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Open Access
Article
Publication date: 11 October 2023

Abdulwasa B. Barnawi, Abdull Rahman A. Alfifi, Z.M.S. Elbarbary, Saad Fahed Alqahtani and Irshad Mohammad Shaik

Traditional level inverter technology has drawbacks in the aspect of Total harmonic distortion (THD) and switching losses for higher frequencies. Due to these drawbacks, two-level…

1095

Abstract

Purpose

Traditional level inverter technology has drawbacks in the aspect of Total harmonic distortion (THD) and switching losses for higher frequencies. Due to these drawbacks, two-level inverters have become unprofitable for high-power applications. Multilevel inverters (MLIs) are used to enhance the output waveform characteristics (i.e. low THD) and to offer various inverter topologies and switching methods.

Design/methodology/approach

MLIs are upgraded versions of two-level inverters that offer more output levels in current and voltage waveforms while lowering the dv/dt and di/dt ratios. This paper aims to review and compare the different topologies of MLI used in high-power applications. Single and multisource MLI's working principal and switching states for each topology are demonstrated and compared. A Simulink model system integrated using detailed circuit simulations in developed in MATLAB®–Simulink program. In this system, a constant voltage source connected to MLI to feed asynchronous motor with squirrel cage rotor type is used to demonstrate the efficacy of the MLI under different varying speed and torque conditions.

Findings

MLI has presented better control and good range of system parameters than two-level inverter. It is suggested that the MLIs like cascade-five-level and NPC-five-level have shown low current harmonics of around 0.43% and 1.87%, respectively, compared to two-level inverter showing 5.82%.

Originality/value

This study is the first of its kind comparing the different topologies of single and multisource MLIs. This study suggests that the MLIs are more suitable for high-power applications.

Details

Frontiers in Engineering and Built Environment, vol. 4 no. 2
Type: Research Article
ISSN: 2634-2499

Keywords

Article
Publication date: 31 May 2023

Blerina Bylykbashi and Risto Vasil Filkoski

The purpose of this study is optimization of existing PV system and by making the optimization to reach the heights energy performance from the system.

Abstract

Purpose

The purpose of this study is optimization of existing PV system and by making the optimization to reach the heights energy performance from the system.

Design/methodology/approach

The methodology used in this work is analytical as well as software using PV*SOL premium software. Both methods are used to achieve a more realistic analysis of the results achieved at the end of the work.

Findings

After analyzing the optimization of the PV system in terms of certain atmospheric conditions, it is clear that the optimization of the system is necessary. Through the optimization of the systems, a better performance of the system is achieved, as well as in the case in question, it affects the increase of the energy generated annually up to 500 kWh.

Originality/value

This work is the original work of the author, which represents a part of the topic of the doctorate.

Details

International Journal of Innovation Science, vol. 16 no. 2
Type: Research Article
ISSN: 1757-2223

Keywords

Article
Publication date: 1 May 2024

Mamun Mishra and Bibhuti Bhusan Pati

Islanding detection has become a serious concern due to the extensive integration of renewable energy sources. The non-detection zone (NDZ) and system-specific applicability…

Abstract

Purpose

Islanding detection has become a serious concern due to the extensive integration of renewable energy sources. The non-detection zone (NDZ) and system-specific applicability, which are the two major issues with the islanding detection methods, are addressed here. The purpose of this paper is to devise an islanding detection method with zero NDZ and, which will be applicable to all types of renewable energy sources using the sequence components of the point of common coupling voltage.

Design/methodology/approach

Here, a parameter using the sequence components is derived to devise an islanding detection method. The parameter derived from the sequence components of point of common coupling voltage is analysed using wavelet transform. Various operating conditions, such as islanding and non-islanding, are considered for several test systems to evaluate the performance of the proposed method. All the simulations are carried out in Simulink/MATLAB environment.

Findings

The results showed that the proposed method has zero NDZ for both inverter- and synchronous generator-based renewable energy sources. In addition, the proposed method works satisfactorily as per the IEEE 1547 standards requirement.

Originality/value

Performance of the proposed method has been tested in several test systems and is found to be better than some conventional methods.

Details

World Journal of Engineering, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1708-5284

Keywords

Open Access
Article
Publication date: 6 July 2023

Zakaria Mohamed Salem Elbarbary, Ahmed A. Alaifi, Saad Fahed Alqahtani, Irshad Mohammad Shaik, Sunil Kumar Gupta and Vijayakumar Gali

Switching power converters for photovoltaic (PV) applications with high gain are rapidly expanding. To obtain better voltage gain, low switch stress, low ripple and cost-effective…

858

Abstract

Purpose

Switching power converters for photovoltaic (PV) applications with high gain are rapidly expanding. To obtain better voltage gain, low switch stress, low ripple and cost-effective converters, researchers are developing several topologies.

