Intensivseminar: Simulationsunterstützer Designprozess von Schaltzellen mit Wide-Bandgap-Leistungshalbleitern
Holger Gerstner,
Fraunhofer IISB;
Achim Endruschat,
Fraunhofer IISB
Power electronic systems using wide bandgap devices (WBG) offer higher efficiency and power density compared to systems based on silicon counterparts. The reduced interelectrode capacitance values as a key component for decreased losses in these hard switching power converters, however, directly result in increased current and voltage slopes during operation. In consequence, the design process of the switching cell becomes more challenging, especially with the low threshold voltage values of commercial available WBG devices. Furthermore, within conventional design processes the impact of circuit board parasitic effects as well as the magnetic coupling between single copper tracks in terms of additional voltage drops does not become obvious until a first hardware setup of the switching cell. In consequence, ancillary iterations with adjusted hardware have to be conducted in order to provide compliance with the requirements of the application or the ratings of the power semiconductor devices.
This presentation highlights the circuit simulation supported design process of switching cells. Using the example of a high-integrated WBG power module, requirements regarding accuracy and applicability of a simulation model and its profitable application are discussed. After an overview of specific modeling processes (e.g. semiconductor devices, conductor paths, magnetic coupling of conductor paths, capacitors) the accuracy of the individual sub models is reviewed compared to the complete simulation model of the switching cell. Particularly, the interference between the individual models and the scope of application for the resulting simulation model is pointed out. In the end, the results of the circuit simulation are compared with measurement results of a double pulse test bench. The high accuracy and accordance between measurement and simulation suggests the replacement of hardware setups by digital twins concerning a circuit simulation model, especially in the early design process. As a result, the complete design process becomes faster, more target-oriented and more resource saving.