question

chrish avatar image
chrish asked

AC-coupled Fronius trips out 3 parallel MPii's off-grid

14.4kWh Lithium

3 x MPii's in parallel set up using VE-Config3

Venus GX sees the Fronius via local link

Fronius Primo 5.0 set to country MG50

Primo ramps up to 2.5kW, batts are at 99%, MPiis then trip on overvoltage

I am measuring the microgrid AC frequency - I do not see it change from 50.00Hz during ramp up

I notice there is no mention in the Victron guides of setting any frequency set points in the Primo

I do know that the Primo can track a changing load via frequency/power control seamlessly/effortlessly as I have seen it done with an off-grid Tesla, via frequency control *only* (ie no data cable)

Is there a Victron ref for frequency settings that should be in the Primo?

I am very happy to change these - we do it with the Volt/Watt response for on-grid all the time.

I ASSUME - that I would set the zero-point in the Primo for (say) 51.5Hz

Please confirm or advise of any other refs?

Thanks ChrisH

AC PV CouplingFroniusovervoltage
1 comment
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Murray van Graan avatar image Murray van Graan commented ·

Are you running off-grid, or ESS?

0 Likes 0 ·
2 Answers
chrish avatar image
chrish answered ·

It is off-grid.

1 comment
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Murray van Graan avatar image Murray van Graan commented ·

I think this happens as the battery reaches full state of charge, and then the fronius continues to produce full power which actually causes the battery voltage to overshoot. If this is so, it’s most likely a Victron setting, related to frequency shifting. Which assistants are you using in the Victron?

0 Likes 0 ·
chrish avatar image
chrish answered ·

I missed stating the Assistant, sorry - its "PV Inverter Support". Installed using VE-Config3

The Fronius can track loads using frequency-shifting - I've seen it on a Tesla. It should therefore have no problem at all ramping down before the Victrons go over -voltage.

2 comments
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Daniël Boekel (Victron Energy Staff) avatar image Daniël Boekel (Victron Energy Staff) ♦♦ commented ·

Hi @chrish

Did you check in VRM if the Multi changes frequency as expected?

And if it does, does the PV inverter react to this?

0 Likes 0 ·
Show more comments