Progress in charging technology is crucial to the success of electromobility. Whether charging with direct or alternating current, the new solutions from Audi for all-electric cars and plug-in hybrids will be extremely convenient for customers. There will also be wireless options. Market launch is scheduled to begin in 2017.
Up to 150 kW of power – fast charging with direct current
Direct current charging with 150 kW of power is the next step. With this technology, a sporty SUV such as the Audi e-tron quattro concept would be able to charge its large 95 kWh battery to 80% capacity in less than half an hour, enough for a cruising range of around 400 kilometers (248.5 mi). A full charge – enough for more than 500 kilometers (310.7 mi) – would take around 50 minutes.
Audi and other German manufacturers use the Combined Charging System (CCS). It enables electric cars to be charged with direct current (DC) and alternating current (AC) using the standard Combo 2 connector. The official charging solution of the European Union, which is based on the CCS standard, has already been ratified. To further promote these standards worldwide, Audi co-founded the Charging Interface Initiative (CharIN) with BMW, Daimler, Opel, Porsche and Volkswagen, connector manufacturers Mennekes and PhoenixContact, and the TÜV SÜD inspection authority in May 2015. In China and Japan, where other standards already exist (GB/T and CHAdeMO, respectively), country-specific requirements will be accommodated. Installation of CCS charging stations has already begun in Europe and the United States. The majority of stations currently available on the market support DC charging with 50 kW.
With a high-performance fast-charging infrastructure along transport axes, all-electric cars would be suitable for universal use. Current efforts are geared toward ensuring the establishment and operation of a fast-charging infrastructure with at least 150 kW by the market launch of the first all-electric sport SUV from Audi. The Audi e-tron quattro concept introduced at the IAA in Frankfurt was equipped with the CCS charging interface. The new standard allows for charging with up to 350 kW.
Audi considers it very important to offer the customers of its all-electric models a very convenient and capable charging system. This also requires cooling of the charging connector while connected to the charging station. This is the only way to continuously transfer the full power without thermally overloading the pins. In real-world driving, DC fast charging represents significant value-added for customers, particularly for long trips.
Audi wireless charging – wireless charging with alternating current
DC fast charging is virtually impossible in the private infrastructure due to the limited grid power. AWC (Audi wireless charging) is an inductive AC charging technology Audi is developing as an alternative that also makes home charging extremely convenient. The company hopes to launch AWC in 2017.
With AWC, the energy is transferred via a floor charging plate connected to the electric grid. The plate has an integrated primary coil and an inverter (AC/AC converter). Connected to a 16 ampere, single-phase outlet, the first-generation system offers a charging power of 3.6 kW, with higher powers of up to 11 kW possible in the next version.
When the customer approaches to within a few meters of the charging plate with his Audi e-tron, the plate establishes radio contact with the car. The driver then sees the precise position of the floor plate on the display. Charging can begin immediately after proper positioning or according to a timer. With the piloted parking systems Audi is currently developing for production use, the car handles positioning itself. The driver can get out of the car and then initiate the parking procedure remotely via her smartphone.
Prior to charging, an integrated electric motor in the floor plate raises the primary coil. This minimizes the distance between it and the secondary coil, which is integrated into the front section of the Audi e-tron floor pan, regardless of the specific vehicle. The floor plate’s alternating electromagnetic field induces an alternating current in the car’s secondary coil across the air gap. An AC/DC converter inverts the current, which is then fed into the high-voltage electrical system. There it charges the battery and powers additional consumers such as the heating or air conditioning as needed. The driver can interrupt the charging process at any time, and charging stops automatically when the battery is full.
Because the alternating field is only generated when a car is over the plate and the coil is active, there is no risk to people or animals. The small air gap prevents the magnetic field from interfering with electronic devices.
The first generation of the AWC technology is ideal for use in home garages or office building parking garages. A later version can be integrated in a modified form into the public infrastructure, such as into the asphalt of roads and parking lots.
The equipment and data specified in this document refer to the model range offered in Germany. Subject to change without notice; errors and omissions excepted.