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Article
Publication date: 10 January 2025

Hajer Jmal, Amal Souissi and Imen Abdennadher

This paper aims to an analytical investigation of a consequent poles (CP) permanent magnet machine, to enhance the accuracy of the predicted air gap flux density and thus of the…

Abstract

Purpose

This paper aims to an analytical investigation of a consequent poles (CP) permanent magnet machine, to enhance the accuracy of the predicted air gap flux density and thus of the machine performance.

Design/methodology/approach

The machine under study is obtained by the substitution of the poles machines (PMs) that corresponds to south poles, of a conventional surface PM (SPM) machine, by iron pieces of same geometry. First, the analytical model of the air gap flux density generated by a SPM topology is presented. To fit the CP concept, such model has been rearranged based on a virtual SPM machine. Then, an improved prediction of the CP machine air gap flux density is addressed by the incorporation of a south pole rotor correction function.

Findings

An improved prediction of the consequent pole PM machines air gap flux density is addressed by the incorporation of a south pole rotor correction function.

Originality/value

The paper proposes an original approach to enhance the prediction of the air gap flux density of consequent pole machines despite the different magnetic permeability of the north and south poles.

Details

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

Keywords

Article
Publication date: 3 July 2024

Anis Abdelkefi, Amal Souissi and Imen Abdennadher

This paper aims at the analytical formulation of the electromagnetic features of flux switching permanent magnet (PM) machines with emphasis on the PM air gap flux density and…

15

Abstract

Purpose

This paper aims at the analytical formulation of the electromagnetic features of flux switching permanent magnet (PM) machines with emphasis on the PM air gap flux density and armature magnetic reaction.

Design/methodology/approach

The PM air gap flux density is formulated considering three different analytical models. These differ by the incorporation of the air gap magnetic saliency level from the stator side. In addition, the armature magnetic reaction is investigated based on a simplified magnetic reluctance circuit that considers the flux switching permanent magnet machines magnetic circuit geometry specification. Then, the no- and on-load torque is predicted based on the two air gap flux densities.

Findings

It has been found that the PM air gap flux density considering the stator saliencies with trapezoidal magnetomotive force waveform presents the highest accuracy. Despite the simplicity of the magnetic equivalent circuit-based approach, the predicted air gap armature magnetic reaction is in good agreement with the finite element analysis (FEA) one. These lead to the analytical predictions of the no- and on-load torque which is characterized by an acceptable accuracy.

Research limitations/implications

This work should be extended to experimental validation of the FEA results regarding the torque production generation.

Originality/value

The paper proposes an improved design-oriented analytical approach with emphasis on the PM air gap flux density and the armature magnetic reaction of flux switching PM machines.

Details

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

Keywords

Article
Publication date: 2 November 2015

Mohamed Wael Zouaghi, Amal Souissi, Imen Abdennadher and Ahmed Masmoudi

The purpose of this paper is to deal with the investigation of no-load operation of tubular linear permanent magnet synchronous machines (T-LPMSMs). It is aimed at the prediction…

Abstract

Purpose

The purpose of this paper is to deal with the investigation of no-load operation of tubular linear permanent magnet synchronous machines (T-LPMSMs). It is aimed at the prediction of the phase flux linkages, the back-EMF and the cogging force using a position varying magnetic equivalent circuit (MEC).

Design/methodology/approach

This study is based on the elaboration and the resolution of the position varying MEC, and the utilization of its results for the prediction of the phase flux linkages, the back-EMF and the cogging force, considering a general topology of T-LPMSMs. Then, a case study is treated with a position varying MEC-based investigation of its no-load features. These are validated by a 2-D finite element analysis (FEA).

Findings

It has been found that the developed position varying MEC can be regarded as an accurate tool that requires a low CPU-time.

Research limitations/implications

Beyond the FEA validation, this work should be extended to an experimental one. Moreover, the position varying MEC validity should be extended to load operation in order to enable the prediction of the force production capability.

Practical implications

The developed position varying MEC could be suitably used for the pre-design of T-LPMSMs. These are currently given an increasing attention in many applications, such as wave energy conversion and free-piston engines.

Originality/value

The paper proposes a position varying MEC for the prediction of the features of T-LPMSMs.

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: 5 August 2021

Amal Yamani, Khaled Hussainey and Khaldoon Albitar

This study aims to investigate the impact of financial instrument disclosures under the International Financial Reporting Standard (IFRS) 7 on the cost of equity capital (COEC).

Abstract

Purpose

This study aims to investigate the impact of financial instrument disclosures under the International Financial Reporting Standard (IFRS) 7 on the cost of equity capital (COEC).

Design/methodology/approach

The sample consists of 56 banks listed in the Gulf cooperation council (GCC) stock markets over 7 years from 2011 to 2017. A self-constructed index is used to measure the compliance level in addition to quantitative methods and panel data regression adopted to test the research hypotheses.

Findings

The authors find that the compliance level with IFRS 7 does not improve from 2011 until 2017 in the GCC banks. The authors also find that compliance with IFRS 7 disclosures reduces the COEC.

Originality/value

The authors also provide new empirical evidence that the level of mandatory financial instruments disclosures under IFRS 7 reduces the COEC. The findings offer policy implications. It shows that compliance with IFRS 7 disclosure requirements leads to desirable economic consequences.

Details

International Journal of Accounting & Information Management, vol. 29 no. 4
Type: Research Article
ISSN: 1834-7649

Keywords

Article
Publication date: 16 December 2019

Amal Hamrouni, Ali Uyar and Rim Boussaada

The purpose of this paper is to test whether or not CSR disclosure (i.e. aggregate as well as its three sub-indicators) reduces the cost of debt for French corporations listed in…

2341

Abstract

Purpose

The purpose of this paper is to test whether or not CSR disclosure (i.e. aggregate as well as its three sub-indicators) reduces the cost of debt for French corporations listed in the SBF 120 index between 2010 and 2015.

Design/methodology/approach

CSR disclosure ratings of firms were collected from the Bloomberg database under three dimensions such as environmental, social and governance (ESG). Then, a pooled regression analysis was run.

Findings

The results indicate that overall CSR disclosure score as a combination of ESG disclosure scores has a negative effect on the cost of debt (i.e. lowers the cost of debt). While environmental disclosure is negatively associated with the cost of debt, social disclosure is unexpectedly positively associated, and governance disclosure has an insignificant association with the cost of debt.

Research limitations/implications

The study has two main limitations. First, the analysis does not consider contractual constraints and obligations that might exist in debt contracts (Jung et al., 2018). Second, the analyses cover a specific time period (i.e. between 2010 and 2015) for a specific country (i.e. France) excluding utilities and the financial sector.

Practical implications

Overall, it is inferred from the results that financial markets for lenders take into account CSR disclosure when assessing the creditworthiness of borrowers. Specifically, environmental disclosure is the only subdimension of CSR that is influential on creditors’ decisions to offer favorable interest rates. In line with this outcome, companies can assess their processes and be more aligned with eco-friendly practices, and investors are particularly advised to invest in those types of firms.

Originality/value

This study extends scant literature on the association between CSR and the cost of debt by exploring how creditors treat CSR dimensions dissimilarly in granting loans to firms. The findings of this study have particular importance as financial debt is one of the most predominant forms of external financing.

Details

Management Decision, vol. 58 no. 2
Type: Research Article
ISSN: 0025-1747

Keywords

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