Breaking performance of protection devices for automotive dc powertrains with a voltage of 450 V

For the application in low-voltage direct current grids technically sophisticated switchgear and protective devices are needed, because of the electrical requirements. A particular case is the dc powertrain of an electric vehicle. Hard requirements are prescribed with regard to volume, weight and power losses of the switchgear in the on-state by the car manufacturers. To ensure personal protection, it is necessary to control the system parameters in every operating condition. Therefore exemplary commercial switchgear has been researched for the application in a high-voltage automotive dc powertrain. The chosen contactors have been investigated focusing on contacts, arcing chambers and switching behavior. The breaking ability has been tested at a voltage of 450 V and prospective currents in the range from 5 A up to 1500 A. The tests include bidirectional power flows as well as time constants of 0 ms and 1 ms.