Physics-Based Multi-Domain Core Loss Modeling of Magnetic Materials via Spherical LLG Approach

Accurate magnetic modeling at high frequencies is critical for designing compact, high-efficiency power converters. Prior work developed a physics-based model using the Landau-Lifshitz-Gilbert (LLG) equation to simulate the nonlinear dynamics of magnetic materials, providing a route to modeling frequency-dependent core loss and permeability. This study utilizes the LLG equation formulated in the spherical coordinate system, not only to exploit the two-dimensional nature of the equation for computational cost reduction, but also to enable further acceleration. This formulation allows the simulation to track only the damping of the magnetization of a macrospin but not its precession. The latter is computationally much more costly but largely irrelevant to core materials, due to the very high precession frequency. The significant acceleration achieved by focusing on damping in the spherical coordinate paves the way for scaling up the model. As a first step towards scaling up, we propose an approach to model domain-domain interactions and domain wall dynamics. Different from those utilized for smaller length scales, this approach is geared towards core materials. Initial results suggest its potential as a scalable physics-based model for core materials at length scales relevant to power electronics.