Wide-band lumped circuit model of the terminal and internal electromagnetic response of a coil with a coaxial insulation system

A wide-band lumped circuit model of a coil with a coaxial insulation system is presented, which can be used to simulate the terminal and internal electromagnetic response. The frequency response of the lumped circuit is experimentally verified up to a few MHz. The circuit parameters are based on data concerning the geometry and materials. The capacitive and resistive response of the insulation system is considered thoroughly, as it is very different from a conventional winding. The model is of special interest for electromagnetic power devices with a coaxial insulation system, e.g. Powerformer(TM) and Dryformer(TM).