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
More filters
Proceedings ArticleDOI
An improved calculation of proximity-effect loss in high-frequency windings of round conductors
Xi Nan,Charles R. Sullivan +1 more
TL;DR: In this paper, the Ferreira method and Dowell method were compared to evaluate the accuracy of each method for predicting proximity-effect losses in round-wire windings and found that the Dowell algorithm can have substantial errors, exceeding 60%.
Journal ArticleDOI
Cost-constrained selection of strand diameter and number in a litz-wire transformer winding
TL;DR: In this article, the relationship between wire size, normalized cost, and normalized loss is shown to have a general form that applies to a wide range of designs, and a practical design procedure is provided, applied to an example design, it leads to less than half the original loss at lower than the original cost, or, alternatively, under one fifth the original costs with the same loss as the original design.
Journal ArticleDOI
A Novel Single-Layer Winding Array and Receiver Coil Structure for Contactless Battery Charging Systems With Free-Positioning and Localized Charging Features
TL;DR: A new single-layer winding array and receiver coil structure with cylindrical ferrite cores for planar contactless battery charging systemsplying with the “Qi” standard, this design enables multiple devices to be placed and charged simultaneously on the wireless charging pad in a free-positioning manner.
Journal ArticleDOI
Overview of Planar Magnetic Technology—Fundamental Properties
TL;DR: The major advantages and disadvantages in the use of planar magnetics for high-frequency power converters are covered in this paper, and a detailed survey of winding conduction loss, leakage inductance, and winding capacitance for planar magnetic technologies is presented.
Journal ArticleDOI
A Methodology for Making a Three-Coil Wireless Power Transfer System More Energy Efficient Than a Two-Coil Counterpart for Extended Transfer Distance
TL;DR: In this article, a three-coil wireless power transfer system is proposed to maximize the magnetic coupling with the receiver coil for efficient power transfer, and the theoretical proof and the conditions for meeting the objective are derived and practically verified in a practical prototype.
References
More filters
Journal ArticleDOI
Improved analytical modeling of conductive losses in gapped high-frequency inductors
TL;DR: In this article, an improved method to predict conductive losses in gapped high frequency inductors is presented and used for parametrization of an equivalent small signal circuit model, based on the superposition of power losses resulting from the well known one-dimensional field calculation and losses due to eddy currents caused by the fringing field of airgaps determined from new analytical 2D-field calculations.
Journal ArticleDOI
A closed-form formula for 2-D ohmic losses calculation in SMPS transformer foils
TL;DR: In this paper, a closed-form formula for calculating ohmic losses in switch-mode power supply (SMPS) transformers is presented, which is based on intensive two-dimensional (2D) finite element method (FEM) simulations.
Proceedings ArticleDOI
Optimization of shapes for round-wire high-frequency gapped-inductor windings
Jiankun Hu,Charles R. Sullivan +1 more
TL;DR: In this article, a numerical method is used to determine the winding shape that minimizes total winding losses in a gapped inductor with round-wire windings, which accounts for proximity effect loss that results from the two-dimensional field in the winding area, and for the effect of the winding on that field.
Proceedings ArticleDOI
Additional losses in high frequency magnetics due to non ideal field distributions
TL;DR: In this article, a finite element modeling effort demonstrates that there are additional losses in high-frequency windings beyond those included in the conventional analysis based on P.L. Dowell's work.
Journal ArticleDOI
Eddy-Current Losses in Rectifier Transformers
TL;DR: In this article, two methods are developed for evaluating the eddy-current losses occurring in a rectifier transformer during operation, i.e., when carrying pulsating currents, based on the analysis of the whole waveshape and the harmonic composition of current curves.