Ferrite for Wireless Power Transfer

[Firenze02]

Hi,
I'm working on a wireless power transfer project (operating frequency 100 kHz). As you probably know, ferrite is usually placed under the coil to create a low reluctance way and reduce the leakage flux.

How the coecive force Hc and the residual magnetic flux Br affect the hysteresis losse?

For example, in the attached file you can find different ferrite types with different Hc and Br.

What is the logical reasoning with which I should choose a soft ferrite with high Hc and low Br or viceversa?

Thank You.

 

[Harald Kapp]

How the coecive force Hc and the residual magnetic flux Br affect the hysteresis losse?

It is not directly Hc and Br that create the magnetic losses, it is the area enclosed by the hysteresis loop. Apart from Hc and Br that area is also defined by the slope of the B/H curve. You'll want to minimize that area. See e.g. here.