Calculation and validation of iron loss in laminated core of power and distribution transformers

2013 ◽  
Vol 33 (1/2) ◽  
pp. 137-146 ◽  
Author(s):  
Xiaoyan Wang ◽  
Zhiguang Cheng ◽  
Li Lin ◽  
Jianmin Wang
Keyword(s):  
Magnetic Flux ◽  
Flux Density ◽  
Core Loss ◽  
Iron Loss ◽  
Magnetic Flux Density ◽  
Content Type ◽  
The Core ◽  
Distribution Transformers ◽  
The Impact ◽  
Transformer Core

Purpose – The purpose of this paper is to present a simple method to analyze the iron loss in the laminated core of power and distribution transformers. Design/methodology/approach – This paper presents a practical method to calculate the no-load loss in the transformer cores. Considering the non-uniformity of the magnetic flux density in the corner areas of the Epstein frames will affect the measurement precision of the Wt-B curves then further affect the core loss calculation in FEM, a dual-Epstein frame method is used to measure the Wt-B curves with the Epstein sample stripes cutting by different angles to the rolling direction. A 2D FEM that considers the type of joints of the core and eddy current effect in the laminations is used to analyze the core loss with multi-angle Wt-B curves. Findings – The impact of lamination thickness, size of gaps and type of joint of the core are considered. Considering the no-load testing conditions, harmonics in the exciting currents are taken into account. Originality/value – Harmonic wave of magnetic flux density in the transformer core is calculated and the core loss in the joint region is calculated by the loss curve measured with dual-Epstein frame. It makes the calculation result of transformer core loss more exactly.

scholarly journals Distributed Magnetic Flux Density on the Cross-Section of a Transformer Core

Electronics ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 297 ◽  
Author(s):  
Lingzhi Li ◽  
Xuhao Du ◽  
Jie Pan ◽  
Adrian Keating ◽  
David Matthews ◽  
...  
Keyword(s):  
Magnetic Flux ◽  
Flux Density ◽  
Cross Section ◽  
Air Gap ◽  
Magnetic Flux Density ◽  
The Core ◽  
The Cross ◽  
Flux Density Distribution ◽  
Transformer Core ◽  
The Relationship

In this paper, the magnetic flux density distribution on the cross-sections of a transformer core is studied. The core for this study consists of two identical U-shaped cores joint at their open surfaces with known air gaps. The magnetic flux density at one of their joint boundary surfaces was measured for different air gaps. A finite element model (FEM) was built to simulate the magnetic flux density and compared with experiment data. Using the validated FEM, the distributed magnetic flux density on the cross-section of the core structure can be obtained when the air gap approaches zero. An engineering model of the density based on the Ampere’s circuit law was also developed and used to explain the relationship between air gap and mean magnetic flux density on the cross-section. The magnetic flux density on the cross-section was found to have a convex-shaped distribution and could be described by an empirical formula. Using this approach, the magnetic flux density distribution in cores with different interlayer insulation was obtained and discussed. This method could also examine the leakage of magnetic flux density in the air gap region when the distance is non-zero, and the relationship between the leakage field and the field in the core structure. The proposed method and model can provide a more detailed understanding for the magnetic field of transformer cores and potential application in designing quiet transformers and condition monitoring.

Simulation of iron losses in induction machines using an iron loss model for rotating magnetization loci in no electrical steel

2022 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Martin Marco Nell ◽  
Benedikt Schauerte ◽  
Tim Brimmers ◽  
Kay Hameyer
Keyword(s):  
Finite Element ◽  
Flux Density ◽  
Core Loss ◽  
Induction Machine ◽  
Iron Loss ◽  
Magnetic Flux Density ◽  
Loss Model ◽  
Content Type ◽  
Iron Losses ◽  
Loss Models

