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Optimization of total harmonic current distortion and torque pulsation reduction in high-power induction motors using genetic algorithms

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第12期9卷 1741-1752页

作者： Arash SAYYAH Mitra AFLAKI alireza rezazadeh Department of Electrical and Computer Engineering University of Illinois at Urbana-ChampaignUrbanaIL 61801USA Graduate School of Management and Economics Sharif University of TechnologyTehranIran Department of Electrical and Computer Engineering Shahid Beheshti UniversityTehranIran

This paper presents a powerful application of genetic algorithm (GA) for the minimization of the total harmonic current distortion (THCD) in high-power induction motors fed by voltage source inverters, based on an approximate harmonic model. That is, having defined a desired fundamental output voltage, optimal pulse patterns (switching angles) are determined to produce the fundamental output voltage while minimizing the THCD. The complete results for the two cases of three and five switching instants in the first quarter period of pulse width modulation (PWM) waveform are presented. Presence of harmonics in the stator excitation leads to a pulsing-torque component. Considering the fact that if the pulsing-torques are at low frequencies, they can cause troublesome speed fluctuations, shaft fatigue, and unsatisfactory performance in the feedback control system, the 5th, 7th, 11th, and 13th current harmonics (in the case of five switching angles) are constrained at some pre-specified values, to mitigate the detrimental effects of low-frequency harmonics. At the same time, the THCD is optimized while the required fundamental output voltage is maintained.

关键词：感应发动机遗传算法优化脉冲宽度调制

Coordination of PSS and TCSC controller using modified particle swarm optimization algorithm to improve power system dynamic performance

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浙江大学学报C辑：计算机与电子（英文版） 2010年第8期11卷 645-653页

作者： alireza rezazadeh Mostafa SEDIGHIZADEH Ahmad HASANINIA Faculty of Electrical and Computer Engineering Shahid Beheshti University Faculty of Engineering and Technology Imam Khomeini International University

This paper develops a modified optimization procedure for coordination of a power system stabilizer (PSS) and a thyristor controlled series compensator (TCSC) controller to enhance the power system small signal *** new approach employs eigenvalue-based and time-domain simulation based objective functions simultaneously to improve the optimization convergence rate.A modified particle swarm optimization (MPSO) algorithm is used as the optimization *** results of simulations and eigenvalue analysis for a single machine infinite bus (SMIB) system equipped with the proposed PSS and TCSC controllers confirm that the new approach is effective in enhancing the system stability.

关键词： Coordination Particle swarm optimization (PSO) Power system stabilizer (PSS) Small signal stability Thyristor controlled series compensator (TCSC) controller

A novel approach to study generalized coupled cubic Schrödinger-Korteweg-de Vries equations

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Journal of Ocean Engineering and Science 2024年第1期9卷 13-24页

作者： Lanre Akinyemi P.Veeresha M.T.Darvishi Hadi rezazadeh Mehmet Senol Udoh Akpan Department of Mathematics Lafayette CollegeEastonPAUSA Department of Mathematics Christ Deemed to be UniversityBengaluru 560029India Department of Mathematics Razi UniversityKermanshah 67149Iran Faculty of Engineering Technology Amol University of Special Modern TechnologiesAmolIran Department of Mathematics Nev¸s ehir HacıBekta¸s Veli UniversityNev¸s ehirTurkey Drexel University Department of MathematicsPhiladelphiaPAUSA

The Kortewegde Vries(KdV)equation represents the propagation of long waves in dispersive media,whereas the cubic nonlinear Schrödinger(CNLS)equation depicts the dynamics of narrow-bandwidth wave packets consisting of short dispersive waves.A model that couples these two equations seems in-triguing for simulating the interaction of long and short waves,which is important in many domains of applied sciences and engineering,and such a system has been investigated in recent *** work uses a modified Sardar sub-equation procedure to secure the soliton-type solutions of the generalized cubic nonlinear Schrödinger-Korteweg-de Vries system of *** various selections of arbitrary parameters in these solutions,the dynamic properties of some acquired solutions are represented graph-ically and *** particular,the dynamics of the bright solitons,dark solitons,mixed bright-dark solitons,W-shaped solitons,M-shaped solitons,periodic waves,and other soliton-type *** re-sults demonstrated that the proposed technique is highly efficient and effective for the aforementioned problems,as well as other nonlinear problems that may arise in the fields of mathematical physics and engineering.

