-
How its expected to work
I expect the system to start feeding in to grid when the battery is full and there is more PV available then the loads are asking for. -
How it doesn’t work as expected
The system does feed in to grid from battery, and from Solar also normally. But when DESS has set the SOC goal to 100% because the grid costs are not very high (but far from negative), the Multi RS units stop producing from the PV array when the battery is full, and all the loads are being fead from grid, even when there is plenty of PV power available (the sun is directly on the PV array). -
Details on the system
3-phase system with 3 Multi RS Solar and a Cerbo GX with energymeter for measuring the grid, and all loads on AC-out of the Multi’s.
Cerbo running on fw version v3.60~25. The Multi’s on v 1.20. All newest at this moment. -
What you’ve already tried to make sure its not a setting or other issue:
On other systems you can set (or unset) the option to feed-in excess DC-coupled PV to grid. But on a system with only Multi RS solar units I can not find the topic “feed in”, and with that, the options for AC-coupled PV and DC-coupled PV.
Does it behave the same on a production release?
I will try that today, if there will be enough sun.
Hello did you test it aleady I have exactly the same on this hardware 3-phase system with 3 Multi RS Solar and a Cerbo GX without energymeter for measuring the grid, and all loads on AC-out of the Multi’s.
Cerbo running on fw version v3.60~46. The Multi’s on v 1.20. All newest at this moment.
Yes, but that did not help. I had to enter the grid code again in the Multi RS’s. After that the system started to feed back to the grid again.
And I am using the newest bèta firmware again, and everything is still working fine.
The re entering of the grid code may be needed after a firmware update in the Multi RS’s?
And I discovered that the system did not use the measurement from the grid energy meter any longer. For me that is not a problem because all of the loads are on AC out connections.
Does re-entering the grid code in the Multi RS units allow excess solar on the AC out to be fed back to the grid again when the batteries are full?
Had the same problem. Only solution for this is to activate the DVCC
I had to re-enter the grid code in the Multi RS’s in Victron Connect app. I do not have DVCC activated.
After re-entering the grid code the DC PV power is being fed to grid again when battery is full. AC PV should be fed back to grid to. I can not check because I do not have AC PV.
Did you check the settings in the Cerbo for feeding back AC coupled and DC coupled Pv power? In menu “settings,system setup,ess,grid feeding”.
Do you have access to this path? In the Settings > System setup > ESS tab, it says the ESS settings are located under the specific RS device tab. However, I don’t see a setting called “Grid Feeding” there.
You’re right. I am sorry. I was looking in another system. A system with Quattro’s.
Did you check the button “allow feeding” on the tab “settings,grid” for the RS in Victron Connect?
Yes, that option is enabled. I am able to feed back to the grid, but not more than 22A, which matches the maximum inverter power of around 5000W.
However, when I also have AC-coupled solar, that extra power is not fed back. Instead, the battery discharges less, so the total feed-in stays limited to 22A, even though I’ve set a higher AC current limit.
For example, if I discharge the battery at 5kW, have 3kW AC-coupled solar, and my AC-out loads are 1kW, the AC-out shows -2kW. You’d expect the system to feed 5kW (battery) + 2kW (from AC-out) into the grid. But what actually happens is that the battery only discharges at 3kW, so the total feed-in stays at 5000W.
This happens even though I set the inverter setpoint to -9000 and the grid setpoint to -9000.
I thought your issue might have the same cause, which is why I asked. Importing from the grid is not a problem, by the way—I can easily import 8000W to power the loads and charge the Victron battery with 5kW.
If anyone knows how to feed back more than 5000W / 22A, I’d love to hear it.
Yes, I do have those settings in the VictronConnect app. You can see that it correctly limits AC import to 40A, but when exporting, it’s limited to 22A. When I enable support for energy meters, it also shows 40A there. But I don’t have an energy meter, so I’ve disabled that option.
You need the external energy meter, otherwise you won’t be able to go above 22A
Thanks! Do you happen to know why that is? Why is the external energy meter needed for exporting, but not for importing? The internal current sensor should be able to measure that too, right? It can measure the incoming current, so why not the outgoing?
It doesn’t know how much current goes through the grid without the external current sensor. Therefore it will always limit at grid current limit. Even if the grid current is a lot lower due to PV power
Yeah, that’s exactly what I want too. I want it to limit based on the 40A I set on the AC-in of the Victron. But right now, it limits export to 22A.
In my setup, all loads are connected to AC-out, so the Victron’s AC-in is directly connected to the grid. That means the AC-in current sensor should measure the same as an external energy meter would. So it seems like the energy meter shouldn’t be necessary in my case.
What Grid code do you use? I know that the German grid code limits export to 22A, try to use the Europe grid code.
I’m using the European Grid Code. May I ask where you found that the German Grid Code limits export to 22A? Maybe there’s something similar in the European code? Or perhaps, since Germany is part of Europe, this 22A limit has been set for all of Europe through the European Grid Code?
I saw it in a german Youtube video. But the grid code “Europe” should be correct as I am experiencing no issues under this grid code.