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Article
Publication date: 1 June 2000

K. Wiak

Discusses the 27 papers in ISEF 1999 Proceedings on the subject of electromagnetisms. States the groups of papers cover such subjects within the discipline as: induction…

Abstract

Discusses the 27 papers in ISEF 1999 Proceedings on the subject of electromagnetisms. States the groups of papers cover such subjects within the discipline as: induction machines; reluctance motors; PM motors; transformers and reactors; and special problems and applications. Debates all of these in great detail and itemizes each with greater in‐depth discussion of the various technical applications and areas. Concludes that the recommendations made should be adhered to.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 19 no. 2
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 2 May 2017

Jan Karthaus, Simon Steentjes, Nora Leuning and Kay Hameyer

The purpose of this paper is to study the variation of the specific iron loss components of electrical steel sheets when applying a tensile mechanical load below the yield…

Abstract

Purpose

The purpose of this paper is to study the variation of the specific iron loss components of electrical steel sheets when applying a tensile mechanical load below the yield strength of the material. The results provide an insight into the iron loss behaviour of the laminated core of electrical machines which are exposed to mechanical stresses of diverse origins.

Design/methodology/approach

The specific iron losses of electrical steel sheets are measured using a standardised single-sheet tester equipped with a hydraulic pressure cylinder which enables application of a force to the specimen under test. Based on the measured data and a semi-physical description of specific iron losses, the stress-dependency of the iron loss components can be studied.

Findings

The results show a dependency of iron loss components on the applied mechanical stress. Especially for the non-linear loss component and high frequencies, a large variation is observed, while the excess loss component is not as sensitive to high mechanical stresses. Besides, it is shown that the stress-dependent iron loss prediction approximates the measured specific iron losses in an adequate way.

Originality/value

New applications such as high-speed traction drives in electric vehicles require a suitable design of the electrical machine. These applications require particular attention to the interaction between mechanical influences and magnetic behaviour of the machine. In this regard, knowledge about the relation between mechanical stress and magnetic properties of soft magnetic material is essential for an exact estimation of the machine’s behaviour.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 36 no. 3
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 1 February 1994

FAN YU, G.D. BAINES and B.J. CHALMERS

This paper describes a versatile electrical machine drive simulation procedure. Based on the trapezoidal rule, an arbitrarily configured power electronic circuit is…

Abstract

This paper describes a versatile electrical machine drive simulation procedure. Based on the trapezoidal rule, an arbitrarily configured power electronic circuit is discretized into an equivalent circuit of companion branches, and nodal equations are then set up automatically. The state equations of electrical machines are also solved using the trapezoidal rule. To simplify the procedure and save computing time, the circuit and motor equations are calculated separately and interfaced through Park's transformation. The generalized procedure described in this paper is illustrated by application to the transient performance of an inverter‐fed permanent‐magnet synchronous motor with high pulse‐width‐modulated chopping ratio and ramped reference signal frequency. Computed results are correlated with experimental measurements.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 13 no. 2
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 1 January 2013

Massimo Barcaro and Nicola Bianchi

The purpose of this paper is to give an overview of the design issues of permanent magnet machines for the hybrid electric and plug‐in electric vehicles, including railway…

Abstract

Purpose

The purpose of this paper is to give an overview of the design issues of permanent magnet machines for the hybrid electric and plug‐in electric vehicles, including railway traction and naval propulsion.

Design/methodology/approach

Focus is given on both synchronous permanent magnet and reluctance machines. An overview of the design rules are provided, covering the topics of: fractional‐slot windings, fault‐tolerant configurations, flux‐weakening capability, and torque quality.

Findings

The peculiarities of these machines and the advanced design considerations to fit the automotive requirements are analyzed.

Originality/value

The paper includes a wide description of innovative electrical machines for electric vehicles, including not only the traction capability, but also analysis of features as weight reduction, torque ripple reduction, increase of fault tolerance, and so on.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 32 no. 1
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 5 May 2015

Andreas Ruf, Simon Steentjes, David Franck and Kay Hameyer

The purpose of this paper is to focus on the frequency-dependent non-linear magnetization behaviour of the soft magnetic material, which influences both the energy loss…

Abstract

Purpose

The purpose of this paper is to focus on the frequency-dependent non-linear magnetization behaviour of the soft magnetic material, which influences both the energy loss and the performance of the electrical machine. The applied approach is based on measured material characteristics for various frequencies and magnetic flux densities. These are varied during the simulation according to the operational conditions of the rotating electrical machine. Therewith, the fault being committed neglecting the frequency-dependent magnetization behaviour of the magnetic material is examined in detail.

