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2015

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Articles 12181 - 12210 of 12617

Full-Text Articles in Physical Sciences and Mathematics

Rfid Card Security For Public Transportation Applications Based On A Novel Neural Network Analysis Of Cardholder Behavior Characteristics, Gürsel Düzenli̇ Jan 2015

Rfid Card Security For Public Transportation Applications Based On A Novel Neural Network Analysis Of Cardholder Behavior Characteristics, Gürsel Düzenli̇

Turkish Journal of Electrical Engineering and Computer Sciences

This paper proposes a novel approach that applies neural network forecasting to security for closed-loop prepaid cards based on low-cost technologies such as RFID and 1-Wire. The security vulnerability of low-cost RFID closed-loop prepaid card systems originates mostly from the card itself. Criminal organizations counterfeit or clone card data. Although high-security prepaid cards exist, they are often too expensive for transport ticketing, and even their security is not guaranteed for a well-defined period of time. Therefore, data encryption systems are used widely against counterfeiting with success. However, it has not been possible to develop countermeasures with comparable success against cloning. …

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Active And Reactive Power Transmission Loss Allocation To Bilateral Contracts Through Game Theory Techniques, Hamed Nafisi, Hossein Mahdinia Roudsari, Seyed Hossein Hosseinian, Hossein Askarian Abyaneh, Vahid Rasouli Disfani Jan 2015

Active And Reactive Power Transmission Loss Allocation To Bilateral Contracts Through Game Theory Techniques, Hamed Nafisi, Hossein Mahdinia Roudsari, Seyed Hossein Hosseinian, Hossein Askarian Abyaneh, Vahid Rasouli Disfani

Turkish Journal of Electrical Engineering and Computer Sciences

Transmission loss has a considerable effect in overall power generation. For fairly distributing the charge of losses to generators and consumers in a deregulated power system, the allocation of this loss is very important. Game-theoretic methods seem fairer for share determination of each participant of a coalition with no discrimination. In this paper, the active and reactive power transmission losses are allocated to bilateral transactions simultaneously through load flow calculations and cooperative game theory solutions. The loss allocation problem and each bilateral transaction are treated as a game and a player of the game, correspondingly. Two game theory-based approaches, the …

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A Model-Based Edge Estimation Method With Increased Edge Localization Accuracy For Medical Images, Mehmet Öztürk, Temel Kayikçioğlu Jan 2015

A Model-Based Edge Estimation Method With Increased Edge Localization Accuracy For Medical Images, Mehmet Öztürk, Temel Kayikçioğlu

Turkish Journal of Electrical Engineering and Computer Sciences

This study proposes an improved method based on a nonlinear parametric model for intensity profile to increase the edge localization accuracy in medical images gathered from different imaging modalities. The edge model consists of three parameters associated with an edge point. It also takes into account local background intensity, noise, and blurring. The Marquardt-Levenberg algorithm is used to estimate the parameters because of its accuracy and good convergence rate. Performance of the proposed method is tested quantitatively by comparing the results with those of the well-known active contour method on synthetic vessel images. Qualitative comparisons on real MRI, coronary angiography, …

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Robust Speed Controller Design For Induction Motors Based On Ifoc And Kharitonov Theorem, Bijan Moaveni, Mojtaba Khorshidi Jan 2015

Robust Speed Controller Design For Induction Motors Based On Ifoc And Kharitonov Theorem, Bijan Moaveni, Mojtaba Khorshidi

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, robust PI controllers are designed to control the speed of induction motors based on a vector control strategy. The design methodology defines the robust stability and robust performance regions in the $k_{p}-k_{i}$ (PI controller coefficients) plane using the Kharitonov theorem. In the control system design procedure, a nonlinear induction motor is modeled as an uncertain linear model. The procedure of modeling the uncertainties is presented. The required scientific foundations for designing a robust PI controller are also introduced in the general case while the necessary equations are derived. In the final step, the design procedure for a …

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A Test And Simulation Device For Doppler-Based Fetal Heart Rate Monitoring, Ahmet Mert, Mana Sezdi̇, Aydin Akan Jan 2015

