Improved core loss calculation method considering the non‐uniform distribution of magnetic flux density in powder cores

Abstract

Utilising powder cores in many power electronics applications have gained much attention due to the attractive magnetic properties of powder core materials. However, the magnetic flux density distribution is non-uniform along the core because the flux is dependent on the core geometry and due to the low relative permeability of the powder core material. The non-uniformity of the magnetic flux density distribution may cause huge calculation errors of core losses. Understanding the effect of the magnetic flux non-uniformity in the powder cores allows the circuit designer to accurately estimate the core losses in powder cores. This work addresses the negative effect of the inherent non-uniform magnetic flux density distribution on the core loss. Furthermore, an equivalent circuit to consider the non-uniform of the magnetic flux density distribution is proposed. The proposed circuit enables the core loss to be estimated more precisely. A reduction of 12% in the core loss measurement error has been reported while utilising the proposed circuit compared to traditional equivalent circuits. Along with the theoretical discussion, finite element method simulation and experimental results are also presented to evaluate the proposed core loss calculation method.