Analyzing Loss Mechanism of High Frequency Ferrite Core Transformer in Power Electronics Based Converter

Abstract

The paper proposes an approach to design a high frequency ferrite core K-winding transformer in power electronics based applications with an objective to reduce both copper and core loss. The core loss in a high frequency transformer is controlled by operating flux density rather than saturation. Therefore, in substantial class of applications, it is necessary to model and limit core loss component through reducing peak ac flux density. The practical challenges in power electronics are addressed, particularly in efficiency and transformer design is improved by introducing optimization. In this paper, the core geometrical constant (Kg) of a magnetic device is generalized, leading to the geometrical constant (Kgfe), a measure of the effective magnetic size of a core in transformer design. A step-by-step guide for replicating the methodology is provided. The Design of a transformer core has been turned into an optimization problem, which is solved for variables such as mean length per turn, window area, core cross section area, window space fraction and mean length of magnetic path, that results in minimum total loss with inequality and equality constraints. A metaheuristics based algorithm, particle swarm optimization, in this case is applied to solve objective function which results in significant reduction in total loss occurred in core and winding. Different dimensions of EE type ferrite core are then estimated based on these optimized variables.