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Article
Publication date: 4 January 2011

Ahmed Masmoudi

The purpose of this paper is to propose an approach to improve the torque production capability of fractional slot permanent magnet machines.

Abstract

Purpose

The purpose of this paper is to propose an approach to improve the torque production capability of fractional slot permanent magnet machines.

Design/methodology/approach

Following an analytical formulation of the electromagnetic torque, two optimization criteria are selected: the maximization of the average torque and the minimization of the torque ripple. For the sake of a simple analysis, the proposed approach assumes that the effects of the machine circumferential and radial parameters, on the torque production capability, are almost decoupled, so that their sizing optimization could be carried out separately.

Findings

The torque production capability of the optimized machine has been confirmed by finite element analysis, which confirms the appropriateness of the proposed sizing approach.

Practical implications

The obtained results should be validated by experiments carried out on a prototype.

Originality/value

The proposed approach has been carried out thanks to the introduction of the torque average value and ripple amplitude iso‐2D curves for circumferential parameters and iso‐3D surfaces for radial ones.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 30 no. 1
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 2 November 2015

Hajer Rebai, Imen Abdennadher and Ahmed Masmoudi

The purpose of this paper is to deal with several approach to recover the torque production capability of a five phase double-layer fractional-slot PM machine under faulty…

Abstract

Purpose

The purpose of this paper is to deal with several approach to recover the torque production capability of a five phase double-layer fractional-slot PM machine under faulty operation. The considered fault is an open-circuit coil in a given phase.

Design/methodology/approach

In a first step, the mean futures, such as the phase back-EMFs and the electromagnetic torque, are computed by finite element analysis under healthy operation, and are taken as references. Then, they are investigated, under a faulty coil, for different approaches to recover the torque production capability.

Findings

A comparison of the potentialities of the torque recovery approaches has clearly highlight the superiority of the approach consisting in the re-adjustment of the current initial phases, in an attempt to equilibrate the resulting air gap MMF.

Research limitations/implications

This work should be extended by an experimental validation of the predicted results regarding the back-EMFs and the electromagnetic torque.

Practical implications

The investigation of the considered five phase fractional-slot PM machine under faulty operation should be extended to several faulty scenarios in order to fulfill the requirements of many applications such as the propulsion systems.

Originality/value

The paper proposes different approaches to recover the torque production capability of a five phase fractional-slot PM machine under faulty operation.

Details

COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering, vol. 34 no. 6
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 12 September 2008

Imen Abdennadher, Ahmed Masmoudi and Ahmed Elantably

The purpose of this paper is to discuss the design of concentrated winding permanent magnet (PM) machines dedicated to propulsion applications considering both surface‐mounted and…

Abstract

Purpose

The purpose of this paper is to discuss the design of concentrated winding permanent magnet (PM) machines dedicated to propulsion applications considering both surface‐mounted and flux‐concentrating arrangements of the PMs.

Design/methodology/approach

Following the selection of a suitable distribution of the concentrated winding, a derivation of the machine inductances is carried out in order to highlight the increase in the flux‐weakening range gained through the substitution of distributed windings by concentrated ones. Then, mmf and finite element analysis are carried out in order to investigate the air gap flux density and the torque production capability of both surface‐mounted and flux‐concentrating PM machines.

Findings

The paper finds that, although both machines provide almost the same average torque, the surface‐mounted PM machine offers lower torque ripple with respect to the flux‐concentrating arrangement: a crucial benefit in electric and hybrid propulsion systems.

Research limitations/implications

The research should be extended to the comparison of the obtained results related to the torque production capability with experimental measurements.

Practical implications

An increase in the efficiency associated with the extension of the flux‐weakening range and a reduction of the volume make the concentrated winding PM machines interesting candidates, especially in large‐scale production applications such as the automotive industry.