A Test And Simulation Device For Doppler-Based Fetal Heart Rate Monitoring, Ahmet Mert, Mana Sezdi̇, Aydin Akan

Turkish Journal of Electrical Engineering and Computer Sciences

The Doppler effect is the preferred technique in fetal heart rate (FHR) monitoring devices. The main objective of the recent studies on the Doppler FHR has been to improve the accuracy. On the other hand, a reliable fetal heart simulator becomes essential for testing Doppler FHR monitoring devices. The motivation of this study is to design a reliable system that will be used to test Doppler FHR monitors. This device generates a similar Doppler frequency shift of fetal cardiac activity including the heart's wall and valve motions. The components of this system are basically a signal generator using a microcontroller …

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New Metrics For Clustering Of Identical Products Over Imperfect Data, Zeki̇ Yetgi̇n, Furkan Gözükara Jan 2015

New Metrics For Clustering Of Identical Products Over Imperfect Data, Zeki̇ Yetgi̇n, Furkan Gözükara

Turkish Journal of Electrical Engineering and Computer Sciences

This paper introduces the concept of product identity-clustering based on new similarity metrics and new performance metrics for web-crawled products. Product identity-clustering is defined here as the clustering of identical products, e.g., for price comparison purposes. Products blindly crawled over web sources, e.g., online marketplaces, have different description formats, where the features describing the same products differ in both number and representation formats. This problem causes imperfect feature vectors, where the vectors are considered to be not uniform in length and structure, with the features of various data types (numeric, categorical), and unknown vector structures. Furthermore, the product information usually …

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Solution Of Tio$_{2}$ Memristor-Capacitor Series Circuit Excited By A Constant Voltage Source And Its Application To Calculate Operation Frequency Of A Programmable Tio$_{2}$ Memristor-Capacitor Relaxation Oscillator, Reşat Mutlu Jan 2015

Solution Of Tio$_{2}$ Memristor-Capacitor Series Circuit Excited By A Constant Voltage Source And Its Application To Calculate Operation Frequency Of A Programmable Tio$_{2}$ Memristor-Capacitor Relaxation Oscillator, Reşat Mutlu

Turkish Journal of Electrical Engineering and Computer Sciences

The memristor is a new-found circuit element and its applications in programmable circuits are also under study. Analysis of most of its combinations with other circuit elements such as resistors, capacitors, and inductors does not exist. In this work, a TiO$_{2}$ memristor model with linear dopant drift speed is used and the solution of a TiO$_{2}$ memristor and capacitor series circuit driven by a constant voltage source is given. It is then used to analyze a novel M-C oscillator circuit. In previous programmable oscillator studies, the memristance of the oscillator was assumed to be constant. However, in this study, the …

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3d Imaging For Ground-Penetrating Radars Via Dictionarydimension Reduction, Muhammed Duman, Ali̇ Cafer Gürbüz Jan 2015

3d Imaging For Ground-Penetrating Radars Via Dictionarydimension Reduction, Muhammed Duman, Ali̇ Cafer Gürbüz

Turkish Journal of Electrical Engineering and Computer Sciences

Ground-penetrating radar (GPR) has been widely used in detecting or imaging subsurface targets. In many applications such as archaeology, utility imaging, or landmine detection, three-dimensional (3D) images of the subsurface region is required for better understanding of the sensed medium. However, a high-resolution 3D image requires wideband data collection both in spatial and time/frequency domains. Match filtering is the main tool for generating subsurface images. Applying match filtering with the data acquisition impulse response for each possible voxel in the 3D region with the collected data requires both a tremendous amount of computer memory and computational complexity. Hence, it is …

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Detection Of Stator Winding Fault In Induction Motor Using Instantaneous Power Signature Analysis, Ahmet Küçüker, Mehmet Bayrak Jan 2015

Detection Of Stator Winding Fault In Induction Motor Using Instantaneous Power Signature Analysis, Ahmet Küçüker, Mehmet Bayrak

Turkish Journal of Electrical Engineering and Computer Sciences

Stator interturn faults are one of the most common faults occurring in induction motors. Early detection of interturn short circuit is important to reduce repair costs. Axial leakage monitoring, zero-sequence components, negative sequence current, and motor current signature analysis have been used for fault detection in early states. In the paper, the instantaneous power signature analysis technique is used to detect these faults, and experimental results for healthy and faulty motors are shown and discussed.

