Very high voltages occur in electric vehicles. The normal 12 volt are no longer sufficient, as even small electric motors take up around 40 kilowatt in power. This would entail current of 3,300 ampere, which in turn necessitates huge cable diameters. By contrast, a voltage of 300 V in our example means there is a current of "only" 130 ampere.
Separating vehicle electrics from high voltage
The 12 V vehicle electrics and the high voltage system must be separated to protect the passengers. IAV's development engineers take full account of all safety-relevant aspects in the high-voltage system during the concept phase. This warrants that no-one is put at risk from the high voltage while the vehicle is moving, in the garage or in the event of an accident.
Crash safety with large deformation zone and sensors
The design and positioning of the high-voltage battery in the vehicle ensures that it survives any accident with the least possible damage. In addition, the signals from the airbag control unit and the crash sensors are used to shut down the high-voltage system quickly. In this case, the voltage in the capacitors and the electric motor is discharged by a special discharge function in the power electronics. For all these challenges, IAV reverts to many years of experience in the development of active and passive safety concepts. For example, we are in a position to carry out all necessary tests on our own crash and sled facility.
Protection for service technicians
The mechanics in the garage also have to be protected from high voltage. IAV's engineers are elaborating requirements for components such as the "maintenance plug" so that the technicians can disconnect the battery blocks from the high-voltage system. Apart from the high-voltage battery, the vehicle is then free of high voltage.
Safeguarding against malfunctions
The probability that an electric vehicle will start to move spontaneously is somewhat higher than in the case of vehicles with conventional drive. There are only a few intermediate stages between energy source and motor. This is why the development of electric vehicles at IAV gives due consideration to the higher probability of malfunctions, with measures being developed to rule them out. In this way, the IAV engineers can warrant 100% safety as in conventional vehicles.