2-Dimensional Eddy Currents In Foils For High-Frequency Power Applications

The increase in resistance at higher frequencies in rectangular conductors has been studied for microwave applications. Low-frequency approximations are also available. To bridge the gap between the two ends, microwave techniques (conformal mapping), along with asymptotic matching, are used to obtain formulae suitable for power foils used in switching converters. The development shows very high accuracy, not only in the intermediate range where switching frequencies lie, but over the entire frequency spectrum. Accuracy is assessed against numerical calculations and experimental measurements. More fundamentally, the basic procedures for using conformal mapping techniques in power electronics are stated.