Audi all-electric F12 “e Sport” prototype rolls out of e performance research project
By Darren Quick
October 16, 2012
Audi has unveiled the first vehicle to result from its three-year “e performance research project” that has just been concluded. Conducted in collaboration with Bosch and a number of institutes at the RWTH Aachen University, the project aimed to develop a scalable electric vehicle technology platform that would serve as the basis for a variety of electric-powered vehicles, from compact city cars to sedans to sports cars. Representing the “e Sport” technology platform, the F12 borrows its exterior styling from the V10-powered Audi R8, but underneath it's electric power all the way.
The performance prototype vehicle is powered by three separate electric motors, each of which can be controlled individually. A synchronous motor at the front axle is used at slow speeds, while the two performance-optimized asynchronous motors at the rear axle join the party at higher speeds to make the e Sport a fully electric quattro. Together, the three motors produce a total of 150 kW (204 hp) and 550 Nm (405.66 lb-ft) of torque.
The motors are powered by two separate battery blocks, each made up of 200 macrocells, which provide an overall capacity of over 38 kWh. A switchable high-voltage electrical system sees the two batteries delivering output voltages of 144 or 216 volts, with the required uniform system voltage provided by a DC/DC converter. To maximize efficiency, the voltage is kept to around 200 volts under normal driving conditions, stepping up to as much as 440 volts when the foot is put down.
The battery system comprises cast aluminum sections that are designed to absorb the bulk of energy resulting from an impact. As an additional safety measure, beveled walls within the two battery blocks allow the macrocells to shift relative to one another in the event of an accident. Audi says that computations and initial tests on the battery components indicate the system can withstand even a side impact with a pole.
Battery temperature is regulated by a heat pump that also takes care of thermal management of the drive system and interior of the vehicle. This system can also store heat in the batteries to cut down on the amount of energy required to heat the interior the next time the car is driven.
Basic drive functions, including Park, Reverse, Neutral and Drive, are controlled via operating buttons in the center console, with all other operations controlled via a removable tablet computer that is housed in the center console. All key information is provided on a user-programmable instrument cluster.
While the curtain has come down on the e performance research project, the first follow up projects focusing on specific components and systems, such as the thermal management system, have already begun. Audi adds that individual technologies developed as part of the research project, such as the carbon fiver reinforced polymer (CFRP) housing developed for the rear battery, are likely to go into production.