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Dr. Mohamed Ibrahim
1 Department of Electrical Energy, Metals, Mechanical Constructions and Systems, Ghent University, Ghent 9000, Belgium

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Research Keywords & Expertise

0 Electric Drives
0 Electric Machines
0 Photovoltaics
0 Finite Element Analysis (FEA)
0 Renewable energies

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Finite Element Analysis (FEA)
Electric Machines
Electric Drives
Photovoltaics

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Journal article
Published: 13 May 2021 in Mathematics
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The switched reluctance machine (SRM) design is different from the design of most of other machines. SRM has many design parameters that have non-linear relationships with the performance indices (i.e., average torque, efficiency, and so forth). Hence, it is difficult to design SRM using straight forward equations with iterative methods, which is common for other machines. Optimization techniques are used to overcome this challenge by searching for the best variables values within the search area. In this paper, the optimization of SRM design is achieved using multi-objective Jaya algorithm (MO-Jaya). In the Jaya algorithm, solutions are moved closer to the best solution and away from the worst solution. Hence, a good intensification of the search process is achieved. Moreover, the randomly changed parameters achieve good search diversity. In this paper, it is suggested to also randomly change best and worst solutions. Hence, better diversity is achieved, as indicated from results. The optimization with the MO-Jaya algorithm was made for 8/6 and 6/4 SRM. Objectives used are the average torque, efficiency, and iron weight. The results of MO-Jaya are compared with the results of the non-dominated sorting genetic algorithm (NSGA-II) for the same conditions and constraints. The optimization program is made in Lua programming language and executed by FEMM4.2 software. The results show the success of the approach to achieve better objective values, a broad search, and to introduce a variety of optimal solutions.

ACS Style

Mohamed Afifi; Hegazy Rezk; Mohamed Ibrahim; Mohamed El-Nemr. Multi-Objective Optimization of Switched Reluctance Machine Design Using Jaya Algorithm (MO-Jaya). Mathematics 2021, 9, 1107 .

AMA Style

Mohamed Afifi, Hegazy Rezk, Mohamed Ibrahim, Mohamed El-Nemr. Multi-Objective Optimization of Switched Reluctance Machine Design Using Jaya Algorithm (MO-Jaya). Mathematics. 2021; 9 (10):1107.

Chicago/Turabian Style

Mohamed Afifi; Hegazy Rezk; Mohamed Ibrahim; Mohamed El-Nemr. 2021. "Multi-Objective Optimization of Switched Reluctance Machine Design Using Jaya Algorithm (MO-Jaya)." Mathematics 9, no. 10: 1107.

Journal article
Published: 25 April 2021 in Mathematics
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This paper presents an enhancement method to improve the performance of the DC-link voltage loop regulation in a Doubly-Fed Induction Generator (DFIG)- based wind energy converter. An intelligent, combined control approach based on a metaheuristics-tuned Second-Order Sliding Mode (SOSM) controller and an adaptive fuzzy-scheduled Extended State Observer (ESO) is proposed and successfully applied. The proposed fuzzy gains-scheduling mechanism is performed to adaptively tune and update the bandwidth of the ESO while disturbances occur. Besides common time-domain performance indexes, bounded limitations on the effective parameters of the designed Super Twisting (STA)-based SOSM controllers are set thanks to the Lyapunov theory and used as nonlinear constraints for the formulated hard optimization control problem. A set of advanced metaheuristics, such as Thermal Exchange Optimization (TEO), Particle Swarm Optimization (PSO), Genetic Algorithm (GA), Harmony Search Algorithm (HSA), Water Cycle Algorithm (WCA), and Grasshopper Optimization Algorithm (GOA), is considered to solve the constrained optimization problem. Demonstrative simulation results are carried out to show the superiority and effectiveness of the proposed control scheme in terms of grid disturbances rejection, closed-loop tracking performance, and robustness against the chattering phenomenon. Several comparisons to our related works, i.e., approaches based on TEO-tuned PI controller, TEO-tuned STA-SOSM controller, and STA-SOSM controller-based linear observer, are presented and discussed.

ACS Style

Mohammed Alhato; Mohamed Ibrahim; Hegazy Rezk; Soufiene Bouallègue. An Enhanced DC-Link Voltage Response for Wind-Driven Doubly Fed Induction Generator Using Adaptive Fuzzy Extended State Observer and Sliding Mode Control. Mathematics 2021, 9, 963 .

AMA Style

Mohammed Alhato, Mohamed Ibrahim, Hegazy Rezk, Soufiene Bouallègue. An Enhanced DC-Link Voltage Response for Wind-Driven Doubly Fed Induction Generator Using Adaptive Fuzzy Extended State Observer and Sliding Mode Control. Mathematics. 2021; 9 (9):963.

Chicago/Turabian Style

Mohammed Alhato; Mohamed Ibrahim; Hegazy Rezk; Soufiene Bouallègue. 2021. "An Enhanced DC-Link Voltage Response for Wind-Driven Doubly Fed Induction Generator Using Adaptive Fuzzy Extended State Observer and Sliding Mode Control." Mathematics 9, no. 9: 963.

