pk-2-pk Flux swing or BH loop area is worst?

[grizedale]

In calculating the hysteresis losses in a smps ferrite core.........is it true that..........

the peak to peak swing of flux density has no bearing on core losses..........

...rather it is the area of the B-H loop which influences core losses by hysteresis?

 

[atripathi]

Not really. Peak to peak swing would impact the loss. Also swing would impact the area of BH loop. Also there would be some eddy current loss, but it's contribution would be much less. Also it is true that area of BH loop represent the Hysteresis loss

The area inside the B-H curve represents lost power. It takes energy to move around the B-H curve and the core loss due to hysteresis is proportional to the area inside the B-H curve.

 

[mtwieg]

The hysteresis loop area gives the actual power loss (neglecting eddy currents in the core), but it's generally infeasible to manually calculate that for any arbitrary situations. You'd basically need a perfect nonlinear transformer model... Rather the manufacturer usually gives loss as a function of Bp-p, which is much easier to deal with, and I assume is very closely related with hysteresis losses. I'm sure there's some heavy math behind it, but probably only the core material engineers are qualified to figure it out.

 

[Mehrshad74]

for frequncies lower than 10khz Bm<0.25 and for 10 to 50 Khz Bm<0.2 and for higher frequencies Bm<0.15 is fine
You can download some ferrite (typically MnZn) datasheets and there are good information about power loss density vs frequency and Bm.