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ND:YAG Laser Pulses Ablation Threshold of Stainless Steel 304

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Materials Sciences and Applications 2015年第7期6卷 634-645页

作者： mitra radmanesh Amirkianoosh Kiani Department of Mechanical Engineering University of New Brunswick Fredericton Canada

Laser processing and laser surface texturing in multiple fields have become a popular topic of study in recent decades. Understanding the principles behind the laser irradiation mechanism is an essential step in choosing the most effective process parameters. Through this study, the effects of power and pulse duration on the structure and surface pattern of stainless steel type 304 were examined, and optimized laser parameters were introduced for desired laser penetration and heat-affected areas on the surface. The analyzed sample was prepared by using variations of pulse durations and different pulsed energies. Looking at the trend of change of non-dimensional temperature along the surface, thickness, and center of the sample, the effects of pulse duration and intensity (corresponding to energy) were observed. Upon considering all the aspects of the irradiated spots, such as heat-affected area diameter, surface patterns, and penetration depth, the advantages and disadvantages of short and long pulse durations are mapped out clearly. Also, a new method to obtain the ablation threshold of stainless steel is introduced, and a thorough analytical solution is obtained.

关键词： Laser Material Processing Laser Surface Treatment Stainless Steel Ablation Threshold

Hybrid extended Fourier series for optimal control of nonlinear algebraic dynamical systems

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控制理论与应用（英文版） 2011年第4期9卷 487-492页

作者： Jalal NAZARZADEH Hamidreza radmanesh Department of Electrical Engineering Shahed University

The paper introduces a new method for finding optimal control of algebraic dynamic systems. The structure of algebraic dynamical systems is nonlinear with quadratic and bilinear terms. A new hybrid extended Fourier series is introduced, and state and control variables of the system are expanded by this series. Moreover, properties of new series are presented, and integration and product operational matrices are obtained. Using operational matrices, optimal control of the systems is converted to a set of simultaneous nonlinear algebraic relations. An illustrative example is included to compare our results with those in the literature.

关键词： Bilinear systems Hybrid extended Fourier series Nonlinear algebraic dynamic systems Quadratic systems Optimal control

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

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

Circuit breakers in HVDC systems: state-of-the-art review and future trends

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Protection and Control of Modern Power Systems 2023年第3期8卷 16-31页

作者： Erfan Taherzadeh Hamid radmanesh Shahram Javadi G.B.Gharehpetian Department of Electrical Engineering Islamic Azad University Central Tehran BranchTehranIran Electrical Engineering Department Amirkabir University of Technology(Tehran Polytechnic)Tehran ***Iran

High voltage direct current(HVDC)systems are efficient solutions for the integration of large-scale renewable energy sources with the main power *** rapid development of the HVDC grid has resulted in a growing interest in DC circuit breakers(DCCBs).A fast and reliable circuit breaker is a necessary requirement in the development of large scale HVDC *** paper provides a comprehensive review and survey of the HVDC CBs and discusses potential research *** principles and the main features of various DCCBs are described and their merits and shortcomings are also highlighted.

关键词： DC circuit breakers(DCCBs) High voltage direct current(HVDC)system Multi-terminal HVDC(MT-HVDC) Fault current isolation Renewable energies Voltage clamping

Using S-statistic for investigating the effect of temperature on hydrodynamics of gas-solid fluidization

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Particuology 2013年第3期11卷 288-293页

作者： Mohammad Reza Tamadondar Reza Zarghami Hedayat Azizpour Navid Mostoufi Jamal Chaouki Ramin radmanesh Multiphase Systems Research Lab. Oil and Gas Processing Centre of ExcellenceSchool of Chemical EngineeringCollege of EngineeringUniversity of Tehran Department of Chemical Engineering Ecole Polytechnique de Montreal

The influence of temperature on fluidization was investigated by a statistical chaotic attractor comparison test known as S-statistic, After calibration of the variables used in this method, the S-test was applied to the radioactive particle tracking （RPT） data obtained from a lab-scale fluidized bed. Experiments were performed with sand as fluidized particles and in temperatures from ambient up to 600 ℃ with superficial gas velocities of 0.29, 0.38 and 0.52 m/s. Considering the behavior of bubbles and comparing with frequency domain analysis, it was concluded that S-statistic is a reliable method for characterization of fluidization process behavior at different temperatures.