Design/methodology/approach

It was decided to use the particle swarm optimization approach for this system in order to compute the precise PI controller gain parameters under steady state and dynamic changing circumstances. A high-gain q- ZS boost converter is used as an intermittent converter between a PV and brushless direct current (BLDC) motor to attain maximum power point tracking, which also reduces the torque ripples. A MATLAB/Simulink environment has been used to build and test the positive output quadratic boost high gain converters (PQBHGC)-1, PQBHGC-8, PQBHGC-4 and PQBHGC-3 topologies to analyse their effectiveness in PV-driven BLDC motor applications. The simulation results show that the PQBHGC-3 topology is effective in comparison with other HG cell DC–DC converters in terms of efficiency, reduced ripples, etc. which is most suitable for PV-driven BLDC applications.

Findings

The simulation results have showed that the PQBHGC-3 gives better performance with minimum voltage ripple of 2V and current ripple of 0.4A which eventually reduces the ripples in the torque in a BLDC motor. Also, the efficiency for the suggested PQBHGC-3 for PV-based BLDC applications is the best with 99%.

Originality/value

This study is the first of its kind comparing the different topologies of PQBHGC-1, PQBHGC-8, PQBHGC-4 and PQBHGC-3 topologies to analyse their effectiveness in PV-driven BLDC motor applications. This study suggests that the PQBHGC-3 topology is most suitable in PV-driven BLDC applications.

Details

Frontiers in Engineering and Built Environment, vol. 4 no. 1
Type: Research Article
ISSN: 2634-2499

Keywords

Open Access
Article
Publication date: 6 May 2021

Zakaria Mohamed Salem Elbarbary and Mohamed Abdullrahman Alranini

Silicon photovoltaics technology has drawbacks of high cost and power conversion efficiency. In order to extract the maximum output power of the module, maximum power point (MPP…

10139

Abstract

Purpose

Silicon photovoltaics technology has drawbacks of high cost and power conversion efficiency. In order to extract the maximum output power of the module, maximum power point (MPP) is used by implying the nonlinear behavior of I-V characteristics. Different techniques are used regarding maximum power point tracking (MPPT). The paper aims to review the techniques of MPPT used in PV systems and review the comparison between Perturb and Observe (P&O) method and incremental conductance (IC) method that are used to track the maximum power and gives a comparative review of all those techniques.

Design/methodology/approach

A study of MPPT techniques for photovoltaic (PV) systems is presented. Matlab Simulink is used to find the MPP using P&O simulation along with IC simulation at a steady temperature and irradiance.

Findings

MATLAB simulations are used to implement the P&O method and IC method, which includes a PV cell connected to an MPPT-controlled boost converter. The simulation results demonstrate the accuracy of the PV model as well as the functional value of the algorithms, which has improved tracking efficiency and dynamic characteristics. P&O solution gave 94% performance when configured. P&O controller has a better time response process. As compared to the P&O method of tracking, the incremental conductance response rate was significantly slower.

Originality/value

In PV systems, MPPT techniques are used to optimize the PV array output power by continuously tracking the MPP under a variety of operating conditions, including cell temperature and irradiation level.

Details

Frontiers in Engineering and Built Environment, vol. 1 no. 1
Type: Research Article
ISSN: 2634-2499

Keywords

Article
Publication date: 19 April 2011

Kemal Altıparmak and Turgut Öziş

The purpose of this paper is to present an approach capable of solving Burgers' equation. Diagonal Padé approximation with a factorization scheme is applied to find numerical…

452

Abstract

Purpose

The purpose of this paper is to present an approach capable of solving Burgers' equation. Diagonal Padé approximation with a factorization scheme is applied to find numerical solutions of the one‐dimensional Burgers' equation by presenting explicit factoring the polynomials of the approximation. The numerical results obtained by this approach, for various values of viscosity, have been compared with the exact solution and are found to be in good agreement with each other.

Design/methodology/approach

In this paper, factorized diagonal Padé approach is applied to solve Burgers' equation. In this method, Burgers' equation is reduced to a system of ordinary differential equations and is solved piecewise analytically to obtain the solution of the problem.

Findings

The results of proposed approach show that when the obtained results are compared to similar methods, this approach gives better accuracy. Also, the graphs with small ν values satisfy the physical properties of the problem; therefore, the approach is promising for nonlinear problems.

Research limitations/implications

The authors' experiments show that the applied method worked fine with Burgers' equation and they hope to extend it to some other nonlinear problems.

Practical implications

The proposed method is easy to implement and the given algorithm is easy to use, even for non experts. The approach is flexible to use high order Padé approximants.

Originality/value

In the approach described in the paper, Padé approximation is calculated in a different manner than the classical approach.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 21 no. 3
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 18 August 2022

Ji-Huan He, Nasser S. Elgazery and Nader Y. Abd Elazem

This paper aims to study the magneto-radiative gas (water vapor) on an unsmooth boundary.

