On the time-domain analysis of analog circuits containing nonlinear inductors

The paper proposes effective solutions to include nonlinear inductors with soft ferromagnetic core in the time-domain circuit analyses. Three inductor models are developed, tested and compared. They are conceived for different degrees of accuracy related to the real devices. The models are robust and reliable due to the modeling concept that avoids numerical instabilities. An enhanced inductor model can serve to numerical analyses aiming the optimization of some constructive parameters (as the airgap length or number of turns). A SPICE implementation was performed and exemplified for different operation conditions.