Finite Element Analysis of Inductor Core Loss Under DC Bias Conditions

Finite element analysis is a popular way to analyze magnetic core loss in complex core structures. However, accurate calculation of the inductor core loss under dc bias conditions is still a challenge, as magnetic properties such as permeability and core-loss density change when a dc premagnetization is present, especially for saturable cores. This paper proposes a method that can accurately calculate the inductor's loss when it works under dc bias current conditions. The method utilizes an effective and simple material model built by curve-fitting the measurement data. To prove the accuracy of this approach, planar inductors built with low-temperature co-fired ceramic ferrite are simulated, and the calculated core losses are experimentally verified.