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Article
Publication date: 13 July 2010

S. Jelassi, R. Romary and J.F. Brudny

The aim of this paper is to estimate the iron losses for an induction machine in the healthy case taking the slotting effect into account and to study the effect of an inter‐turn…

Abstract

Purpose

The aim of this paper is to estimate the iron losses for an induction machine in the healthy case taking the slotting effect into account and to study the effect of an inter‐turn short‐circuit on these losses. Theoretical results are then compared with experimental ones.

Design/methodology/approach

A simple analytical model of iron losses allows one to calculate and to appreciate the contribution of the slotting effect on induction machine iron losses without and with an inter‐turn stator short‐circuit. This semi‐analytical approach is based on the iron stator and rotor flux density repartition which is deduced from the air‐gap flux density.

Findings

The iron losses are not only due to the fundamental air‐gap flux density, but also to the slotting harmonics. In fact, the slotting effect generates harmonic flux density waves with very low magnitudes but with high‐angular velocities, leading to non‐negligible harmonic iron dynamic losses which have similar values on both the stator and the rotor. The inter‐turn short‐circuit generates an iron losses and a slotting harmonic contribution increase.

Research limitations/implications

Experimental measurements give the total iron losses. They do not allow separating the fundamental and the slotting harmonics contribution.

Practical implications

The knowledge of the iron losses behaviour in the healthy machine taking into account the slotting effect is important to optimize the design. The fault contribution on these losses allows one to estimate the damage which can be engendered by the fault.

Originality/value

Generally, iron losses studies and calculations are performed numerically using finite element software. The analytical approach can be interesting because it allows one to make faster calculations and to analyze the influence of the machine geometric parameters.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 29 no. 4
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 1 April 2006

Heon Lee, Heegon Moon, Semyung Wang and Kyungbae Park

Aims to discuss iron loss analysis and experimenting with linear oscillating actuator for linear compressor.

Abstract

Purpose

Aims to discuss iron loss analysis and experimenting with linear oscillating actuator for linear compressor.

Design/methodology/approach

The iron loss analysis of the linear oscillating actuator is performed by using ANSYS and iron loss curves, which is obtained by an Epstein test apparatus.

Findings

The way to calculate the iron loss of the linear oscillating actuator for the linear compressor and the method to experiment the iron loss of that can be studied.

Research limitations/implications

Iron loss analysis of the linear compressor considering the motor part and the structure part is needed.

Originality/value

Each iron loss analysis method examined here can be used to analyze the iron loss of the linear motor.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 25 no. 2
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 13 November 2009

Zbigniew Gmyrek

The purpose of this paper is to discuss a new method of iron loss estimation under pulse width modulation (PWM) converter supply. The proposed method concerns the longitudinal…

Abstract

Purpose

The purpose of this paper is to discuss a new method of iron loss estimation under pulse width modulation (PWM) converter supply. The proposed method concerns the longitudinal magnetisation.

Design/methodology/approach

A novel method of iron loss estimation applies values of iron losses that come from a single higher harmonic coexisting with a DC‐bias field. This method considers non‐linearity of ferromagnetic. Results of estimation are validated using experimental results.

Findings

The paper formulates that the dependence of iron losses come from harmonics, on DC‐bias field. Moreover, it formulates possibilities of their utilization to iron loss estimation in case of deformed flux. On the other hand, it discusses the influence of DC‐bias field on static hysteresis and classical eddy current losses.

Research limitations/implications

Experimental verification will still be needed as to the accuracy of the proposed model and applicability to various magnetic materials.

Practical implications

The paper provides an easy mathematical method of iron loss estimation, under PWM voltage supply.

Originality/value

The paper explains how to use an analytical method and results of iron losses come from single harmonics, obtained under coexistence with DC‐bias field, to iron loss estimation in case of longitudinal magnetisation where deformed magnetic flux occurs.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 28 no. 6
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 6 November 2017

Longfei Zhu, Wenming Tong, Xueyan Han and Jianguo Zhu

The specific iron losses of amorphous alloy material are extremely low compared with silicon steel material. The iron losses of motors may reduce by replacing the silicon steel…

Abstract

Purpose

The specific iron losses of amorphous alloy material are extremely low compared with silicon steel material. The iron losses of motors may reduce by replacing the silicon steel core with an amorphous alloy core. However, one drawback of amorphous alloy material is that the specific iron losses will increase a lot after the motor manufacturing process. This paper aims to study the influences of interlaminar insulator solidifying and annealing on amorphous alloy material. The iron losses of motors made of amorphous alloy and baseline silicon steel sheets are compared and discussed.

