Individual phase regulation does not maintain grid setpoint

DIY
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1

I’m seeing odd behaviour with a three-phase MultiPlus-II setup when using “Individual Phase” regulation mode.

My setup:

  • 3-phase MultiPlus-II system

  • Grid setpoint configured to 30W

  • VM-3P75CT energy meter configured in “mode”

  • Solar inverters connected on AC-out on L2 and L3

When I switch “Multiphase regulation” to “Individual phase”, the system is no longer able to maintain the configured grid setpoint. Instead, the import/export per phase starts deviating quite wildly from the setpoint, and the sum of all phases combined as well.

It almost looks like the MultiPlus units stop taking the VM-3P75CT remote energy meter into account in this mode, and instead start relying on their own internal measurements. I’m not fully certain, but that is what the behaviour suggests.

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When I switch back to “Total of all phases”, the system immediately behaves correctly again and is able to hold the configured setpoint properly.

total-of-all-phases
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Previously, the behaviour was that each individual phase would settle around ~30W, which seemed reasonable.

I first noticed this on v3.80~21 beta, but after reverting back to v3.72 stable I’m still seeing exactly the same behaviour.

2

You mean 3.72? 3.73 is in beta.
As it is not beta specific, I will relocate this to the main section.

3

Yes indeed. 3.72 shows the same behaviour.

4

If you lower your setpoint to 0, do the individual inverters respond?
It looks like it is trying to maintain the setpoint on each individual phase.