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I am currently looking into the academic paper "SOFT-SWITCHING ACTIVE-CLAMP FLYBACK MICROINVERTER FOR PV APPLICATIONS" from http://studentsrepo.um.edu.my/8036/7/rasedul.pdf and I am trying to come up with an adapted version of the proposed circuit for 240-250V AC. I went through the design steps but I am getting stuck at one point: On page 56 it says "The value of the total capacitance Ctotal depends on the maximum allowable dead time Td and can be obtained as...", but how do I know what the "maximum allowable dead time Td" is? I assume it needs to be set/specified based on something?

Jenny
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  • Jenny, if we are done here, please take note of this: What should I do when someone answers my question. If you are still confused about something then leave a comment to request further clarification. – Andy aka Jul 09 '23 at 09:13
  • @Andyaka I already left a comment under your answer stating that I still neeed further clarification. To determine Td I need Cr, to determine Cr I need Ctotal, to determine Ctotal I need Td again, so I am back at the beginning needing a way to determine Td. – Jenny Aug 08 '23 at 15:56

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how do I know what the "maximum allowable dead time Td" is? I assume it needs to be set/specified based on something?

It's stated in the document you linked on page 96. If you used CTRL-F you can find all instances of "dead" in the document. That's how I found this formula.

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Andy aka
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  • That isn't a maximum time though if it needs to be greater than or equal, it's the minimum time then, or am I reading it wrong? – Jenny Jun 27 '23 at 14:08
  • @Jenny the way I see it is that "by design" your circuit has to exceed the minimum time by a small margin but, if your margin is too high it will effect the overall performance of the power supply i.e. your design's effectiveness at driving loads diminishes near linearly with how big $T_d$ is. So, you make its value a little bit bigger than the minimum value and, you calculate how much the maximum value could by by circuit analysis then, that's the number you need. – Andy aka Jun 27 '23 at 16:25
  • I can't determine that value without determining Cr first though, and to determine Cr I need to determine Ctotal, which requires knowing Td. Those are depending on each other apparently. – Jenny Jul 09 '23 at 16:57