Journal ArticleDOI
Computationally efficient winding loss calculation with multiple windings, arbitrary waveforms, and two-dimensional or three-dimensional field geometry
TLDR
The squared-field-derivative method for calculating eddy-current (proximity effect) losses in round-wire or litz-wire transformer and inductor windings is derived in this paper.Abstract:
The squared-field-derivative method for calculating eddy-current (proximity-effect) losses in round-wire or litz-wire transformer and inductor windings is derived. The method is capable of analyzing losses due to two-dimensional and three-dimensional field effects in multiple windings with arbitrary waveforms in each winding. It uses a simple set of numerical magnetostatic field calculations, which require orders of magnitude less computation time than numerical eddy-current solutions, to derive a frequency-independent matrix describing the transformer or inductor. This is combined with a second, independently calculated matrix, based on derivatives of winding currents, to compute total AC loss. Experiments confirm the accuracy of the method.read more
Citations
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Journal ArticleDOI
A Unipolar Coil Arrangement Method for Improving the Coupling Coefficient Without Ferrite Material in Wireless Power Transfer Systems
TL;DR: In this article, the authors proposed a unipolar coil arrangement method (UCAM) for improving the power transfer capability and transmission efficiency in wireless power transfer systems compared with conventional coils having the same self-inductances and outer dimensions.
Proceedings ArticleDOI
Accurate calculation of winding resistance and influence of interleaving to mitigate ac effect in a medium-frequency high-power transformer
Annoy Kumar Das,Haonan Tian,Zhongbao Wei,Sriram Vaisambhayana,Shuyu Cao,Anshuman Tripathi,Philip Carne Kjar +6 more
TL;DR: In this paper, Dowells and Ferreira's methods, which are computationally cost-effective among other analytical methods, are discussed to calculate winding resistance at higher switching frequency, which is a key parameter to characterize performance of a medium-frequency (MF) high power (HP) transformer.
Journal ArticleDOI
Improved calculation of winding losses in gapped inductors
TL;DR: In this article, an improved presentation of the winding losses in inductors using a correction loss factor is reported, which is tuned using FEM calculations, and an approximation of kF as a function of a parameter κ is provided.
Proceedings ArticleDOI
Design considerations for a high efficiency 3 kW LLC resonant DC/DC transformer
TL;DR: In this article, the design principles, procedures and considerations for a 3 kW high efficiency LLC resonant DC/DC transformer are presented, and a converter prototype is built, which achieves 98.24% efficiency at nominal load.
Journal ArticleDOI
A metal additively manufactured (MAM) heat exchanger for electric motor thermal control on a high-altitude solar aircraft – Experimental characterisation
TL;DR: In this article, a metal additively manufactured (MAM) integrated heat exchanger for cooling part of the electric propulsion system of a high-altitude solar-powered aircraft is described.
References
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Journal ArticleDOI
Effects of eddy currents in transformer windings
TL;DR: In this article, the effect of eddy currents on transformer windings is considered and a method is derived for calculating the variation of winding resistance and leakage inductance with frequency for transformers with single-layer, multilayer and sectionalised windings.
Journal ArticleDOI
Optimal choice for number of strands in a litz-wire transformer winding
TL;DR: In this paper, the number and diameter of strands to minimize loss in a litz-wire transformer winding is determined, and a power law to model insulation thickness is combined with standard analysis of proximity effect losses to find the optimal stranding.
Journal ArticleDOI
Improved analytical modeling of conductive losses in magnetic components
TL;DR: In this paper, the authors propose an orthogonality between skin effect and proximity effect to calculate the AC resistance of round conductor windings, which gives more accurate answers than the basic one-dimensional method because the exact analytical equations for round conductors can be used.
Journal ArticleDOI
Optimizing the AC resistance of multilayer transformer windings with arbitrary current waveforms
TL;DR: In this article, the authors present a new formula for the optimum foil or layer thickness, without the need for Fourier coefficients and calculations at harmonic frequencies, which is simple, straightforward and applies to any periodic wave shape.