Ahmed Selema

Ahmed Selema
Ghent University | UGhent · Department of Electromechanical Systems and Metal Engineering

IEEE Member
Electrical Machines, Electromagnetics, Additive manufacturing

About

20
Publications
5,160
Reads
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123
Citations
Citations since 2017
20 Research Items
123 Citations
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Introduction
Electrical machines, Electromagnetics, Material characterization, Additive manufacturing, Energy-efficient motor design, and Machines losses & cooling, AC HF conduction losses, Windings insulation, Thermal Deterioration, Iron Losses, Switched Reluctance Machines, Flux Switching Machines, 3D Printed Machines
Additional affiliations
October 2020 - present
Ghent University
Position
  • PhD Student
Description
  • Electromagnetic design and modelling of electric machines towards high performance (high power density, high efficiency and reliability, etc) for industrial applications.
September 2016 - October 2020
Menoufia University
Position
  • Lecturer

Publications

Publications (20)
Article
Full-text available
Recent advances in electrical machines and energy storage technologies make electric vehicles (EVs) feasible replacements to conventional internal combustion engines. One of the main challenges of high speed electrical machines is providing maximum output power with minimum energy losses, weight, and volume. At high frequency operation, the conduct...
Article
Nowadays, going beyond the 2D conventionally laminated structures is essential for improving the functionality of an electrical machine during the design process. Additive manufacturing (AM) offers unmatched 3D freedom for processing metal-based materials optimized for weight and cost effectiveness. Using this technology, new families of electrical...
Article
Full-text available
In high speed electrical machines, one of the main challenges that can be faced is the high frequency losses in the machine windings due to both skin and proximity effects. This paper studies the effect of using different types of magnet wires on the AC losses in the winding of high speed electric machines. Using finite element modelling (FEM), the...
Article
Full-text available
Although it is well known that the magnetic properties of electrical steel can be deeply affected by the cutting process, it is still not clear how to accurately evaluate these effects on a prototyped machine on its final shape, especially at a high frequency or a high power rating. This research provides a more practical method for accurate measur...
Conference Paper
-Today, Additive manufacturing (AM) offers more feasible solutions to the manufacturing and assembly of electrical machines with complex 3D designs such as axial flux motors. With particular focus on 3D printing of magnetic materials, this paper discusses the development of AM stator core for yokeless and segmented armature (YASA) axial flux machin...
Conference Paper
Among different AC motors, the synchronous reluctance machines (SynRM) have been an attractive choice for automotive applications. In a typical inverter-fed AC drive system, the stator windings carry a current with a large harmonic content, resulting in an increased AC loss. This paper investigates the additional copper losses caused by non-sinusoi...
Article
Full-text available
The ever-increasing demand for higher-power dense electrical machines has resulted in different electrical, mechanical, and thermal stresses, which can eventually cause machine failure. For this reason, the management of stresses and losses must be thoughtfully investigated to have a highly reliable electrical machine. The literature agrees that wi...
Article
Nowadays, additive manufacturing (AM) is becoming a more feasible solution for scalable electric drives compared to traditional production systems. Also, with the significantly growing automotive sector, innovation in electric machine technology is evolving rapidly. With the unmatched freedom in geometry, AM offers a great deal of flexibility in th...
Article
Full-text available
In high-speed and high-frequency electric machines, one of the major issues that impacts the performance and capability of a machine is the high-frequency eddy current losses in the windings. This work deals with AC winding losses in flat rectangular conductors. Aiming for eddy current loss mitigation, two different materials are investigated and c...
Poster
Full-text available
Introduction Additive manufacturing (AM) has been growing remarkably in the past few years. Thanks to the advantages of unmatched flexibility, this technology opens the door for new design solutions with greater material efficiency, which are not possible through conventional machining techniques. AM can be utilized in a wide range of applications,...
Article
Full-text available
Metal additive manufacturing (AM) has been growing remarkably in the past few years. Thanks to the advantages of unmatched flexibility and zero material waste, this clean technology opens the door for new design solutions with greater material efficiency, which are not possible through conventional machining techniques. In this paper, we provide a...
Conference Paper
This article introduces three-phase synchronous reluctance motor (SynRM) drive system based on matrix converter. A SynRM is selected in this drive system due to its higher efficiency and better cooling compared to induction machines. In this drive system, matrix converter is used to control SynRM as there is no big DC link capacitor in this convert...
Conference Paper
Full-text available
In high speed electrical machines, one of the main challenges that can be faced is the high frequency conduction losses in the machine windings due to both skin and proximity effects. This paper studies the effect of using different types of magnet wires on the AC losses of the electric machine windings. Using finite element modelling (FEM), the co...
Article
This paper presents a new three-phase flux switching generator (FSG), which is mainly designed for variable-speed low power wind turbines. The magnetless structure of this generator not only reduces the machine cost but also increases the flux controllability. In order to shorten the field and armature end-windings, non-overlapped concentrated wind...
Conference Paper
This paper presents a design of a three phase Flux-Switching Generator (FSG). In this design, the machine brushless construction can be obtained by putting all the active parts in the stator. There are two winding sets embedded in the stator slots. One, is referred to as three phase armature winding, supplies power to a dc load through a three-phas...
Cover Page
Recently, there has been widespread use of electric machines and power electronics in many applications. New applications of electric machines have emerged. Novel control strategies and new circuit topologies have contributed to further performance improvements of electric machine and power electronics. In the proposed special issue, we want to foc...
Article
Full-text available
This study proposes a new three-phase dual-rotor middle-stator brushless flux switching generator for 400 Hz diesel-driven aircraft ground power units. For the proposed machine, both field and armature windings are hosted in the stator in such a way that not only fulfils brushless structure, but also realises the flux switching function. Moreover,...
Conference Paper
Full-text available
This paper introduces a design of a three-phase flux switching machine (FSM), which is mainly designed for a 400 HZ aircraft auxiliary power unit. In this design, there are two winding sets embedded in the stator slots. One, is referred to as three phase armature windings, supply the power to the aircraft electrical system. The other winding, namel...

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Projects

Projects (4)
Project
This research provides a more practical method for accurate measurement of magnetic losses in electrical steel with consideration of material degradation effects due to the manufacturing process ( e.g. cutting, stacking, interlocking, 3D printing, ...).
Project
Electrical Machines have been traditionally made from thin laminated steel which is stacked resulting in an extruded 2D shape and 2D magnetic circuit; X and Y are fully used, the Z axis isn’t. In this project we will explore the Third Dimension. Using additive manufacturing, the machine can be pressed into a true 3D form with thermal and magnetic isotropy in X Y and Z. We will look at a the material engineering, the component production process and a range of new machine topologies and their various applications.
Project
In high speed electrical machines, one of the main challenges that can be faced is the high frequency conduction losses in the machine windings due to both skin and proximity effects. This study presents the effect of using different types of magnet wires on the AC losses of the electric machine windings. Using finite element modelling (FEM), the conductors are subdivided into multiple strands to calculate the losses in each conductor and in each layer. Further, aiming at loss minimization, different arrangements are introduced and compared at a wide range of frequencies. Moreover, recommendations are provided based on the obtained results and comparison.