Wideband Macro-Modelling of Power Modules for Transient Electromagnetic Analysis

Abstract:
This work focuses on the modelling of frequency dependent parasitic elements of power modules for the application in transient switching analysis. The switching properties of power modules are typically determined by parasitic elements models extracted from 3D electromagnetic solvers. Previous works in power electronics neglected the frequency dependency of parasitic elements in transient simulations. This leads to erroneous results such as wrong prediction of dynamic and static current sharing between semiconductors, or erroneous prediction of oscillation frequency and amplitude for example. In this work, we are extracting frequency dependent parasitic elements using 3D simulation tools and apply the vector fitting technique to generate wideband macro-models of the power modules. Examples from industrial power modules validate the proposed procedure and are used to examine differences to commonly applied approaches. We demonstrate that using wideband macro-models improves the accuracy and reliability of numerical switching analyses.