A Semiempirical Model to Determine HF Copper Losses in Magnetic Components With Nonlayered Coils

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.