How does a Charging Station stop a charge with an EV connected

I'm trying to control a charging station with a raspberry pi. The software is almost finished by there is something missing in the electrical architecture of my CS. The EV is connected to the CS with a three-phase alternating current.

When I connect the vehicle to the CS the charge starts (the charge begins automatically without login with a password or without any kind of authentication).

I want to be able to control the charge, so if I send a request to my Rpi, I want the charge to be stopped even if the car is still connected to the CS, or charge at any time I want with the car still connected to the CS (stop the current between the CS and the EV)

How could I do that? I was thinking of adding breakers between the CS and the connector, but how could I control breakers from my Rpi? Or are there another electric components who could this job? I feel I am missing something in the electrical architecture but not sure what it is.

• How do you control the charge based on the state of charge of the battery? Commented Aug 5, 2022 at 8:02
• Note, cross posted here: electronics.stackexchange.com/q/630066/152903 Commented Aug 5, 2022 at 8:28
• Well I don't control it yet, I want to control the voltage given to the car first. After that I will see how to get the SoC of the EV Commented Aug 5, 2022 at 8:34
• "I feel I am missing something" You are but experimenting with high power 3 phase power circuitry is not a safe way of building up your missing expertise. What are you trying to achieve by controlling your charger? Can this really not be done with existing commercial products? Commented Aug 5, 2022 at 10:15
• @CarlWitthoft Actually, this is only true with DC charging stations ("fast chargers). Single phase AC (and I assume 3-phase) charging stations use a pilot signal from the station to the car. This is a square wave with varying duty cycle to control how much amperage the car is allowed to draw. There is also a protocol where the car connects different resistors across the pilot signal to control the application of AC power to the car. Commented Aug 6, 2022 at 6:23