Experimental setup for evaluation of electrical face contacts for high-current applications

The transmission of high electrical power via separable contact connections is a key challenge in the context of the energy transition. A well-known example is the charging interface of electric vehicles. To counteract the presently long charging time of battery systems, an innovative fast charging system using a face contact instead of classic plug-in contacts is being developed. To enable charging power in the megawatt range, an electrical contact surface is functionalized in such a way that, on the one hand, the contact resistance is reduced and, on the other hand, the thermal as well as the mechanical properties are improved. In addition to the simulation-based design of the contact surfaces and the development of manufacturing technologies, the required measurement and testing technology is a fundamental challenge. In this article the experimental setup for the long-term test of the electrical face contacts is being introduced. Using the test bench, electrical contacts can be automatically evaluated with regard to their temperature development and contact resistance at normal forces of up to 500 N with a current load of up to 600 A DC under constant or cyclic conditions. In this context the test procedure as well as first results of the thermo-mechanical properties of a face contact setup are being discussed.