Search results for: voltage stability.
1771 Determining the Best Method of Stability Landslide by Using of DSS (Case Study: Landslide in Hasan Salaran, Kurdistan Province in Iran)
Authors: S. Kamyabi, M. Salari, H. Shahabi
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One of the processes of slope that occurs every year in Iran and some parts of world and cause a lot of criminal and financial harms is called landslide. They are plenty of method to stability landslide in soil and rock slides. The use of the best method with the least cost and in the shortest time is important for researchers. In this research, determining the best method of stability is investigated by using of Decision Support systems. DSS is made for this purpose and was used (for Hasan Salaran area in Kurdistan). Field study data from topography, slope, geology, geometry of landslide and the related features was used. The related data entered decision making managements programs (DSS) (ALES).Analysis of mass stability indicated the instability potential at present. Research results show that surface and sub surface drainage the best method of stabilizing. Analysis of stability shows that acceptable increase in security coefficient is a consequence of drainage.
Keywords: Landslide, Decision Support systems, stability, Hasan Salaran landslide, Kurdistan province, Iran.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 17541770 Radiation Stability of Pigment ZnO Modified by Nanopowder
Authors: Chundong Li, V. V. Neshchimenko, M. M. Mikhailov
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The effect of the modification of ZnO powders by ZrO2, Al2O3, TiO2, SiO2, CeO2 and Y2O3 nanoparticles with a concentration of 1-30 wt % is investigated by diffuse reflectance spectra within the wavelength range 200 to 2500 nm before and after 100 keV proton and electron irradiation. It has been established that the introduction of nanoparticles ZrO2, Al2O3 enhances the optical stability of the pigments under proton irradiation, but reduces it under electron irradiation. Modifying with TiO2, SiO2, CeO2, Y2O3 nanopowders leads to decrease radiation stability in both types of irradiation. Samples modified by 5 wt. % of ZrO2 nanoparticles have the highest stability of optical properties after proton exposure. The degradation of optical properties under electron irradiation is not high for this concentration of nanoparticles. A decrease in the absorption of pigments modified with nanoparticles proton exposure is determined by a decrease in the intensity of bands located in the UV and visible regions. After electron exposure the absorption bands have in the whole spectrum range.
Keywords: Irradiation, nanopowders, radiation stability, zinc oxide.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 22121769 Seasonal Based Pollution Performance of 11kV and 33kV Silicon Composite Insulators
Authors: N. Sumathi, R. Srinivasa Rao
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This paper presents the experimental results of 11 kV and 33 kV silicon composite insulators under artificial salt and urea polluted conditions. The tests were carried out under different seasons like summer, winter, and monsoon. The artificial pollution is prepared by properly dissolving the salt and urea in the water. The prepared salt and urea pollutions are sprayed on the insulators and dried up for sufficiently large time. The process is continued until a uniform layer is formed on the surface of insulator. For each insulator rating, four samples were tested. The maximum leakage current and breakdown voltage were measured. From experimental data, performance of test specimen is evaluated by comparing breakdown voltage and leakage current during different seasons when exposed to salt and urea polluted conditions. From these results the performance of the insulators can be predicted when they are installed in industrial, agricultural, and coastal areas. The experimental tests were carried out in the High Voltage laboratory using two stage cascade transformer having the rating of 1000 kVA, 500 kV.Keywords: Silicon composite insulators, Urea pollution, Leakage current, Breakdown voltage, salt pollution, artificial pollution.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 18751768 A New Empirical Expression of the Breakdown Voltage for Combined Variations of Temperature and Pressure
Authors: Elyse Sili, Jean Pascal Cambronne
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In aircraft applications, according to the nature of electrical equipment its location may be in unpressurized area or very close to the engine; thus, the environmental conditions may change from atmospheric pressure to less than 100 mbar, and the temperature may be higher than the ambient one as in most real working conditions of electrical equipment. Then, the classical Paschen curve has to be replotted since these parameters may affect the discharge ignition voltage. In this paper, we firstly investigate the domain of validity of two corrective expressions on the Paschen-s law found in the literature, in case of changing the air environment and known as Peek and Dunbar corrections. Results show that these corrections are no longer valid for combined variation of temperature and pressure. After that, a new empirical expression for breakdown voltage is proposed and is validated in the case of combined variations of temperature and pressure.Keywords: Gas breakdown, gas density, Paschen curve, temperature effects
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 48951767 PTH Moment Exponential Stability of Stochastic Recurrent Neural Networks with Distributed Delays
Authors: Zixin Liu, Jianjun Jiao Wanping Bai
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In this paper, the issue of pth moment exponential stability of stochastic recurrent neural network with distributed time delays is investigated. By using the method of variation parameters, inequality techniques, and stochastic analysis, some sufficient conditions ensuring pth moment exponential stability are obtained. The method used in this paper does not resort to any Lyapunov function, and the results derived in this paper generalize some earlier criteria reported in the literature. One numerical example is given to illustrate the main results.