关键词： S-statisticEffect of temperatureParticle trajectoryFluidized bed

Nonlinear Identification of the External Power System Dynamic Equivalent for the Study System

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Nonlinear Identification of the External Power System Dynami...

Series transformer based diode-bridge-type solid state fault current limiter

第二十七届中国控制会议

作者： Hamidreza radmanesh Hamed Shakouri G. Mehdi Karrari Engineering Faculty Shahed University Industrial Engineering Faculty University of Tehran Electrical Engineering Faculty Amirkabir University of Tech

ISBN: (纸本)9787900719706

Based on the concept of the external power system dynamic equivalent for the study system,in this paper a reduced-order artificial neural network is proposed,which is constructed to model the external *** mastermind behind the proposed method is to identify the external part as a dynamic-algebraic ANN,and this separation between dynamic equations in the state space form and algebraic equations is useful to solve the prediction *** obtain this model,the system should be excited by some disturbances,and according to the measured data on the boundary nodes,identification procedure is ***,the trained network can be used to predict behavior of the external system in a high degree of accuracy.

关键词： Dynamic equivalent Multi-machine system Artificial neural networks Nonlinear identification

来源： cnki会议评论

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Frontiers of Information Technology & Electronic Engineering 2015年第9期16卷 769-784页

作者： Amir HEIDARY Hamid radmanesh Seyed Hamid FATHI G.B.GHAREHPETIAN Electrical Engineering Department Islamic Azad University Electrical Engineering Department Amirkabir University of Technology Electrical Engineering Department Aeronautical University of Science and Technology

We propose a novel series transformer based diode-bridge-type solid state fault current limiter （SSFCL）. To control the fault current, a series RLC branch is connected to the secondary side of an isolation series transformer. Based on this RLC branch, two current limiting modes are created. In the first mode, R and C are bypassed via a paralleled power electronic switch （insulated-gate bipolar transistor, IGBT） and L remains connected to the secondary side of the transformer as a DC reactor. In the second mode, the series reactor impedance is not enough to limit the fault current. In this case, the fault current can be con- trolled by selecting a proper on-off duration of the parallel IGBT, across the series damping resistor （R） and capacitor, which inserts high impedance into the line to limit the fault current. Then, by controlling the magnitude of the DC reactor current, the fault current is reduced and the voltage of the point of common coupling （PCC） is kept at an acceptable level. In addition, in the new SSFCL, the series RC branch, connected in parallel with the IGBT, serves as a snubber circuit for decreasing the transient recovery voltage （TRV） of the IGBT during on-off states. Therefore, the power quality indices can be improved. The measure- ment results of a built prototype are presented to support the simulation and theoretical studies. The proposed SSFCL can limit the fault current without any delay and successfully smooth the fault current waveform.

关键词： Solid state fault current limiter (SSFCL) Power quality Voltage sag Point of common coupling (PCC) Isolationtransformer

Studying Effect of Magnetizing Curve Nonlinearity Index on the Occurring Chaotic Ferroresonance Oscillation in Autotransformers

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Energy and Power Engineering 2011年第2期3卷 79-86页

作者： Hamid radmanesh Mehrdad Rostami Jafar Khalilpour Electrical Engineering Department Shahid Sattari Aeronautical University of Science & Technology Tehran Iran Electrical Engineering Department Shahed University Tehran Iran

This paper investigates the effect of iron core saturation characteristic degree on the onset of chaotic ferrore-sonance and duration of transient chaos in an autotransformer. The transformer chosen for study has a rating of 50 MVA, 635.1 kV, the magnetization characteristic of the autotransformer is modeled by a single-value two-term polynomial with q = 5, 7, 11. The core loss is modeled by a linear resistance and is considered a fix value for it. Simulation results are derived by using MATLAB software and nonlinear dynamics tool such as bifurcation and phase plan diagrams. It is shown settling down to the chaotic region is increased when degree of core nonlinearity is gone from 5 to 11.

关键词： Linear Core Losses Chaotic Ferroresonance Bifurcation Diagrams Autotransformers