I am not sure. I have not done a set up like yours.
On the phase compensation though in a three phase set up, depending one your local regulations if there are any, sometimes set to individual phase halps with power control on each individual phase rather than is being a sum of them.
First you should check, what kind of billing method your grid-provider is using:
If you are billed per phase (Sometimes called Gross-Metering) trying to charge more on phase 1, because you feedin on 2 and 3 will make you pay for the electricity pulled from grid on phase 1. Then, you should set the Multiphase-Regulation to “Individual” to avoid this.
If you are billed in total (Saldating Metering) then you only pay for the “total” that apparently is pulled from Grid. In that case, you can set Multiphase-Regulation to “Total of all phases” and the Multi will then pull some hundred watts from grid on L1 to charge, as long as it can be compensated on L2 and L3 to have a “0 total”.
For the later setup, make sure you use a grid meter supporting saldating-measurements, else the figures in VRM don’t fit reality well.
Also, with a supported BMS being present and reporting a CVL/CCL, you should enable DVCC and set the controlling BMS to your BMS (Most the time “auto” will do that right). The inverter then should just state “External Control” rather than bulk / absorb / etc., if i’m not mistaken.
I am using an EM540 grid meter
→ the meter is saldating / summing all phases (Total of all phases)
ESS multi-phase regulation is set to “Total of all phases”
DVCC is enabled
The BMS is connected via CAN and used as the controlling BMS
(CVL/CCL are provided by the BMS, inverter is under external control)
Grid billing is also saldating (which is the common case here).
From my understanding, this should allow the Multi to increase grid import on L1, as long as it is compensated by feed-in on L2/L3, keeping the total close to zero.
This is exactly what the system does – but only up to about 25 A battery charge current, even though the BMS allows 30 A CCL and no CVL is active.
So my remaining questions are:
Is there an internal charger current limit inside the Multi that applies independently of the BMS CCL?
Or is there an additional ESS control limit that prevents further increasing charge power on a single phase, even when saldating is active?
If there is a documented limitation or a relevant setting, I would appreciate a pointer.
Also compare the battery monitors and which you are displaying. It may be well possible that the battery is already reporting 30A, but the multiplus concludes 25A and that is your current display battery monitor.
And finally, the limit set by the battery is also not a decimal precision thing. It may allow / request 25A even if it’s actual capability is somewhere between 0 and 25A.
Or let’s phrase it like that: it’s a limit not to exceed, not a current request. The actual current flowing is depending on the difference between the battery voltage and the applied chargevoltage, which is suspect to be limited as well through differerent mechanics.