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A New Approach To The Development Of A Nonlinear Model For Micro-Pelton Turbines, Mahmut Temel Özdemi̇r, Ahmet Orhan Jan 2015

A New Approach To The Development Of A Nonlinear Model For Micro-Pelton Turbines, Mahmut Temel Özdemi̇r, Ahmet Orhan

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, a new approach that is closer to the real turbine without abandoning the advantages of nonlinear modeling simplicity compromising the simplicity of the nonlinear model is proposed. The purpose of the study is to contribute to making theoretical studies of microhydroelectric power plants (MHPPs) more realistic. Studies on their control, especially frequency control, have increased with the expansion of grid-connected power plants. However, some problems have occurred when converting simulation studies of the frequency control to practical studies. The reasons for these problems are that the systems cannot be modeled completely. In this study, first, the nonlinear …

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A Novel Asymmetrical Connection Balance Transformer For Traction Power Supply, Zhiwei Xu, Longfu Luo, Zhiwen Zhang, Yong Li Jan 2015

A Novel Asymmetrical Connection Balance Transformer For Traction Power Supply, Zhiwei Xu, Longfu Luo, Zhiwen Zhang, Yong Li

Turkish Journal of Electrical Engineering and Computer Sciences

Balance transformers can usually eliminate the zero sequence current and suppress the negative sequence current. This paper develops a novel approach for balance transformers, which is different from the traditional one with two-phase or three-phase symmetrical windings. First, the basic principle and the connected scheme of the transformer are clarified. Second, this paper derives the relationship between the primary and the second windings from a mathematical model for the new approach. Third, the balance condition (i.e. the neutral current in the primary side is zero) and the decoupling condition of the two-phase system are also obtained. Finally, the correctness and …

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Exact Solution Of Conducting Half Plane Problems In Terms Of A Rapidly Convergent Series And An Application Of The Multiplicative Calculus, Ali̇ Uzer Jan 2015

Exact Solution Of Conducting Half Plane Problems In Terms Of A Rapidly Convergent Series And An Application Of The Multiplicative Calculus, Ali̇ Uzer

Turkish Journal of Electrical Engineering and Computer Sciences

The problem of cylindrical wave incidence on a conducting half plane has been considered. A modal solution for Green's function of the problem is transformed into contour integral representations in a complex plane. Some contour deformations and changes of variables are then made for the integrals. Finally, the resultant integrals are transformed back into a series, which converges rapidly to the exact solution when the observation angles are close to the reflection/shadow boundaries (RSBs) of the conducting half plane. The multiplicative calculus is employed in deriving an expression that can be used for obtaining approximate solutions when the observation angles …

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Automatic Classification Of Harmonic Data Using $K$-Means And Least Square Support Vector Machine, Hüseyi̇n Eri̇şti̇, Vedat Tümen, Özal Yildirim, Belkis Eri̇şti̇, Yakup Demi̇r Jan 2015

Automatic Classification Of Harmonic Data Using $K$-Means And Least Square Support Vector Machine, Hüseyi̇n Eri̇şti̇, Vedat Tümen, Özal Yildirim, Belkis Eri̇şti̇, Yakup Demi̇r

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, an effective classification approach to classify harmonic data has been proposed. In the proposed classifier approach, harmonic data obtained through a 3-phase system have been classified by using $k$-means and least square support vector machine (LS-SVM) models. In order to obtain class details regarding harmonic data, a $k$-means clustering algorithm has been applied to these data first. The training of the LS-SVM model has been realized with the class details obtained through the $k$-means algorithm. To increase the efficiency of the LS-SVM model, the regularization and kernel parameters of this model have been determined with a grid …

