Solar charging by means of a power manager

[Zwerius]

Hello all,

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:
• consumed power i3
• consumed power E-up
• consumed power rest of the house (appliances, heat-pump, lighting, etc.)
• produced PV-power
and an output (0-10V) to be used for
• controlling the charging power of the cars (only one car is (nowadays)/ will (in the future) be charged at the same time)
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?

 

[bwilson4web]

You might start here: https://www.openevse.com

Bob Wilson

 

[EVMan]

If in case , the net metering is done , on an hourly basis, you can design a system which just shuts off the charge based on the voltage generation.
Set charger to 15 Amp.
Then based on expected generation, keep charge off and on, to match generation on an hourly basis.
This will be much simpler and easier. but slower.

 

[Zwerius]

Sorry to Bob Wilson. I was not able to respond earlier.
I new the website openevse, that you are referring to.
But as far as I understand, the chargers they are describing, are not able to be controlled by a 0-10V input signal.
And also they have a minimum charging amperage of 6 A at 230 V.
And I would like to go lower if my solar panels production minus the domestic consumption is lower than 6A at 230 V.
So what I'm actually looking for is a charger with an input signal of 0-10V controlling the charger between 0 and 2.3 kW (or maybe up to 3.68 kW) on the output .

to EVman:
Unfortunately our metering is realtime, so not on an hourly basis. I had already thought about what you are proposing, but it will not work for us.

 

[alohart]

But as far as I understand, the chargers they are describing, are not able to be controlled by a 0-10V input signal.
And also they have a minimum charging amperage of 6 A at 230 V.
And I would like to go lower if my solar panels production minus the domestic consumption is lower than 6A at 230 V.

6 A is the minimum charging current in the J1772 standard to which North American EV's conform. I don't know whether such a minimum charging current is specified in the European EV charging standard. If so, it might be that the i3's on-board charger (the external device used for EV charging isn't a charger but is an intelligent switch) or the intelligent charging switch won't work at less than the minimum current specified by the relevant charging standard. This might be worth checking before spending too much time trying to control an intelligent EV charging switch at current levels less than the minimum current specified by the relevant charging standard.