Modeling magnetic devices using SPICE: Application to variable inductors

In this paper a methodology to develop SPICE-based models of complex magnetic devices is presented. The proposed methodology is based on a reluctance equivalent circuit (REC), which allows the user to study both the magnetic and electric behavior of the structure under any operating conditions. The different elements required to implement the reluctance model, namely, constant reluctances, variable reluctances and windings, are implemented using SPICE behavioral modeling. These elements can thus be used to build a complete model for any magnetic device. The modeling process is illustrated with a particular example for a variable inductor. Simulations and experimental results are presented and compared to evaluate the accuracy and usefulness of the proposed modeling procedure.