Design/methodology/approach

This paper opted for an exploratory study using the experimental analysis and loss separation methods. Two amorphous alloy cores are produced and tested. The iron losses of motors made of amorphous alloy and silicon steel sheets are calculated and compared based on the measured specific iron losses. Three wound amorphous alloy core samples are made and measured. The iron losses are separated and compared by considering the manufacturing influences.

Findings

This paper provides empirical insights about what change is brought in amorphous alloy material after manufacturing. The results have shown that, for amorphous alloy cores without the annealing process, the loss increase caused by solidifying is mainly the eddy current loss, while it is mainly the hysteresis loss component for annealed amorphous alloy cores.

Originality/value

This paper presents for the first time the measured results of manufactured amorphous alloy cores. This paper fulfils the need to manufacture amorphous alloy motors properly for the producers.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 36 no. 6
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 26 June 2019

Benedikt Groschup, Silas Elfgen and Kay Hameyer

The cutting process of the electric machine laminations causes residual mechanical stress in the soft magnetic material. A local magnetic deterioration can be observed and the…

Abstract

Purpose

The cutting process of the electric machine laminations causes residual mechanical stress in the soft magnetic material. A local magnetic deterioration can be observed and the resulting local and global iron losses increase. A continuous local material model for the consideration of the changing magnetization properties has been introduced in a previous work as well as an a priori assessment of iron losses. A local iron loss calculation considering both a local magnetization and local loss parameters misses yet. The purpose of this study is to introduce a local iron loss calculation model considering both a local magnetization and local loss parameters.

Design/methodology/approach

In this paper, an approach for local iron loss simulation is developed and a comparison to the cut-edge length-dependent loss model is given. The comparison includes local loss distribution in the lamination as well as the impact on the overall motor efficiency and vehicle range in an electric vehicle driving cycle.

Findings

For an analysis of the resulting local iron loss components, both the local magnetization and iron loss parameters must be considered using physically based models. Consistently, a local iron loss model is presented in the work. The developed model can be used to gain detailed information of the local loss distribution inside the machine. The comparability of this local iron loss with the cut-edge length approach for overall system characteristics, e.g. efficiency or driving range, is shown.

Originality/value

A local iron loss simulation approach is a physical accurate model to describe the influence of cutting techniques on electric machine characteristics. A comparison with the less complicated a priori assessment gives detailed information about the necessity of the local model under consideration of the given problem.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 38 no. 4
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 2 January 2018

Wenju Yan, Hao Chen, Lei Chen and Kai Wang

This paper aims to establish a modified variable coefficient calculation model to analyse the control parameter effect on the iron loss of switched reluctance motor under pulse…

Abstract

Purpose

This paper aims to establish a modified variable coefficient calculation model to analyse the control parameter effect on the iron loss of switched reluctance motor under pulse width modulation (PWM) mode.

Design/methodology/approach

The finite element model is solved to get the flux density by python language. Due to non-sinusoidal flux density feature and the effect of PWM excitation, the Fourier transform is applied in consideration of harmonic components. To improve the accuracy of iron loss computation, the effect of minor loops is considered by using the rain-flow counting method.

Findings

When the speed fluctuates around the set speed and the fluctuations are relatively small, it is useful to reduce the iron loss with smaller duty ratio and turn-on angle or greater duty ratio and smaller turn-off angle. The iron loss is less affected by chopping frequency, while the iron loss increases obviously with higher conduction angles. The iron loss under non-energy-returnable-voltage-chop mode is greater than energy-returnable-voltage-chop mode.

Originality/value

The modified variable coefficient MIEM5 iron loss model is proposed to improve the accuracy of iron loss calculation. Then the control parameters such as duty ratio, chopping frequency, turn on angle and turn off angle are analysed under PWM mode.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 37 no. 1
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 5 November 2021

Benedikt Schauerte, Martin Marco Nell, Tim Brimmers, Nora Leuning and Kay Hameyer

The magnetic characterization of electrical steel is typically examined by measurements under the condition of unidirectional sinusoidal flux density at different magnetization…

Abstract

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.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering , vol. 41 no. 2
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 17 February 2022

Ali Jamali Fard and Mojtaba Mirsalim

This paper aims to present an adaptive method based on finite element analysis to calculate iron losses in switched reluctance motors (SRMs). Calculation of iron losses by…