关键词： CNLS equation Modiﬁed Sardar sub-equation method KdV equation Solitons Long and short waves

The new soliton solutions for long and short-wave interaction system

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Journal of Ocean Engineering and Science 2022年第5期7卷 485-491页

作者： Sayyed Masood Zekavatmand Hadi rezazadeh Mustafa Inc Javad Vahidi Mohammad Bagher Ghaemi Department of Applied Mathematics Iran University of Science and TechnologyTehranIran Faculty of Engineering Technology Amol University of Special Modern TechnologiesAmolIran Department of Computer Engineering Biruni UniversityIstanbulTurkey Firat University Science FacultyDepartment of MathematicsElazig 23119 Turkey Department of Medical Research China Medical University HospitalChina Medical UniversityTaichungTaiwan Department of Mathematical Sciences University of South AfricaPretoria 0002South Africa

The goal of this paper is to discover modern soliton solutions to long and short-wave interaction system by procedures called extended rational sine-cosine and rational sinh-cosh *** assume that the equation has a hypothetical soliton *** reorganizing the resulting equations,we obtain a system of *** Maple software,we get unknown coefficients in the system and writing them in the original equation,we obtain new solition solutions of the *** results show that the soliton solutions generated by the method for the long and short-wave interaction system are bright,kink type,bright periodic and dark *** provided 3-D figures to illustrate the *** results indicate that the method employed in this paper is superior than some other methods used in the literature to solve the same system equations.

关键词： Extended rational sine-cosine method Extended rational sinh-cosh method

Turbine blade temperature calculation and life estimation-a sensitivity analysis

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Propulsion and Power Research 2013年第2期2卷 148-161页

作者： Majid rezazadeh Reyhani Mohammad Alizadeh alireza Fathi Hiwa Khaledid Amirkabir University of Technology(Tehran Polytechnic) Tehran15875-4413Iran School of Mechanical Engineering College of EngineeringUniversity of TehranTehran4563-11155Iran K.N.T University Tehran19697-64499lran Sharif Universiry of Teclmology Tehran11365-11155Iran

The overall operating cost of the modern gas turbines is greatly influenced by thedurability of hot section components operating at high *** turbine operatingconditions,some defects may occur which can decrease hot section *** the present paper,methods used for calculating blade temperature and life are demonstrated and *** methods,a set of sensitivity analyses on the parameters affecting temperature and life ofa high pressure,high temperature turbine first stage blade is carried *** are:(1)blade coating thickness,(2)coolant inlet pressure and temperature(asa result of secondary air system),and(3)gas turbine load *** show thatincreasing thermal bamier coating thickness by 3 times,leads to rise in the blade life by *** addition,considering inlet cooling temperature and pressure,deviation in temperaturehas greater effect on blade *** of the interesting points that can be realized from theresults is that 300 hours operation at 70%load can be equal to one hour operation atbase load.

关键词： Conjugate heat transfer Life assessment Sensitivity analysis Gas turbine Blade

New soliton wave solutions of a(2+1)-dimensional Sawada-Kotera equation

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Journal of Ocean Engineering and Science 2023年第5期8卷 527-532页

作者： Kong Debin Hadi rezazadeh Najib Ullah Javad Vahidi Kalim U.Tariq Lanre Akinyemi Department of Mathematics Yantai Nanshan UniversityShandong 265713China Faculty of Engineering Technology Amol University of Special Modern TechnologiesAmolIran Department of Mathematics COMSATS University IslamabadIslamabad 45550Pakistan Department of Applied Mathematics Iran University of Science and TechnologyTehranIran Department of Mathematical Sciences University of South AfricaPretoria 0002South Africa Department of Mathematics Mirpur University of Science and TechnologyMirpur 10250(AJK)Pakistan Department of Mathematics Lafayette CollegeEastonPennsylvaniaUnited States

In this work,we studied a(2+1)-dimensional Sawada-Kotera equation(SKE).This model depicts non-linear wave processes in shallow water,fluid dynamics,ion-acoustic waves in plasmas and other phe-nomena.A couple of well-established techniques,the Bäcklund transformation based on the modified Kudryashov method,and the Sardar-sub equation method are applied to obtain the soliton wave solution to the(2+1)-dimensional *** illustrate the behavior of the nonlinear model in an appealing fashion,a variety of travelling wave solutions are formed,such as contour,2D,and 3D *** pro-posed approaches are proved more convenient and dominant for getting analytical solutions and can also be implemented to a variety of physical models representing nonlinear wave phenomena.