Originality/value

The paper proposes an approach to design and performance investigation of concentrated winding PM machines considering both surface‐mounted and flux‐concentrating arrangements of the PMs.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 27 no. 5
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 1 January 2013

Imen Abdennadher and Ahmed Masmoudi

The paper is aimed at the investigation of the magnetic forces generated by fractional slot surface mounted PM machines, considering a comparative study between two topologies: a…

Abstract

Purpose

The paper is aimed at the investigation of the magnetic forces generated by fractional slot surface mounted PM machines, considering a comparative study between two topologies: a 9 slot/10 pole machine and a 12 slot/10 pole machine.

Design/methodology/approach

Following the distribution of the armature windings using the star of slots approach, an investigation of the magnetic forces developed by both machines under study, using 3D finite element analysis (FEA). Prior to such investigation, a 2D FEA based sizing procedure is carried out in order to select a set of suitable geometrical parameters. Then, the comparison between both machines is extended to the torque production capability.

Findings

It has been found that the 9 slot/10 pole machine has a pic value of the average magnetic force reaching almost 40N which is located in one side of the air gap. Such a peak does not exceed 7N in the 12 slot/10 pole machine and is located in two diametrically‐opposite areas of the air gap.

Research limitations/implications

This work should be extended by an experimental validation of the FEA results regarding the magnetic force generation.

Practical implications

The list of the selection criteria of fractional slot PM machines should be extended to the magnetic force generation in order to fulfil the requirements of many applications such as the propulsion systems.

Originality/value

The paper proposes a combined electromagnetic‐mechanical approach to investigate the magnetic forces generated by fractional slot surface mounted PM machines using 2D and 3D finite element analysis.

Details

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

Keywords

Article
Publication date: 1 January 2013

Ikhlas Bouzidi, Ahmed Masmoudi and Nicola Bianchi

This paper aims to the design and feature investigation of an interior permanent magnet synchronous machine (IPMSM) dedicated to propulsion applications.

Abstract

Purpose

This paper aims to the design and feature investigation of an interior permanent magnet synchronous machine (IPMSM) dedicated to propulsion applications.

Design/methodology/approach

The design approach as well as the performance investigation of the studied machine are based on a two‐dimensional finite element analysis. This latter is extended to a comparison study with other rotor topologies.

Findings

It has been found that the studied IPMSM offers higher performances than the usual PM machine topologies. This highlights the fact that the rotor design greatly affects the performance of PM machines.

Research limitations/implications

Many continuations of the developed works shall be treated in the future, such as: an optimization of the IPMSM design, an extension of the optimization to the machine‐inverter association, and a validation of the foreseen performance by experiments carried out on a prototype of the IPMSM.

Practical implications

The machine under study could be integrated in electric propulsion applications especially as a wheel‐mounted motor.

Originality/value

The paper treats the design and performance investigation of a new topology of IPM machines. It is a five‐phase concentrated winding synchronous machine with permanent magnet buried in an outer rotor.

Details

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

Keywords

Article
Publication date: 12 August 2021

Wasiq Ullah, Faisal Khan, Muhammad Umair and Bakhtiar Khan

This paper aims to reviewed analytical methodologies, i.e. lumped parameter magnetic equivalent circuit (LPMEC), magnetic co-energy (MCE), Laplace equations (LE), Maxwell stress…

Abstract

Purpose

This paper aims to reviewed analytical methodologies, i.e. lumped parameter magnetic equivalent circuit (LPMEC), magnetic co-energy (MCE), Laplace equations (LE), Maxwell stress tensor (MST) method and sub-domain modelling for design of segmented PM(SPM) consequent pole flux switching machine (SPMCPFSM). Electric machines, especially flux switching machines (FSMs), are accurately modeled using numerical-based finite element analysis (FEA) tools; however, despite of expensive hardware setup, repeated iterative process, complex stator design and permanent magnet (PM) non-linear behavior increases computational time and complexity.

