Short Circuit and Avalanche Effects in 12V Power Distribution for Automated Driving

For the legal deployment of automated vehicles the power distribution within is a key topic. This system has to be fail-operational in case of faults to reach the safe state according to the standard. Switching off loads and short circuits is driving the required switches into avalanche. Exceeding the avalanche energy destroys the device and the system might change into an unsafe state. Through creating a fail-operational power distribution, electric parameters are changing and not all effects are visible immediately. This paper shows results of the SPICE simulation under worst case conditions to analyze specific electric influences within a fail-operational power distribution. Furthermore, not all devices which are expected to go into avalanche are driven into avalanche.