Inductive Charging For Electric Cars: Green Vehicles Articles: Eco20/20

Inductive Charging For Electric Cars

Providing customers with an easy to use product is one of many goals for electric vehicle manufacturers; and simplifying the charging process has been a high priority on the list. Until now, electric car owners have always either connected their cars to a cable for charging or swapped out their batteries at designated electric car stations. But the upsizing of inductive charging technologies is redefining the electric vehicle charging process, and may someday lead to redesigning the roads.

The Basics of Inductive Charging

* Inductive charging is a type of short-distance wireless energy transfer, as opposed to direct-wired energy transfer which is called conductive charging. Inductive charging uses an induction coil in a base station to create an alternating electromagnetic field between a charging plate and an inductive pick-up coil in a device (in this case, a car). When the electricity is transferred from the energy source a voltage converter converts the alternating current of the magnetic field to direct current, which is fed into the car's battery pack.

Automobile Makers are Testing the Concept

* Rolls-Royce Motor Cars has chosen HaloIPT to supply the induction charging technology for the 102EX, an electric test vehicle they've developed to explore alternatives to internal combustion for the first time in the company's history.

o HaloIPT has previously conducted a trial of wireless charging with buses in New Zealand and Milan. The company's UK development partner, Arup, has fitted Citroën electric cars with receiver pads on their undersides, and demonstrated how they could be recharged by parking over a transmitter pad in the road. Arup, is part of the Coventry and Birmingham Low Emission Demonstrators (CABLED) Consortium, which is responsible for the UK's largest trial of electric vehicles.

* Toyota recently began working with Massachusetts-based WiTricity on a wireless charging test project that WiTricity calls 'resonance technology', which they claim is more efficient than normal induction-based charging

o According to WiTricity, their specially designed power sources and capture devices are able to transfer power over distances well beyond the size of the source device by taking advantage of magnetic resonance, which they describe as "the natural frequency at which energy can most efficiently be added to an oscillating system".

* Nissan intends to use inductive charging for their Zero Emission Vehicle (ZEV) electric car; but the company is also developing fast-charging facilities for shopping lots and service stations.

* Volvo and Flanders' Drive, an automotive testing and development group sponsored by the Flemish government, are partnering to test an induction charging system on some of Volvo's C30 electric vehicles. (The C30 vehicles currently use a charging plug.)

Industry leaders hope to someday bring this technology onto the motorways. They envision a dynamics in-motion system, consisting of a series of plates laid under the surface of designated lanes that would allow motorists to charge as they drive. Such a system would solve the driving range issues faced by electric vehicles today, and researchers believe it's technologically possible; but skeptics don't see it as an economically realistic goal and the concept is a long way from development. As it stands, no one has even ventured a guess as to how much it would cost, how long the designated lane would have to be, or how fast a battery could be recharged.