Hi There,
Just wondering if anybody can shed any light on this situation. An ESS system, connect to the Grid in Australia with grid code Australia A. No AC coupled PV, just DC coupled.
When running loads on the AC output, the system is drawing 50% power form the grid and 50% from the battery, even when the battery is 90% full.
System is 3 phase with 2 multiplus-ii 48/5000 on each phase.
Are you required to have Multiphase Regulation set to Individual Phase for regulatory or metering reasons?
Total of All Phases is much more efficient as noted in the documentation.
I don’t think the regulation needs individual phase regulation (at least not in my case in Australia) as net metering is used.
I think “Multiphase regulation” should be set to “Multiphase”. It may not fix the problem but needs to be set in the first instance for it to work correctly.
Thanks for all of the replies, everybody. Yes, it does have the “Inverter AC Output in use” option enabled, this just displays differently in the new remote portal UI.
I have changed multiphase regulation to total of all phases, it makes no difference.
When there is is some kind of restriction on current available form the BMS, I have seen the ESS do something similar, but that doesn’t appear to be the case in this instance.
Do you mean you have 3 multiplus one per phase?
6 inverters total, 2 inverters on each phase
Do you have loads before the inverter?
Can you post a screenshot of actual loads for your system size?
The 400w load screenshots are not helpful to show the 50/50 issue.
Why does it make a difference what the size of the loads are?
When the battery SOC is above the set point, it should only draw from the grid for loads over the capacity of the inverter.
Small measurements on the systems are inaccurate due to tolerances, larger ones are more helpful for troubleshooting.
To add on to what nick is saying → with parrallel systems particularly, you need to test current sharing on ac and out for balance.
That’s a good point, I have come across the issue in the past when the output ac cables are too large and it draws too much from one inverter. I will check with the installer on the cables used. Still not sure that would produce this result though…
