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

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)

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Assessment of fracture process in forta and polypropylene fiber-reinforced concrete using experimental analysis and digital image correlation

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Frontiers of Structural and Civil Engineering 2022年第12期16卷 1633-1652页

作者： seyed hamid KALALI hamid ESKANDARI-NADDAF seyed Ali EMAMIAN Department of Civil Engineering Hakim Sabzevari UniversitySabzevar ***Iran

This paper aims to characterize the evolution of the fracture process and the cracking behavior in fortaferro(FF)and polypropylene(PP)fiber-reinforced concrete under the uniaxial compressive loading using experimental analysis and digital image correlation(DIC)on the surface *** this purpose,6 mix designs,including two FF volume fractions of 0.10%,and 0.20%and three PP volume fractions of 0.20%,0.30%,and 0.40%,in addition to a control mix were evaluated according to compressive strength,modulus of elasticity,toughness index,and stress–strain *** influence of fibers on the microstructural texture of specimens was analyzed by scanning electron microscope(SEM)*** show that FF fiber-reinforced concrete specimens demonstrated increased ductility and strength compared to PP *** results revealed that the major crack and fracture appeared at the peak load of the control specimen due to brittleness and sudden gain of large lateral strain,while a gradual increase in micro-crack quantity at 75%of peak load was observed in the fiber specimens,which thenbegan to connect with each other up to the final *** accuracy of the results supports DIC as a reliable alternative for the characterization of the fracture process in fiber-reinforced concrete.

关键词： fiber-reinforced concrete forta-ferro and polypropylene fiber fracture process cracking behavior digital image correlation

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Parallel resonance type fault current limiting circuit breaker

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High Voltage 2020年第1期5卷 76-82页

作者： hamid Radmanesh seyed hamid Fathi Electrical Engineering Department Shahid Sattari Aeronautical University of Science and TechnologyTehranIran Electrical Engineering Department Amirkabir University of TechnologyTehranIran

The main goal of this study is introducing a novel fault current limiter based on parallel resonance structure(PRFCL)for high voltage *** normal mode,the PRFCL reactor is short-circuited via a rectifier bridge DC output voltage and LC resonance tank shows negligible impedance in the *** a fault,the rectifier bridge switches are turned off,so that the parallel resonance LC tank connects to the line with high *** impedance of the resonance structure can limit the fault current,*** is shown that the suggested PRFCL can act as a breaker and opens the line during the fault *** order to show the suggested PRFCL abilities,MATLAB software is used to simulate the normal and fault *** addition,a scale-down prototype is implemented to confirm the simulation *** comparative study shows that PRFCL has acceptable performance in normal and current limiting operation modes.

关键词： period fault limiting

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Laboratory large-scale pullout investigation of a new reinforcement ofcomposite geosynthetic strip

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Journal of Rock Mechanics and Geotechnical Engineering 2021年第5期13卷 1147-1159页

作者： Mehrdad Tajabadipour seyed hamid Lajevardi Department of Civil Engineering Sirjan University of TechnologySirjanIran Department of Civil Engineering Arak BranchIslamic Azad UniversityArakIran

In this paper,more than 70 large-scale pullout tests were performed to evaluate the performance of an innovative composite geosynthetic strip(CGS)reinforcement in sandy *** CGS reinforcement is composed of a geosynthetic strip(GS)and parts of a scrap truck tire as transverse *** experimental pullout results for the CGS reinforcement were compared with the suggested theoretical equations and ordinary reinforcements,including the GS,the steel strip(SS),and the steel strip with rib(SSR).The pullout test results show that adding three transverse members to the GS reinforcement(CGS3)with S/H?6.6(where S and H are the space and height of the transverse members,respectively)increases pullout resistance by more than 120%,170%,and 50%compared to the GS,the SS,and the SSR,*** result shows that the CGS3(CGS with three transverse members)reinforcement needs at least 55.5%,63%,and 33.3%smaller length compared to the GS,the SS,and the SSR,*** general,implementation of mechanically stabilized earth wall(MSEW)with the proposed strip may help geotechnical engineers prevent costly designs and solve the problem of MSEW implementation in cases where there are limitations of space.