Journal article
Published: 08 March 2021 in Mathematics
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The design of switched reluctance motor (SRM) is considered a complex problem to be solved using conventional design techniques. This is due to the large number of design parameters that should be considered during the design process. Therefore, optimization techniques are necessary to obtain an optimal design of SRM. This paper presents an optimal design methodology for SRM using the non-dominated sorting genetic algorithm (NSGA-II) optimization technique. Several dimensions of SRM are considered in the proposed design procedure including stator diameter, bore diameter, axial length, pole arcs and pole lengths, back iron length, shaft diameter as well as the air gap length. The multi-objective design scheme includes three objective functions to be achieved, that is, maximum average torque, maximum efficiency and minimum iron weight of the machine. Meanwhile, finite element analysis (FEA) is used during the optimization process to calculate the values of the objective functions. In this paper, two designs for SRMs with 8/6 and 6/4 configurations are presented. Simulation results show that the obtained SRM design parameters allow better average torque and efficiency with lower iron weight. Eventually, the integration of NSGA-II and FEA provides an effective approach to obtain the optimal design of SRM.

ACS Style

Mohamed El-Nemr; Mohamed Afifi; Hegazy Rezk; Mohamed Ibrahim. Finite Element Based Overall Optimization of Switched Reluctance Motor Using Multi-Objective Genetic Algorithm (NSGA-II). Mathematics 2021, 9, 576 .

AMA Style

Mohamed El-Nemr, Mohamed Afifi, Hegazy Rezk, Mohamed Ibrahim. Finite Element Based Overall Optimization of Switched Reluctance Motor Using Multi-Objective Genetic Algorithm (NSGA-II). Mathematics. 2021; 9 (5):576.

Chicago/Turabian Style

Mohamed El-Nemr; Mohamed Afifi; Hegazy Rezk; Mohamed Ibrahim. 2021. "Finite Element Based Overall Optimization of Switched Reluctance Motor Using Multi-Objective Genetic Algorithm (NSGA-II)." Mathematics 9, no. 5: 576.

Journal article
Published: 09 February 2021 in Mathematics
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The torque density and efficiency of synchronous reluctance machines (SynRMs) are greatly affected by the geometry of the rotor. Hence, an optimal design of the SynRM rotor geometry is highly recommended to achieve optimal performance (i.e., torque density, efficiency, and power factor). This paper studies the impact of considering the current angle as a variable during the optimization process on the resulting optimal geometry of the SynRM rotor. Various cases are analyzed and compared for different ranges of current angles during the optimization process. The analysis is carried out using finite element magnetic simulation. The obtained optimal geometry is prototyped for validation purposes. It is observed that when considering the effect of the current angle during the optimization process, the output power of the optimal geometry is about 3.32% higher than that of a fixed current angle case. In addition, during the optimization process, the case which considers the current angle as a variable has reached the optimal rotor geometry faster than that of a fixed current angle case. Moreover, it is observed that for a fixed current angle case, the torque ripple is affected by the selected value of the current angle. The torque ripple is greatly decreased by about 34.20% with a current angle of 45° compared to a current angle of 56.50°, which was introduced in previous literature.

ACS Style

Hegazy Rezk; Kotb B. Tawfiq; Peter Sergeant; Mohamed Ibrahim. Optimal Rotor Design of Synchronous Reluctance Machines Considering the Effect of Current Angle. Mathematics 2021, 9, 344 .

AMA Style

Hegazy Rezk, Kotb B. Tawfiq, Peter Sergeant, Mohamed Ibrahim. Optimal Rotor Design of Synchronous Reluctance Machines Considering the Effect of Current Angle. Mathematics. 2021; 9 (4):344.

Chicago/Turabian Style

Hegazy Rezk; Kotb B. Tawfiq; Peter Sergeant; Mohamed Ibrahim. 2021. "Optimal Rotor Design of Synchronous Reluctance Machines Considering the Effect of Current Angle." Mathematics 9, no. 4: 344.

Journal article
Published: 04 February 2021 in Mathematics
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Due to the expected increase in the electric vehicles (EVs) sales and hence the increase of the price of rare-earth permanent magnets, the switched reluctance motors (SRMs) are gaining increasing research interest currently and in the future. The SRMs offer numerous advantages regarding their structure and converter topologies. However, they suffer from the high torque ripple and complex control algorithms. This paper presents an improved direct instantaneous torque control (DITC) strategy of SRMs for EVs. The improved DITC can fulfill the vehicle requirements. It involves a simple online torque estimator and a torque error compensator. The turn-on angle is defined analytically to achieve wide speed operation and maximum torque per ampere (MTPA) production. Moreover, the turn-off angles are optimized for minimum torque ripples and the highest efficiency. In addition, this paper provides a detailed comparison between the proposed DITC and the most applicable torque control techniques of SRMs for EVs, including indirect instantaneous torque control (IITC), using torque sharing function (TSF) strategy and average torque control (ATC). The results show the superior performance of the proposed DITC because it has the lowest torque ripples, the highest torque tor current ratio, and the best efficiency over the low and medium speed ranges. Moreover, the comparison shows the advantages of each control technique over the range of speed control. It provides a very clear overview to develop a universal control technique of SRM for EVs by merging two or more control techniques.

ACS Style

Mahmoud Hamouda; Amir Abdel Menaem; Hegazy Rezk; Mohamed Ibrahim; László Számel. Comparative Evaluation for an Improved Direct Instantaneous Torque Control Strategy of Switched Reluctance Motor Drives for Electric Vehicles. Mathematics 2021, 9, 302 .

