Resonant Tank Design of Interleaved LLC DC-DC Converter CRD-60DD12N-K and CRD30DD12N-K

Henry

Hi,

In the reference design of the Interleaved LLC DC-DC Converters CRD-60DD12N-K and CRD30DD12N-K, there is no resonant tank design.

I try to draw gain curve of two circuits with FHA method and my curve at 500V and full load for parallel case never get enough gain needed. I guess my equivalent output impedance on the primary side Rac is different from Wolfspeed's design. I am using Rac=6*(n/pi)^2*Ro. What is the formula of Rac in two circuits B and C in the attachment?

Can Wolfspeed provides detailed design of the resonance tank of the above two circuits? Transformer structure in the circuit B and C are different, so are the design of the 2 resonance tanks and Rac different?

Forum_Moderator

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FrankWei

Hi Henry,

Yes, you are correct. comparing to the delta connections at secondary, with full bridge rectifiers, the actual required turns ratio Ns/Np should be doubled.

you can double check it by calculation and simulation. thank you.

Regards,

Frank

TBhatia

Hi, 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.