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Full-Text Articles in Engineering

Tracking Control Of Elastic Joint Parallel Robots Via State-Dependent Riccati Equation, Si̇nan Kiliçaslan Jan 2015

Tracking Control Of Elastic Joint Parallel Robots Via State-Dependent Riccati Equation, Si̇nan Kiliçaslan

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, a methodology for the tracking control of parallel robots having elastic joints based on the state-dependent Riccati equation is developed. Structural stiffness and damping characteristics of the joints are modeled as torsional springs and dampers, respectively. First an open-tree system is obtained by cutting some joints of the parallel robot open and its dynamic equations are written. Closed loops are then represented as constraint equations. The first and second derivatives of dependent (unactuated) joint variables are expressed in terms of independent (actuated) joint variables by making use of the constraint equations. Taking the independent joint variables, the …


Demand Response In The Day-Ahead Operation Of An Isolated Microgrid In The Presence Of Uncertainty Of Wind Power, Javad Olamaei, Saleh Ashouri Jan 2015

Demand Response In The Day-Ahead Operation Of An Isolated Microgrid In The Presence Of Uncertainty Of Wind Power, Javad Olamaei, Saleh Ashouri

Turkish Journal of Electrical Engineering and Computer Sciences

This paper explores the utilization of demand response in the day-ahead operation of an isolated microgrid in the presence of wind units. The operation of the network with high penetration wind units (i.e. uncertainty of wind units) is modeled as a unit commitment problem. In addition, electrical power storage is modeled in a daily power curve to decrease the effect of uncertainty in the wind units. Due to avoiding large-scale complexities and the deeper study effect of demand-side management on operations, the considered network is regarded as an isolated microgrid. The demand-side management is studied as demand shifting. The simulation …


Quality Of Service Assessment: A Case Study On Performance Benchmarking Of Cellular Network Operators In Turkey, Rana Kadioğlu, Yaser Dalveren, Ali̇ Kara Jan 2015

Quality Of Service Assessment: A Case Study On Performance Benchmarking Of Cellular Network Operators In Turkey, Rana Kadioğlu, Yaser Dalveren, Ali̇ Kara

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents findings on performance benchmarking of cellular network operators in Turkey. Benchmarking is based on measurements of standard key performance indicators (KPIs) in one of the metropolitan cities of Turkey, Ankara. Performance benchmarking is formulated by incorporating customer perception by conducting surveys on how important KPIs are from the user's point of view. KPIs are measured, with standard test equipment, by drive test method on specified routes. According to the performance benchmarking results, the GSM and UMTS network operators achieving the best performance were determined in Ankara. Speech qualities of network operators, as the most popular service, were …


Model-Based Test Case Prioritization Using Cluster Analysis: A Soft-Computing Approach, Ni̇da Gökçe, Fevzi̇ Belli̇, Mübari̇z Emi̇nli̇, Beki̇r Taner Di̇nçer Jan 2015

Model-Based Test Case Prioritization Using Cluster Analysis: A Soft-Computing Approach, Ni̇da Gökçe, Fevzi̇ Belli̇, Mübari̇z Emi̇nli̇, Beki̇r Taner Di̇nçer

Turkish Journal of Electrical Engineering and Computer Sciences

Model-based testing is related to the particular relevant features of the software under test (SUT) and its environment. Real-life systems often require a large number of tests, which cannot exhaustively be run due to time and cost constraints. Thus, it is necessary to prioritize the test cases in accordance with their importance as the tester perceives it, usually given by several attributes of relevant events entailed. Based on event-oriented graph models, this paper proposes an approach to ranking test cases in accordance with their preference degrees. For forming preference groups, events are clustered using an unsupervised neural network and fuzzy …


Predictive Control Of A Constrained Pressure And Level System, Erkan Kaplanoğlu, Taner Arsan, Hüseyi̇n Selçuk Varol Jan 2015

Predictive Control Of A Constrained Pressure And Level System, Erkan Kaplanoğlu, Taner Arsan, Hüseyi̇n Selçuk Varol