Keywords: Stochastic recurrent neural networks, pth moment exponential stability, distributed time delays.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 12551766 Improved Robust Stability Criteria of a Class of Neutral Lur’e Systems with Interval Time-Varying Delays
Authors: Longqiao Zhou, Zixin Liu, Shu Lü
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This paper addresses the robust stability problem of a class of delayed neutral Lur’e systems. Combined with the property of convex function and double integral Jensen inequality, a new tripe integral Lyapunov functional is constructed to derive some new stability criteria. Compared with some related results, the new criteria established in this paper are less conservative. Finally, two numerical examples are presented to illustrate the validity of the main results.
Keywords: Lur’e system, Convex function, Jensen integral inequality, Triple-integral method, Exponential stability.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15171765 Recent Advances in Pulse Width Modulation Techniques and Multilevel Inverters
Authors: Satish Kumar Peddapelli
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This paper presents advances in pulse width modulation techniques which refers to a method of carrying information on train of pulses and the information be encoded in the width of pulses. Pulse Width Modulation is used to control the inverter output voltage. This is done by exercising the control within the inverter itself by adjusting the ON and OFF periods of inverter. By fixing the DC input voltage we get AC output voltage. In variable speed AC motors the AC output voltage from a constant DC voltage is obtained by using inverter. Recent developments in power electronics and semiconductor technology have lead improvements in power electronic systems. Hence, different circuit configurations namely multilevel inverters have became popular and considerable interest by researcher are given on them. A fast space-vector pulse width modulation (SVPWM) method for five-level inverter is also discussed. In this method, the space vector diagram of the five-level inverter is decomposed into six space vector diagrams of three-level inverters. In turn, each of these six space vector diagrams of three-level inverter is decomposed into six space vector diagrams of two-level inverters. After decomposition, all the remaining necessary procedures for the three-level SVPWM are done like conventional two-level inverter. The proposed method reduces the algorithm complexity and the execution time. It can be applied to the multilevel inverters above the five-level also. The experimental setup for three-level diode-clamped inverter is developed using TMS320LF2407 DSP controller and the experimental results are analyzed.
Keywords: Five-level inverter, Space vector pulse wide modulation, diode clamped inverter.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 77711764 Linear Stability Characteristics of Wake-Shear Layers in Two-Phase Shallow Flows
Authors: Inta Volodko, Valentina Koliskina
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Linear stability of wake-shear layers in two-phase shallow flows is analyzed in the present paper. Stability analysis is based on two-dimensional shallow water equations. It is assumed that the fluid contains uniformly distributed solid particles. No dynamic interaction between the carrier fluid and particles is expected in the initial moment. Linear stability curves are obtained for different values of the particle loading parameter, the velocity ratio and the velocity deficit. It is shown that the increase in the velocity ratio destabilizes the flow. The particle loading parameter has a stabilizing effect on the flow. The role of the velocity deficit is also destabilizing: the increase of the velocity deficit leads to less stable flow.Keywords: Linear stability, Shallow flows, Wake-shear flows.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 12501763 Delay-Dependent Stability Criteria for Linear Time-Delay System of Neutral Type
Authors: Myeongjin Park, Ohmin Kwon, Juhyun Park, Sangmoon Lee
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This paper proposes improved delay-dependent stability conditions of the linear time-delay systems of neutral type. The proposed methods employ a suitable Lyapunov-Krasovskii’s functional and a new form of the augmented system. New delay-dependent stability criteria for the systems are established in terms of Linear matrix inequalities (LMIs) which can be easily solved by various effective optimization algorithms. Numerical examples showed that the proposed method is effective and can provide less conservative results.
