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greendovefarms asked

AC Coupled PV Fronius 8.2 with a Quattro 15kv too slow to throttle

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. (3 to 5 min)

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 ?

MultiPlus Quattro Inverter ChargerFroniusAC PV Coupling
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Alexandra avatar image Alexandra ♦ commented ·


How are they connected data wise?

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greendovefarms avatar image greendovefarms Alexandra ♦ commented ·

There is no data connection to the victron system

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Alexandra avatar image Alexandra ♦ greendovefarms commented ·


So how does the Victron system know there is a Fronius in the system?

Set up the comms. Then the victron will know what is being produced. The Fronius should also be set for comms through the data card.

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greendovefarms avatar image greendovefarms Alexandra ♦ commented ·

My reply before was incorrect

The fronius is connected to the Lan as is the GXCC and the Quattro

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Paul B avatar image Paul B greendovefarms commented ·

The Quattro should be connected to the CCGXs VE-BUS. Port

the CCGX is then also connected to your router via its ethernet port,

I presume the fronius is connected correctly and if so have you also setup the PV inverter options in the CCGX


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2 Answers
Paul B avatar image
Paul B answered ·

I have also had this issue, and I agree that the victron units are too slow to react. and thus the batteries get overcharged or a high battery voltage occurs.

I think that this hz control was designed in the Lead Acid days and its not been updated for the new LifeP04 days

from what I have found out is that

1. the battery bank size is two small to absorb the extra time it takes for the quattro and the multiplus units to adjust the Hz

2. I ended up installing a contractor in my grid tie units output to the W1 relay and then installed a assistant to turn w1 off depending when battery voltage was say 55v

then another assistant to turn on back on when battery voltage dropped to 54v

its a bit of a cluge, but this just makes the grid tie units think there has been a power failure and they turn off, thus the quattros charging then stops.

It would be nice to see the hz respond more quickly but at the moment I dont think its going to happen

I tired heaps of different ways to get it to respond better. the only way that worked is what you have done reduce the charge voltage. and thus when the overrun occurs then there is enough buffer in the battery to absorb it.

However make sure you are on the latest 482 firmware as you never know when they may adjust it to work better.

Well thats my thoughts hope it helps

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greendovefarms avatar image
greendovefarms answered ·

At the moment the ac solar does the bulk of the work to charge the storage and the dc couple finishes the last 10or so ah drawn from the system to fully recharge, seems to work the way it is, it has been alto more stable since I have added another 10kWh of storage giving 20kWh total

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