Hey!
Simple question but haven't found the answer yet...is it possible to combine a Victron Phoenix Inverter 48/5000 with a Fronius Primo 5.0 for an AC-coupled PV installation? I have no need for a Victron charger as I am off-grid.
asked
AC-coupled PV. Off-Grid. Fronius PRIMO with Victron Phoenix?
What I mean is...I know the inverters/chargers support this. Do the inverters as well?
I would not think so because the Phoenix does not have any charging capability. it would not be able to accept energy in from its AC-OUT because it will not be able to put that energy into the battery.
Do you already have the Phoenix Inverter or are you thinking about buying one?
If you are still thinking about it, why not consider a MultiPlus? They are not very much more money and it will give you the opportunity to charge from a generator if you need to.
I'm sure someone who actually knows the answer will respond, it's the weekend / family time etc.
Hey! I understood that the inverter is bi-directional? At least it is on the multi and quattro right? And that it thus would be possible to charge the batteries via the AC-out on the Victron, using the power from the ac-coupled fronius?
I am considering my options. Have one inverter, but need a heavier one. See my other question!☺. I also have a solar charger so I would use that to DC charge as well. As i do not need a charging connection, i was wondering of just getting the 48/5000 instead of the 48/5000/70.
On the one hand, there is no charging capability, so the 1:1 rule is broken, if the grid is suddenly lost, but this is an off-grid set up, so that doesn't apply.
I have a gut feel that during a heavy load fluctuation the Fronius still needs a release valve while transitioning, but the one has to wonder what happens in the perfectly allowable straight grid tied situation with no Phoenix?
So the way I see it, it boils down to the ability of the Phoenix to regulate itself and the Fronius during sudden load fluctuations.
I too, am interested in this answer.
Hey you all! Thx for the answers! Great community!
I was hoping to use a 48/5000 with an AC-coupled Fronius. Was hoping the bi-directional Victron inverter would be able to charge the attached battery bank, i.e. through the inverter itself, using the power of the Fronius. If the attached battery bank gets fully charged and in the absence of loads, the victron inverter should do the frequency regulation thing to power down the fronius. Since I plan to also attach DC-coupled PV to the battery bank, I would not need an AC input on the Victron. And thus would be able to save a bit of money getting a 48/5000 instead of a 48/5000/70. I would prefer to get an AC-coupled PV fronius Primo 5.0 because combined with the 48/5000 this would give me the possibility of 10 kW AC-loads, 5kW from the Fronius and 5kW from the Victron (on sunny days when the Fronius is giving full power and the Victron has enough battery power). If this is not possible with a 48/5000, I'll get a 48/5000/70 although I'll never use the AC-input.
Hello Stijn,
I have just been told by others in Victron that I was wrong, and will update my Answer. You CAN use the VE.bus inverter model in this way, as it still has a bi-directional torroidal transformer that can invert or charge. It just does not have an AC-input.
This feature will need further documentation.
Hi Stijn,
I have learned something from this question - thanks for asking it and my apologies if I have confused you. I now have confirmation from Matthijs.
You can use the Pheonix VE.Bus Inverter models with an AC-solar inverter. The units toroidal transformers can operate bi-directionally on the AC-output.
The current documentation says "In both grid-connected and off-grid systems with PV inverters installed on the output of a Multi, Inverter or Quattro,". I will work to improve this an further clarify.
You will need to override some settings in VEConfigure when setting up the unit, as this is not normally used.
Guy, this is very interesting.
So it follows then, that when the batteries are charged the inverter can still control the PV inverters output via frequency shifting in general, and via protocols if Fronius specific?
And normal 1:1 rules still apply.
Hey! No worries about confusing me. The problem I have is that I do not have access to the VE software and so couldn't check myself. And before buying all this expensive equipment I had to make sure that it would all work together as intended. So thank you for getting into this for me. Much appreciated! Further on, it seems more people got something out of this!
Hey all...on more question...
https://www.victronenergy.com/live/ac_coupling:start#rule_definition
In the example given on the page above, a heavy load is switched off that was powered by both the PV inverter and the Victron. This will cause an AC spike on the ACout of the Victron as the frequency shifting is fast but not fast enough. The ACspike on the ACout will cause a DCspike through the bi-directional inverter as the Victron cannot modulate the pulse widths fast enough. This might damage the batteries if they are (almost) full. How then exactly is this all remedied?
This is an issue, and one reason I myself prefer DC coupled solar.
The impact is all proportional.
If the batteries are very large; if the AC solar array is very small, if the Victron Inverter is very large - then it is all absorbed nicely.
HOWEVER
If the batteries are very small, and the AC solar array is very large and the Victron inverter is very small - then the impact could lead to operation outside of spec and shutdowns.
Depending on battery technology and self protection, you may have other issues.
Depending on the nature of the load, you may need to adjust the design of the system, or it's configuration so as to reduce the charge voltages and leave additional voltage headroom in the system.
I had a customer with a troublesome tree, and the there would be a periodic 'sunburst' as the sun came out from behind it and caused a big and predictable spike in solar as the MPPT couldn't react fast enough. We had to reduce the voltage and usable capacity of the system.
I have experienced the same issues explained below,
Quattro 15kv, Fronius Primo 8.2 with 7900w PV, 3 x Kilowatt labs 3.55kw modules, 2300w PV running thru a 150/70 Victron charge controller, Off Grid MG50
Maximum charge voltage of the modules are 54v and if they are fully charged and the AC PV is supplying 4000w with 4000w Quattro loads and the loads drop off, The system is way too slow to react in shifting the HZ to throttle the AC PV.
I had to reduce the max charge voltage of the modules via the Quattro to 53v to allow a full volt of slow down time. Seems to be working at the moment.
Is there any way to increase the speed the Quattro ramps up the HZ to throttle the Fronius?
(I’m using the standard settings in the VE configure assistant to control the Fronius)
Should I Adjust Victron HZ shift values in the inverter to suit the Fronius values?
What are the correct Fronius Primo 8.2 inverter HZ shift values ?
EDIT - This answer has been edited to remove the factually incorrect parts to prevent any confusion.
You say you have no reason for a charger because you are off grid?
Being off grid is EVERY reason to have a charger.
You can also use the AC-input charger function of the Multi to charge the batteries from a petrol or diesel generator. An essential function in a reliable off-grid system.
