PLECS Model CAB400M12XM3

luke13

Hello,

I'm currently running a simulation with a VSI powering a PMSM in PLECS. Therefore i'm using your thermal model for the CAB400M12XM3 modules. The temperatures and power dissipation of the switches look good. The only thing is that when i try to calculate the junction temperature of the sic-mosfets by hand there is a difference of nearly 50 K. The power dissipation (conduction and switching losses) for each mosfet in the simulation and the calculation by hand only differ by 10W, so I don't where the huge difference in the temperatures are coming from.

For the calculation by hand I do:

TH = 6*Pv*RthHF+TF then TC = 2*Pv*RthCH+TH and TJ = Pv*RthJC+TC

Pv is power dissipation for one mosfet and i do the calculation 3 times to adjust the power dissipation to the rising junction temperature.

Is it right that i need to enter 0.15 K/W for the thermal interface resistance in the mosfet model (see picture below)?

I also attached the plecs model.

Appreciate your help.

Best regards,

Lukas

Inverter_PMSM_thermo.plecs