Calculation and Analysis of the Winding Loss of High-Frequency Transformer Based on Finite Element Method
01 Oct 2018-
TL;DR: In this article, the effects of skin effect and proximity effect on the winding loss of high frequency transformers under the high frequency conditions are described and a two-dimensional (2D) loss calculation models for high-frequency transformer windings are established.
Abstract: The winding losses of high-frequency transformer are closely related to the wingding structures and arrangements. Find out the relationship between the structure and the size of the loss of winding is of great significance to high-frequency transformer design and manufacturing. The effects of skin effect and proximity effect on the winding loss of high frequency transformers under the high frequency conditions are described. A two-dimensional (2D) loss calculation models for high-frequency transformer windings are established. The effects of winding layout, winding thickness, frequency, and layer spacing on transformer winding losses are analyzed.
Citations
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08 Jul 2020
TL;DR: In this article, an improved version of the equation for determining the series resistance of a single wire is proposed, and a mathematical approximation to calculate the conductor resistance for any operation frequency is provided.
Abstract: Efficiency of the power converters is an important specification that determines their success on the market, being the losses a critical part that influences greatly the operation capabilities of the converter. To analyse with the required precision, the losses of magnetic component, both magnetic core and electric winding losses, usually Finite Element Method (FEM) analysis is carried out. The eddy currents effects are divided primordially in skin and proximity effects. The attention is focused on single wire alone case to better understanding the skin effect influence, proposing an improved version of the equation for determining the series resistance of a single wire. It also introduces a mathematical approximation to calculate the conductor resistance for any operation frequency. All the theoretical assumptions and conclusions are supported by numerical simulations using Finite Element Method analysis.
5 citations
Cites background from "Calculation and Analysis of the Win..."
...Nevertheless, the winding losses produced by high frequency current (due to the skin and the proximity effects) rise together with increasing frequency which in turn reduces the efficiency [5-6]....
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25 Sep 2020
TL;DR: In this article, the authors gave a complete design and analysis of a 105 W Flyback transformer operating in a critical conduction mode and showed a complete loss analysis of the flyback transformer which includes calculating core loss and copper loss (both AC and DC winding loss).
Abstract: The paper gives a complete design and analysis of a 105 W Flyback transformer operating in a critical conduction mode. One of the challenges of CrCM Flyback is the high peak and RMS current that flows in the converter which lead to a higher winding loss in the transformer. Selecting a transformer core and wire size become an important criterion for an efficient operation of the converter. The paper shows a complete loss analysis of the Flyback transformer which includes calculating core loss and copper loss (both AC and DC winding loss). Four transformers were built for the 105 W Flyback prototype and their loss breakdown has been shown.
3 citations
23 Aug 2021
TL;DR: In this article, the authors carried out the computation of the winding Eddy loss which fosters in mapping the hotspot temperature in the transformer windings, and employed the Finite Element Method (FEM) based Ansys Maxwell to treat the magnetic flux density calculations at the hub of individual winding conductors.
Abstract: The integration of classical transformer design procedures with the staggering speed and coherent versatility of modernistic computational methods to evaluate and manage stray losses in transformers incite better understanding into the transformer design philosophy especially for renewable energy (RE) application. This is on account of tools suchlike Finite Element Method (FEM) that can perform several unwieldy and iterative computations in a judicious and stepwise approach yielding transformer designs that meet the stringent technical specification of REs. In the present work, the key objective is to carry out the computation of the winding Eddy loss which fosters in mapping the hotspot temperature in the transformer windings. To enable the computation of dispersed winding Eddy loss, FEM based Ansys Maxwell is employed to treat the magnetic flux density calculations at the hub of individual winding conductors. The vector decomposition of the flux density gives winding Eddy loss as a result of axial and radial magnetic flux leakage components.
2 citations
Journal Article•
TL;DR: In this paper, a new material amorphous alloy is applied in this design for reducing loss, and the core loss and winding loss are analyzed based on optimal efficiency, a procedure for optimum design of high-power electronic transformer is presented.
