Charging of Electric Vehicles

Charging the batteries of a vehicle (battery or plug-in hybrid) electrically charged from an external power source can occur with or without the use of a physical cable connection: in the first case we speak of conductive charging, in the second, usually, of wireless, contactless or plugless charging that can be distinguished into: stationary (without relative motion between emitter and receiver and with driverless vehicle on board, e.g. a parked car or a bus at the terminus), static (always without relative motion between emitter and receiver but with vehicle in temporary stop and with driver / passengers on board,  e.g. a bus at the stop or a car at the traffic light) or dynamic (with relative motion between emitter, made with a succession of coils, and receiver, then with vehicle in motion).

The conductive charge is the most widespread and consolidated. The inductive one is still limited (for the stationary or static case) or in the experimental phase (for the dynamic case) and there are few applications. In the case of conductive charging, the charging infrastructures, often commonly called charging stations, can be in a private, public or semi-public place, slow or fast charging (depending on the power delivered), alternating current (AC) or direct current (DC).These technologies are rapidly spreading: about 20 ̇000 charging points in the world in 2010, 1.45 million in 2015, over 7 million in 2019. This estimate includes private (assuming one charging point for each electric vehicle on the road) and public (190 ̇000 in 2015, more than 800 ̇000 in 2019), both slow (≤22kW) and fast (>22kW) charging stations. The stock of public charging points is dominated by China by 2020 (about 75% of fast charging points and over 50% of slow charging points), followed by Europe and finally by the United States and the rest of the world to about the same extent. It is estimated that the global annual growth rate of public charging units will be around 33.4% between 2021 and 2028.In Italy, at the end of 2020, there were 19 ̇324 charging points in 9 ̇709 stations, of which about 80% were public and 20% private accessible to the public (however, about 20% were not usable due to technical or authorization problems), with an annual growth of 81% compared to 2019. At the national level, Enel, ABB, A2A and Duferco Energia stand out as the main installers/operators of charging devices, while many other companies stand out as manufacturers, suppliers of systems, components and services.Enel and ABB, for example, have recently made available the 350 kW ultra-fast charging station which, if the conditions of acceptability of this power for a certain time by the battery together with certain environmental conditions exist, is able to recharge a latest generation e-car in 15÷30 minutes. Numerous associations such as ANAE, ANFIA, Assoelettrica, CLASS, Euromobility, Federauto, Motus-E, UNRAE, support electric mobility, while CNR, ENEA, IIT, RSE and some private operators are active in research. Currently the development trends are oriented on the increase in power (and therefore in the charging speed), on the automation of conductive charging and on the development of wireless charging with the vehicle stationary (static wireless charging) or even in motion (dynamic wireless charging).