Design/methodology/approach

This paper reviews various alternate analytical methodologies for electromagnetic performance calculation. In above-mentioned analytical methodologies, no-load phase flux linkage is performed using LPMEC, magnetic co-energy for cogging torque, LE for magnetic flux density (MFD) components, i.e. radial and tangential and MST for instantaneous torque. Sub-domain model solves electromagnetic performance, i.e. MFD and torque behaviour.

Findings

The reviewed analytical methodologies are validated with globally accepted FEA using JMAG Commercial FEA Package v. 18.1 which shows good agreement with accuracy. In comparison of analytical methodologies, analysis reveals that sub-domain model not only get rid of multiples techniques for validation purpose but also provide better results by accounting influence of all machine parts which helps to reduce computational complexity, computational time and drive storage with overall accuracy of ∼99%. Furthermore, authors are confident to recommend sub-domain model for initial design stage of SPMCPFSM when higher accuracy and low computational cost are primal requirements.

Practical implications

The model is developed for high-speed brushless AC applications.

Originality/value

The SPMCPFSM enhances electromagnetic performance owing to segmented PMs configuration which makes it different than conventional designs. Moreover, developed analytical methodologies for SPMCPFSM reduce computational time compared with that of FEA.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering , vol. 40 no. 3
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 26 August 2014

Imen Abdennadher and Ahmed Masmoudi

The purpose of this paper is to investigate the magnetic forces generated by a 12 slot/10 pole concentrated winding PM machines, considering a comparative study between two…

Abstract

Purpose

The purpose of this paper is to investigate the magnetic forces generated by a 12 slot/10 pole concentrated winding PM machines, considering a comparative study between two topologies: a surface mounted permanent magnet (SPM) machine and an interior PM (IPM) machine.

Design/methodology/approach

Following a description of the main characteristics of the concentrated winding permanent magnet machines (CWPMMs) under comparison, an investigation of the magnetic forces developed by both machines under study is carried out using finite element analysis (FEA).

Findings

A 2D FEA-based investigation has highlighted that the SPM machine develops higher magnetic forces than the IPM one. However, and following a 3D FEA, it has been found that the distribution of the magnetic forces along the air gap of the SPM machine is almost homogenous while it is concentrated in two opposite positions in the air gap of the IPM machine.

Research limitations/implications

This work has treated almost all features of the machines under comparison, except the power losses. These should be investigated with emphasis on the PM eddy current losses is so far as the harmonic content of the armature air gap MMF is high.

Practical implications

The list of the selection criteria of CWPMMs should be extended to the magnetic force cancellation in order to fulfill the requirements of many applications such as the automotive ones.

Originality/value

The paper proposes a combined electromagnetic-mechanical approach to investigate the magnetic forces generated by CWPMMs using 2D and 3D FEA.

Details

COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering, vol. 33 no. 5
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 4 January 2011

Amina Ibala, Ahmed Masmoudi, Glynn Atkinson and Alan G. Jack

This paper aims at the derivation of an accurate reluctance model of a transverse flux permanent magnet machine (TFPM) and its validation by finite element analysis (FEA).

Abstract

Purpose

This paper aims at the derivation of an accurate reluctance model of a transverse flux permanent magnet machine (TFPM) and its validation by finite element analysis (FEA).

Design/methodology/approach

Analytical prediction of the different reluctances in the core, the permanent magnets, and the air. These reluctances characterize the paths of both main and leakage fluxes. Then, a validation of the proposed reluctance model is carried out using FEA. An interesting application of the proposed reluctance consists in the assessment of the TFPM torque production capability.

Findings

The torque yielded by the reluctance model of the TFPM and the one computed using 3D‐FEA are in good agreement. This result is of great importance in so far as the CPU time required for 3D‐FEA computation is much more higher than the one consumed in the resolution of the reluctance model.

Research limitations/implications

Further validation of the results yielded by the proposed reluctance model through their comparison with experimental measurements shall be treated in the future.

Practical implications

The proposed reluctance model is of great interest for the TFPM sizing. It could be useful in the pre‐design procedure of the machine.

