Finite element analysis of inductor core loss under DC bias condition

Finite element method is a popular way to analyze the magnetic core loss in complex core structures. But accurate calculation of the inductor core loss under DC bias condition is still a challenge because the magnetic properties like permeability and core loss density will change when a DC pre-magnetization is present, especially for saturable core. This paper proposes a method which can accurately calculate the inductor loss when it works under DC bias current condition. The method utilizes the material model built by curve fitting the measurement data. This model is effective and simple. To prove this approach, planar inductors built with low temperature co-fired ceramic (LTCC) ferrite are simulated and the calculated core losses are experimentally verified.