Purpose Various iron loss models can be used for the simulation of electrical machines. In particular, the effect of rotating magnetic flux density at certain geometric locations in a machine is often neglected by conventional iron loss models. The purpose of this paper is to compare the adapted IEM loss model for rotational magnetization that is developed within the context of this work with other existing models in the framework of a finite element simulation of an exemplary induction machine. Design/methodology/approach In this paper, an adapted IEM loss model for rotational magnetization, developed within the context of the paper, is implemented in a finite element method simulation and used to calculate the iron losses of an exemplary induction machine. The resulting iron losses are compared with the iron losses simulated using three other already existing iron loss models that do not consider the effects of rotational flux densities. The used iron loss models are the modified Bertotti model, the IEM-5 parameter model and a dynamic core loss model. For the analysis, different operating points and different locations within the machine are examined, leading to the analysis of different shapes and amplitudes of the flux density curves. Findings The modified Bertotti model, the IEM-5 parameter model and the dynamic core loss model underestimate the hysteresis and excess losses in locations of rotational magnetizations and low-flux densities, while they overestimate the losses for rotational magnetization and high-flux densities. The error is reduced by the adapted IEM loss model for rotational magnetization. Furthermore, it is shown that the dynamic core loss model results in significant higher hysteresis losses for magnetizations with a high amount of harmonics. Originality/value The simulation results show that the adapted IEM loss model for rotational magnetization provides very similar results to existing iron loss models in the case of unidirectional magnetization. Furthermore, it is able to reproduce the effects of rotational flux densities on iron losses within a machine simulation.

Effect of Antimony on the Structure, Texture and Magnetic Properties of High Efficiency Non-Oriented Electrical Steel

2012 ◽  
Vol 602-604 ◽  
pp. 435-440 ◽  
Author(s):  
Na Li ◽  
Li Xiang ◽  
Pei Zhao
Keyword(s):  
Magnetic Properties ◽  
Magnetic Flux ◽  
Flux Density ◽  
High Efficiency ◽  
Electrical Steel ◽  
Core Loss ◽  
Magnetic Flux Density ◽  
Antimony Content ◽  
The Core ◽  
Maximum Value

The effect of antimony on the structure, texture and magnetic properties of high efficiency non-oriented electrical steel were investigated. The results showed that antimony played an important role on inhibiting the grain growth and enhancing the fraction of favorable texture in the annealed steels. With the increase of antimony content, core loss of specimens monotonously increased and the magnetic flux density increased firstly and then decreased. The magnetic properties of specimen results showed that the magnetic flux density in the steel with 0.12% antimony reached the maximum value, while the core loss didn’t increase obviously. However, when the antimony content in steel reached 0.22%, the magnetic properties deteriorated significantly. This is maybe that the addition of antimony in steels inhibited the development of {111} texture content and increased the intensity of Goss and {100} texture on the grain boundary.

Adaptation and parametrization of an iron loss model for rotating magnetization loci in NO electrical steel

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Benedikt Schauerte ◽  
Martin Marco Nell ◽  
Tim Brimmers ◽  
Nora Leuning ◽  
Kay Hameyer
Keyword(s):  
Magnetic Flux ◽  
Flux Density ◽  
Electrical Steel ◽  
Electrical Machines ◽  
Iron Loss ◽  
Magnetic Flux Density ◽  
Loss Model ◽  
Content Type ◽  
One Dimensional ◽  
Iron Losses

