SIMPLE MODEL OF SELF AND MUTUAL IMPEDANCES FOR COILS ON FERROMAGNETIC CORES

摘要

A simple impedance representation of a coil on a ferromagnetic core is proposed in this paper. An accurate solution of the Maxwell's equations of the coil is approximated by analytical methods, such as Fade approximation. The result gives a simple representation of self and mutual impedances for coils on cores as a rational function. Calculation time is shortened and effects of parameters on the impedance are easily investigated, because the proposed approximation is carried out without numerical technique and the method removes complex Bessel and Elliptic functions from the accurate formulas. A lumped equivalent circuit, which approximately expresses the frequency dependency of a coil on a core, is also derived from the approximated rational function.