Theoretical analysis of the electrical and magnetic field distributions ina toroidal core with circular cross section

With the rapid development of high-frequency magnetic components, it is imp ortant to know the distributions of the electrical and magnetic fields in t he ferrimagnetic cores. In this paper, an improved model for analyzing the distributions of electrical and magnetic fields in a toroidal core is given . It supplies the basis for the theoretical analysis of the iron loss in th e magnetic cores, which is helpful in evaluating experimental results. On t he basis of calculated results, we find that the magnetic held produced by the eddy current and displacement current due to the electrical field will shield the magnetic flux from the inner portion of the core cross section. This results in a flux skin effect analogous to the skin effect in the cond uctors of a winding. This phenomenon becomes more obvious when frequency in creases.