Please take a minute to review and accept our Terms of Use.
Welcome to the PLECS User Forum, where you can ask questions and receive answers from other members of the community.

Many technical questions regarding PLECS are answered on the Technical Solutions page of our website. Tutorial videos, specific application examples, and pre-recorded webinars are available on our YouTube page. Please follow us on LinkedIn for the latest Plexim news.

At t=0.0154 Negative loss values for component... Should I set voltage Vce in negative value for turn off loss of diode?

+1 vote
asked Mar 12, 2020 by Razon (26 points)
Please see the section "Semiconductor Loss Specification" on Page 141 of our current user manual. Depending on whether you are using separate switch and diode components, or a combined switch with diode, there are certain considerations regarding the voltage and current regions for defining conduction and switching losses (see the table we provide on the next page).

Otherwise, you may need to clamp the loss values to zero at the lower axes limits. This is due to that fact that the engine linearly extrapolates past the limits you specify and during simulation startup there could be small numerical discrepancies leading to a negative voltage or current being used in the lookup table. Therefore, you might add a voltage row at e.g., -1V, and current column at e.g., -1A.

If these ideas don't help, you should post your model and thermal description files.

Thanks, Kris Eberle

Please log in or register to answer this question.