Method and apparatus for controlling the authorization of charging processes of electric vehicles

The invention relates to a method for controlling the authorization of charging processes of electric vehicles. According to the invention a control unit between a main terminal and a plurality of charging sockets is provided, which are connected via a power line to the control unit. A loaded vehicle is connected to one of the charging sockets and the total charging current is detected, which is led by the main port on the control unit to the charging sockets. Charging current requests are received from each of vehicles connected to the charging sockets to the control unit and the total charging current is compared with the sum of the charging currents that are reported to vehicles that are connected to the charging sockets. The charging sockets are switched off when the total charge current exceeds the sum. The connecting a loaded vehicle comprises transmitting an authorization information from the vehicle to the control unit. The authorization information is compared by the control unit with a list of eligible vehicles to verify the validity of the vehicle. The transmission of requests and charging current of authorization information is provided by modulating an AC signal on the power line, wherein the AC signal representative of the authorization request or the charging current request. The invention further relates to a control unit for carrying out the invention.