Description of function
The power electronics applies an alternating voltage displaced by 120° to the coils. This generates a magnetic field that alternates
its direction continuously. This characteristic is also used to drive the rotary-mounted magnets. If the positive edge of the sine
wave is applied to the coil, the north pole is attracted; when it is the negative edge, the south pole is attracted. The motor begins to
turn. The faster the frequency of the power electronics, the quicker the motor turns. In recuperation, a voltage is induced in the
stator coils by the magnetic field of the permanent magnets. This energy is used to charge the battery. As the electric drive motors
on the Audi e-tron GT are permanently excited synchronous motors, the rotation of the field in the stator is just as fast as the speed
of the rotor. The motors are fully regulated by the power electronics, which process the driver’s requests.
Reference
Further information on this topic can be found in Service TV programme 0568 TV "Electric drives – Motors".
Electric drive control unit (power electronics)
Introduction
Power electronics have become an integral part of today’s electrical engineering. They have the task of converting electric energy
using electronic components – be it from alternating voltage to direct voltage or vice versa. To be able to switch high three-figure
ampere currents, power electronics are being further developed on a daily basis. There are two different versions of the electric
drive control unit on the Audi e‑tron GT (type F8). Each of the power electronics is connected to the vehicle body via a potential
equalisation line.
Electric drive control unit for front axle J1234 (300 A version)
Electric drive control unit for front axle J1234 is bolted onto the electric drive motor. The contact between the control electronics
and the electric drive motor is fixed.
Contacts on front axle
684_362
Note
Electric drive control unit for front axle J1234 must under no circumstances be opened.
27
English 
