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A novel control strategy based on a look-up table for optimal operation of MTDC systems in post-contingency conditions

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Protection and Control of Modern Power Systems 2022年第1期7卷 40-50页

作者： seyed Mohsen Alavi reza Ghazi Department of Electrical Engineering Ferdowsi University of MashhadMashhadIran

Multi terminal VSC-HVDC systems are a promising solution to the problem of connecting offshore wind farms to AC *** power sharing and appropriate control of DC-link voltages are essential and must be maintained dur-ing the operation of VSC-MTDC systems,particularly in post-contingency *** traditional droop control methods cannot satisfy these requirements,and accordingly,this paper proposes a novel centralized control strategy based on a look-up table to ensure optimal power sharing and minimum DC voltage deviation immediately during post-contingency conditions by considering converter *** also reduces destructive effects(e.g.,frequency devia-tion)on onshore AC grids and guarantees the stable operation of the entire MTDC *** proposed look-up table is an array of data that relates operating conditions to optimal droop coefficients and is determined according to N-1 contingency analysis and a linearized system *** constraints and contingencies such as wind power changes,converter outage,and DC line disconnection are considered in its formation *** performed on a 4-terminal VSC-MTDC system in the MATLAB-Simulink environment validate the effectiveness and superiority of the proposed control strategy.

关键词： Optimal power sharing DC voltage deviation Adaptive droop control Multi-terminal HVDC(MTDC) Voltage source converter(VSC)

Fault ride-through capability improvement in a DFIG-based wind turbine using modified ADRC

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Protection and Control of Modern Power Systems 2022年第1期7卷 751-787页

作者： seyed reza Mosayyebi seyed Hamid Shahalami Hamed Mojallali Electrical Engineering Department Faculty of EngineeringUniversity of GuilanRashtIran

In this paper,an overview of several strategies for fault ride-through(FRT)capability improvement of a doubly-fed induction generator(DFIG)-based wind turbine is *** and parameter variations have adverse effects on the performance of these *** is desirable to use a control method that is robust to such *** disturbance rejection control(ADRC)is one of the most common methods for eliminating the effects of *** improve the performance of the conventional ADRC,a modified ADRC is introduced that is more robust to disturbances and offers better *** non-derivability of the fal function used in the conventional ADRC degrades its efficiency,so the modified ADRC uses alternative functions that are derivable at all points,i.e.,the odd trigonometric and hyperbolic functions(arcsinh,arctan,and tanh).To improve the effciency of the proposed ADRC,fuzzy logic and fractional-order functions are used *** fuzzy fractional-order ADRC(FFOADRC),all disturbances are evaluated using a nonlinear fractional-order extended state observer(NFESO).The performance of the suggested structure is investigated in MATLAB/*** simulation results show that during disturbances such as network voltage sag/swell,using the modified ADRCs leads to smaller fluctuations in stator flux amplitude and DC-link voltage,lower variations in DFIG velocity,and lower total harmonic distortion(THD)of the stator *** demonstrates the superiority over conventional ADRC and a proportional-integral(PI)***,by chang-ing the crowbar resistance and using the modified ADRCs,the peak values of the waveforms(torque and currents)can be controlled at the moment of fault occurrence with no significant distortion.

关键词： Doubly-fed induction generator(DFIG) Auto disturbance rejection control(ADRC) Fault ride-through(FRT) Wind turbine Nonlinear fractional-order extended state observer(NFESO)

Application of computational fluid dynamics in design of viscous dampers-CFD modeling and full-scale dynamic testing

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Earthquake Engineering and Engineering Vibration 2023年第4期22卷 1065-1080页

作者： Hassan Lak seyed Mehdi Zahrai seyed mohammad Mirhosseini Ehsanollah Zeighami Department of Civil Engineering Collage of EngineeringArak BranchIslamic Azad UniversityArak ***Iran School of Civil Engineering College of EngineeringUniversity of TehranTehran ***Iran

Computational fluid dynamics(CFD)provides a powerful tool for investigating complicated fluid *** paper aims to study the applicability of CFD in the preliminary design of linear and nonlinear fluid viscous *** fluid viscous dampers were designed based on CFD *** first device was a linear viscous damper with straight *** second was a nonlinear viscous damper containing a one-way pressure-responsive valve inside its *** dampers were detailed based on CFD simulations,and their internal fluid flows were ***-scale specimens of both dampers were manufactured and tested under dynamic *** to the tests results,both dampers demonstrate stable cyclic behaviors,and as expected,the nonlinear damper generally tends to dissipate more energy compared to its linear *** compatibility was achieved between the experimentally measured damper force-velocity curves and those estimated from CFD *** a thermography camera,a rise in temperature of the dampers was measured during the *** was found that output force of the manufactured devices was virtually independent of temperature even during long duration ***,temperature dependence can be ignored in CFD models,because a reliable temperature compensator mechanism was used(or intended to be used)by the damper manufacturer.

