Test-bench container for long-term tests of power semiconductors and control circuits

• Subject Area: Electrical Engineering and Information Technology
• Term: Funded in 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 470141928

A permanent test station container for measurements on medium-voltage power semiconductors is requested. The research equipment, a long-term test station in a container, enables the working group to carry out characterization measurements on the one hand and medium-voltage endurance tests on the other hand. Nominal voltages of up to 4kV and nominal currents of up to 2kA can be generated, which represent various loads for the components under investigation. So that the behavior of the power semiconductors and their drive circuit can be examined. Continuous monitoring of various measurement parameters by means of a system of measurement cards with a control computer allows round-the-clock operation. Also, the special safety architecture, which is equipped with several levels, leads to the safest possible continuous operation. A design as a separate test station container allows an extension of the laboratory capacities and reduces in the worst case the fault effect on the container.To perform a continuous test in the medium voltage range, at least four power semiconductors are required, which are connected to a DC link converter with two half bridges. An inductive or inductive-capacitive load is connected to the load output so that an alternating current can be generated by modulating the power semiconductors. Due to the inductive load, most of the power is reactive power, so that only the losses have to be fed in. Thus, a megawatt converter can be operated with quite low feed-in power of a few 10kW. The main losses are switching and conduction losses of the power semiconductors and the losses of the load inductance. In addition to the power supply, a water cooling system with defined supply temperatures and flow rates is required to cool the power semiconductors in a defined manner. A constant water cooling ensures a constant thermal resistance of the heat sink, which is crucial for the thermal characterization of the test object. Only in this way can statements be made about the aging of the module. This long-term test container enables the working group to characterize power semiconductors and their control in endurance tests and to determine their lifetime. The transition from single switching tests to continuous operation is very useful, so that possible weak points of research results can be found before testing in the field. A test station container allows a closed system with very good monitoring capability.

• DFG Programme: Major Research Instrumentation
• Major Instrumentation: Dauerversuch-Prüfplatzcontainer für Leistungshalbleiter und Ansteuerschaltungen
• Instrumentation Group: 2780 Spezielle Meß- und Prüfgeräte für Halbleiter und Röhren (außer 620-659)
• Applicant Institution: Universität Rostock
• Leader: Dr.-Ing. Jan Fuhrmann