Digital Twin Validation and Thermal Control Aspects in a Power Conversion Module

A thermal Digital Twin Computational Fluid Dynamics (CFD) model is built of a power conversion device with three converter cells in parallel. The model is validated against measurements over the usage domain using a Design Of Experiments (DOE) experimental scenario. Next, the CFD model is used to predict the temperatures in use condition, that cannot be reproduced in the current experimental set-up, and to investigate control options. The results demonstrate that validation of the model necessitates a thorough investigation of the experimental conditions and inclusion of relevant experimental conditions in the validation model. Comparison of use- versus measurement- conditions demonstrates that the temperature of the main dissipating transistor components in the convertors is different, but the temperature at the control ICs is not. Finally, the work demonstrates that it is not possible to use a cell-based thermal control algorithm in this multiple converter configuration because the converter cells thermally influence each other: component temperatures are influenced by the heat load from all converter cells, and it is not possible to use the temperature of the cell control IC as a proxy for the temperature of the cell transistor.