Keywords: Neutral systems, Time-delay, Stability, Lyapunovmethod, LMI.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 18831762 Stability Analysis of a Human-Mosquito Model of Malaria with Infective Immigrants
Authors: Nisha Budhwar, Sunita Daniel
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In this paper, we analyse the stability of the SEIR model of malaria with infective immigrants which was recently formulated by the authors. The model consists of an SEIR model for the human population and SI Model for the mosquitoes. Susceptible humans become infected after they are bitten by infectious mosquitoes and move on to the Exposed, Infected and Recovered classes respectively. The susceptible mosquito becomes infected after biting an infected person and remains infected till death. We calculate the reproduction number R0 using the next generation method and then discuss about the stability of the equilibrium points. We use the Lyapunov function to show the global stability of the equilibrium points.Keywords: Susceptible, exposed, infective, recovered, infective immigrants, reproduction number, Lyapunov function, equilibrium points, global stability.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 12961761 New Strategy Agents to Improve Power System Transient Stability
Authors: Mansour A. Mohamed, George G. Karady, Ali M. Yousef
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This paper proposes transient angle stability agents to enhance power system stability. The proposed transient angle stability agents divided into two strategy agents. The first strategy agent is a prediction agent that will predict power system instability. According to the prediction agent-s output, the second strategy agent, which is a control agent, is automatically calculating the amount of active power reduction that can stabilize the system and initiating a control action. The control action considered is turbine fast valving. The proposed strategies are applied to a realistic power system, the IEEE 50- generator system. Results show that the proposed technique can be used on-line for power system instability prediction and control.Keywords: Multi-agents, Fast Valving, Power System Transient Stability, Prediction methods,
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 18531760 Design and Characterization of a CMOS Process Sensor Utilizing Vth Extractor Circuit
Authors: Rohana Musa, Yuzman Yusoff, Chia Chieu Yin, Hanif Che Lah
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This paper presents the design and characterization of a low power Complementary Metal Oxide Semiconductor (CMOS) process sensor. The design is targeted for implementation using Silterra’s 180 nm CMOS process technology. The proposed process sensor employs a voltage threshold (Vth) extractor architecture for detection of variations in the fabrication process. The process sensor generates output voltages in the range of 401 mV (fast-fast corner) to 443 mV (slow-slow corner) at nominal condition. The power dissipation for this process sensor is 6.3 µW with a supply voltage of 1.8V with a silicon area of 190 µm X 60 µm. The preliminary result of this process sensor that was fabricated indicates a close resemblance between test and simulated results.Keywords: CMOS Process sensor, Process, Voltage and Temperature (PVT) sensor, threshold extractor circuit, Vth extractor circuit.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 7571759 Studies on Various Parameters Involved in Conjugation of Starch with Lysine for Excellent Emulsification Properties Using Response Surface Methodology
Authors: Sourish Bhattacharya, Priyanka Singh
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The process parameters, starch-water ratio (A, (w/v) %), pH of suspension (B), Temperature(C, °C) and Time (D, hrs.)., were optimized for the preparation of starch-lysine conjugate and studying their effect on stability of emulsions by calculating emulsion stability index using response surface methodology. The optimized conditions are pH 9.0, temperature 60oC, reaction time 6 hrs, starch:water ratio 1:2.5, having emulsion stability index was 0.72.