Abstract

Purpose

This paper aims to present an adaptive method based on finite element analysis to calculate iron losses in switched reluctance motors (SRMs). Calculation of iron losses by analytical formulas has limited accuracy. On the other hand, its estimation in rotating electrical machines through fully dynamic simulations with a fine time-step is time-consuming. However, in the initial design process, a quick and sufficiently accurate method, i.e. a value close to that of iron losses, is always welcome. The method presented in this paper is a semi-analytical approach. The main problem is that iron losses depend on d B/d t. Therefore, the accuracy of the calculation of iron losses depends on the accuracy of the calculation of the first derivative of the flux density waveform. When adopting a magnetostatic model to estimate the iron losses, an important question arises: by how many magnetostatic simulations can the iron losses be estimated within the desired accuracy? In the proposed algorithm, the aim is not to accurately calculate the value of iron losses in SRMs. The objective is to find a numerical error criterion to calculate iron losses in SRMs with a minimum number of magnetostatic simulations.

Design/methodology/approach

A finite element solver is developed by authors in MATLAB to solve the 2 D nonlinear magnetostatic problem using the Newton–Raphson method. A parametric program is developed to create geometry and mesh. The proposed method is implemented in MATLAB using the developed solver. Counterpart simulations are done in the ANSYS Maxwell software to validate the accuracy of the results generated by the developed solver.

Findings

The performance of the proposed method is studied on a 12/8 (500 W) SRM. Three scenarios are studied. The first one is the calculation of iron losses by uniform refinement, and the second one is by adaptive refinement, and the last one is by adaptive refinement started by particular initial points (switching points). According to the results, the proposed method substantially reduces the number of magnetostatic simulations without sacrificing accuracy.

Originality/value

The main novelty of this paper is introducing an error criterion to find the minimum number of magnetostatic simulations that are needed to calculate iron losses with the desired accuracy.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering , vol. 41 no. 5
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 16 November 2010

A. Belahcen, E. Dlala, K. Fonteyn and M. Belkasim

The purpose of this paper is to find out how to model iron losses in electrical machines accurately and efficiently.

Abstract

Purpose

The purpose of this paper is to find out how to model iron losses in electrical machines accurately and efficiently.

Design/methodology/approach

The starting point was a previously developed vector hysteresis model that was designed and incorporated into the 2D time‐stepping finite‐element (FE) simulation of induction machines. The developed approach here is a decoupling between the vector hysteresis model and the 2D FE model of the machine. The huge time consumption of the incorporated hysteresis model required some new approach to make the model computationally efficient. This is dealt with through an a posteriori use of the vector hysteresis model.

Findings

In this research, it was found that the vector hysteresis model, although used in an a posteriori scheme is able to accurately predict the iron losses as far as these losses are small enough not to affect the other operation characteristics of the machine.

Research limitations/implications

The research methods reported in this paper deal mainly with induction machines. The methods should be applied for transient operations of the induction machines as well as for other types of machines. The fact that the iron losses do not affect very much the operation characteristics of the machine is based on the fact that the air gap field plays a major role in these machines. The method cannot be applied to other magnetic devices where the iron losses are the main loss component.

Originality/value

The paper is of practical value for designers of electrical machines, who use FE programs. The methods presented here allow them to use a different FE package to simulate the machine and own routines (based on the presented methods) to predict the iron losses without loss of accuracy and in a reasonably short time.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 29 no. 6
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 24 June 2019

Jan Karthaus, Benedikt Groschup, Robin Krüger and Kay Hameyer

Due to the increasing amount of high power density high-speed electrical machines, a detailed understanding of the consequences for the machine’s operational behaviour and…

Abstract

Purpose

Due to the increasing amount of high power density high-speed electrical machines, a detailed understanding of the consequences for the machine’s operational behaviour and efficiency is necessary. Magnetic materials are prone to mechanical stress. Therefore, this paper aims to study the relation between the local mechanical stress distribution and magnetic properties such as magnetic flux density and iron losses.

Design/methodology/approach

In this paper, different approaches for equivalent mechanical stress criteria are analysed with focus on their applicability in electrical machines. Resulting machine characteristics such as magnetic flux density distribution or iron are compared.

Findings

The study shows a strong influence on the magnetic flux density distribution when considering the magneto-elastic effect for all analysed models. The influence on the iron loss is smaller due to a high amount of stress-independent eddy current loss component.

Originality/value

The understanding of the influence of mechanical stress on dimensions of electrical machines is important to obtain an accurate machine design. In this paper, the discussion on different equivalent stress approaches allows a new perspective for considering the magneto-elastic effect.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 38 no. 4
Type: Research Article
ISSN: 0332-1649

Keywords

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