关键词： fluid viscous damper passive control dynamic testing energy dissipation device computational fluid dynamic thermography

Automatic recognition of sonar targets using feature selection in micro-Doppler signature

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Defence Technology（防务技术） 2023年第2期20卷 58-71页

作者： Abbas Saffari seyed-Hamid Zahiri mohammad Khishe Department of Electrical Engineering University of BirjandBirjandIran Department of Electrical Engineering Imam Khomeini Marine Science UniversityNowshahrIran

Currently,the use of intelligent systems for the automatic recognition of targets in the fields of defence and military has increased *** primary advantage of these systems is that they do not need human participation in target recognition *** paper uses the particle swarm optimization(PSO)algorithm to select the optimal features in the micro-Doppler signature of sonar *** microDoppler effect is referred to amplitude/phase modulation on the received signal by rotating parts of a target such as *** different targets'geometric and physical properties are not the same,their micro-Doppler signature is *** Inconsistency can be considered a practical issue(especially in the frequency domain)for sonar target *** using 128-point fast Fourier transform(FFT)for the feature extraction step,not all extracted features contain helpful *** a result,PSO selects the most optimum and valuable *** evaluate the micro-Doppler signature of sonar targets and the effect of feature selection on sonar target recognition,the simplest and most popular machine learning algorithm,k-nearest neighbor(k-NN),is used,which is called k-PSO in this paper because of the use of PSO for feature *** parameters measured are the correct recognition rate,reliability rate,and processing *** simulation results show that k-PSO achieved a 100%correct recognition rate and reliability rate at 19.35 s when using simulated data at a 15 dB signal-tonoise ratio(SNR)angle of 40°.Also,for the experimental dataset obtained from the cavitation tunnel,the correct recognition rate is 98.26%,and the reliability rate is 99.69%at ***,the k-PSO has an encouraging performance in automatically recognizing sonar targets when using experimental datasets and for real-world use.

关键词： Micro-Doppler signature Automatic recognition Feature selection k-NN PSO

A comparison study on polymeric nanocomposite foams with various carbon nanoparticles:adjusting radiation time and effect on electrical behavior and microcellular structure

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International Journal of Smart and Nano Materials 2022年第3期13卷 504-528页

作者： mohammad Aghvami-Panah Ao Wang Mahyar Panahi-Sarmad seyed Armin seyed Esfahani Amir Abbas Seraji Mehrnaz Shahbazi reza Ghaffarian Seifollah Jamalpour Xueliang Xiao Key Laboratory of Eco-Textiles Ministry of EducationJiangnan UniversityWuxiJiangsuChina Department of Polymer Engineering AmirKabir University of TechnologyTehranIran Department of Chemical Engineering Auburn UniversityAuburnALUSA Department of Chemical Engineering Faculty of EngineeringShahid Chamran University of AhvazAhvazIran

The effect of carbon black(CB),carbon nanotube(CNT),and graphene(G)on foaming,electrical conductivity(EC),and electromagnetic interference(EMI)shielding of polystyrene(PS)foam that has been produced via microwave heating operation and supercritical carbon dioxide(CO_(2))was *** containing 1 wt%,CNT,and G reached over 90%porosity after 30 s and 3 min radiation time,respectively;however,PS/CB foam did not expand properly even after 3.5 *** addition,the expansion ratio of PS/CB and PS/G was one-sixth and one-half of PS/CNT,respectively-due to the great CNT’s ability to convert microwave radiation to *** of solid and porous nanocomposites has been increased via raising filler content;however,PS/CNT displayed the highest value at the same volume *** ascending trend could not endure during foaming,so a remarkable optimum-point has been observed for nanocomposite ***,EMI-shielding properties of solid and foam nanocomposites were discussed.

关键词： Microcellular foams Polymer-matrix composites EMI shielding carbonic particles microwave

Using ELECTRE-TRI and FlowSort methods in a stock portfolio selection context

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Financial Innovation 2022年第1期8卷 331-365页

作者： Mir seyed mohammad Mohsen Emamat Caroline Maria de Miranda Mota mohammad reza Mehregan mohammad reza Sadeghi Moghadam Philippe Nemery Department of Industrial Management Faculty of Management and AccountingAllameh Tabataba’i UniversityTehran 14348-63111Iran Universidade Federal de Pernambuco RecifeBrazil University of Tehran TehranIran SAP BeLux BrusselsBelgium

In recent years,multi-criteria sorting problems have become an interesting topic for researchers working on multi-criteria *** and Choice Expressing REality(ELECTRE)-TRI and FlowSort are well-known approaches suggested for such a *** current study aimed to implement ELECTRE-TRI and FlowSort methods in the stock portfolio selection(SPS)as one of the most popular and important decision-making subjects and compare the outcomes of each method to understand how these methods perform in SPS *** this study,the best–worst method was applied to determine the weights of *** approaches for ELECTRE-TRI and 15 approaches for FlowSort were ***,19 different approaches were considered to select stocks from a large pool of *** indicated that the model parameter should be properly defined to minimize inconsistencies and improve the power of the model.