Keywords: Emulsion stability index, pH of suspension, Starch-water ratio, Temperature, Time.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 18501758 New Delay-Dependent Stability Criteria for Neural Networks With Two Additive Time-varying Delay Components
Authors: Xingyuan Qu, Shouming Zhong
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In this paper, the problem of stability criteria of neural networks (NNs) with two-additive time-varying delay compenents is investigated. The relationship between the time-varying delay and its lower and upper bounds is taken into account when estimating the upper bound of the derivative of Lyapunov functional. As a result, some improved delay stability criteria for NNs with two-additive time-varying delay components are proposed. Finally, a numerical example is given to illustrate the effectiveness of the proposed method.
Keywords: Delay-dependent stability, time-varying delays, Lyapunov functional, linear matrix inequality (LMI).
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16101757 Genetically Optimized TCSC Controller for Transient Stability Improvement
Authors: Sidhartha Panda, N.P.Padhy, R.N.Patel
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This paper presents a procedure for modeling and tuning the parameters of Thyristor Controlled Series Compensation (TCSC) controller in a multi-machine power system to improve transient stability. First a simple transfer function model of TCSC controller for stability improvement is developed and the parameters of the proposed controller are optimally tuned. Genetic algorithm (GA) is employed for the optimization of the parameter-constrained nonlinear optimization problem implemented in a simulation environment. By minimizing an objective function in which the oscillatory rotor angle deviations of the generators are involved, transient stability performance of the system is improved. The proposed TCSC controller is tested on a multi-machine system and the simulation results are presented. The nonlinear simulation results validate the effectiveness of proposed approach for transient stability improvement in a multimachine power system installed with a TCSC. The simulation results also show that the proposed TCSC controller is also effective in damping low frequency oscillations.
Keywords: Genetic algorithm, TCSC, transient stability, multimachinepower system.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 23841756 Zero Voltage Switched Full Bridge Converters for the Battery Charger of Electric Vehicle
Authors: Rizwan Ullah, Abdar Ali, Zahid Ullah
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This paper illustrates the study of three isolated zero voltage switched (ZVS) PWM full bridge (FB) converters to charge the high voltage battery in the charger of electric vehicle (EV). EV battery chargers have several challenges such as high efficiency, high reliability, low cost, isolation, and high power density. The cost of magnetic and filter components in the battery charger is reduced when switching frequency is increased. The increase in the switching frequency increases switching losses. ZVS is used to reduce switching losses and to operate the converter in the battery charger at high frequency. The performance of each of the three converters is evaluated on the basis of ZVS range, dead times of the switches, conduction losses of switches, circulating current stress, circulating energy, duty cycle loss, and efficiency. The limitations and merits of each PWM FB converter are reviewed. The converter with broader ZVS range, high efficiency and low switch stresses is selected for battery charger applications in EV.Keywords: Electric vehicle, PWM FB converter, zero voltage switching, circulating energy, duty cycle loss, battery charger.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 24301755 An Hybrid Approach for Loss Reduction in Distribution Systems using Harmony Search Algorithm
Authors: R. Srinivasa Rao
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Individually Network reconfiguration or Capacitor control perform well in minimizing power loss and improving voltage profile of the distribution system. But for heavy reactive power loads network reconfiguration and for heavy active power loads capacitor placement can not effectively reduce power loss and enhance voltage profiles in the system. In this paper, an hybrid approach that combine network reconfiguration and capacitor placement using Harmony Search Algorithm (HSA) is proposed to minimize power loss reduction and improve voltage profile. The proposed approach is tested on standard IEEE 33 and 16 bus systems. Computational results show that the proposed hybrid approach can minimize losses more efficiently than Network reconfiguration or Capacitor control. The results of proposed method are also compared with results obtained by Simulated Annealing (SA). The proposed method has outperformed in terms of the quality of solution compared to SA.Keywords: Capacitor Control, Network Reconfiguration, HarmonySearch Algorithm, Loss Reduction, Voltage Profile.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 21681754 Switching Rule for the Exponential Stability and Stabilization of Switched Linear Systems with Interval Time-varying Delays
Authors: Kreangkri Ratchagit
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This paper is concerned with exponential stability and stabilization of switched linear systems with interval time-varying delays. The time delay is any continuous function belonging to a given interval, in which the lower bound of delay is not restricted to zero. By constructing a suitable augmented Lyapunov-Krasovskii functional combined with Leibniz-Newton-s formula, a switching rule for the exponential stability and stabilization of switched linear systems with interval time-varying delays and new delay-dependent sufficient conditions for the exponential stability and stabilization of the systems are first established in terms of LMIs. Numerical examples are included to illustrate the effectiveness of the results.
