An electric vehicle charging station is a charging station specially designed for electric vehicles, which is usually based on a fuel pump. Colloquially, it is therefore sometimes referred to as an electric charging station or charging station. Official documents refer to charging points, although by definition only one vehicle can be connected to a charging point at a time. The expansion of the charging infrastructure is seen as an important instrument for promoting electric mobility.
Charging stations can be open to the public or the public and, in the simplest case, consist of a socket where the vehicle can be charged via a cable connection and a charger (conductive charging system for electric vehicles). There are chargeable, free and club-operated charging stations for their members. Corresponding fast-charging stations are primarily intended for long-distance traffic in order to give users of electric vehicles the opportunity to charge their vehicle with high performance in a short time. For daily commuter traffic, on the other hand, where usually only a few kilowatt hours of electrical energy are consumed, a normal socket is usually sufficient for charging.
Today’s accumulator cells can only be charged with direct current. The term direct current and alternating current charging describes the form in which the electricity is fed into the vehicle.
With AC charging, the electric car is connected single-phase via an in-cable control box (ICCB) or directly via a charging cable to a household socket and thus to the power grid. This means that only charging capacities <3.6 kW are transmitted permanently. 16.2 kW to 3.6 kW can be transmitted permanently via a wall charging station with a type 2 plug. Depending on the provider, AC charging with up to 3.6 kW is referred to as standard charging or emergency charging. The charger is integrated in the vehicle. The on-board chargers in some electric cars are sometimes limited in their power to charging at standard household sockets (3.6 kW) and are not able to charge in three phases. Vehicles with the Type 1 charging connector only charge single-phase.
Image source: https://www.sciencedirect.com/science/article/pii/S2352484722017346
With DC charging, DC current is fed directly into the vehicle from the charging station. It is provided via a powerful charger in the charging station either from the mains or from large buffer batteries at solar charging stations. There is only one battery management system in the vehicle that communicates with the charging station to adjust the amperage or switch it off when the battery is full. The power electronics are located in the charging station. Because of the powerful charger, the charging stations are relatively expensive. DC charging enables very high charging capacities due to the external charger. This leads to short loading times.
With regard to the charging stations, there are already further concepts. A dense network of charging stations with high charging capacities would make large traction batteries in electric cars superfluous. Traction batteries with high cycle stability and medium charging capacity would then be sufficient.
There are also concepts to allow electric cars to interact with the power grid using vehicle-to-grid technology and thus use them as electricity storage and suppliers of ancillary services. Electric cars as well as plug-in hybrids can be charged in the power grid when there are (renewable) surpluses and feed energy back into the power grid when there is a lack of energy. In this way, electric cars could provide a large part of the controllable energy consumption.