Journal ArticleDOI
Effects of eddy currents in transformer windings
P.L. Dowell
- Vol. 113, Iss: 8, pp 1387-1394
TLDR
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.Abstract:
The effects of eddy currents in transformer windings are 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. The method consists in dividing the winding into portions, calculating the d.c. resistances and d.c. leakage inductances of each of these portions, and then multiplying the d.c. values by appropriate factors to obtain the corresponding a.c. values. These a.c. values are then referred to, say, the primary winding and summed to give the total winding resistance and leakage inductance of the transformer. Formulas are derived and quoted for calculating the d.c. resistances and leakage inductances of the winding portions. Theoretical expressions are derived for the variation with frequency etc. of the factors by which the d.c. values must be multiplied to obtain the corresponding a.c. values. These expressions are presented in the form of graphs, permitting the factors to be read as required.read more
Citations
More filters
Journal ArticleDOI
Copper Loss Analysis of EV Charging Coupler
Shuo Wang,David G. Dorrell +1 more
TL;DR: In this article, the magnetic field of the coupler is estimated and the core and copper losses of a charging coupler are analyzed using Litz-wire to reduce eddy current loss.
Proceedings ArticleDOI
An improved AC loss model for the optimization of planar-coil inductors
TL;DR: In this article, a computationally efficient method for calculating ac winding losses in planar-coil inductors is presented, which is employed in a multi-objective optimization algorithm to determine inductor designs which minimize power loss while maximizing power density.
Journal ArticleDOI
Frequency Optimization for Inductive Power Transfer Based on AC Resistance Evaluation in Litz-Wire Coil
TL;DR: In this paper, the authors proposed a volume integral method to evaluate the overall effect of the magnetic field on the induction resistance, and the optimized frequency for the maximum efficiency was obtained, using the squared field calculation and resulting ac resistance evaluation.
Journal ArticleDOI
Transistor Inverter Design Optimization in the Frequency Range Above 5 kHz Up to 50 kVA
Jacobus D. Van Wyk,J.A. Ferreira +1 more
TL;DR: In this paper, the design of inverters for industrial applications including static power supplies, light welding equipment, and high-speed motor control at input voltages from 30 to 300 V are described.
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.
References
More filters
Journal ArticleDOI
Effective resistance to alternating currents of multilayer windings
Edward Bennett,Sidney C. Larson +1 more
TL;DR: 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.
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
Effective Resistance to Alternating Currents of Multilayer Windings
Journal ArticleDOI
Eddy-Current Losses in Cylindrical Conductors, with Special Applications to the Alternating Current Resistances of Short Coils
TL;DR: In this article, it is shown that a considerable proportion of the effective resistance of inductive coils when used at radio frequencies is caused by the eddy-currents set up in the wires of the coils by the alternating magnetic field in which they are situated, and that in extreme cases the alternating current resistance may amount to more than one hundred times the direct current resistance.
Journal ArticleDOI
Heat Losses in the Conductors of Alternating-Current Machines
TL;DR: In this article, the authors show how hyperbolic functions of complex angles may be applied to the solution of the problem of heat losses in rectangular conductors that are embedded in open slots.