Large ESS not hitting grid setpoint when charging from AC-Solar PV

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teemischer asked Jun 26, '24

Large ESS not hitting grid setpoint when charging from AC-Solar PV

Hi Folks,

we just commissioned a rather large ESS installation and it generally seems to work fine, but there is some strange behaviour: It does not regulate exactly to the grid setpoint when charging from AC solar.

System is 12xQuattro 15k with 36x15kWh GobelPower Batteries. Gridmeter is a EM540.

At night everything works fine, System hits the setpoint, so everything is powered from the batteries, not from the grid. BUT: Only during daytime when there is plenty of sun from the AC inverter, the system partially uses power from the grid - which of course is not what I want.

Does anyone have an explaination for why my ESS is doing this?

Or is it just "normal" that ESS can't actually hit the grid setpoint when several Quattros are running in parallel?

thanks,

TM

P.S. There have been some similar problems in the forum before, but none I looked at had a solution. (e.g. https://community.victronenergy.com/questions/234822/multiplus-ii-parallel-ess-not-hitting-grid-setpoin.html)

ess grid setpoint not reached

1719397247623.png (87.9 KiB)

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Answer 1 · 2024-07-01T10:23:11Z

teemischer answered · Jul 01 at 10:23 AM

No answers?

Strange since several people have reported similar problems and no real solutions have been provided here (at least I could not find any) @Guy Stewart (Victron Community Manager)

Short summary again: System with 4 parallel Quattros per phase does not hit grid setpoint when charging from AC PV. Works fine when no AC charging is happening during night. And it always works fine with only 1 Quattro per Phase, no matter what.

So my thinking is: Something is odd when running several quattros in parallel per phase.

Just to add more info:

- Running latest Firmware 552 on Quattros

- Latest VenusOS on Ekrano

- Gridmeter is EM540

- Again: Everything works, just not when charging from AC PV

Let me know if you need anything else.

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Answer 2 · 2024-07-10T09:07:51Z

cel answered · Jul 10 at 09:07 AM

Hi Teemischer

Have you had a look at your grid meter, L3 as the example

50.1Amps for 1590W?

This would be a power factor of 0.13

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teemischer commented · Jul 14 at 03:36 PM

Good catch, thanks, you are right, I did not notice the hickup in this particular screenshot. But it just seems to be bad timing of the VRM communication/screen update only.

The Gridmeter is a EM530 and is running fine, see here.

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