3

Is it possible to use SIMPLIS to draw the gain curve of the LLC converter?

enter image description here

Because FHA analysis is not very accurate when the operating frequency is above the resonant frequency.

If it can, what kind of element I should use in SIMPLIS.

Power JJ
  • 357
  • 1
  • 8
  • The real challenge will be in quantifying all the circuit parasitics. An ideal-only SIMPLIS simulation of the resonant tank and switching elements likely won't be any more accurate than the FHA. I wouldn't go too far pre-simulating; get a starting point, build it and sweep it to see the actual real-world performance. – Adam Lawrence Apr 18 '23 at 16:41
  • @AdamLawrence, In the idea situation, SIMPLIS also can't do that? – Power JJ Apr 20 '23 at 14:29
  • It can - I'm just not sure if for a first approximation it will give you more useful information than the FHA would. The parasitic elements can dominate the performance of the circuit. – Adam Lawrence Apr 20 '23 at 15:32
  • Hi @AdamLawrence, Could you tell me how to do that? – Power JJ Apr 23 '23 at 13:12
  • https://www.simplistechnologies.com/support/downloads/examples – Adam Lawrence Apr 24 '23 at 12:29
  • @AdamLawrence, The SIMPLIS example file doesn't have the gain curve. – Power JJ Apr 24 '23 at 22:06
  • But you can easily vary the frequency and plot the response yourself. – Adam Lawrence Apr 25 '23 at 13:58
  • @AdamLawrence Do you mean to vary the frequency manually and draw the gain curve by myself? I can't get the gain curve by SIMPLIS itself? – Power JJ Apr 26 '23 at 22:10
  • @AdamLawrence I solved the issue, thanks. – Power JJ Apr 28 '23 at 16:26

1 Answers1

1

You can draw a basic LLC circuit in any simulator, and feed it with sin wave while stepping frequency and/or load, and then you can observe the resonant tank gain at these frequencies similar to the graphs you attached. This way, what the simulator will show you, is not quite exact (no parasitics are considered), but it is good enough to design and predict the behavior of a physical LLC converter.

enter image description here

upload file enter link description here

xyz
  • 11
  • 2
  • Would be really nice if it's possible to draw a curve pack using different reflected load resistances (R1 in your circuit) which correspond to different Q's. – Rohat Kılıç Jun 29 '23 at 11:25