关键词： Multi-criteria decision-making ELECTRE-TRI FlowSort Best-worst method Finance

Prediction of the Behavior of a Power System Using Root Cause Failure Analysis

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Fluid Dynamics & Materials Processing 2022年第3期18卷 815-833页

作者： seyed mohammad seyed Hosseini Kamran Shahanaghi Safar Shasfand Iran University of Science and Technology Tehran***Iran

The thermo-economic performance of a gas turbine is simulated using a fish bone technique to characterize the major equipment failure *** a fault tree analysis and a Pareto technique are implemented to identify the related failure modes,and the percentage and frequency of failures,respectively.A pump 101 and drier 301 belonging to the Tabriz Petrochemical Company are considered for such analysis,which is complemented with a regression method to determine a behavioral model of this equipment over a twenty-year *** findings indicate that 81%of major failure factors in production equipment are related to the executive procedures(24%),human error(22%),poor quality of materials and parts(20%),and lack of personnel training(15%).

关键词： Combined heat and power root analysis thermoeconomic performance fault tree Pareto behavioral model

A novel technology for control of variable speed pumped storage power plant

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Journal of Central South University 2016年第8期23卷 2008-2023页

作者： seyed mohammad Hassan Hosseini mohammad reza Semsar Department of Electrical Engineering Islamic Azad University

Variable speed pumped storage machines are used extensively in wind power plant and pumped storage power plant. This paper presents direct torque and flux control(DTFC) of a variable speed pumped storage power plant(VSPSP). By this method both torque and flux have been applied to control the VSPSP. The comparison between VSPSP's control strategies is studied. At the first, a wind turbine with the capacity 2.2 k W and DTFC control strategies simulated then a 250 MW VSPSP is simulated with all of its parts(including electrical, mechanical, hydraulic and its control system) by MATLAB software. In all of simulations, both converters including two-level voltage source converter(2LVSC) and three-level voltage source converter(3LVSC) are applied. The results of applying 2LVSC and 3LVSC are the rapid dynamic responses with better efficiency, reducing the total harmonic distortion(THD) and ripple of rotor torque and flux.

关键词：抽水蓄能电站磁通控制变速 MATLAB软件电压源换流器技术风力发电直接转矩

Mechanistic simulation of fracture effects on miscible CO_(2)injection

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Petroleum Research 2022年第4期7卷 437-447页

作者： seyed mohammad Hossein Hashemi Behnam Sedaee Institute of Petroleum Engineering School of Chemical EngineeringCollege of EngineeringUniversity of TehranIran

Miscible injection of carbon dioxide(CO_(2))into oil reservoirs as an Enhanced Oil Recovery(EOR)method has proved to be highly *** to the volume of the world's recoverable oil resides inside the fractured reservoirs,investigation of the controlling parameters in the efficient injection of miscible CO_(2) is of paramount importance,mainly owing to the intricacies and complexities associated with this *** complexity in fractured reservoirs arises due to the presence of two distinct media for fluid transfer(i.e.,matrix and fracture network)and the corresponding differences in fluid ***,performance of miscible carbon dioxide injection in these reservoirs was investigated through mechanistic simulation model in the form of dual-porosity(DP),and dual porosity-dual permeability(DPP).Moreover,due to limited supply and high injection costs of this gas in its pure form,performance of the miscible CO_(2) injection combined with C_(1),N_(2),and H_(2)S was also surveyed and compared to pure gas injection case.A sensitivity analysis was also performed based on fracture porosity,fracture horizontal and vertical permeability,matrix horizontal permeability,block height shape factor,matrix capillary pressure,and impure injected components in DP and DPP models,showing that matrix horizontal permeability and capillary pressure have the greatest,and porosity has the lowest impact on miscibility performance and oil recovery in these *** the end,after investigating the effect of different injection cases on miscibility performance and oil recovery,it was concluded that the highest oil recovery in miscible gas injection obtained through optimization of a gas composition having the lowest minimum miscibility pressure(MMP)and the lowest density.

关键词： Naturally fractured reservoir Carbon dioxide Miscibility Impurity Simulation