All, i have a new victron ESS with pylontech and 3x5kw Multiplus, plus (independent) production.
For several reasons i want to control the system externally.
Nothing connected to the power output. No meter connected.
This works well most of the time, and the actual power reported on "Grid Power (modbus regs 820..) is closely matching the setpoints set via MQTT and validated by reading from (vebus ID) registers 37,40,41.
However, there are times where the multiplus seem to do what they want. I might give instruction to charge the batteries with 4kW each, but one of them "produces" and the battery discharges ..
Often in that situation also the "AC Input" tile does only show a bar and no more data.
I have to say i have some 5kW+ water pumps which may kick in and stop at any time, which is of course not a really stable load .. as they are (like everything) on the "grid" side of the inverters, this is handled by the public grid, providing power until the multipluses eventually provide the power.
Questions:
- Are there any accessible registers which i should look at in this situation ?
- is there a limit how often a setpoint update should happen - over MQTT, over Modbus/TCP ?
- how fast will/should the Multiplus usually switch from new setpoint to "do" what is asked for ?
- from charging the battery to generating output power ?
- from 4kW charge to 1kW produce ?
- anything i have wrong in my thinking ?
Happy to get some logs, showing the modbus read responses on the AC Input vs Setpoint values, where one can see that they seem to be "disconnected", at other times, they are following by few W ..
Johannes
