I am problem with my Victron ESS system and would appreciate any advice or experiences with similar behavior.
System configuration:
3 × MultiPlus-II 5000 in a three-phase configuration
Ekrano GX
3 × SmartSolar MPPT charge controllers
4 × Pylontech US5000 batteries
The system normally works as expected, supplying household loads from the batteries and regulating grid power according to the configured grid setpoint.
It frequently happens that one or more MultiPlus-II units start vibrating or humming noticeably. At the same time, grid power import suddenly increases, even though the household load does not appear to have changed significantly. After some time, the system returns to a more stable operating condition.
I have observed this behavior with different grid setpoints, approximately −100 W, −500 W and +200 W. Changing the setpoint does not seem to resolve the problem.
I use the internal MultiPlus-II energy measurement to measure power imported from and exported to the grid, configured for individual phase measurements.
Would it help to use an independent external energy meter, such as the Victron VM-3P75CT, as the grid meter for ESS?
Has anyone experienced similar behavior, particularly vibration occurring at the same time as a sudden increase in grid power import?
Thank you for any suggestions or advice based on your experience.
The grid setpoint value is set to 0 W in both the video and the screenshots.
You can clearly see in the 2nd image that the system has switched to “Passthru” mode. This shouldn’t normally happen and may indicate a communication problem with the BMS. In this case, the Multis pass through the required current and you end up drawing power from the grid.
It would be interesting to see some other charts from the same time … Have a look at your widgets and see if you can find any battery data that might be useful to us …
Do you have Multis with a jack plug on the external current sensor, or the newer version with a clamp?
Could you post your configuration file here as well …
Why are you using an ESS system and also an assistant to switch off AC1? Is that supposed to be an emergency shutdown?
I’ve had the humming from the Multis too ever since I set Reactive Power to “Q as a Function of Input Voltage” instead of “fixed Cos Phi” in the “Grid” section … though I’m using the German grid code.
