneider was solid and well within the correct range. My Fluke 76 meter showed 60.0 Hz and 121.8 volts on each leg, 243.4 from leg A to B at my backup loads panel. 5 of my iQ7's stay producing, always the same 5. The other 11 seem to take turns going offline. The production seems to just fall short of matching my load, so the battery is just slowly discharging, even in full sun. During the last real power failure, I tried messing around with turning the breakers in the Enphase combine off to reset the iQ7 inverters, but for some really odd reason, that caused the frequency to shift down to just 57.1 Hz. That locked out all of the Enphase inverters as a bad grid. To get it back, I had to shut down the XW which was supplying all of my power at the time. When it came back up, it was at 60.0 Hz again, and the same 5 iQ7's resumed producing after 5 minutes.
Enphase pushed a firmware update, and I can no longer change profiles or see the logs.
Enphase pushed a firmware update, and I can no longer change profiles or see the logs.
You might want to check the firmware version on the micros. After the v04.28.xx firmware updates on the iQ7 it appears only profiles with anti-islanding disabled will work reliably when off grid.
You don't have access as the installer?
GXMnow
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Correct.
I had an installer password that got me into the Envoy and I was able to read the logs and set the profile, but after the firmware update where you need the token now, I can only view basic status. I can no longer see the logs or change the grid profile. When I try my installer password now, it give me an unauthorized error.
I guess I can either pay for the Enlighten Manager or take the proper courses on the Enphase web site to get it back.
GXMnow
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Enphase remotely handles updates, but the inverters are autonomous and will just keep making power with no data connection. They only thing I would lose if Enphase shut down would be the Enlighten cloud app that tracks the production. IT would be nice to have a local version of that so you don't need the internet to see what it's doing. It would be easy to be a power monitor on the entire array and see what the production is, but it would not give the data for each panel like I get through Enlighten.
Hedges
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"I can no longer see the logs or change the grid profile."
You've lost the ability to configure them. Was that only available through the web, not something you could do locally?
Of course we also want to be able to read status.
My equipment, SI has a display and I can query and do at least some settings with membrane keypad.
The various SB and the TriPower (also SI) I access either via RS-485 or Ethernet.
I used to use Sunny Boy Control, a box with buttons and display, now use a PC.
There ought to be a way to talk to Enphase locally. It passes through Ethernet, so if not accessible, they are just denying you access.
The Wyze mesh routers I got, had to download app to iPhone to configure it. Later received a spam text from them. Haven't figured out to reset the app password that I've already lost. I think their configuration is local, and web was just to download, but don't know for sure.
You've lost the ability to configure them. Was that only available through the web, not something you could do locally?
Of course we also want to be able to read status.
My equipment, SI has a display and I can query and do at least some settings with membrane keypad.
The various SB and the TriPower (also SI) I access either via RS-485 or Ethernet.
I used to use Sunny Boy Control, a box with buttons and display, now use a PC.
There ought to be a way to talk to Enphase locally. It passes through Ethernet, so if not accessible, they are just denying you access.
The Wyze mesh routers I got, had to download app to iPhone to configure it. Later received a spam text from them. Haven't figured out to reset the app password that I've already lost. I think their configuration is local, and web was just to download, but don't know for sure.
wheisenburg
Independent Solar Consultant
Right now when running on grid my voltage at the controller runs 124-125. When off grid it run around 119. It doesn't seem like, over voltage is the issue. I have heard that Enphase is aware that they have an issue. They supposedly did a firmware fix in their IQ7s and are working on the IQ8s. If that's true it would seem a little pointless for me to waste too much time and money experimenting if the only thing that will really fix it is new firmware.
You need to use a special $500.00 configuration tool to adjust the voltage on the Schneider
wheisenburg
Independent Solar Consultant
I took their courses so I could get access. It didn't take too long. Funny thing is even then, I can only change profiles from the installer tool on my phone. It doesn't work on the website.
Changing profiles is something only the installer should be allowed to do in a controlled setup.
Allowing it from the installer website could make it vulnerable to attacks or hacking.
Put in a ticket to Enphase support and ask them for IQ8 AC coupling support or names of profiles that work with the XW 6848 Pro. A few years back, they had profiles for Tesla, SMA, Schneider and Victron, but that was pre IQ8.
Sorry that it takes so much time for something that should work right out of the box.
