Hi, I have a MultiPlus-II 48/5000/70 GX in L1, running ESS, with 16A current limit in a 230V three-phase grid system. We have AC coupled PV. The unit is parallel with house loads, with nothing in the AC outs.
The PV and grid data is sent to the unit via MQTT. We have a slow measurement from our grid smart meter’s P1 port, which gets refreshed every 10s. Home assistant handles the data and sends it to Victron, but this does not appear to add much additional delay.
Here is a snapshot of the invertercharger load and grid power. As you can see, the Multiplus-II oscillates quite a bit. Is there a way to adjust the Multiplus-II unit’s regulation PI parameters or such to correct this behavior? My background is in industrial controllers, and to me this looks exactly like a control loop that is tuned too tight. I am aware that this sounds like the usual nail and hammer comparison, but anyway.. My Multiplus-II is running FW 556. Thank you.
Peak shaving seems to be set to “Above minimum SOC only”. I have 16A set as grid current limit thru VEConfig and later VRM as well. Should I add limits to the peak shaving function as well, since it seems that it cannot be fully disabled?
ESS is designed for 1 Hz update rates, and you are giving it a 0.1 Hz update rate.
I believe your intuition is on target here. There is also a “fast loop” setting that is used for up to 10 Hz updates for the Victron and EM540 energy meters. Sounds like you need a “slow loop”.
Setting multiphase regulation to “individual phases” might provide different behavior (though the efficiency will be less). No never mind, you are single phase, sorry.
I have a similiar grid metering setup, but I get updates every 5 seconds and I’ve never had oscillations longer than a minute or two, that visibly decreased. From reading other posts here, my gut feeling is that 10 seconds is just too slow for the control loop to be stable.
Thank you both for your assistance. I have tried to get faster updates from my smart grid meter. Some smart meters apparently output data faster if you use the DTR pin, but mine just seems to block sending if DTR is low. Otherwise it retains its 10s refresh rate.
Update: I was able to try the RefreshTime remotely. I modified the grid dbus driver to publish the RefreshTime, and verified with MQTT explorer that it is present on the driver data set.
