I'm trying to evaluate the thermal performance of this converter (attached) by analysing the IGBT switch losses. Within subsystem 2 (Sub 2) there is an interleave full bridge converter design. Inverter 1 contains the thermal network that is giving me trouble.
I'm attempting to use the Infineon IKW40N120CS7 IGBT and Diode thermal models (attached). Based on the datasheet specifications it should be a suitable device for the application.
When I attempt to run the model I get the following errors:
"Thermometer Converter_Termal_Model/Sub2/Inverter1/IGBT1:Tj may measure infinite temperatures caused by the impulsive heat sources listed below. These sources should be connected to a thermal capacitance or a fixed temperature. - Converter_Termal_Model/Sub2/Inverter1/IGBT1:Q"
My initial thoughts were that the thermal circuit (heatsink and thermal resistor) parameters were too large for the IGBT to realise that there was a thermal network in place. But despite trying a range of thermal resistance and thermal capacitance I am unable to get the system working.
Could someone please let me know what I've got wrong?