Impact of Non-Uniform Flux Density on Core Losses: A Case Study on Standard Core Geometries

The non-uniform flux density distribution inside magnetic cores leads to increased overall losses when compared to the commonly used uniform flux density assumption. This effect is amplified if rectangular based core shapes are used, where flux crowding in the corner sections plays a major role in the losses. To evaluate the effect of this non-uniform flux density distribution, computationally heavy FEM simulations are needed, in most cases incompatible with the preliminary design process of core selection. To solve this issue, this work analyses the flux distribution in a wide range of standard commercial core geometries and sizes with the aid of FEM simulations. The increment of losses between uniform and non-uniform flux densities are shown, allowing to quickly evaluate the impact of the flux distribution in the magnetic core selection process. Since the core losses depend on material parameters, these are evaluated in a wide range of the Steinmetz parameter β, based on typical ranges of the β parameter extracted from the open-source MagNet database.