Inductance of Coil in Nonhomogenous Surrounding

The paper introduces the concept of the complex inductance as a parameter of a coil loaded by sinusoidal current and placed near an electrically well conductive body in which the magnetic field of the coil induces eddy currents. Studied will be only axi-symmetric cylindrical coils and the paper shows how easily their complex inductances can be determined by means of professional programs for electromagnetic field analysis. The suggested methodology is illustrated on computation of the inductance of a ring coil placed near a conductive slab. Investigated is also dependence of the complex inductance on frequency.