Keywords: Switching design, exponential stability and stabilization, switched linear systems, interval delay, Lyapunov function, linear matrix inequalities.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15261753 Tuning a Fractional Order PID Controller with Lead Compensator in Frequency Domain
Authors: Tahmine. V. Moghaddam, N. Bigdeli, K. Afshar
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To achieve the desired specifications of gain and phase margins for plants with time-delay that stabilized with FO-PID controller a lead compensator is designed. At first the range of controlled system stability based on stability boundary criteria is determined. Using stability boundary locus method in frequency domain the fractional order controller parameters are tuned and then with drawing bode diagram in frequency domain accessing to desired gain and phase margin are shown. Numerical examples are given to illustrate the shapes of the stabilizing region and to show the design procedure.Keywords: Fractional controller, Lead compensator, Stabilityregions, Stability boundary locus
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 25891752 Interethnic and Interconfessional Agreements are Major Factors of the Political Stability in the Republic of Kazakhstan
Authors: Zhengisbek Tolen, Kubash Mengdigali, Dinara Akbolat, Elnura Assyltaeva, Aliya Alimzhanova
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In the article the historical formation of interethnic and interconfessional agreement policy in Kazakhstan and their developing features at present time will be analyzed. The successfully pursued by Kazakhstan at the present in the direction of ethnic and confessional policy is regarded as a major factor in promoting stability for the country.Keywords: Political stability, interethnic relationship, interconfessional agreement, tolerance.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 13761751 Space-Vector PWM Inverter Feeding a Permanent-Magnet Synchronous Motor
Authors: A. Maamoun, Y. M. Alsayed, A. Shaltout
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The paper presents a space-vector pulse width modulation (SVPWM) inverter feeding a permanent-magnet synchronous motor (PMSM). The SVPWM inverter enables to feed the motor with a higher voltage with low harmonic distortions than the conventional sinusoidal PWM inverter. The control strategy of the inverter is the voltage / frequency control method, which is based on the space-vector modulation technique. The proposed PMSM drive system involving the field-oriented control scheme not only decouples the torque and flux which provides faster response but also makes the control task easy. The performance of the proposed drive is simulated. The advantages of the proposed drive are confirmed by the simulation results.
Keywords: permanent-magnet synchronous motor, space-vectorPWM inverter, voltage/frequency control.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 67011750 Determination of the Optimal DG PV Interconnection Location Using Losses and Voltage Regulation as Assessment Indicators Case Study: ECG 33 kV Sub-Transmission Network
Authors: Ekow A. Kwofie, Emmanuel K. Anto, Godfred Mensah
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In this paper, CYME Distribution software has been used to assess the impacts of solar Photovoltaic (PV) distributed generation (DG) plant on the Electricity Company of Ghana (ECG) 33 kV sub-transmission network at different PV penetration levels. As ECG begins to encourage DG PV interconnections within its network, there has been the need to assess the impacts on the sub-transmission losses and voltage contribution. In Tema, a city in Accra - Ghana, ECG has a 33 kV sub-transmission network made up of 20 No. 33 kV buses that was modeled. Three different locations were chosen: The source bus, a bus along the sub-transmission radial network and a bus at the tail end to determine the optimal location for DG PV interconnection. The optimal location was determined based on sub-transmission technical losses and voltage impact. PV capacities at different penetration levels were modeled at each location and simulations performed to determine the optimal PV penetration level. Interconnection at a bus along (or in the middle of) the sub-transmission network offered the highest benefits at an optimal PV penetration level of 80%. At that location, the maximum voltage improvement of 0.789% on the neighboring 33 kV buses and maximum loss reduction of 6.033% over the base case scenario were recorded. Hence, the optimal location for DG PV integration within the 33 kV sub-transmission utility network is at a bus along the sub-transmission radial network.