关键词： Pullout resistance Composite geosynthetic strip(CGS) Soilegeosynthetic interface Scrap tires Large-scale pullout tests

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Fast AC reactor-based fault current limiters application in distribution network

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High Voltage 2018年第3期3卷 232-243页

Almost all of the fault current limiters(FCLs)have a negligible voltage drop during normal operation mode of the power system and show considerable impedance during the fault *** addition,the most of the FCLs employ a reactor to limit the fault current,which carrying a DC current and named DC reactor-based FCL(DRFCL)or carrying AC current named AC reactor-based FCL(ARFCL).Here,a novel ARFCL is introduced for radial distribution networks ***,the ARFCL performance on the limitation of the fault current is compared with DRFCL in a simple radial distribution *** MATLAB software is used to simulate both FCLs performance and their effect on the fault *** laboratory prototype of the ARFCL is built and tested for the evaluation of the ARFCL performance during normal and fault operation *** simulation and experimental results show the superiority of ARFCL to control the fault current,fast,and set the point of common coupling voltage in an acceptable range.

关键词： period fault distribution

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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

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A Novel Approach for Energy and Water Conservation by Using Silver-Carbon Quantum Dots Hybrid Nanofluids in Wet Cooling Towers Systems

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Journal of Thermal Science 2021年第5期30卷 1827-1841页

作者： hamid Mousavi seyed MOSTAFA Tabatabaee Ghomshe ALIMORAD Rashidi MASOUMEH Mirzaei Department of Chemical Engineering Mahshahr BranchIslamic Azad UniversityMahshahrIran Nanotechnology Research Center Research Institute of Petroleum Industry(RIPI)West Blvd.Azadi Sports ComplexP.O.Box 146651998TehranIran

This study presents the use of Silver-Carbon Quantum Dots(Ag-CQD)hybrid nanofluids,prepared by a facile wet chemical method,for heat transfer enhancement of wet cooling towers *** samples were characterized using different analyses,including FT-IR,XRD and *** synthesizing the CQD,it was hybridized with silver nanoparticles and dispersed in water,using ultrasonic *** viscosity and density of the prepared nanofluid were investigated as a function of temperature and nanoparticles concentration,which demonstrated that there were no noticeable changes at lower particles ***,thermal conductivity and convective heat transfer coefficient were measured to evaluate the heat transfer enhancement of the *** 45℃ and 0.5 wt%,the most significant thermal conductivity improvement compared to the base fluid was 24%;and 28%enhancement of the heat transfer coefficient was obtained at Reynolds number of *** nanofluid performance was evaluated in a wet cooling tower for investigating the efficiency and water consumption *** results indicated that the efficiency of the cooling tower,by applying Ag-CQD nanofluid,enhanced from 23.72%to 28.23%;consequently,the amount of the consumed water decreased from 80.76 mL·min^(−1)to 69.67 mL·min^(−1).The results proved that the prepared nanofluid is a successful and promising candidate to enhance heat transfer.

关键词： nanofluid carbon quantum dot silver hybrid heat transfer wet cooling tower

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FEM and ANN analyses of short and tall geosynthetic reinforced soil walls:Evaluation of various effective aspects and ASSHTO acceptable design methods

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Frontiers of Structural and Civil Engineering 2024年第10期18卷 1576-1594页

作者： hamid Reza RAZEGHI Ali Akbar Heshmati RAFSANJANI seyed Meisam ALAVI School of Civil Engineering Iran University of Science and TechnologyTehran 13114-16846Iran

In addition to confined investigations on tall geosynthetic reinforced soil(GRS)walls,a remarkable database of such walls must be analyzed to diminish engineers’concerns regarding the American Association of State Highway and Transportation Officials(AASHTO)Simplified or Simplified Stiffness Method in *** are also uncertainties regarding reinforcement load distributions of GRS walls at the ***,the current study has implemented a combination of finite element method(FEM)and artificial neural network(ANN)to distinguish the performance of short and tall GRS walls and assess the AASHTO design methods based on 88 FEM and 10000 ANN *** were conspicuous differences between the effectiveness of stiffness(63%),vertical spacing(22%),and length of reinforcements(14%)in the behavior of short and tall walls,along with predictions of geogrid load *** differences illustrated that using the Simplified Method may exert profound repercussions because it does not consider wall ***,the Simplified Stiffness Method(which incorporates wall height)predicted the reinforcement load distributions at backfill and connections ***,a Multilayer Perceptron(MLP)algorithm with a low average overall relative error(up to 2.8%)was developed to propose upper and lower limits of reinforcement load distributions,either at backfill or connections,based on 990000 ANN predictions.