AMA Style

Mahmoud Hamouda, Amir Abdel Menaem, Hegazy Rezk, Mohamed Ibrahim, László Számel. Comparative Evaluation for an Improved Direct Instantaneous Torque Control Strategy of Switched Reluctance Motor Drives for Electric Vehicles. Mathematics. 2021; 9 (4):302.

Chicago/Turabian Style

Mahmoud Hamouda; Amir Abdel Menaem; Hegazy Rezk; Mohamed Ibrahim; László Számel. 2021. "Comparative Evaluation for an Improved Direct Instantaneous Torque Control Strategy of Switched Reluctance Motor Drives for Electric Vehicles." Mathematics 9, no. 4: 302.

Journal article
Published: 05 January 2021 in Mathematics
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The interest in motor drive systems with a number of phases greater than three has increased, mainly in high-power industrial fields due to their advantages compared with three-phase drive systems. In this paper, comprehensive mathematical modeling of a five-phase matrix converter (MC) is introduced. Besides that, the direct and indirect space vector modulation (SVM) control methods are compared and analyzed. Furthermore, a mathematical model for the MC with the transformation between the indirect and direct topology is constructed. The indirect technique is used to control the five-phase MC with minimum switching losses. In this technique, SVM deals with a five-phase MC as a virtual two-stage converter with a virtual DC link (i.e., rectifier and inverter stages). The voltage gain is limited to a value of 0.79. Moreover, to analyze the effectiveness of the control technique and the advantages of the MC, a static R-L load is employed. However, the load can also be an industrial load, such as hospital pumping or vehicular applications. The presented analysis proves that the MC gives a wide range of output frequencies, and it has the ability to control the input displacement factor and the output voltage magnitude. In addition, the absence of the massive DC link capacitors is an essential feature for the MC, resulting in increased reliability and a reduced size converter. Eventually, an experimental validation is conducted on a static load to validate the presented model and the control method. It is observed that good matching between the simulation and the experimental results is achieved.

ACS Style

Kotb B. Tawfiq; Mohamed N. Ibrahim; Hegazy Rezk; Elwy E. El-Kholy; Peter Sergeant. Mathematical Modelling, Analysis and Control of a Three to Five-Phase Matrix Converter for Minimal Switching Losses. Mathematics 2021, 9, 96 .

AMA Style

Kotb B. Tawfiq, Mohamed N. Ibrahim, Hegazy Rezk, Elwy E. El-Kholy, Peter Sergeant. Mathematical Modelling, Analysis and Control of a Three to Five-Phase Matrix Converter for Minimal Switching Losses. Mathematics. 2021; 9 (1):96.

Chicago/Turabian Style

Kotb B. Tawfiq; Mohamed N. Ibrahim; Hegazy Rezk; Elwy E. El-Kholy; Peter Sergeant. 2021. "Mathematical Modelling, Analysis and Control of a Three to Five-Phase Matrix Converter for Minimal Switching Losses." Mathematics 9, no. 1: 96.

Short communication
Published: 22 December 2020 in Energy Reports
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Flux switching generators with permanent magnets (PMs) on the stator is a good alternative to traditional synchronous generators for gearless wind turbines. This paper is dedicated to the comparison of the 3-phase rare-earth and ferrite PM flux switching generators considered in gearless wind generator application (332 rpm, 1784 W). The machines are designed and optimized using the Nelder–Mead algorithm coupled with 2D FEM model. The objective function is built taking into account the following objectives: the average efficiency of the generators over the wind turbine profile, the required power of the AC–DC converter, the quantity of the magnets and the torque ripple. It is found that the ferrite PM flux switching generator can be an attractive alternative to the rare-earth one. The averaged efficiency of the generator with ferrite PM is higher by 4.1% than that of the rare-earth one. The active power of the ferrite generator is also higher in a wide range of powers. Although the mass of the ferrite PM generator is 2.4 times higher, the costs of the generators are approximately similar since the rare-earth magnets are much more expensive than ferrite ones.

ACS Style

Vladimir Prakht; Vladimir Dmitrievskii; Vadim Kazakbaev; Mohamed N. Ibrahim. Comparison between rare-earth and ferrite permanent magnet flux-switching generators for gearless wind turbines. Energy Reports 2020, 6, 1365 -1369.

AMA Style

Vladimir Prakht, Vladimir Dmitrievskii, Vadim Kazakbaev, Mohamed N. Ibrahim. Comparison between rare-earth and ferrite permanent magnet flux-switching generators for gearless wind turbines. Energy Reports. 2020; 6 ():1365-1369.

Chicago/Turabian Style

Vladimir Prakht; Vladimir Dmitrievskii; Vadim Kazakbaev; Mohamed N. Ibrahim. 2020. "Comparison between rare-earth and ferrite permanent magnet flux-switching generators for gearless wind turbines." Energy Reports 6, no. : 1365-1369.

Short communication
Published: 22 December 2020 in Energy Reports
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The switched reluctance motors (SRMs) are powerful alternatives for electric vehicles (EVs). However, the high torque ripple is the main obstacle for their acceptance in high-performance applications. This paper introduces an improved indirect instantaneous torque control (IITC) strategy of SRMs for EVs. It aims to achieve the vehicle requirements including maximum torque per ampere (MTPA), minimum torque ripple, high efficiency, and extended speed range. First, a simple analytical formulation that determines the most efficient turn-on angle for torque production is developed. Second, A modified torque sharing function (TSF) is introduced to compensate for torque tracking errors. To accurately represent the SRM, its magnetic characteristics are calculated using finite element method (FEM). They are employed to build machine model and implement the required transformations. Finally, the particle swarm optimization (PSO) algorithm is adopted to determine the best control parameters for the conventional IITC. This is done basically for comparison and verification purposes. The results show the feasibility and effectiveness of the proposed control over extended speed range.

