Power Switches for the 42V-PowerNet Solution for Power Net Protection and Applications

Abstract

The demand for more electrical power in future cars is the motivation to think about a change of the voltage level from 14 VDC to 42 VDC. The more of available power, together with the possibility of steady arcing the potential risks increase. The dissipation of power within an arc could cause serious damage, e.g. the ignition of flammable material. Therefore not only the loads have to be adapted to the new power level, but also does one have to think about new safety and protection strategies. We would like to present our approach of arc-detection and leakage current monitoring. But to detect the fault condition is only the first half of the solution. If an error occurs, there has to be some device capable of separating the fault path and only the fault path from the rest of the power net. In this paper we will show how we had made our relays capable of this task. A possible power net protecting system could be build with these relays together with a combination of an arcing sensor and a leakage current detector. If the detection time is sufficiently short, the breaking capacity of these relays is remarkable. With the tyco μK relay we successfully switched several times a 520 A short circuit peak. This was achieved even though this relay is not bigger than a lump of sugar and has a continuos current rating of 30 A.