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A model for estimating the total eddy current losses in ring ferrite cores is proposed, which is based on a microstructure model of the electrical parameters of the material (conductivity and permittivity) and on the solution of the wave equations in the core. The presented model, combined with state-of-the-art estimation of the hysteresis losses, gives good agreement with the core loss measurements, over a wide range of frequencies (10–700 kHz). [ABSTRACT FROM AUTHOR]

A fast and accurate model of the transformer leakage inductance is crucial for optimization-based design of galvanically isolated converters. Analytical models are fastly executable, and therefore, especially suitable for such optimizations. This article compares several analytical leakage inductance per unit length models with respect to the accuracy and computational effort. The considered models are applicable to E-Core and U-Core transformers. 2D FEM simulations are used as a benchmark to evaluate the model accuracy, whereas the computation time is extracted as an indicator for computational effort. Six different transformer prototypes provide the geometries for the comparison. Based on the conducted comparisons, Roth's model is the most accurate. Rogowski's model is the fastest low-error model. Margueron's model is the most versatile as it takes the finite permeability of the core into account. The conducted comparisons lay the foundation for accurate and fast Double-2D modeling of the transformer leakage inductance as it is executed for the two main cross sections of E-core and U-core transformers: inside the transformer window, and outside the transformer window. This article is accompanied by a supplementary document summarizing the equations of Roth's and Margueron's model. [ABSTRACT FROM AUTHOR]

Modern wide-bandgap devices, such as SiC- or GaN-based devices, feature significantly reduced switching losses, and the question arises if soft-switching operating modes are still beneficial. For most of the semiconductor devices, only limited information is available to estimate the switching losses. Especially, if a wide operating range is desired, excessive measurements have to be performed to determine the switching losses for arbitrary operating points. Therefore, in this paper, a fast calculation method to determine the switching losses based on the charge equivalent approximation of the mosfet capacitances, relying only on datasheet parameters, is presented. In addition, the turn-off losses at high switching currents are investigated, and an analytical expression to estimate the maximum current range for which the mosfet can be turned off with negligible switching losses is proposed. [ABSTRACT FROM AUTHOR]