ACS Style

Mahmoud Hamouda; Amir Abdel Menaem; Hegazy Rezk; Mohamed N. Ibrahim; László Számel. An improved indirect instantaneous torque control strategy of switched reluctance motor drives for light electric vehicles. Energy Reports 2020, 6, 709 -715.

AMA Style

Mahmoud Hamouda, Amir Abdel Menaem, Hegazy Rezk, Mohamed N. Ibrahim, László Számel. An improved indirect instantaneous torque control strategy of switched reluctance motor drives for light electric vehicles. Energy Reports. 2020; 6 ():709-715.

Chicago/Turabian Style

Mahmoud Hamouda; Amir Abdel Menaem; Hegazy Rezk; Mohamed N. Ibrahim; László Számel. 2020. "An improved indirect instantaneous torque control strategy of switched reluctance motor drives for light electric vehicles." Energy Reports 6, no. : 709-715.

Journal article
Published: 13 November 2020 in Mathematics
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With the growing robustness of modern power systems, the occurrence of load curtailment events is becoming lower. Hence, the simulation of these events constitutes a challenge in adequacy indices assessment. Due to the rarity of the load curtailment events, the standard Monte Carlo simulation (MCS) estimator of adequacy indices is not practical. Therefore, a framework based on the enhanced cross-entropy-based importance sampling (ECE-IS) method is introduced in this paper for computing the adequacy indices. The framework comprises two stages. Using the proposed ECE-IS method, the first stage’s purpose is to identify the samples or states of the nodal generation and load that are greatly significant to the adequacy indices estimators. In the second stage, the density of the input variables’ conditional on the load curtailment domain obtained by the first stage are used to compute the nodal and system adequacy indices. The performance of the ECE-IS method is verified through a comparison with the standard MCS method and the recent techniques of rare events simulation in literature. The results confirm that the proposed method develops an accurate estimation for the nodal and system adequacy indices (loss of load probability (LOLP), expected power not supplied (EPNS)) with appropriate convergence value and low computation time.

ACS Style

Amir Abdel Menaem; Rustam Valiev; Vladislav Oboskalov; Taher S. Hassan; Hegazy Rezk; Mohamed N. Ibrahim. An Efficient Framework for Adequacy Evaluation through Extraction of Rare Load Curtailment Events in Composite Power Systems. Mathematics 2020, 8, 2021 .

AMA Style

Amir Abdel Menaem, Rustam Valiev, Vladislav Oboskalov, Taher S. Hassan, Hegazy Rezk, Mohamed N. Ibrahim. An Efficient Framework for Adequacy Evaluation through Extraction of Rare Load Curtailment Events in Composite Power Systems. Mathematics. 2020; 8 (11):2021.

Chicago/Turabian Style

Amir Abdel Menaem; Rustam Valiev; Vladislav Oboskalov; Taher S. Hassan; Hegazy Rezk; Mohamed N. Ibrahim. 2020. "An Efficient Framework for Adequacy Evaluation through Extraction of Rare Load Curtailment Events in Composite Power Systems." Mathematics 8, no. 11: 2021.

Journal article
Published: 31 August 2020 in Energies
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In this study, a simulation-based coyote optimization algorithm (COA) to identify the gains of PI to ameliorate the water-pumping system performance fed from the photovoltaic system is presented. The aim is to develop a stand-alone water-pumping system powered by solar energy, i.e., without the need of electric power from the utility grid. The voltage of the DC bus was adopted as a good candidate to guarantee the extraction of the maximum power under partial shading conditions. In such a system, two proportional-integral (PI) controllers, at least, are necessary. The adjustment of (Proportional-Integral) controllers are always carried out by classical and tiresome trials and errors techniques which becomes a hard task and time-consuming. In order to overcome this problem, an optimization problem was reformulated and modeled under functional time-domain constraints, aiming at tuning these decision variables. For achieving the desired operational characteristics of the PV water-pumping system for both rotor speed and DC-link voltage, simultaneously, the proposed COA algorithm is adopted. It is carried out through resolving a multiobjective optimization problem employing the weighted-sum technique. Inspired on the Canis latrans species, the COA algorithm is successfully investigated to resolve such a problem by taking into account some constraints in terms of time-domain performance as well as producing the maximum power from the photovoltaic generation system. To assess the efficiency of the suggested COA method, the classical Ziegler–Nichols and trial–error tuning methods for the DC-link voltage and rotor speed dynamics, were compared. The main outcomes ensured the effectiveness and superiority of the COA algorithm. Compared to the other reported techniques, it is superior in terms of convergence rapidity and solution qualities.

ACS Style

Jouda Arfaoui; Hegazy Rezk; Mujahed Al-Dhaifallah; Mohamed N. Ibrahim; Mami Abdelkader. Simulation-Based Coyote Optimization Algorithm to Determine Gains of PI Controller for Enhancing the Performance of Solar PV Water-Pumping System. Energies 2020, 13, 4473 .

AMA Style

Jouda Arfaoui, Hegazy Rezk, Mujahed Al-Dhaifallah, Mohamed N. Ibrahim, Mami Abdelkader. Simulation-Based Coyote Optimization Algorithm to Determine Gains of PI Controller for Enhancing the Performance of Solar PV Water-Pumping System. Energies. 2020; 13 (17):4473.