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Determination Of Electromagnetic Properties Of Steel For Prediction Of Stray Losses In Power Transformers, Leonardo Strac, Damir Zarko Jan 2015

Determination Of Electromagnetic Properties Of Steel For Prediction Of Stray Losses In Power Transformers, Leonardo Strac, Damir Zarko

Turkish Journal of Electrical Engineering and Computer Sciences

This paper introduces a method for determination of equivalent linear electromagnetic parameters (constant complex permeability and electrical conductivity) of nonlinear magnetic steel, which can be used in a time-harmonic finite-element simulation to yield the same losses in the volume of that material as the measured ones. The conductivity and the static hysteresis loop of the steel have been measured, from which complex permeability as a function of flux density has been extracted. The indirect measurement of losses in various samples of nonmagnetic and magnetic steel has been carried out using a physical model of a transformer core with a coil. …

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Ofdma-Based Multicast With Multiple Base Stations, Ahmet Ci̇hat Kazez, Tolga Gi̇ri̇ci̇ Jan 2015

Ofdma-Based Multicast With Multiple Base Stations, Ahmet Ci̇hat Kazez, Tolga Gi̇ri̇ci̇

Turkish Journal of Electrical Engineering and Computer Sciences

We consider an orthogonal frequency division multiple access (OFDMA)-based multicast system where multiple base stations transmit a multicast session to a multicast group. The goal is to maximize the multicast rate (i.e. the minimum achievable user rate) subject to a total power constraint. We assume the use of an erasure code (e.g., a Reed--Solomon code) or rateless code (e.g., Luby transform code). This facilitates each user to accumulate rates from their best subchannels, so that the achievable multicast rate is not limited to the worst user. The resource allocation problem involves determining the transmitting base station at each OFDMA subchannel, …

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Intelligent Text Classification System Based On Self-Administered Ontology, Manoj Manuja, Deepak Garg Jan 2015

Intelligent Text Classification System Based On Self-Administered Ontology, Manoj Manuja, Deepak Garg

Turkish Journal of Electrical Engineering and Computer Sciences

Over the last couple of decades, web classification has gradually transitioned from a syntax- to semantic-centered approach that classifies the text based on domain ontologies. These ontologies are either built manually or populated automatically using machine learning techniques. A prerequisite condition to build such systems is the availability of ontology, which may be either full-fledged domain ontology or a seed ontology that can be enriched automatically. This is a dependency condition for any given semantics-based text classification system. We share the details of a proof of concept of a web classification system that is self-governed in terms of ontology population …

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Prescient: A Predictive Channel Access Schemefor Ieee 802.15.4-Compliant Devices Considering Ieee 802.11 Coexistence, Tolga Çöplü, Sema Fatma Oktuğ Jan 2015

Prescient: A Predictive Channel Access Schemefor Ieee 802.15.4-Compliant Devices Considering Ieee 802.11 Coexistence, Tolga Çöplü, Sema Fatma Oktuğ

Turkish Journal of Electrical Engineering and Computer Sciences

Coexistence is among the most significant challenges for IEEE 802.15.4-compliant devices in indoor environments. Previous works have shown that IEEE 802.11-compliant devices are the major sources of interference in the 2.4 GHz industrial, scientific, and medical band. In order to overcome the coexistence problem, IEEE 802.15.4-compliant devices should monitor the communication channel and access the channel when it is not in use. In this study, the impact of IEEE 802.11 traffic on IEEE 802.15.4 communication is analyzed and a novel predictive channel access scheme, PRESCIENT (PREdictive channel access SCheme for IEee 802.15.4-compliaNT devices), is proposed. The performance evaluation of the …

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Optimal Ipfc Damping Controller Design Based On Simplex Method And Self-Tuned Fuzzy Damping Scheme In A Two-Area Multimachine Power System, Ahmet Mete Vural, Kami̇l Çağatay Bayindir Jan 2015

Optimal Ipfc Damping Controller Design Based On Simplex Method And Self-Tuned Fuzzy Damping Scheme In A Two-Area Multimachine Power System, Ahmet Mete Vural, Kami̇l Çağatay Bayindir

