Journal ArticleDOI
Effective resistance to alternating currents of multilayer windings
Edward Bennett,Sidney C. Larson +1 more
TLDR
In this article, a multilayer winding carrying an alternating current, such as the windings illustrated in figures 1, 2, and 3, each layer of copper lies in the alternating magnetic field set up by the current in all the other layers.Abstract:
IN any multilayer winding carrying an alternating current, such as the windings illustrated in figures 1, 2, and 3, each layer of copper lies in the alternating magnetic field set up by the current in all the other layers. Eddy currents are set up in each layer in a direction to partly neutralize the magnetic intensities in the interior of the copper wire in each layer. As a result of the eddy-current losses in the copper, the effective resistance of the winding to the alternating current it carries may be many times its resistance to continuous currents.read more
Citations
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Journal ArticleDOI
Analytical winding foil thickness optimisation of inductors conducting harmonic currents
TL;DR: In this article, the authors presented analytical winding power loss minimisation of foil inductors conducting ac harmonic currents with and without dc offset, for a pulsewidth-modulated dc-dc boost converter operating in discontinuous conduction mode.
Proceedings ArticleDOI
Comparison of analytical methods for calculating the AC resistance and leakage inductance of medium-frequency transformers
TL;DR: In this article, a detailed investigation and comparison of different analytical expressions for the high-frequency resistance of medium-frequency transformers is presented, made by 2D FEM simulations and experimental tests with suitable transformers.
Journal ArticleDOI
An Analytical Correction to Dowell's Equation for Inductor and Transformer Winding Losses Using Cylindrical Coordinates
TL;DR: In this article, the effect of winding curvature on the losses relative to Dowell's equation was examined by solving the problem completely in cylindrical coordinates, and a mathematical model was derived for the relative error between the two solutions.
Proceedings ArticleDOI
Derivation of optimum winding thickness for duty cycle modulated current waveshapes
TL;DR: In this paper, a unified approach was proposed to derive exact AC resistance formulas for pulsed, rectangular and triangular waveforms, with variable duty cycle, in every case an approximation to the AC resistance versus layer thickness curve is derived and the optimum point can be found with a simple calculation involving the number of harmonics (related to rise time), the duty cycle and number of layers.
Journal ArticleDOI
Semi-Empirical Model for Precise Analysis of Copper Losses in High-Frequency Transformers
TL;DR: This paper gathers intensive 2-D finite-element method (FEM) simulations into a base formula by means of a multivariable regression process to establish a novel semiempirical formula with five determinant geometrical parameters that is suitable for the majority of practical applications.
References
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Journal ArticleDOI
Eddy Currents in Large Slot-Wound Conductors
TL;DR: In this article, the authors discuss the more important causes of eddy currents in heavy conductors carrying alternating currents and surrounded on three sides by iron, and propose a method to identify the most important causes.
Journal ArticleDOI
Eddy Current Losses in Armature Conductors
TL;DR: In this paper, an extension to the author's paper in Vo. XXXIX Pages 997 to 1047 on Eddy Current Losses in Armature Conductors is presented. And in this extension, additional formulas are given for the cases where transposed coils are used and also methods given for quickly estimating the increased loss due to eddy currents.
Journal ArticleDOI
Heat Losses in Stranded Armature Conductors
TL;DR: In this article, the authors extended the method of complex hyperbolic functions to the solution of the problem of heat losses in stranded conductors embedded in rectangular slots, where the insulation between the strands was assumed to have no appreciable thickness.