I'm new to PLECS and am wondering how to correctly implement a heatsink in my circuit, a 3-Level ANPC SiC VSI. For my switches (Wolfspeed C3M0021120K), I use the thermal description provided by the manufacturer, one for the MOSFET and one for the intrinsic body diode. I have compiled both into a masked Switch submodel.
In the thermal description, under the thermal chain, the same thermal RC chain in the form of a 4th-order Cauer network is specified for both the MOSFET and the intrinsic body diode.
- This Cauer network represents the dynamic Zth_junction_to_case of the MOSFET switch, right?
Furthermore, In your demo models, sometimes each individual switch submodel (consisting of a MOSFET and its body diode) has its own heatsink with Rth_Case_to_Heatsink (thermal grease) implemented. But sometimes there is noch extra heatsink...
- So What would be the correct approach here? Option a) or b) ? (see photos)