Keywords: Distributed generation photovoltaic, DG PV, optimal location, penetration level, sub-transmission network.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 13201749 Bode Stability Analysis for Single Wall Carbon Nanotube Interconnects Used in 3D-VLSI Circuits
Authors: Saeed H. Nasiri, Rahim Faez, Bita Davoodi, Maryam Farrokhi
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Bode stability analysis based on transmission line modeling (TLM) for single wall carbon nanotube (SWCNT) interconnects used in 3D-VLSI circuits is investigated for the first time. In this analysis, the dependence of the degree of relative stability for SWCNT interconnects on the geometry of each tube has been acquired. It is shown that, increasing the length and diameter of each tube, SWCNT interconnects become more stable.Keywords: Bode stability criterion, Interconnects, Interlayer via, Single wall carbon nanotubes, Transmission line method, Time domain analysis
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 18311748 Supergrid Modeling and Operation and Control of Multi Terminal DC Grids for the Deployment of a Meshed HVDC Grid in South Asia
Authors: Farhan Beg, Raymond Moberly
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The Indian subcontinent is facing a massive challenge with regards to energy security in its member countries; to provide reliable electricity to facilitate development across various sectors of the economy and consequently achieve the developmental targets. The instability of the current precarious situation is observable in the frequent system failures and blackouts.
The deployment of interconnected electricity ‘Supergrid’ designed to carry huge quanta of power across the Indian sub-continent is proposed in this paper. Not only enabling energy security in the subcontinent it will also provide a platform for Renewable Energy Sources (RES) integration. This paper assesses the need and conditions for a Supergrid deployment and consequently proposes a meshed topology based on Voltage Source High Voltage Direct Current (VSC- HVDC) converters for the Supergrid modeling. Various control schemes for the control of voltage and power are utilized for the regulation of the network parameters. A 3 terminal Multi Terminal Direct Current (MTDC) network is used for the simulations.
Keywords: Super grid, Wind and Solar energy, High Voltage Direct Current, Electricity management, Load Flow Analysis.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 28111747 A Grid Current-controlled Inverter with Particle Swarm Optimization MPPT for PV Generators
Authors: Hanny H. Tumbelaka, Masafumi Miyatake
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This paper proposes a three-phase four-wire currentcontrolled Voltage Source Inverter (CC-VSI) for both power quality improvement and PV energy extraction. For power quality improvement, the CC-VSI works as a grid current-controlling shunt active power filter to compensate for harmonic and reactive power of loads. Then, the PV array is coupled to the DC bus of the CC-VSI and supplies active power to the grid. The MPPT controller employs the particle swarm optimization technique. The output of the MPPT controller is a DC voltage that determines the DC-bus voltage according to PV maximum power. The PSO method is simple and effective especially for a partially shaded PV array. From computer simulation results, it proves that grid currents are sinusoidal and inphase with grid voltages, while the PV maximum active power is delivered to loads.Keywords: Active Power Filter, MPPT, PV Energy Conversion.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 21561746 Analysis of Resistance Characteristics of Conductive Concrete Using Press-Electrode Method
Authors: Chun-Yao Lee, Siang-Ren Wang
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This paper aims to discuss the influence of resistance characteristic on the high conductive concrete considering the changes of voltage and environment. The high conductive concrete with appropriate proportion is produced to the press-electrode method. The curve of resistivity with the changes of voltage and environment is plotted and the changes of resistivity are explored.Keywords: conductive concrete, resistivity.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15771745 A Linear Relation for Voltage Unbalance Factor Evaluation in Three-Phase Electrical Power System Using Space Vector
