I try to optimize my energy usage in my home automation.
Therefore I'm reading Grid L1,L2,L3 (via EM24) + Battery data + Victron PV + External PV + Critical laods via Modbus.
That also works fine. The only problem is that AC Loads (AC-Lasten) seems to be calculated. Or do I oversee the correct Modbus register?
I tried to calculate the AC-Loads on my MP II 48/3kV in the following way (what is never precise):
First I need to know if the Battery is charged or discharged:
1. If Battery usage > 1 (postive) -> charging: Set "usable Victron PV power" to "PV Power Victron - Battery usage"
2. If Battery usage < 1 (negative) -> discharged: Set "usable Victron PV power" to "PV Power Victron + Battery usage * (-1)"
3. If "usable Victron PV power" > 2550 Watts then hard set to 2550 Watts (because I limited my Inverter to 2300 Watt net to feed in)
4. Calculate "usable Victron PV power" = "usable Victron PV power" * 0.9 because only roughly 90% of the Watts coming from battery can be really used by the Inverter (net to grid)
Secondly I tried to get the total usage in the System:
AC Loads = "usable Victron PV power" + "External PV Inverter" + "Sum of Grid (EM24)" - "Critical Loads"
The problem is AC loads are never correct calculated. I have sitautions where reality in Remote Control shows 300 Watt on AC Loads, but my calculation is even negative (e.g. -150). Then there are other situations where it fits roughly.
So any best practices to calculate AC Loads or is there even a modbus register that I have not seen?
