How to use the plecs model for WolfPAK ?

WEN

Dear support team,

Could you have guideline for quick build the circuit by module model do plecs simulation.
because I realize here which can not use the wolfpak model.

Forum_Moderator

Thank you for your post, it has been approved and we will respond as soon as possible.

BlakeNelson

Hello Wen,

First, I would highly recommend this guide from Plexim, as it is a great starting point on the topic: https://www.plexim.com/sites/default/files/tutorials_categorized/plecs/thermal_domain.pdf

The model you selected is a "sub-cycle average" model, which is not what you are looking for. While it is much faster than a "switched" model, but does not calculate losses or temperatures (while the switched model does). Instead of using the half-bridge building block, I would recommend putting together a model using the individual MOSFET and diode blocks in this configuration:

The MOSFET and diode are placed on a heatsink, as PLECS will ignore the thermal domain without it. Additionally, each switch position has a external thermal resistance, Rth,ext. The bottom side of that resistor is attached to a temperature source (not shown) which defines fluid (or ambient) temperature. Since the MOSFET model already includes Rth,jc, the external thermal resistances represent the performance of the cooling system (i.e. the resistance case to fluid or case to ambient). You can find more details in this discussion:

https://forum.wolfspeed.com/discussion/comment/1207#Comment_1207

Finally, there is a separate diode model used to calculate the body-diode losses. You can find more details about it in this discussion:

https://forum.wolfspeed.com/discussion/comment/1486#Comment_1486

I am of course happy to answer any other questions you might have!

Thanks,

Blake

BlakeNelson

I hope that this answered your question. I will close this discussion for now but if you have a follow up question, please "Start a New Discussion" and we would be glad to support you further.

Blake