关键词： Modified Kudryashov method Sardar-sub equation method Bäcklund transformation(2+1)-dimensional SKE Soliton wave solutions

Active Control of A Piston-Type Absorbing Wavemaker with Fully Reflective Structure

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China Ocean Engineering 2020年第5期34卷 730-737页

作者： Saeed MAHJOURI Rasoul SHABANI Ghader rezazadeh Peyman BADIEI Department of Mechanical Engineering Faculty of EngineeringUrmia UniversityUrmiaIran South Ural state University ChelyabinskRussian Federation cDepartment of Civil Engineering Tehran UniversityTehranIran

Multiple reflections of the waves between structure and wavemaker in hydraulic flumes could change the frequency content of the desired incident wave or result in resonance. A prominent approach to avoid multiple reflections is active control of the wavemaker. This paper proposes a simple and practical active control algorithm for piston-type wavemaker. The block diagram of the control system is presented in real time domain. It is shown that there is no need to use any transfer function or filter in the feedback and feed forward loops and the use of constant gains can yield acceptable results. In the operating frequency range(0.25-2 Hz), it is revealed that the proposed system is very effective at suppressing the excitation of resonant sloshing for regular wave. In the case of irregular waves, it is depicted that the experimental waves agree quite well with the desired wave elevation in frequency domain. In addition, comparison of the results obtained both with and without absorption discloses the good characteristics in time domain.

关键词： wave flume piston-type wavemaker active absorption mathematical modeling reflective waves

A computational study of a capsule lateral migration in microchannel flow

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Acta Mechanica Sinica 2013年第4期29卷 513-525页

作者： M.Navidbakhsh M.rezazadeh Department of Mechanical Engineering Iran University of Science and Technology

A numerical method is used to model a capsule migration in a microchannel with small Reynolds number Re = 0.01. The capsule is modeled as a liquid drop sur- rounded by a neo-Hookean elastic membrane. The numer- ical model combines immersed boundary with lattice Boltz- mann method （IB-LBM）. The LBM is used to simulate fixed Cartesian grid while the IBM is utilized to implement the fluid-structure interaction by a set of Lagrangian moving grids for the membrane. The effect of shear elasticity and bending stiffness are both considered. The results show the significance of elastic modulus and initial lateral position on deformation and morphological properties of a circular cap- sule. The wall effect becomes stronger as the capsule ini- tial position gets closer to the channel wall. As the elastic modulus of membrane increases, the capsule undergoes less pronounced deformation and velocity in direction x is de- creased, thus, the capsule motion is slower than the back- ground flow. The best agreement between the present model and experiments for migration velocity takes place for the capsule with normal to moderate membrane elastic modulus. The results are in good agreement with experiment study of Coupier et al. and previous numerical studies. Therefore, the IB-LBM can be employed to make prediction in vitro and in vivo studies of capsule deformation.

关键词： Capsule. Lateral migration. Lattice Boltzmann.Immersed boundary ~ Deformation ~ Initial position

Studying thin film damping in a micro-beam resonator based on non-classical theories

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Acta Mechanica Sinica 2016年第3期32卷 369-379页

作者： Mina Ghanbari Siamak Hossainpour Ghader rezazadeh Mechanical Engineering Department Sahand University of Technology Mechanical Engineering Department Faculty of Engineering Urmia University

In this paper, a mathematical model is presented for studying thin film damping of the surrounding fluid in an in-plane oscillating micro-beam resonator. The proposed model for this study is made up of a clamped-clamped micro-beam bound between two fixed layers. The microgap between the micro-beam and fixed layers is filled with air. As classical theories are not properly capable of predicting the size dependence behaviors of the micro-beam,and also behavior of micro-scale fluid media, hence in the presented model, equation of motion governing longitudinal displacement of the micro-beam has been extracted based on non-local elasticity theory. Furthermore, the fluid field has been modeled based on micro-polar theory. These coupled equations have been simplified using Newton-Laplace and continuity equations. After transforming to non-dimensional form and linearizing, the equations have been discretized and solved simultaneously using a Galerkin-based reduced order model. Considering slip boundary conditions and applying a complex frequency approach, the equivalent damping ratio and quality factor of the micro-beam resonator have been obtained. The obtained values for the quality factor have been compared to those based on classical theories. We have shown that applying non-classical theories underestimate the values of the quality factor obtained based on classical theo-ries. The effects of geometrical parameters of the micro-beam and micro-scale fluid field on the quality factor of the resonator have also been investigated.

关键词： Thin film damping micro-electromechanical systems(MEMS) Micro-polar theory