In technical terms, a permanently excited, three phase synchronous machine is fitted in the Volkswagen e-up!. Behind the complicated name is, simply, an electric motor, which is defined as synchronous because its rotor rotates with a speed synchronous to the circular moving magnetic field of the stator and as a result runs smooth even at low speeds. This is partly due to the special type of current, consisting of three single alternating currents which flow through the coils of the stator. The magnets installed in the rotor of the e-up! are permanently of northern or southern polarity.
The e-up! features a friction-optimised 1-speed transmission which spins at 10,000 revolutions per minute. The e-motor is connected to the front wheels, powering them via the transmission and prop shafts.
The Engine Control Unit
The central engine control unit takes over drive management with newly developed functionality, such as the optimisation of engine response for more comfortable and harmonic load changes, and the dynamic driveability that comes with it. The customer can choose between three distinct driving programs with different driving characteristics and driving power. The engine control unit takes over the control of the thermal and energy management of the drive and secondary units, with regard to maximum electric range as well as comfortable climate control and component protection. Requirements for assistance systems such as cruise control or Adaptive Cruise Control (ACC) are also coordinated here.
The Power Electronics
The power electronics of the e-up!, as the conduit between the battery and the electric motor, ensures that the correct current is always available. It is connected to the electric motor by a three-phase line and by a traction lead to the battery. A range of 296 to 418 volts are used in the e-up!, depending on the battery potential. When the engine is running, the power electronics transform the alternating current into three-phase alternating current. In generator mode the alternating current is transformed into direct current, in order to charge the battery. Additionally, an integrated direct current converter in the power electronics feeds the 12-volt electrical system of the vehicle.