Hang in there, pressure is building up on Enphase to fix this.
Allowing it from the installer website could make it vulnerable to attacks or hacking.
Put in a ticket to Enphase support and ask them for IQ8 AC coupling support or names of profiles that work with the XW 6848 Pro. A few years back, they had profiles for Tesla, SMA, Schneider and Victron, but that was pre IQ8.
Sorry that it takes so much time for something that should work right out of the box.
Hang in there, pressure is building up on Enphase to fix this.
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The IQ gateway has no batteries and lasts only 1/2 sec when power is turned off or drops below 60V AC, but it could possibly detect a power fault even if it stays on.
The IQ gateway is the only "port" that can communicate via PLC with the IQ 8's.
Here is something you could try:
- Disconnect IQ8's and shut down the IQ gateway.
- switch off the grid and go to backup mode with some load
- connect the IQ8's but leave the gateway switched off (no communications with IQ8's) and see if the IQ8's lock on to the micro-grid.
- don't feed more than 2-3 kW into the backup grid so AC coupling does not kick in and batteries should not be full.
The IQ gateway is the only "port" that can communicate via PLC with the IQ 8's.
Here is something you could try:
- Disconnect IQ8's and shut down the IQ gateway.
- switch off the grid and go to backup mode with some load
- connect the IQ8's but leave the gateway switched off (no communications with IQ8's) and see if the IQ8's lock on to the micro-grid.
- don't feed more than 2-3 kW into the backup grid so AC coupling does not kick in and batteries should not be full.
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fromport
Solar Addict
Iq8's in case of a cold start for micro grid forming inject DC on the ac lines to the IQ gateway which is installed in the combiner but fed grom the enpower smart switch to start the IQ gateway before a micro grid is generated.
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zanydroid
Solar Wizard
Ah that is cute. Doesn’t that backfeed the neighbors though? I guess it’s ok if like 12v and doesn’t go past the utility transformer either
fromport
Solar Addict
I wrote combiner, but I meant the enpower smart switch.
The IQ gateway though physically in the combiner box is fed from the ensemble. It has the relays to keep the DC contained to do the start-up to micro grid forming. The Enphase system will never feed DC to the grid/utility transformer
GXMnow
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From a PC, you should be able to to the ip address of the Enphase Envoy. Get the token, then sign in as installer and do it on your local network. I was able to do that before we needed the token.
The web site has never worked for me either.
zanydroid
Solar Wizard
Hmm. How does the ensemble have the power to bootstrap this correctly? Or does it have a N.O. transfer relay to grid, with a tap on the grid side of that to power any circuitry needed to join the grid? That feels like it would have the right properties but I'm just shooting from the hip.
GXMnow
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That is an interesting question.
In the Schneider XM-Pro, the transfer relay and inverter are in the same box and it has full access to the battery bank for power. When it is running off grid, it is obviously in free run making it's own 60 Hz (or 50 Hz) from an internal crystal clock. When the grid comes back, it is monitoring both the AC1 and AC2 inputs. Whichever one "qualifies" as good power will then be used as a reference. It takes it a few seconds to slowly shift it's internal generated 60 Hz phase to match the phase of the incoming power. Once they are in sync, it will then close the transfer relay. I have seen it connect in under a minute, but it still abides by the UL rules and won't export power until after 5 minutes, but it will do grid support on the output side during that time delay.
On the Enphase Ensemble, the gateway device must somehow be able to tell the iQ8's how to shift their phase to line up with the incoming grid power before it can transfer back. And it then also needs to not export power for 5 minutes. I would guess the gateway also has some kind of twin power supplies so it can work from the grid side or the local power from the iQ inverters or batteries.
zanydroid
Solar Wizard
Got it. How does the XW-Pro work in a "black start" state with no battery charge?
Potentially if the Enphase has enough interlocks (basic island detection, normally open, ... I don't think normally open as I said above is enough because how would the microinverters know the gateway is actually installed in front of it. this is very tricky and I'm not sure how robust these implementations are required to be per UL and grid standards wrt stupid stuff happening) then the micros can always send some DC down to bootstrap the process. Having an emergency reserve battery simplifies this all greatly.
GXMnow
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The simple answer... It doesn't. At least not on it's own.