Purpose The magnetic characterization of electrical steel is typically examined by measurements under the condition of unidirectional sinusoidal flux density at different magnetization frequencies. A variety of iron loss models were developed and parametrized for these standardized unidirectional iron loss measurements. In the magnetic cross section of rotating electrical machines, the spatial magnetic flux density loci and with them the resulting iron losses vary significantly from these unidirectional cases. For a better recreation of the measured behavior extended iron loss models that consider the effects of rotational magnetization have to be developed and compared to the measured material behavior. The aim of this study is the adaptation, parametrization and validation of an iron loss model considering the spatial flux density loci is presented and validated with measurements of circular and elliptical magnetizations. Design/methodology/approach The proposed iron loss model allows the calculation and separation of the different iron loss components based on the measured iron loss for different spatial magnetization loci. The separation is performed in analogy to the conventional iron loss calculation approach designed for the recreation of the iron losses measured under unidirectional, one-dimensional measurements. The phenomenological behavior for rotating magnetization loci is considered by the formulation of the different iron loss components as a function of the maximum magnetic flux density Bm, axis ratio fAx, angle to the rolling direction (RD) θ and magnetization frequency f. Findings The proposed formulation for the calculation of rotating iron loss is able to recreate the complicated interdependencies between the different iron loss components and the respective spatial magnetic flux loci. The model can be easily implemented in the finite element analysis of rotating electrical machines, leading to good agreement between the theoretically expected behavior and the actual output of the iron loss calculation at different geometric locations in the magnetic cross section of rotating electrical machines. Originality/value Based on conventional one-dimensional iron loss separation approaches and previously performed extensions for rotational magnetization, the terms for the consideration of vectorial unidirectional, elliptical and circular flux density loci are adjusted and compared to the performed rotational measurement. The presented approach for the mathematical formulation of the iron loss model also allows the parametrization of the different iron loss components by unidirectional measurements performed in different directions to the RD on conventional one-dimensional measurement topologies such as the Epstein frames and single sheet testers.

Modelling transformer core joints using Gaussian models for the magnetic flux density and permeability

2010 ◽  
Vol 4 (9) ◽  
pp. 761 ◽  
Author(s):  
I. Hernández ◽  
F. de León ◽  
J.M. Cañedo ◽  
J.C. Olivares-Galván
Keyword(s):  
Magnetic Flux ◽  
Flux Density ◽  
Magnetic Flux Density ◽  
Gaussian Models ◽  
Transformer Core

scholarly journals A Novel Excitation Approach for Power Transformer Simulation Based on Finite Element Analysis

2021 ◽  
Vol 11 (21) ◽  
pp. 10334
Author(s):  
Wen-Ching Chang ◽  
Cheng-Chien Kuo
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Magnetic Flux ◽  
Flux Density ◽  
Power Transformer ◽  
Core Loss ◽  
Power Transformers ◽  
Magnetic Flux Density ◽  
External Excitation ◽  
Element Method

Power transformers play an indispensable component in AC transmission systems. If the operating condition of a power transformer can be accurately predicted before the equipment is operated, it will help transformer manufacturers to design optimized power transformers. In the optimal design of the power transformer, the design value of the magnetic flux density in the core is important, and it affects the efficiency, cost, and life cycle. Therefore, this paper uses the software of ANSYS Maxwell to solve the instantaneous magnetic flux density distribution, core loss distribution, and total iron loss of the iron core based on the finite element method in the time domain. . In addition, a new external excitation equation is proposed. The new external excitation equation can improve the accuracy of the simulation results and reduce the simulation time. Finally, the three-phase five-limb transformer is developed, and actually measures the local magnetic flux density and total core loss to verify the feasibility of the proposed finite element method of model and simulation parameters.

scholarly journals Performance of Inductive Coupled Power Transfer Versus the Coil Shape - Investigation using Finite Element Analysis

2018 ◽  
Vol 225 ◽  
pp. 01017 ◽  
Author(s):  
Mohd Fakhizan Romlie ◽  
Kevin Lau ◽  
Mohd Zaifulrizal Zainol ◽  
Mohd Faris Abdullah ◽  
Ramani Kannan
Keyword(s):  
Magnetic Flux ◽  
Flux Density ◽  
Coupling Coefficient ◽  
Mutual Inductance ◽  
Magnetic Flux Density ◽  
Power Transfer ◽  
Element Analysis ◽  
Spiral Coil ◽  
The Impact ◽  
Coil Shape

The objective of this paper is to investigate the impact of the spiral coil shape of inductive coupled power transfer on its performance. The coil shapes evaluated are: circular, square and pentagon spiral shapes. The coils are modelled in Ansoft Maxwell software. Simulations are carried out to determine the mutual inductance, coupling coefficient and magnetic flux density. The performance in term of magnetic flux density, mutual inductance and coupling coefficient of the three coils shapes are compared. Of the three shapes, the pentagon is shown to have the best performance in term of its mutual inductance, coupling coefficient and magnetic flux density.

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