Automation of Modular Multilevel Converter Topology Evaluation including Thermal Monitoring

Modular Multilevel converter systems are subject to current research in the field of power electronics. Although several different topologies are developed and in use, topology evaluation is usually performed purely simulatively. In this paper, the basics and setup of an automated test system for multilevel converter hardware are presented. Its focus is on flexibility, accuracy and data acquisition in the context of rapidly changing research initiatives.An exemplary test setup is built, demonstrating the usage of such a system to find the optimal gate voltage in a battery powered multilevel application depending on the load current provided by the system. In addition to efficiency measurements, monitoring via thermal imaging is integrated into the system. The results show a sweet spot in the evaluated multilevel converter’s efficiency at a load current of 15A. Furthermore, the optimal gate voltage is strongly dependent on the load current since the auxiliary power consumption impacts the overall efficiency.