Under the e-tron name, Audi has been resolutely driving electrification of the powertrain. Audi’s technology matrix contains numerous options to create an ideally tailored solution for each customer The matrix begins with the new 48-volt onboard network enabling highend technologies such as the electric biturbo in the RS 5 TDI concept, continuing via hybrid and plug-in hybrid models up to sports cars and future top-of-the-line models with pure electric traction and high ranges. For these designs to be successful, the charging process needs to be both simple and convenient. The Audi wireless charging (AWC) system fulfills both of these demands. All it requires is that the car be parked over an induction plate inserted into the ground which then proceeds to charge the battery.
The way forward: plug-in hybrid technology
For Audi, plug-in hybrid technology is an excellent path to the mobility of the future. Cars using two powertrains flexibly depending on the situation bring together the best of both worlds, the combustion engine and the electric motor, achieving range, sportiness, safety and everyday convenience as well as local avoidance of emissions.
The interaction of the combustion engine with an electric motor opens up new avenues for engineers in that it enables deliberate shifting of load points to achieve an operating situation where the combustion engine runs at low consumption and low emissions. In urban traffic, the electric motor enables local absence of emissions. This is a requirement in many urban areas of the world and thus especially important.
Since the launch of the A3 Sportback e-tron* last year, Audi has been successful in plug-in hybrid technology. This technology is now being continually deployed throughout Audi’s model range with the medium and upper segment next in line. Audi is committed to introducing a new e-tron model every year. At the same time, Audi is working on purely-electric vehicles with high-capacity batteries and powerful motors requiring no compromises in terms of range and usability.
Refueling in maximum comfort: Audi wireless charging
Mobility for the future as being developed by Audi has many aspects. One of them is convenient supply of electricity for e-tron models. Audi has been working intensely on contactless charging via induction, known as Audi wireless charging (AWC).
In AWC technology, energy is fed from a plate in the ground which is connected to the power grid and can sit on the tarmac or be embedded in it. A primary coil and an inverter (AC/AC converter) are integrated into this plate. When the coil becomes active, it creates an alternating magnetic field. Based on the technology’s current status, Audi at present has a 3.6 kW charging plate working like a conventional socket with 16 amperes. In the future, however, higher power versions may become feasible.
When an Audi e-tron comes within a few feet of the plate, a positioning process begins in which the ground plate and the car establish contact via radio. A symbol in the display informs the driver of the plate’s exact position. Once the car is correctly sited above the plate, its symbol will turn green and the system will suggest initiating the charging process.
The charging process begins as soon as the car comes to a stop above the plate The charging process can, however, be interrupted at any time. The ground plate’s alternating electromagnetic field induces an alternating current across the air gap in the secondary coil integrated into the car. At about 25 centimeters (9.8 in) long and wide, this is fairly compact and sits in the front area of the car’s underside.
An AC/DC converter then rectifies the induced alternating current and feeds it into the high-voltage onboard network, where it can charge the battery and at the same time power devices such as the heater or the air-conditioned. The driver can interrupt the charging process at any time. Charging stops automatically when the battery is fully charged.
Efficiency in Audi’s AWC technology as measured from the grid to the battery is more than 90 percent. Adverse weather conditions such as rain, ice or snow will not affect operation of the magnetic field. Because the magnetic field is only generated when an automobile comes to a stop overhead and the coil is activated, it is harmless for humans and animals.
Audi believes that this highly convenient charging technology will significantly raise the share of electric driving in plug-in hybrid models. As a first deployment step, AWC is ideally suited for a residential garage or a company parking lot. In later deployment steps, the technology could also be integrated into the public infrastructure.
Equipment, data and prices specified in this document refer to the model range offered in Germany. Subject to change without notice.