Cauer Ladder Network Representation of a Nonlinear Eddy-Current Field Using a First-Order Approximation

An approximation approach is proposed for the analysis of nonlinear quasi-static eddy currents adopting a Cauer ladder network (CLN). When there are nonlinear magnetic materials in the analysis domain, the electric and magnetic modes and their corresponding values for resistors and inductors in the CLN may vary according to the level of saturation in the core. Considering the effects of the modes and their magnitudes on the saturation imposes a heavy computational burden, which brings the efficiency of the CLN method into question. This article studies a first-order approximation of the nonlinear CLN method to keep the nonlinearization procedure computationally effective, simple, and accurate. Numerical tests are carried out for a 2-D nonlinear inductor excited with rectangular and sinusoidal excitations to show the accuracy of the proposed nonlinear resolution method.