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Copper losses in magnetic coils depend on several geometrical parameters, as well as on frequency, in a way that makes their analytical modeling a quite difficult task. In this paper, we describe how we use a finite-element-analysis software to investigate a series of issues critical to the accurate determination of high-frequency copper losses in layered coils. Some of the issues we investigate are the impact of the edge effect and the winding pitch on the overall copper losses. We examine the effective resistance of windings with a hexagonal conductor arrangement and the validity range of the classic models for copper losses in windings with round solid wire. The results of this work help us to fully understand the real impact of two-dimensional effects in layered windings of real rather than ideal magnetics. They constitute a tool for the accurate calculation of losses, which is necessary for an optimized magnetic component design in power electronics applications. [ABSTRACT FROM AUTHOR]

While in numerous power electronics applications, transformers and inductors with nonlayered windings are used, the absence up until now of any theoretical or even empirical model for their HF effective resistance calculation leads magnetic component designers to make high-error approximations. The typical approach until now has been to consider them as layered and apply some of the existent relevant models. The present paper establishes a new semiempirical model for the accurate determination of HF copper losses in windings with the random conductor distribution, a case that cannot be treated by any analytical method. This model is based on the statistical treatment of numerical results coming from a large number of simulations carried out with finite-element analysis software, and incorporates only three easily determinable parameters. The selected range for each of these parameters ensures that the model is suitable for the majority of practical applications. The theoretical analysis is verified by experimental measurements on different forms of winding geometries. A detailed investigation of the new formula reveals its inherent advantages on copper loss calculation when designing nonlayered coils. [ABSTRACT FROM AUTHOR]