关键词： geosynthetics short and tall GRS walls artificial intelligence MLP AASHTO Simplified and Simplified Stiffness Methods

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Presentation of machine learning methods to determine the most important factors affecting road traffic accidents on rural roads

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Frontiers of Structural and Civil Engineering 2022年第5期16卷 657-666页

作者： hamid MIRZAHOSSEIN Milad SASHURPOUR seyed Mohsen HOSSEINIAN Vahid Najafi Moghaddam GILANI Civil–Transportation Planning Department Faculty of Technical and EngineeringImam Khomeini International University(IKIU)Qazvin 34148-96818Iran School of Civil Engineering Iran University of Science and Technology(IUST)Tehran 13114-16846Iran

The purpose of this research was to develop statistical and intelligent models for predicting the severity of road traffic accidents(RTAs)on rural *** Logistic Regression(MLR)was used to predict the likelihood of *** more accurate prediction,Multi-Layer Perceptron(MLP)and Radius Basis Function(RBF)neural networks were *** indicated that in MLR,the model obtained from the backward method with the correct percent of 84.7%and R2 value of 0.893 was the best method for predicting the likelihood of ***,MLR showed that the variables of not paying attention to the front not paying attention to the frontroad ahead,followed byand then vehicle-motorcycle/bike accidents were the greatest *** the models,MLP had a better performance,so that the prediction accuracy of MLR,MLP,and RBF were 84.7%,96.7%,and 92.1%,*** model,due to higher accuracy,showed that the variable of reason of accident had the highest effect on the prediction of accidents,and considering MLR results,the variables of not paying attention to the front and then vehicle-motorcycle/bike accidents had the most influence on the occurrence of ***,motorcyclists and cyclists are more prone to accidents,and appropriate solutions should be adopted to enhance their safety.

关键词： safety rural accidents multiple logistic regression artificial neural networks

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Functionalized Graphene Oxide with Bismuth and Titanium Oxide Nanoparticles for Efficiently Removing Formaldehyde from the Air by Photocatalytic Degradation-Adsorption Process

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Journal of Analysis and Testing 2023年第4期7卷 444-458页

作者： Mohsen Mohammadi Asl hamid Shirkhanloo Nabiollah Mansouri seyed Ali Reza Haji seyed Mirzahosseini Farideh Atabi Department of Environmental Engineering Faculty of Natural Resource and EnvironmentScience and Research BranchIslamic Azad UniversityTehran 14778-93855Iran Research Institute of Petroleum Industry(RIPI) West BoulevardOlympic VillageTehran 14857-33111Iran

Formaldehyde(HCHO)is formed through the oxidation of volatile organic compounds(VOCs)and can cause human *** oxide and titanium oxide nanoparticles-functionalized nanographene oxide(Bi_(2)O_(3)/TiO_(2)@NGO)were used to rapidly remove the HCHO from the air by a photocatalytic degradation-adsorption process(PC-DAP).The formaldehyde vapor in pure air was generated in a dynamic system within a chamber,and flowed over Bi_(2)O_(3)/TiO_(2)@NGO adsorbent inside a fixed-bed quartz reactor(FBQR)under UV irradiation at optimized conditions(250C).At atmospheric pressure,the flow rate and gas hourly space velocity(GHSV)were adjusted to 300 mL/min and 100-450 L/h,*** radicals of HCHO and nanographene oxide(NGO)were generated through the UV-photochemical process,enhancing the chemical adsorption through the radicals’*** the other hand,the semi-degradation process by catalytic oxidation process converted some HCHO into raw materials of CO_(2)and H_(2)O,while the unconverted HCHO was physically absorbed by ***,the HCHO concentration in the outlet system was measured by gas chromatography with a flame ionization detector(GC-FID)after derivatizing formaldehyde with 2,4-dinitrophenylhydrazine(DNPH)and ***,efficient removal of HCHO from the air,the removal efficiency of more than 95%,was achieved through physical/chemical adsorption and the *** mean removal efficiencies for HCHO with Bi_(2)O_(3)-TiO_(2)@NGO,TiO_(2)@NGO,Bi_(2)O_(3)@NGO,and NGO were 98.7%,73.6%,61.8%,and 11.4%,respectively(n=10,RSD<5%).The methodology was validated by spiking different concentrations of standard HCHO into pure air.

关键词： Formaldehyde removal Air Functionalized graphene oxide UV radiation Photocatalytic degradation-adsorption process

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