Design/methodology/approach

The influence of non-linear frequency-dependent material properties is studied by variation of the frequency-dependent magnetization characteristics. Two different non-oriented electrical steel grades having the same nominal losses at 1.5 T and 50 Hz, but different thickness, classified as M330-35A and M330-50A are studied in detail. Both have slightly different magnetization and loss behaviour.

Findings

This analysis corroborates that it is important to consider the frequency-dependency and saturation behaviour of the ferromagnetic material as well as its magnetic utilization when simulating electrical machines, i.e., its performance. The necessity to change the magnetization curve according to the applied frequency for the calculation of operating points depends on the applied material and the frequency range. Using materials, whose magnetization behaviour is marginally affected by frequency, causes a deviation in the flux-linkage and the electromagnetic torque in a small frequency range. However, analysing larger frequency ranges, the frequency behaviour of the material cannot be neglected. For instance, a poorer magnetizability requires a higher quadrature current to keep the same torque leading to increased copper losses. In addition, the applied iron-loss model plays a central role, since changes in magnetization behaviour with frequency lead to changes in the iron losses. In order to study the impact, the iron-loss model has to be capable to incorporate the harmonic content, because particularly the field harmonics are influenced by the shape of the magnetization curve.

Originality/value

This paper gives a close insight on the way the frequency-dependent non-linear magnetization behaviour affects the energy loss and the performance of electrical machines. Therewith measures to tackle this could be derived.

Details

COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering, vol. 34 no. 3
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 1 January 2013

Luigi Alberti, Elisabetta Tedeschi, Nicola Bianchi, Maider Santos and Alessandro Fasolo

The purpose of this paper is to investigate the impact of control strategy selection on the power performance of wave energy converters for different ratings of the Power…

Abstract

Purpose

The purpose of this paper is to investigate the impact of control strategy selection on the power performance of wave energy converters for different ratings of the Power Take‐Off (PTO) system.

Design/methodology/approach

The case of a point absorber equipped with an all‐electric PTO is considered. The effect of control techniques and electrical generator design is analyzed from a theoretical standpoint and then verified through integrated hydrodynamic‐electric simulations.

Findings

It has been proved that control parameters that maximize the power extraction from the waves can be derived based on the power and torque constraints imposed by the electrical machine.

Originality/value

An optimized and integrated approach to the control strategy selection and generator design for point absorbers has been presented, which maximizes the electric power generation from sea waves under real conditions and represents a good trade‐off for the PTO from both the technical and the economic standpoint.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 32 no. 1
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 25 June 2019

Aron Szucs, Zlatko Kolondzovski, Jan Westerlund and Juha Vahala

The thermal management of electrical insulations poses a challenge in electrical devices as electrical insulators are also thermal insulators. Diamond is the best solid…

Abstract

Purpose

The thermal management of electrical insulations poses a challenge in electrical devices as electrical insulators are also thermal insulators. Diamond is the best solid electrical insulator and thermal conductor. This can lead to a paradigm change for electrical machine winding and lamination insulation design and thermal management. The paper introduces these techniques and discusses its effect for the design of electrical machines and its potential consequences for electromagnetic analysis, for example, in multi-physics modelling. The diamond winding insulation is patent-pending, but the diamond enriched lamination insulation is published for the benefit of the scientific community.

Design/methodology/approach

The windings of electrical machines are insulated to avoid contact between the coil and other conductive components, for example, the stator core. The principle of using mica tape and resin impregnation has not changed for a century and is well established to produce main insulation on a complex conductor shape and size. These insulations have poor heat-conducting properties. Similarly, the insulation of laminated steel sheets comprising the stator and rotor restrict heat flow. Diamond-based insulation provides a new path. Increased thermal conductivity means reduced temperature rise and the reduced thermal time constants in multi-physics simulations and system analysis.

Findings

The largest benefit of a diamond-based core insulation is in electrical machines in which the losses are conducted axially to the coolant. These are machines with radial ducts and effective cooling in the end regions. The main benefit will be in reducing the number of radial ducts that positively affect the size, production costs and the copper losses of the machine. The increased thermal conductivity of the diamond insulation system will reduce the thermal constants noticeably. These will affect system behavior and the corresponding simulation methods.

Originality/value

Diamond insulation can lead to a paradigm change for electrical machine winding and lamination insulation design and thermal management. It might also lead to new modeling requirements in system analysis.