Abstract

Purpose

This paper aims to study the magneto-radiative gas (water vapor) on an unsmooth boundary.

Design/methodology/approach

This paper provided a numerical treatment via the implicit Chebyshev pseudo-spectral method to investigate unsteady compressible magneto-radiative gas (water vapor Pr = 1) flow near a heated vertical wavy wall through porous medium in the presence of inclined magnetic field. The impacts of viscous dissipation, temperature-dependent fluid properties, thermal conductivity and viscosity in the presence of nonlinear thermal radiation are studied. The sinusoidal surface is transformed into a flat one using a suitable transformation. The comparison figures of published data with the present outcomes illustrate a good match. The present steady-state outcomes are presented for the temperature, velocity, Nusselt number and the shearing stress through figures for several interested physical parameters, namely, compressibility, magnetic, radiation, viscosity–temperature variation, thermal conductivity–temperature variation, surface sinusoidal waveform and porous parameters.

Findings

The present numerical outcomes confirm the importance of applying nonlinear thermal radiation cases in all studies that investigate heat transfer under the influence of thermal radiation.

Originality/value

A mathematical model is established for a wavy boundary, and Chebyshev pseudo-spectral method is adopted for the numerical study.

Article
Publication date: 29 March 2011

Mehdi Dehghan, Mehdi Tatari and Asma Azizi

The purpose of this paper is to consider the well‐known Falkner‐Skan equation. This equation appears in the modelling of various phenomena in physics and engineering.

Abstract

Purpose

The purpose of this paper is to consider the well‐known Falkner‐Skan equation. This equation appears in the modelling of various phenomena in physics and engineering.

Design/methodology/approach

The He's variational iteration method which is a very efficient tool for solving different kinds of problems, is employed for solving this problem.

Findings

Some other approaches are introduced to compare the efficiency of the new procedure. Several test examples are given to show the advantages of the present method over other existing techniques.

Originality/value

In this paper, a new and efficient technique is proposed to solve the Falkner‐Skan equation.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 21 no. 2
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 3 March 2020

Asmaa F. Elelamy, Nasser S. Elgazery and R. Ellahi

This paper aims to investigate a mathematical model with numerical simulation for bacterial growth in the heart valve.

Abstract

Purpose

This paper aims to investigate a mathematical model with numerical simulation for bacterial growth in the heart valve.

Design/methodology/approach

For antibacterial activities and antibodies properties, nanoparticles have been used. As antibiotics are commonly thought to be homogeneously dispersed through the blood, therefore, non-Newtonian fluid of Casson micropolar blood flow in the heart valve for two dimensional with variable properties is used. The heat transfer with induced magnetic field translational attraction under the influence of slip is considered for the resemblance of the heart valve prosthesis. The numeral results have been obtained by using the Chebyshev pseudospectral method.

Findings

It is proven that vascular resistance decreases for increasing blood velocity. It is noted that when the magnetic field will be induced from the heart valve prosthesis then it may cause a decrease in vascular resistance. The unbounded molecules and antibiotic concentration that are able to penetrate the bacteria are increased by increasing values of vascular resistance. The bacterial growth density cultivates for upswing values of magnetic permeability and magnetic parameters.

Originality/value

To the best of the authors’ knowledge, this is the first study to investigate a mathematical model with numerical simulation for bacterial growth in the heart valve.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 30 no. 11
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 7 February 2022

Nasser S. Elgazery, Asmaa F. Elelamy, Elena Bobescu and R. Ellahi

The study aims to determine an efficiency of external magnetic field on the bacteria surrounded by thousands of magnetic magnetite nanoparticles. The interstitial nanoliquid in…

Abstract

Purpose

The study aims to determine an efficiency of external magnetic field on the bacteria surrounded by thousands of magnetic magnetite nanoparticles. The interstitial nanoliquid in which an artificial bacteria swims in biological cell is utilized with variable thermal conductivity. Two dimensions unsteady motion of second grade fluid are considered. The stretching wall is taken as a curved surface pattern.

Design/methodology/approach

The mathematical results have been obtained by Chebyshev pseudospectral method.

Findings

The impact of the various governing parameters is described by numerical tables and diagrams. It is proven that the pure blood velocity curves are higher when compared with the magnetite/blood. It is demonstrated from clinical disease that dangerous tumors show diminished blood flow. This study concludes that the blood velocity profile increases by increasing the values of fluid parameters. This implies that the medication conveyance therapy lessens the tumor volume and helps in annihilating malignancy cells. The blood temperature distribution raises as the magnetite nanoparticles concentration increases. Consequently, the physical properties of the blood can be enhanced by immersing the magnetite nanoparticles. Further, the present outcomes cleared the thermal conductivity as, a variable function of the temperature, has an important role to enhance the heat transfer rate.

Originality/value

To the best of authors’ knowledge, this study is reported for the first time.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 32 no. 9
Type: Research Article
ISSN: 0961-5539

Keywords

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