Course instructor:
Prof. Dr. Uwe Scheuermann (Semikron)
Dirk Malipaard (Fraunhofer Institut IISB)
Thermal engineering of power electronic systems is a key to achieve high performance and reliability. In the focus of the tutorial is the thermal simulation and verification of the 100 kW medium power SEMIKUBE IGBT converter which is equipped with thermal sensors. The attendees should have basic knowledge on power semiconductor devices and power electronics systems.
Part 1: At the beginning the basics of heat exchange are described. Next it will be explained how to design the con-verter resulting in the knowledge of static heat sources due to losses of active and passive components. The tools used are Spice and Simulink. For the practical thermal simulation training, participants can choose between a thermal net-work simulation using LTspice™ or the Finite Element Method (FEM). The results will be compared to thermal measurements of the converter using thermocouples and an infrared camera.
Part 2: After a detailed description of the results of the first part the impact of thermal behavior of the converter on the reliability is discussed in detail. For doing that the know-ledge of the dynamics of heat sources is mandatory: It means simulation and measurement of the thermal impedance is the basis for further investigations. But it is also necessary to know about functional and reliability requirements, mission profiles, and physics of failure to build-in reliability during the design phase. Of course finally components and systems have to be tested physically to get estimations on their reliability. If the reliability has to be improved advanced cooling can help. Principles and cooling systems will be described.