If I still had only the AC coupled energy from the Enphase microinverters, there is no self "Dark Start" if the batteries run down below the inverter low battery cut off voltage. The system will be stuck without some form of external intervention. When running off grid, I have it set to shut down the inverter at 30% state of charge (based on the voltage on Li NMC cells). So if this happens, my power will go off and it will stay off. If the grid stays down until after sunrise, I would then have to use my laptop to log into the gateway and change the low voltage cut off to below the battery voltage. Then the inverter can start back up and in 5 minutes, the Enphase inverters can resume making power and hopefully start to recharge the system.
Now that I have added the DC coupled solar panels, it will be able to self start. The DC charge controller will begin charging the batteries as the sun comes up. Once the battery voltage recovers by 1 volt the inverter will start back up and then in another 5 minutes, the Enphase inverters will be able to start making power again.
Another option is using a generator when the battery runs too low. The XW-Pro even has the logic and will output a relay closure to auto start a generator at your set battery voltage limit. But my 25 year old Coleman generator is not stable enough to be an AC source to the XW-Pro, and it also does not have auto start capability. What I did the one time we had a long outage was I had the generator power my refrigerator and some lights directly. We turned off most of the loads on the XW output, and I used my 600 watt charger from the generator to the battery bank to get it back up enough to get us through the night without having the loud generator running after midnight. I am thinking of getting the Signiture Solar Chargeverter to make better use of my old tank of a generator. In theory, it should be able to push over 4,500 watts of charge power straight into the batteries. I just need to get the generator to keep running under that load. When the XW-Pro tried to draw from it, the rpm would dip a bit and it would disconnect from the frequency change. And it would just keep trying every minute or so. The Chargeverter does not care about the frequency, so it should be able to stay charging as the governor settles. But now that I have the DC panels, do I really need it??
zanydroid
Solar Wizard
OK, that sounded as bad as I assumed the worst case would be. Not exactly everyday user friendly. I mean, I would have no problem doing it, and probably most people who DIY can probably follow the recipe. But it probably ought to be written down and tested.
I would assume Enphase is a lot easier, and they managed to lobby/"bribe" UL etc to accept their implementation as code-kosher.
I guess for the DC panels (assuming on RSD) you just need to supply power to the transmitter to close the RSD FETs.
The fast charging could be useful for grey days and peace of mind, also it's a light /smallish piece of equipment. (I've also been theorycrafting whether that chargeverter would be useful. I have a 3kW PSW generator so most likely not unless I want to decouple the AC frequency so that the hybrid can do something clever with it).
I would assume Enphase is a lot easier, and they managed to lobby/"bribe" UL etc to accept their implementation as code-kosher.
I guess for the DC panels (assuming on RSD) you just need to supply power to the transmitter to close the RSD FETs.
The fast charging could be useful for grey days and peace of mind, also it's a light /smallish piece of equipment. (I've also been theorycrafting whether that chargeverter would be useful. I have a 3kW PSW generator so most likely not unless I want to decouple the AC frequency so that the hybrid can do something clever with it).
The IQ gateway needs at least 80V AC on L1 and N to startup. Tried DC up to 30V does not work, would need DC up to 80V but don't have a DC power supply to test it. Have a modified IQ gateway that can run off 5V DC power and can stay on all the time!
In Sunlight-only backup, the IQ8's need to generate 240V on L1 and L2 for the IQ system controller and the IQ gateway to work.
This is no different from buying a 48V inverter or a PV inverter that generates 240V plus an auto transformer to create the N.
The key is just to recognize when the inverter is allowed to do that! For that, it needs to reliably detect that the MID relay is off.
The most likely way to do this is an impedance check. Utility transformers have a very low %Z impedance between 2 and 5. 60 Hz impedance without the grid is much higher and depends on the NFT and the loads, cannot measure it right now.
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Hedges
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Can it be told to shut down at SoC, wait until the sun ought to be up, then make AC again so GT PV can produce? SI has some such features, although I haven't tried to implement.
When it is producing AC and GT PV is producing power, is there a load-shed mechanism to automatically disconnect excessive loads that exceed production and cause SoC to continue decreasing instead of increasing?
Load-shed should also prevent reaching too low SoC. I have one stage (all loads disconnected) but plan for 2-stage which will disconnect large loads sooner.
Could feed a charger, of course, but I would like to rectify AC and feed PV (or turbine) input of GT inverter, AC couple that. This allows SI to remain the voltage and frequency source.
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