Chicago/Turabian Style

Jouda Arfaoui; Hegazy Rezk; Mujahed Al-Dhaifallah; Mohamed N. Ibrahim; Mami Abdelkader. 2020. "Simulation-Based Coyote Optimization Algorithm to Determine Gains of PI Controller for Enhancing the Performance of Solar PV Water-Pumping System." Energies 13, no. 17: 4473.

Journal article
Published: 26 August 2020 in Mathematics
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This paper proposes a novel photovoltaic water pumping system (PVWPS) with an improved performance and cost. This system doesn’t contain a DC-DC converter, batteries nor rare-earth motors. Removing the aforementioned components will reduce the whole cost and increase the reliability of the system. For enhancing the performance of the PVWPS, a ferrite magnet synchronous reluctance motor (FMSynRM) is employed. Besides, the motor inverter is utilized to drive the motor properly and to extract the maximum available power of the PV system. This is performed using a suggested control strategy that controls the motor inverter. Furthermore, to show the effectiveness of the proposed PVWPS, the performance of the proposed system is benchmarked with a PVWPS that is employing a pure SynRM. Moreover, the complete mathematical model of the system components and the control is reported. It is proved that the flow rate employing the proposed system is increased by about 29.5% at a low irradiation level (0.25 kW/m2) and 15% at a high irradiation level (1 kW/m2) compared to the conventional solar system using a pure synchronous reluctance motor (SynRM). An experimental laboratory test bench is built to validate the theoretical results presented in this research work. Good agreement between the theoretical and the experimental results is proved.

ACS Style

Mohamed N. Ibrahim; Hegazy Rezk; Mujahed Al-Dhaifallah; Peter Sergeant. Modelling and Design Methodology of an Improved Performance Photovoltaic Pumping System Employing Ferrite Magnet Synchronous Reluctance Motors. Mathematics 2020, 8, 1429 .

AMA Style

Mohamed N. Ibrahim, Hegazy Rezk, Mujahed Al-Dhaifallah, Peter Sergeant. Modelling and Design Methodology of an Improved Performance Photovoltaic Pumping System Employing Ferrite Magnet Synchronous Reluctance Motors. Mathematics. 2020; 8 (9):1429.

Chicago/Turabian Style

Mohamed N. Ibrahim; Hegazy Rezk; Mujahed Al-Dhaifallah; Peter Sergeant. 2020. "Modelling and Design Methodology of an Improved Performance Photovoltaic Pumping System Employing Ferrite Magnet Synchronous Reluctance Motors." Mathematics 8, no. 9: 1429.

Research article
Published: 23 August 2020 in International Journal of Energy Research
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Perovskite solar cells (PSCs) are in the forefront of third‐generation of photovoltaics and gained a lot of attention as a very promising green technology toward direct solar energy conversion to electricity. PSCs are fabricated following solution‐processed techniques at low temperature and they present high power conversion efficiency exceeding 25%, enabling them to be attractive alternative to the silicon‐based devices. This research work proposes an efficient and cost‐effective photovoltaic (PV) pumping system based on PSCs. For this purpose, lab‐scale PSCs were fabricated and their characteristics were determined. In parallel, the geometry of a synchronous reluctance motor (SynRM) driving a 350 m3/day water pump was optimized for maximizing the output power, while minimizing the torque ripple simultaneously. In addition, a perovskite solar array feeding the SynRM via an inverter was designed and implemented. The inverter was properly regulated by a control system which optimized the maximum available power of the PSCs solar array and the SynRM characteristics. Finally, laboratory measurements were performed, including a power generator simulating the behavior of the PSCs array feeding the SynRM. The obtained results confirmed the experimental validation of the proposed approach.

ACS Style

Alaa A. Zaky; Mohamed N. Ibrahim; Hegazy Rezk; Eleftherios Christopoulos; Ragab A. El Sehiemy; Evangelos Hristoforou; Antonios Kladas; Peter Sergeant; Polycarpos Falaras. Energy efficiency improvement of water pumping system using synchronous reluctance motor fed by perovskite solar cells. International Journal of Energy Research 2020, 44, 11629 -11642.

AMA Style

Alaa A. Zaky, Mohamed N. Ibrahim, Hegazy Rezk, Eleftherios Christopoulos, Ragab A. El Sehiemy, Evangelos Hristoforou, Antonios Kladas, Peter Sergeant, Polycarpos Falaras. Energy efficiency improvement of water pumping system using synchronous reluctance motor fed by perovskite solar cells. International Journal of Energy Research. 2020; 44 (14):11629-11642.

Chicago/Turabian Style

Alaa A. Zaky; Mohamed N. Ibrahim; Hegazy Rezk; Eleftherios Christopoulos; Ragab A. El Sehiemy; Evangelos Hristoforou; Antonios Kladas; Peter Sergeant; Polycarpos Falaras. 2020. "Energy efficiency improvement of water pumping system using synchronous reluctance motor fed by perovskite solar cells." International Journal of Energy Research 44, no. 14: 11629-11642.

