Transient Core-Loss Simulation for Ferrites With Nonuniform Field in SPICE

A methodology to develop a subcircuit model for core loss simulation in LTspice is presented. The subcircuit implements the dynamic core loss model used in the transient solver of finite-element analysis (FEA) in order to provide equivalent results in the time domain for ferrite materials. The wipe-out rule is applied in the simulation so that the core loss during the transient behavior can be predicted. A field factor is derived from an effective flux density for a nonuniform flux distribution to simplify the relationship between the current and the field for arbitrary magnetic core shapes. The interface of the subcircuit is capable of being integrated to any power stage simulations. Simulation results of core loss equivalent to the FEA on an exemplary plate-core inductor are obtained from the subcircuit that significantly reduces computational cost.