Details

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

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Article
Publication date: 15 November 2011

Erich Schmidt

The purpose of this paper is to discuss the state of the art of finite element analysis of electrical machines and transformers. Electrical machines and transformers are…

Abstract

Purpose

The purpose of this paper is to discuss the state of the art of finite element analysis of electrical machines and transformers. Electrical machines and transformers are prime examples of multi‐physical systems involving electromagnetics, thermal issues, fluid dynamics, structural mechanics as well as acoustic phenomena. An accurate operational performance with different electrical and mechanical load situations is more and more evaluated using various numerical analysis methods including the couplings between the various physical domains. Therefore, numerical analysis methods are increasingly utilized not only for the verification of contractual values of existing machines, but also for the initial design process and for the design optimization of new machines.

Design/methodology/approach

The finite element method is the most powerful numerical analysis method for such multi‐physical devices. Since optimizations with respect to the overall performance and also the total manufacturing costs will become more important, the utilization of coupled multi‐physical analyses is of growing interest. For the fast and powerful application of this numerical analysis method, special attention should be given to the requirements of these electromagnetic devices.

Findings

Various methods of coupling the different physical domains of multi‐field finite element analyses are described. Thereby, weakly coupled cascade algorithms can be used with most problems in the field of electrical machines and transformers. On the other hand, a prime objective is to derive comprehensive, multi‐physical simulation models which are easily incorporated into design tools used by engineering professionals.

Research limitations/implications

The development of robust and reliable computer‐aided tools for an optimal design of multi‐physical devices such electrical machines and transformers has to argue about the best possible coupling of various simulation methods. Special consideration shall be paid more and more to a treatment of uncertainties and tolerances by means of statistical and probabilistic approaches.

Originality/value

The paper discusses state of the art of finite element analyses of the mentioned devices. Various optimized methods of modelling and analysis concerning the repetitive structure of electrical machines for electromagnetic analyses are compared with their advantages and drawbacks. Further, various methods of coupling the different domains of multi‐field analyses in case of electrical machines and transformers are described.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 30 no. 6
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 9 September 2013

Anouar Belahcen, Katarzyna Fonteyn, Reijo Kouhia, Paavo Rasilo and Antero Arkkio

– The purpose is to implement and compare different approaches for modelling the magnetostriction phenomenon in iron sheet used in rotating electrical machines.

Abstract

Purpose

The purpose is to implement and compare different approaches for modelling the magnetostriction phenomenon in iron sheet used in rotating electrical machines.

Design/methodology/approach

In the force-based approach, the magnetostriction is modelled as a set of equivalent forces, which produce the same deformation of the material as the magnetostriction strains. These forces among other magnetic forces are computed from the solution of the finite element (FE) field computation and used as loads for the displacement-based mechanical FE analysis. In the strain-based approach, the equivalent magnetostrictive forces are not needed and an energy-based model is used to define magnetomechanically coupled constitutive equations of the material. These equations are then space-discretised and solved with the FE method for the magnetic field and the displacements.

Findings

It is found that the equivalent forces method can reproduce the displacements and strains of the structure but it results in erroneous stress states. The energy-based method has the ability to reproduce both the stress and strains correctly; thus enabling the analysis of stress-dependent quantities such as the iron losses and the magnetostriction itself.

Research limitations/implications

The investigated methods do not account for hysteresis and other dynamic effects. They also require long computation times. With the available computing resources, the computation time does not present any problem as far as they are not used in everyday design procedures but the modelling of dynamic effect needs to be elaborated.

Originality/value

The developed and implemented methods are verified with measurements and simulation experiments and applied to as complex structure as an electrical machine. The problems related to the different approaches are investigated and explained through simulations.

Details

COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering, vol. 32 no. 5
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 1 June 2000

A. Savini

Gives introductory remarks about chapter 1 of this group of 31 papers, from ISEF 1999 Proceedings, in the methodologies for field analysis, in the electromagnetic…

Abstract

Gives introductory remarks about chapter 1 of this group of 31 papers, from ISEF 1999 Proceedings, in the methodologies for field analysis, in the electromagnetic community. Observes that computer package implementation theory contributes to clarification. Discusses the areas covered by some of the papers ‐ such as artificial intelligence using fuzzy logic. Includes applications such as permanent magnets and looks at eddy current problems. States the finite element method is currently the most popular method used for field computation. Closes by pointing out the amalgam of topics.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 19 no. 2
Type: Research Article
ISSN: 0332-1649

Keywords

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