How about doing this with existing technology? OpenEVSE and OpenEnergyMonitor...
OpenEVSE will already monitor and report consumption and track excess solar power setting the charge rate accordingly.
OpenEnergyMonitor Emonpi has 2 current measurement CTs. Place one on your grid input and the other on your solar output. OpenEVSE will report consumption to OpenEnergyMonitor every 30 seconds.
In my country (the Netherlands) we nowadays are having a system where you can supply PV-power to the grid and take power from the grid for the same rates (it is called : "salderingsregeling").
However this system will come to an end in a few years.
From then on, you will be paying about € 0,20/kWh for what you will be using from the grid and you will be getting payed around € 0,06 for power you are supplying to the grid.
So it is becoming more important to use a maximum of the produced solar power directly (so whithout using the grid as temporary "storage").
We have a net zero energy house. See:https://geen-energierekening-meer.weebly.com/ (in Dutch).
This is including heat pump for heating and DHW and the consumption of two electric cars, being a BMW-i3 and VW-E-Up.
I want to build a power management system by means of a PLC, with following inputs:
and an output (0-10V) to be used for
So for this I will need a charger from which the charging power can be controlled by means of a 0-10V input signal.
The chargers that we are using now have a maximum power of 2.3 kW (10 Amps at 230 V). Which is fine for us.
Does anyone know of a charger that I could build, using this 0-10V input signal for powercontrol?