Turkish Journal of Electrical Engineering and Computer Sciences

This paper develops a novel self-tuned fuzzy damping control scheme for an interline power flow controller (IPFC) to suppress the interarea mode of oscillations in a multimachine power system. The nonlinear adaptive damping controller is based on coordinated operation of two fuzzy inference systems. The first one produces the required $q$-axis voltage reference of the quasi multipulse series converter in response to generator angle oscillations, while the second one is used to tune the output of the first one online for further reducing the error signal using a given set of fuzzy rules. The simplex method is employed to search …

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Dielectric Loaded Tem Horn-Fed Ridged Horn Antenna Designfor Ultrawideband Ground-Penetrating Impulse Radar, Ahmet Serdar Türk, Ahmet Kenan Keski̇n, Mustafa Dağcan Şentürk Jan 2015

Dielectric Loaded Tem Horn-Fed Ridged Horn Antenna Designfor Ultrawideband Ground-Penetrating Impulse Radar, Ahmet Serdar Türk, Ahmet Kenan Keski̇n, Mustafa Dağcan Şentürk

Turkish Journal of Electrical Engineering and Computer Sciences

A modified double-ridged horn structure is proposed to obtain ultrawideband antenna characteristics over a bandwidth ratio of greater than 40:1 for impulse radar systems. The Vivaldi-shaped TEM horn feeder has been designed to extend the lower cut-off frequency and the partial dielectric loading technique using a small lens inward while the aperture has been implemented to enhance the gain of the standard double-ridged horn antenna without changing the physical dimensions. The starting frequency of the antenna operation band is lowered from 800 MHz to 400 MHz. Moreover, approximately 5 dB gain increment level is achieved from 4 to 10 GHz. …

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A New Bitwise Voting Strategy For Safety-Critical Systems With Binary Decisions, Mustafa Seçki̇n Durmuş, Oytun Eri̇ş, Uğur Yildirim, Mehmet Turan Söylemez Jan 2015

A New Bitwise Voting Strategy For Safety-Critical Systems With Binary Decisions, Mustafa Seçki̇n Durmuş, Oytun Eri̇ş, Uğur Yildirim, Mehmet Turan Söylemez

Turkish Journal of Electrical Engineering and Computer Sciences

The main issue in controlling safety-critical systems such as nuclear power reactors or railway interlocking systems is to provide high safety and reliability where the risk ratio is at the highest level because small errors might result in hazardous accidents (e.g., death or injury of many people). The N-version programming technique, where N-different modules run in parallel, can be used to improve the reliability and safety of such systems at the desired safety level. Decisions of N-different modules are then evaluated by another component, usually known as the voter, using different voting strategies. In the current study a bitwise voting …

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Energy Economy In Regulated And Market-Based Power System: Case Study In Serbia, Mileta Zarkovic, Ivan Skokljev Jan 2015

Energy Economy In Regulated And Market-Based Power System: Case Study In Serbia, Mileta Zarkovic, Ivan Skokljev

Turkish Journal of Electrical Engineering and Computer Sciences

This study presents a possible process of simulating power plant generation planning. The process combines expected overall industry costs, associated cost uncertainty, and expected CO$_{2}$ emissions for different generations, variations of future fossil fuel costs, carbon prices, plant investment costs, and demand, including price elasticity impacts. Uncertainty in the decision stems from the elasticity of prices of fuel and electricity. The aim of this paper is to apply fuzzy numbers to power generation planning and to use a Monte Carlo simulation to check. Simulations are demonstrated through a case study of an electricity industry with coal and lignite, combined cycle …

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Optimal Integration Of Hybrid (Wind--Solar) System With Diesel Power Plant \Newline Using Homer, Muhammad Noman Siddique, Aftab Ahmad, Muhammad Kashif Nawaz, Syed Basit Ali Bukhari Jan 2015

