Second-Order Approximation of Nonlinear Eddy-Current Problems by a Cauer Ladder Network

In this article, a second-order approximation is proposed for nonlinear eddy-current (EC) problems via parametric Cauer ladder network (CLN) method. Through the CLN method, an orthogonal sequence of electric and magnetic modes along with the equivalent circuit parameters are generated by magnetostatic finite element analysis. When there are nonlinear materials in the medium, the modes and their corresponding values in equivalent circuit may vary according to the core’s saturation level. This article introduces new algorithms to generate second-order CLN (SO-CLN) based on intensity of the first and second magnetic modes. Additionally proper handling of circuit equations is also included. Numerical tests are carried out over a 2-D nonlinear inductor with bulk type conductive-magnetic core to show the accuracy of the proposed method.