Fast and Accurate Finite Element-Based and Magnetic Equivalent Circuit Models for Magnetically Controlled Transformers

Abstract

This paper presents a finite element-based dynamic modeling framework for magnetically controlled transformers. The model relies on pre-solving multiple static finite element simulations and storing the resulting windings flux linkages as functions of primary, secondary, and DC biasing currents in lookup-tables. Material non-linearities and geometry 3-D effects are inherently captured within the model. This flexible modeling approach allows to model transformers with different pre-magnetization methods. Additionally, a parameterized magnetic equivalent circuit model is developed. It is shown that the model of the control winding supply affects the simulation results. Both models are validated against the results from a dual active bridge converter, showing a good agreement with the experimental measurements.