Abstract: The high-power electronic transformer is the most essential part for switched mode power supply(SMPS) since it determines about 25% of the overall volume and more than 30% of the overall weight.It is well known that the loss of transformer of high-power electronic transformer is considerably large.Thus a new material amorphous alloy is applied in this design for reducing loss.The core loss and winding loss are analyzed.Based on optimal efficiency,a procedure for optimum design of high-power electronic transformer is presented.The operating magnetic flux density and current density are treated as variables in calculating main parameters of transformer by MATLAB program.It provides optimal parameters of electronic transformer for efficiency maximization.The temperature field and electric field are simulated by ANSYS.The results of simulation prove that this design of the electronic transformer is reasonable.
1 citations
References
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01 Aug 1966
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.
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.
1,246 citations
TL;DR: In this paper, the frequency-dependent resistance in Litz-wire planar windings for domestic induction heating appliances is analyzed and the magnetic field necessary to evaluate the external proximity losses is as well analytically calculated considering the complete winding and load properties.
Abstract: In this paper, the frequency-dependent resistance in Litz-wire planar windings for domestic induction heating appliances is analyzed. For these inductors, in which the size is not an essential constraint, an analytical model is developed based on the superposition of different loss effects in the wire. Eddy current losses, including conduction losses and proximity-effect losses, both internal and external, were considered and modeled. The magnetic field necessary to evaluate the external proximity losses is as well analytically calculated considering the complete winding and load properties. To verify this model and its limitations, several inductors with different wires and numbers of turns were constructed and results with both non-loaded and loaded inductors are compared with theoretical predictions.
149 citations
07 Jul 2011
TL;DR: In this article, the impact of peak-to-peak flux density ΔB, frequency f, DC premagnetization H DC, temperature T, core shape, minor and major loops, flux waveform, and material on core loss calculation is considered.
Abstract: Loss models of inductive components are thoroughly investigated, thereby all different aspects of loss modeling are considered. The impact of peak-to-peak flux density ΔB, frequency f, DC premagnetization H DC , temperature T, core shape, minor and major loops, flux waveform, and material on core loss calculation are considered. In order to calculate winding losses, formulas for round conductors and litz wires, each including skin- and proximity effects (including the influence of an air-gap fringing field) are included. A high level of accuracy is achieved by combining the best state-of-the-art approaches and by embedding newly-developed approaches into a novel loss calculation framework. The loss models are verified by FEM simulations and experimental measurements.
134 citations
TL;DR: In this paper, a new empirical core loss calculation method, flux-wave-form-coefficient Steinmetz equation, is proposed and verified for the nanocrystalline material under resonant operations, which are often employed in high frequency power converter applications.
Abstract: The loss density of the nanocrystalline magnetic material is experimentally characterized up to 500 kHz and above 1 Tesla in this paper. B-H hysteresis magnetization curves and loss density of the material under various operating temperatures up to 150degC are measured and presented. The core preparing effect on magnetic loss density is also identified by experiments, which provides information necessary to practical magnetic designs. A new empirical core loss calculation method, flux-wave-form-coefficient Steinmetz equation, is proposed and verified for the nanocrystalline material under resonant operations, which are often employed in high-frequency power converter applications. The proposed approach is either more accurate or easier to use than the previous methods.
130 citations
TL;DR: In this paper, a 3D simulation of the connector allows the determination of the current values depending on the position of the strands in the wire This current distribution is transferred to a 2D rotationally symmetric simulation of a system (windings, coils, etc) The current values are permuted between different strands to simulate the twisting of strands inside the litz wire.
Abstract: For inductive components such as coils, inductors or transformers, litz wires with isolated strands are used to decrease conduction losses in applications with higher operating frequencies Depending on the inner structure of these wires, the frequency dependent losses differ extremely Until now simulations have not sufficiently matched experimental measurements The usual simulation approach has been to assume the initial current values in all strands in the litz wire to be the same In this paper, a 3-D simulation of the connector allows the determination of the current values depending on the position of the strands in the wire This current distribution is transferred to a 2-D rotationally symmetric simulation of the system (windings, coils, etc) The current values are permuted between different strands to simulate the twisting of strands inside the litz wire With this new method a very good agreement with measured losses was achieved and demonstrates how simulation allows one to improve the performance of litz wires
97 citations