Choosing Powder core torroid for Two Transistor Forward

[cupoftea]

Hi,
We are doing a 370W peak Two Tran Fwd from a PFC output (400V).
Average power is 1/4 of max.
We have chosen the Micrometals MS106xxx torroid for the 2TF output inductor.
2TF output inductor Peak and pedestal currents are around 13A and 8A respectively.

We find that the MS106060 is the best choice, however, all from MS106040 to MS106160 would be useable.
(that's 7 torroids)
So how do you isolate the most optimal one straight away?
The attached excel does it for us, but takes a lot of calculation time.

The higher u(r) ones give a wider range of inductance change from pk to pedestal. The lowest u(r) one just needs
too many turns. Its a bit of a judgement call with three close contenders, but the MS106060
wins the day for us.

Any quicker ways of isolating the most optimal one?

 

[Easy peasy]

freq ? delta B in your designs ? which has lowest core loss with turns that fit ? when is core loss = 70% or wire loss ?

 

[cupoftea]

Thanks, freq is 120kHz. I see the point of youir questions, and i would add that the other factor was the variation of inductance between the peak and pedestal currents.
There were a number of torroids where the number of turns and core loss were very similar.
The delta B is in the excel doc, with "CLxxxxxx" being the tab name.