Optimal Integration Of Hybrid (Wind--Solar) System With Diesel Power Plant \Newline Using Homer, Muhammad Noman Siddique, Aftab Ahmad, Muhammad Kashif Nawaz, Syed Basit Ali Bukhari

Turkish Journal of Electrical Engineering and Computer Sciences

Most energy worldwide is supplied through conventional energy sources, such as thermal, hydro, and nuclear. There have been serious energy crises in the last couple of years and so it is essential to consider renewable energy sources. This paper proposes a cost-effective solution for integrating a wind--solar system with an existing diesel power plant of a grid-connected site at Taxila, Pakistan. In the case of nonavailability of power from the grid, this diesel power plant acts as a standby system. Three cases were considered in this paper: 1) using the diesel power plant during load-shedding hours; 2) assisting the system …

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A Novel Control Method For A Vsc-Hvdc System In A Grid-Connected Wind Farm, Yingpei Liu, Ran Li Jan 2015

A Novel Control Method For A Vsc-Hvdc System In A Grid-Connected Wind Farm, Yingpei Liu, Ran Li

Turkish Journal of Electrical Engineering and Computer Sciences

The voltage source converter-high voltage direct current (VSC-HVDC) transmission is the ideal integration technology for grid-connected wind farms. A passivity-based control (PBC) method for VSC-HVDC when the wind farm voltage is unbalanced is proposed in this paper. The mathematical model of a VSC with unbalanced voltage is established. The PBC theory including dissipation inequality and system strict passivity is introduced, and then the stability of PBC is proven in light of the Lyapunov stability theory. According to PBC theory, a Euler--Lagrange mathematical model of a VSC is constructed. After that, the strict passivity of the VSC is proven. On the …

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A Statistical Analysis Of Wind Speed Data Using Burr, Generalized Gamma, And Weibull Distributions In Antakya, Turkey, İlker Mert, Cuma Karakuş Jan 2015

A Statistical Analysis Of Wind Speed Data Using Burr, Generalized Gamma, And Weibull Distributions In Antakya, Turkey, İlker Mert, Cuma Karakuş

Turkish Journal of Electrical Engineering and Computer Sciences

The wind energy potential of the Antakya area was statistically analyzed based 8 years of wind data sets (2002--2009). The 4-parameter Burr, 3-parameter generalized gamma, and conventional Weibull distributions were regarded as suitable statistical models for describing wind speed profiles. The suitability of the models was tested by $R^{2}$, \textit{RMSE}, chi-squared, and Kolmogorov--Smirnov analysis. According to goodness-of-fit tests, the Burr distribution was found to be more suitable than the generalized gamma or Weibull distributions for representing the actual probability of wind speed data for Antakya. Based on the capacity factors estimated by the Burr model at a hub height, the …

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Evaluation Of Field Data And Simulation Results Of A Photovoltaic System In Countries With High Solar Radiation, Serkan Abbasoğlu, Akinola Adeyinka Babatunde Jan 2015

Evaluation Of Field Data And Simulation Results Of A Photovoltaic System In Countries With High Solar Radiation, Serkan Abbasoğlu, Akinola Adeyinka Babatunde

Turkish Journal of Electrical Engineering and Computer Sciences

The objective of this study is to examine the conformity of different simulation tools in analyzing the performance of photovoltaic (PV) systems in countries with high solar radiation. Primarily an installed system was evaluated and the results were compared with the simulation results of 3 globally known PV software tools: pvPlanner, PVsyst, and Homer. The parameters evaluated in this study are energy production, specific yield, performance ratio, and capacity factor. Detailed explanations are presented for monthly, seasonal, and annual variation of installed system data and simulation results. Northern Cyprus is selected as a case study due to high solar radiation …

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Design, Application, And Power Performance Analyses Of A Micro Wind Turbine, Hayati̇ Mamur Jan 2015

Design, Application, And Power Performance Analyses Of A Micro Wind Turbine, Hayati̇ Mamur