Research article
Published: 10 August 2020 in International Journal of Electronics
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In this paper, a new topology for a shunt active power filter using a matrix converter is proposed. The topology analysis, description of the associated control technique, steady-state and dynamic performance are also presented in this study. The proposed topology doesn’t contain the bulky DC-link capacitor. In addition, the parameters of the proposed filter are robust against the change in the load and the THD percentage is the same under this condition. So, the proposed filter parameters don’t require to be retuned with load change. Moreover, a simple and compact form can be realized. The reference currents are calculated using a synchronous reference frame theory. Space vector modulation and hysteresis current control are used to control the rectifier and inverter stages in the indirect matrix converter to obtain the required injected filter current. Finally, a simulation model and an experimental prototype are implemented using Matlab/Simulink program and DSP1104, respectively with a detailed analysis to the obtained results which confirm the effectiveness and the high accuracy performance of the proposed topology.

ACS Style

Kotb B. Tawfiq; Arafa S. Mansour; Mohamed N. Ibrahim; E. E. El-Kholy; Peter Sergeant. Design, implementation and performance analysis of shunt active filter based on a matrix converter. International Journal of Electronics 2020, 108, 395 -410.

AMA Style

Kotb B. Tawfiq, Arafa S. Mansour, Mohamed N. Ibrahim, E. E. El-Kholy, Peter Sergeant. Design, implementation and performance analysis of shunt active filter based on a matrix converter. International Journal of Electronics. 2020; 108 (3):395-410.

Chicago/Turabian Style

Kotb B. Tawfiq; Arafa S. Mansour; Mohamed N. Ibrahim; E. E. El-Kholy; Peter Sergeant. 2020. "Design, implementation and performance analysis of shunt active filter based on a matrix converter." International Journal of Electronics 108, no. 3: 395-410.

Journal article
Published: 05 August 2020 in IEEE Access
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This paper investigates the performance of 3-phase synchronous reluctance machines (SynRMs) when upgrading their stator to 5-phase, keeping the same rotor. The design of the 5-phase stator has been optimized to select the optimal dimensions of the slots and teeth. Moreover, a combined star-pentagon winding is employed to further improve the machine performance. Different winding configurations have been studied and compared using 2D Ansys Maxwell transient simulations. It is observed that at optimal current angle and rated current, the average torque is increased by 17.41% when changing the 3-phase stator with the proposed 5-phase one. In addition, the efficiency of the 5-phase SynRM is increased by about 0.8% compared to 3-phase SynRM. At 3 times the rated speed, the torque and efficiency are significantly increased by around 33% and 3.5% respectively. Moreover, the 5-phase SynRM shows a superior performance in the faulty case with one phase opened. It works at 98.84% of the rated torque of the healthy 3-phase machine, whereas the 3-phase machine works at only 43.35% with huge torque ripple (228%). Finally, an experimental validation using the reference 3-phase machine has been done.

ACS Style

Kotb B. Tawfiq; Mohamed N. Ibrahim; E. E. El-Kholy; Peter Sergeant. Performance Improvement of Existing Three Phase Synchronous Reluctance Machine: Stator Upgrading to 5-Phase With Combined Star-Pentagon Winding. IEEE Access 2020, 8, 143569 -143583.

AMA Style

Kotb B. Tawfiq, Mohamed N. Ibrahim, E. E. El-Kholy, Peter Sergeant. Performance Improvement of Existing Three Phase Synchronous Reluctance Machine: Stator Upgrading to 5-Phase With Combined Star-Pentagon Winding. IEEE Access. 2020; 8 (99):143569-143583.

Chicago/Turabian Style

Kotb B. Tawfiq; Mohamed N. Ibrahim; E. E. El-Kholy; Peter Sergeant. 2020. "Performance Improvement of Existing Three Phase Synchronous Reluctance Machine: Stator Upgrading to 5-Phase With Combined Star-Pentagon Winding." IEEE Access 8, no. 99: 143569-143583.

Original paper
Published: 24 July 2020 in Electrical Engineering
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Refurbishing electrical machines to have a higher performance and/or reliability is a clear trend in the circular economy. This paper investigates the gain in efficiency, torque density and reliability with replacing the windings and the iron of the stator of existing three-phase synchronous reluctance machines (SynRMs), resulting in a multiphase machine. The stator housing, shaft, bearings and the rotor are not changed, to keep the cost of refurbishing low. As the housing and rotor are kept, logical constraints are to have the same inner and/or outer stator diameters, air gap length and axial length. In the new windings, an identical copper volume is considered as a constraint. An optimization technique is coupled to 2D finite element method to select the optimal slot dimensions. Case studies showed that it is possible to replace the stator of existing three-phase SynRMs with a better performance multiphase one. It is found that the average torque, efficiency and power factor of the five-phase SynRM are increased by 11.78%, 0.72% and 5.54%, respectively, compared to a three-phase SynRM at rated conditions. At higher speeds (three times rated value), the efficiency and average torque are greatly improved by about 3.64% and 33.67%, respectively, compared to the three-phase SynRM. Moreover, a faulty case of one phase opened is also investigated. The five-phase SynRM works at 75.45% of the healthy rated torque of the three-phase SynRM, whereas the three-phase SynRM works at only 43%. Measurements on an existing 5.5-kW, three-phase SynRM confirm the observed results.

ACS Style

Kotb B. Tawfiq; Mohamed N. Ibrahim; E. E. El-Kholy; Peter Sergeant. Refurbishing three-phase synchronous reluctance machines to multiphase machines. Electrical Engineering 2020, 103, 139 -152.

