Both entities cooperate in the development of a novel inductive charger for trams which does not need ground-vehicle communication

The transparency energy is produced through an electromagnetic field.

Thus, the company has a charging alternative for cities which is more comfortable, safe and has less visual impact.

The wireless charging methods are increasingly more common in the automotive and mobile telephony sectors, where many manufacturers bet on devices which do not require wires or plugs to charge the batteries of electrical vehicles and smartphones. This type of chargers, called inductive, transfer the energy from the issuer to the receiver through an electromagnetic field induced in between.

Public transport has been the last one to benefit from this method. The railroad company from Guipuzcoa CAF and the Technological Centre IK4-IKERLAN have developed a wireless charging system of trams which does not require, unlike the conventional methods, any type of direct electrical contact, such as catenaries, wires or plugs, to charge train batteries.

The novel device comprises two coils which are in charge of inducing the electromagnetic field which enables the transfer of energy. The first coil, called primary or issuer, is buried underground, where it remains connected to the electrical network, in areas where the tram makes its stops. The second coil, called secondary or receiver, is installed at the bottom of the train and carries a small converter.

Thus, when the tram reaches the area where the primary coil has been placed, this one generates current and produces an electromagnetic field which induces another current in the secondary coil, transferring the power which charges the train batteries. This energy transfer is safe by nature and does not affect passengers, since it can only be activated when there is a tram on top.

“Thanks to this development, we can take advantage of the stops the tram makes along its way to charge the batteries automatically, with no need to perform any action by the driver, such as the moment we wait for a traffic light, while passengers get off at a stop or when parking in the own parking space,” as explained by Irma Villar, in charge of the project in IK4-IKERLAN..