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, design, implementation, and power performance analyses of a micro wind turbine (MWT) system are presented. An original permanent magnet synchronous generator (PMSG) that reduced cogging torque was employed as a generator in the MWT. A novel blade form offering better performance at low wind speeds was also utilized for the MWT blades. Power performance analyses of the MWT were carried out for different wind regimes by truck testing. Performance coefficient, cut-in, and cut-out of the MWT were determined as 27.7{\%}, 2.7 m/s, and 20 m/s at the end of the truck testing, respectively. Moreover, a new supervisory …

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Electromagnetic Performance Analysis Of Multilayer Interior Pmsm With Fractional Slot Concentrated Windings For Electric Vehicle Applications, Zhiwei Zhang, Libing Zhou Jan 2015

Electromagnetic Performance Analysis Of Multilayer Interior Pmsm With Fractional Slot Concentrated Windings For Electric Vehicle Applications, Zhiwei Zhang, Libing Zhou

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents the design and analysis of fractional slot multilayer interior permanent magnet synchronous machines (PMSMs) with concentrated winding for electric vehicles applications. The major advantages of concentrated winding will be analyzed first. The significant design consideration of multilayer interior permanent magnet machines will be illustrated, as well. Finally, the advanced finite element method will be employed to verify the detailed electromagnetic performance of the proposed interior PMSMs.

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Performance Improvement Of Three-Phase Self-Excited Induction Generator Feeding Induction Motor Load, Jyotirmayee Dalei, Kanungo Barada Mohanty Jan 2015

Performance Improvement Of Three-Phase Self-Excited Induction Generator Feeding Induction Motor Load, Jyotirmayee Dalei, Kanungo Barada Mohanty

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, the transient and steady-state performances of an isolated self-excited induction generator driven by a wind turbine and feeding power to a dynamic load such as a three-phase induction motor are analyzed. Mathematical modeling and simulation study of the whole system, including the wind turbine, induction generator, capacitor, pulse width modulated voltage source inverter, and dynamic load, are carried out with closed-loop voltage and frequency controller. The complete system is modeled in the stationary $d-q$ frame and validated by comparing simulation and experimental results at no-load. The same mathematical model is then used to study the transient performance …

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The Integrated Control Of Fuzzy Logic And Model-Based Approach For Variable-Speed Wind Turbine, Jian Yang, Dongran Song, Hua Han, Pengsha Tong, Ling Zhou Jan 2015

The Integrated Control Of Fuzzy Logic And Model-Based Approach For Variable-Speed Wind Turbine, Jian Yang, Dongran Song, Hua Han, Pengsha Tong, Ling Zhou

Turkish Journal of Electrical Engineering and Computer Sciences

For a variable-speed wind turbine (VSWT), the primary objective of control is to maximize power generation while maintaining the desired rotor speed and avoiding equipment overloads. To fulfill the control objectives, the classical model-based control (MBC) has been widely used, which refers to two controllers: torque controller (TC) and pitch controller (PC). In this work, the drawbacks of MBC for VSWTs are studied extensively. It reveals that there are transition issues between the TC and PC, and over-speed problems under large turbulent wind when only MBC is taken. To improve the control performance of the VSWT, an integrated control solution …

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Mppt Of Pv Array Using Stepped-Up Chaos Optimization Algorithm, Lihua Wang, Xueye Wei, Yuqin Shao, Tianlong Zhu, Junhong Zhang Jan 2015

Mppt Of Pv Array Using Stepped-Up Chaos Optimization Algorithm, Lihua Wang, Xueye Wei, Yuqin Shao, Tianlong Zhu, Junhong Zhang

Turkish Journal of Electrical Engineering and Computer Sciences

In order to achieve maximum efficiency, a maximum power point tracking (MPPT) scheme should be applied in photovoltaic systems. Among all the MPPT schemes, the chaos optimization scheme is one of the hot topics in recent years. In this study, a novel stepped-up chaos optimization algorithm is presented. A chaos mapping $x_{n+1} =\mu \sin (\pi x_{n} )$ is used as a chaos generator to produce a chaos variable. In the process of MPPT, a coarse search is done to find the current optimal solution in a certain range, and then a fine search reduces the space of optimized variables. Compared …

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