AMA Style

Kotb B. Tawfiq, Mohamed N. Ibrahim, E. E. El-Kholy, Peter Sergeant. Refurbishing three-phase synchronous reluctance machines to multiphase machines. Electrical Engineering. 2020; 103 (1):139-152.

Chicago/Turabian Style

Kotb B. Tawfiq; Mohamed N. Ibrahim; E. E. El-Kholy; Peter Sergeant. 2020. "Refurbishing three-phase synchronous reluctance machines to multiphase machines." Electrical Engineering 103, no. 1: 139-152.

Journal article
Published: 23 July 2020 in Mathematics
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Switched reluctance motors (SRMs) have been receiving great attention in electric vehicle (EV) applications. However, the complicated control and inherent torque ripples are the major drawbacks of SRMs. This paper introduces a numerical estimation method for the optimum control parameters of SRM based on a simplified average torque control (ATC) strategy for EVs. The proposed control aims to simplify the control algorithm to cut down complexity and cost. Besides, it aims to achieve all the vehicle requirements. A multi-objective optimization problem is set to determine the most efficient excitation parameters that can fulfill the vehicle requirements. The objective function has two terms: torque ripple and efficiency. Proper constraints for both turn-on and turn-off angles are included in order to achieve high-performance control, maximum torque per Ampere (MTPA) production, and reliable operation. Besides, additional toque constraints are involved to ensure fast dynamics, high-performance torque tracking capability, and parameter insensitivity. The motor model is accurately achieved based on the experimentally measured torque and flux characteristics. Several simulations are executed to prove the feasibility and effectiveness of the proposed control. Moreover, experimental results are obtained to validate the theoretical findings. It is observed that the proposed control has a significant reduction of torque ripples compared to the conventional control methods. The average reduction ratio of torque ripple over the speed range is about 72.43%. Besides, the proposed control succeeds in maintaining a very good efficiency and high torque/current ratio. It also has a fast-dynamic performance.

ACS Style

Mahmoud Hamouda; Amir Abdel Menaem; Hegazy Rezk; Mohamed N. Ibrahim; László Számel. Numerical Estimation of Switched Reluctance Motor Excitation Parameters Based on a Simplified Structure Average Torque Control Strategy for Electric Vehicles. Mathematics 2020, 8, 1213 .

AMA Style

Mahmoud Hamouda, Amir Abdel Menaem, Hegazy Rezk, Mohamed N. Ibrahim, László Számel. Numerical Estimation of Switched Reluctance Motor Excitation Parameters Based on a Simplified Structure Average Torque Control Strategy for Electric Vehicles. Mathematics. 2020; 8 (8):1213.

Chicago/Turabian Style

Mahmoud Hamouda; Amir Abdel Menaem; Hegazy Rezk; Mohamed N. Ibrahim; László Számel. 2020. "Numerical Estimation of Switched Reluctance Motor Excitation Parameters Based on a Simplified Structure Average Torque Control Strategy for Electric Vehicles." Mathematics 8, no. 8: 1213.

Journal article
Published: 06 March 2020 in IEEE Access
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In this work, the Coyote Optimization Algorithm (COA) is implemented for estimating the parameters of single and three-phase power transformers. The estimation process is employed on the basis of the manufacturer's operation reports. The COA is assessed with the aid of the deviation between the actual and the estimated parameters as the main objective function. Further, the COA is compared with well-known optimization algorithms i.e. particle swarm and Jaya optimization algorithms. Moreover, experimental verifications are carried out on 4 kVA, 380/380 V, three-phase transformer and 1 kVA, 230/230 V, single-phase transformer. The obtained results prove the effectiveness and capability of the proposed COA. According to the obtained results, COA has the ability and stability to identify the accurate optimal parameters in case of both single phase and three phase transformers; thus accurate performance of the transformers is achieved. The estimated parameters using COA lead to the highest closeness to the experimental measured parameters that realizes the best agreements between the estimated parameters and the actual parameters compared with other optimization algorithms.

ACS Style

Mohamed I. Abdelwanis; Amlak Abaza; Ragab A. El-Sehiemy; Mohamed N. Ibrahim; Hegazy Rezk. Parameter Estimation of Electric Power Transformers Using Coyote Optimization Algorithm With Experimental Verification. IEEE Access 2020, 8, 50036 -50044.

AMA Style

Mohamed I. Abdelwanis, Amlak Abaza, Ragab A. El-Sehiemy, Mohamed N. Ibrahim, Hegazy Rezk. Parameter Estimation of Electric Power Transformers Using Coyote Optimization Algorithm With Experimental Verification. IEEE Access. 2020; 8 (99):50036-50044.

Chicago/Turabian Style

Mohamed I. Abdelwanis; Amlak Abaza; Ragab A. El-Sehiemy; Mohamed N. Ibrahim; Hegazy Rezk. 2020. "Parameter Estimation of Electric Power Transformers Using Coyote Optimization Algorithm With Experimental Verification." IEEE Access 8, no. 99: 50036-50044.

Journal article
Published: 21 November 2019 in Mathematics
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The parameters of electric machines play a substantial role in the control system which, in turn, has a great impact on machine performance. In this paper, a proposed optimal estimation method for the electrical parameters of induction motors is presented. The proposed method uses the particle swarm optimization (PSO) technique. Further, it also considers the influence of temperature on the stator resistance. A complete experimental setup was constructed to validate the proposed method. The estimated electrical parameters of a 3.8-hp induction motor are compared with the measured values. A heat run test was performed to compare the effect of temperature on the stator resistance based on the proposed estimation method and the experimental measurements at the same conditions. It is shown that acceptable accuracy between the simulated results and the experimental measurements has been achieved.

