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Output of Time until system reaches thermal Steady State Operation

0 votes
221 views

Hello,

I would like to investigate different modulation strategies for a 3-LVL-ANPC-SiC topology under different operating points regarding overall efficiency and power dissipation (temperature) per switch.

And I would like to obtain the steady-state operating point of my system regarding the Junction Temperatures of my switches and my heatsink by using a steady state analysis.
Unfortunately, only the value of my 5-fold electrical period duration (5*Tel=5*1/fel=5/250Hz=0.02s) is displayed on the time axis. 

  • Is there a way to have PLECS indicate the time value from which my system has reached its thermal steady state? 
  • Since the Steady State Analysis is relatively time-consuming: Are there maybe setting options, tips/tricks that can shorten the simulation time?

I would really appreciate an answer. I have attached pictures to illustrate the problem.

Kind regards 

THK

asked Feb 5 by THK (22 points)

1 Answer

0 votes
The steady-state analysis is not able to tell you how long the system would take to reach steady state via transient heating. You would have to run a regular (transient) simulation and time this yourself (either manually or via a tic, toc function in a script).

There are lots of things that may help to improve simulation speed and the duration of a steady-state analysis, but it is all very model-dependent. This can include the solver type itself, solver settings, steady-state analysis tool settings, the number of states in the model, electrical/thermal time constants and the complexity of the circuit and control model itself. If you are able to include your model file here we may be able to advise, but we cannot just provide generic feedback based on your statement and screenshots alone, unfortunately.
answered Feb 5 by Kris Eberle (1,595 points)

Hello KrIs,

thank you very much for your answer. 

I really appreciate your offer for more advise.

Therefore I'm sending you my PLECS model files and the edited PLECS thermal descriptions from Wolfspeed. Perhaps this is helpful for my other questions I posted yesterday as well.

https://forum.plexim.com/8415/diode-turn-threshold-anpc-necessary-circuit-model-options 

https://forum.plexim.com/8413/algebraic-variable-resistor-different-modulation-strategies

https://forum.plexim.com/8414/algebraic-parasitic-capacitance-different-modulation-strategies

 

Best regards

THK

 

 

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