Originality/value

The paper proposes a new reluctance model where the leakage fluxes are accurately predicted.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 30 no. 1
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 12 September 2008

Helmi Aloui, Amina Ibala, Ahmed Masmoudi, Mohamed Gabsi and Michel Lécrivain

The purpose of this paper is to propose improvement of the generation capability of a claw pole alternator with DC excitation in the stator (CPAES) using analytical investigation…

Abstract

Purpose

The purpose of this paper is to propose improvement of the generation capability of a claw pole alternator with DC excitation in the stator (CPAES) using analytical investigation based on a dedicated reluctant model.

Design/methodology/approach

The paper analyzes the effects of geometry and material transformations of the magnetic circuit on the generation capability of the CPAES as well as the reduction of claw‐claw leakage flux by inserting permanent magnets in between adjacent claws.

Findings

The generation capability could be improved considering the proposed geometry and material changes of the magnetic circuit of the CPAES. The inclusion of permanent magnets in between adjacent claws offers an increase of the alternator generation due to the reduction of the claw‐claw leakage flux.

Research limitations/implications

The research should be extended by building a new prototype of the CPAES in order to compare analytical results and experimental ones.

Practical implications

A new concept with no brush‐ring for excitation and an improvement of the generation capability of the alternator make the CPAES an interesting candidate especially in large‐scale production applications such as the automotive industry.

Originality/value

The paper proposes a new alternator topology called claw pole alternator with DC excitation in the stator (CPAES) and an analytical approach to improve the generation capability of such a concept, which represents a crucial challenge in electric generation systems especially in automotive applications.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 27 no. 5
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 7 November 2016

Lidija Petkovska, Goga Vladimir Cvetkovski and Paul Lefley

In the present paper the influence of the magnetization patterns of rotor magnets on the performance characteristics of a surface permanent magnet (SPM) motor has been…

Abstract

Purpose

In the present paper the influence of the magnetization patterns of rotor magnets on the performance characteristics of a surface permanent magnet (SPM) motor has been investigated. The purpose of this paper is to show how the electromagnetic and electromechanical characteristics of this type of motor can be significantly changed by applying various magnetization patterns of permanent magnets (PM) on the rotor surface.

Design/methodology/approach

First, a survey of possible and most frequently used magnetization patterns for PM motors is presented. The research is focussed on the comparison of performance characteristics and is developed at three levels. The study starts with investigation of a conventional SPM motor having segmented PM, and two magnetization patterns are considered: parallel and radial. As there was no significant difference in motor performance at parallel and radial magnetization, for further investigation only radial magnetization, being more conventional, was considered. In the second step, the counterparts of SPM with two Halbach array configurations, under the constraint of fixed magnet volume, are studied. Finally, detailed comparative analyses of SPM at radial, Halbach 1, and Halbach 2 magnetic patterns are presented. The advantages and drawbacks of the suggested magnetic configurations are then discussed.

Findings

The authors have shown how the magnetization pattern of rotor PM can have a substantial impact on the SPM motor performance characteristics. From the analysis of magnetic field properties at various types of magnetization, it is observed that both the shape and the rates of the characteristics, for radial magnetization and Halbach 2 configuration, exhibit similar features. This is because the Halbach 2 array cancels the magnetic flux above the PM – that is, it strengthens the magnetic field in the rotor, and enhances the coupling between the rotor and stator magnetic field. It is worth emphasizing that, because of less saturation of the magnetic core and lower iron loss at Halbach 1 and Halbach 2 magnetization, it is possible to increase the armature current and consequently increase the electromagnetic torque. This finding could be an interesting for further research.

Originality/value

The paper presents an original comparative analysis of the performance characteristics of a surface permanent motor at various magnetization patterns. The novelty of the paper is seen in the introduction of two Halbach magnetization arrays for PM and improvement of the performance characteristics of the analysed motor.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 35 no. 6
Type: Research Article
ISSN: 0332-1649

Keywords

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