ACS Style

Hegazy Rezk; Asmaa A. Elghany; Mujahed Al-Dhaifallah; Abo Hashema M. El Sayed; Mohamed N. Ibrahim; Rezk; Al- Dhaifallah; El Sayed. Numerical Estimation and Experimental Verification of Optimal Parameter Identification Based on Modern Optimization of a Three Phase Induction Motor. Mathematics 2019, 7, 1135 .

AMA Style

Hegazy Rezk, Asmaa A. Elghany, Mujahed Al-Dhaifallah, Abo Hashema M. El Sayed, Mohamed N. Ibrahim, Rezk, Al- Dhaifallah, El Sayed. Numerical Estimation and Experimental Verification of Optimal Parameter Identification Based on Modern Optimization of a Three Phase Induction Motor. Mathematics. 2019; 7 (12):1135.

Chicago/Turabian Style

Hegazy Rezk; Asmaa A. Elghany; Mujahed Al-Dhaifallah; Abo Hashema M. El Sayed; Mohamed N. Ibrahim; Rezk; Al- Dhaifallah; El Sayed. 2019. "Numerical Estimation and Experimental Verification of Optimal Parameter Identification Based on Modern Optimization of a Three Phase Induction Motor." Mathematics 7, no. 12: 1135.

Journal article
Published: 13 November 2019 in Mathematics
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The direct coil cooling method is one of the existing cooling techniques for electric machines with concentrated windings, in which cooling tubes of conductive material are inserted between the windings. In such cases, eddy current losses are induced in those cooling tubes because of the time variant magnetic field. To compute the cooling tubes losses, either a transient finite element simulation (mostly based on commercial software), or a full analytical method, which is more complex to be constructed, is required. Instead, this paper proposes a simple and an accurate combined semi-analytical-finite element method to calculate the losses of electric machines having cooling tubes. The 2D magnetostatic solution of the magnetic field is obtained e.g., using the free package “FEMM”. Then, the eddy current losses in the tubes are computed using simple analytical equations. In addition, the iron core losses could be obtained. In order to validate the proposed method, two cases are investigated. In Case 1, a six-toothed stator of a switched reluctance machine (SRM), without rotor, is employed in which six cooling tubes are used while in Case 2 a complete rotating SRM is studied. The proposed method is validated by a 2D transient simulation in the commercial software “ANSYS Maxwell” and also by experimental measurements. Evidently, the proposed method is simple and fast to be constructed and it is almost free of cost.

ACS Style

Mohamed Nabil Fathy Ibrahim; Peter Sergeant. Prediction of Eddy Current Losses in Cooling Tubes of Direct Cooled Windings in Electric Machines. Mathematics 2019, 7, 1096 .

AMA Style

Mohamed Nabil Fathy Ibrahim, Peter Sergeant. Prediction of Eddy Current Losses in Cooling Tubes of Direct Cooled Windings in Electric Machines. Mathematics. 2019; 7 (11):1096.

Chicago/Turabian Style

Mohamed Nabil Fathy Ibrahim; Peter Sergeant. 2019. "Prediction of Eddy Current Losses in Cooling Tubes of Direct Cooled Windings in Electric Machines." Mathematics 7, no. 11: 1096.

Journal article
Published: 07 October 2019 in IEEE Access
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The interest in photovoltaic (PV) pumping systems has increased, particularly in rural areas where there is no grid supply available. However, both the performance and the cost of the whole system are still an obstacle for a wide spread of this technology. In this article, a hybrid photovoltaic (PV)-thermoelectric generator (TEG) is investigated for pumping applications. The electric drivetrain comprises a synchronous reluctance motor and an inverter. A control strategy for the drivetrain is employed to execute two main tasks: 1) driving the motor properly to achieve a maximum torque per Amphre condition and 2) maximizing the output power of the PV system at different weather conditions. This means that the conventional DC-DC converter is not used in the proposed system. Moreover, batteries, which are characterized by short life expectancy and high replacement cost, are also not used. It is found that the motor output power and the pump flow rate are increased by about 9.5% and 12% respectively when the hybrid PV-TEG array is used compared to only using PV array. Accordingly, the performance, cost and complexity of the system are improved. Measurements on an experimental laboratory setup are constructed to validate the theoretical results of this work.

ACS Style

Mohamed N. Ibrahim; Hegazy Rezk; Mujahed Al-Dahifallah; Peter Sergeant. Hybrid Photovoltaic-Thermoelectric Generator Powered Synchronous Reluctance Motor for Pumping Applications. IEEE Access 2019, 7, 146979 -146988.

AMA Style

Mohamed N. Ibrahim, Hegazy Rezk, Mujahed Al-Dahifallah, Peter Sergeant. Hybrid Photovoltaic-Thermoelectric Generator Powered Synchronous Reluctance Motor for Pumping Applications. IEEE Access. 2019; 7 (99):146979-146988.

Chicago/Turabian Style

Mohamed N. Ibrahim; Hegazy Rezk; Mujahed Al-Dahifallah; Peter Sergeant. 2019. "Hybrid Photovoltaic-Thermoelectric Generator Powered Synchronous Reluctance Motor for Pumping Applications." IEEE Access 7, no. 99: 146979-146988.