Authors: Dana M. Ragab, Jasim A Ghaeb
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The Voltage Unbalance Factor (VUF) index is recommended to evaluate system performance under unbalanced operation. However, its calculation requires complex algebra which limits its use in the field. Furthermore, one system cycle is required at least to detect unbalance using the VUF. Ideally unbalance mitigation must be performed within 10 ms for 50 Hz systems. In this work, a linear relation for VUF evaluation in three-phase electrical power system using space vector (SV) is derived. It is proposed to determine the voltage unbalance quickly and accurately and to overcome the constraints associated with the traditional methods of VUF evaluation. Aqaba-Qatrana-South Amman (AQSA) power system is considered to study the system performance under unbalanced conditions. The results show that both the complexity of calculations and the time required to evaluate VUF are reduced significantly.
Keywords: Power quality, space vector, unbalance evaluation.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 9421744 Characterization of Responsivity, Sensitivity and Spectral Response in Thin Film SOI photo-BJMOS -FET Compatible with CMOS Technology
Authors: Hai-Qing Xie, Yun Zeng, Yong-Hong Yan, Jian-Ping Zeng, Tai-Hong Wang
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Photo-BJMOSFET (Bipolar Junction Metal-Oxide- Semiconductor Field Effect Transistor) fabricated on SOI film was proposed. ITO film is adopted in the device as gate electrode to reduce light absorption. Depletion region but not inversion region is formed in film by applying gate voltage (but low reverse voltage) to achieve high photo-to-dark-current ratio. Comparisons of photoelectriccharacteristics executed among VGK=0V, 0.3V, 0.6V, 0.9V and 1.0V (reverse voltage VAK is equal to 1.0V for total area of 10×10μm2). The results indicate that the greatest improvement in photo-to-dark-current ratio is achieved up to 2.38 at VGK=0.6V. In addition, photo-BJMOSFET is compatible with CMOS integration due to big input resistanceKeywords: Photo-BJMOSFET, Responsivity, Sensitivity, Spectral response.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15391743 New Stability Analysis for Neural Networks with Time-Varying Delays
Authors: Miaomiao Yang, Shouming Zhong
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This paper studies the problem of asymptotically stability for neural networks with time-varying delays.By establishing a suitable Lyapunov-Krasovskii function and several novel sufficient conditions are obtained to guarantee the asymptotically stability of the considered system. Finally,two numerical examples are given to illustrate the effectiveness of the proposed main results.
Keywords: Neural networks, Lyapunov-Krasovskii, Time-varying delays, Linear matrix inequality.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 17221742 Slope Stability of an Earthen Levee Strengthened by HPTRM under Turbulent Overtopping Conditions
Authors: Fashad Amini, Lin Li
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High performance turf reinforcement mat (HPTRM) is one of the most advanced flexible armoring technologies for severe erosion challenges. The effect of turbulence on the slope stability of an earthen levee strengthened by high performance turf reinforcement mat (HPTRM) is investigated in this study for combined storm surge and wave overtopping conditions. The results show that turbulence has strong influence on the slope stability during the combined storm surge and wave overtopping conditions. Among the surge height, peak wave force and turbulent force. The turbulent force has the ability to stabilize the earthen levee at the large wave force the turbulent force has strongest effect on the FS. The surge storm acts as an independent force on the slope stability of the earthen levee. It just adds to the effects of the turbulent force and wave force on the slope stability of HPTRM strengthened levee.
Keywords: Slope stability, strength reduction method, HPTRM, levee, overtopping.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2406