Turkish Journal of Electrical Engineering and Computer Sciences

The focus of this paper is the implementation of a constrained predictive control algorithm implemented in Multi-Parametric Toolbox (MPT), which is a free MATLAB toolbox for design, analysis, and implementation of controllers for constrained linear, nonlinear, and hybrid systems. In general, MPT is used for modeling systems offline. The novelty of this study is that real-time mode MPT is used in process control. We also combined the Model Predictive Control Toolbox with MPT. This novel controller is considered a real-time controller of level-pressure systems. In this study, a special type of model predictive control algorithm, the constrained continuous-time generalized control, …


A New Hysteresis Band Current Control Technique For A Shunt Active Filter, Murat Kale, Engi̇n Özdemi̇r Jan 2015

A New Hysteresis Band Current Control Technique For A Shunt Active Filter, Murat Kale, Engi̇n Özdemi̇r

Turkish Journal of Electrical Engineering and Computer Sciences

This paper proposes a hysteresis band (HB) current control technique to reduce the power losses in a shunt active filter. During a switching period in the zero-crossing region, the inverter output current flows through a transistor. By changing the direction, it flows through the free-wheeling diode of the same switch in an inverter leg, or vice versa. The shunt active filter current typically has 6 zero-crossing regions during a fundamental frequency cycle. This paper presents a HB current control technique where there is not any switching in these 6 zero-crossing regions per period, which results in reducing the power losses. …


Approximations Of Higher-Order Fractional Differentiators And Integrators Using Indirect Discretization, Richa Yadav, Maneesha Gupta Jan 2015

Approximations Of Higher-Order Fractional Differentiators And Integrators Using Indirect Discretization, Richa Yadav, Maneesha Gupta

Turkish Journal of Electrical Engineering and Computer Sciences

This paper describes new approximations of fractional order integrators (FOIs) and fractional order differentiators (FODs) by using a continued fraction expansion-based indirect discretization scheme. Different tenth-order fractional blocks have been derived by applying three different s-to-z transforms described earlier by Al-Alaoui, namely new two-segment, four-segment, and new optimized four-segment operators. A new addition has been done in the new optimized four-segment operator by modifying it by the zero reflection method. All proposed half (s$^{\pm 1/2})$ and one-fourth (s$^{\pm 1/4})$ differentiator and integrator models fulfill the stability criterion. The tenth-order fractional differ-integrators (s$^{\pm \alpha })$ based on the modified new optimized …


Using The Finite Element Method To Calculate Parameters For A Detailed Model Of Transformer Winding For Partial Discharge Research, Seyed Mohammad Hassan Hosseini, Seyed Mohsen Enjavi Madar, Mehdi Vakilian Jan 2015

Using The Finite Element Method To Calculate Parameters For A Detailed Model Of Transformer Winding For Partial Discharge Research, Seyed Mohammad Hassan Hosseini, Seyed Mohsen Enjavi Madar, Mehdi Vakilian

Turkish Journal of Electrical Engineering and Computer Sciences

Power transformers are considered to be one of the most essential and costly pieces of equipment in a power system. Identifying insulation faults in the shortest possible time prevents the occurrence of irreparable damage. Partial discharge (PD) is one of the most significant insulation faults. The first step in the study of PD is the precise modeling of transformer winding at high frequencies. In this paper, the finite element method is used to calculate the parameters for a detailed model of transformer winding. For this reason, a detailed model of transformer winding and the analytic formulations are first presented for …


Mechanical Fault Detection In Permanent Magnet Synchronous Motors Using Equal Width Discretization-Based Probability Distribution And A Neural Network Model, Mehmet Akar, Mahmut Heki̇m, Umut Orhan Jan 2015

Mechanical Fault Detection In Permanent Magnet Synchronous Motors Using Equal Width Discretization-Based Probability Distribution And A Neural Network Model, Mehmet Akar, Mahmut Heki̇m, Umut Orhan

Turkish Journal of Electrical Engineering and Computer Sciences

This paper focuses on detecting the static eccentricity and bearing faults of a permanent magnet synchronous motor (PMSM) using probability distributions based on equal width discretization (EWD) and a multilayer perceptron neural network (MLPNN) model. In order to achieve this, the PMSM stator current values were measured in the cases of healthy, static eccentricity, and bearing faults for the conditions of three speeds and five loads. The data was discretized into several ranges through the EWD method, the probability distributions were computed according to the number of current values belonging to each range, and these distributions were then used as …


Estimating Facial Angles Using Radon Transform, Mohamad Amin Bakhshali, Mousa Shamsi Jan 2015

Estimating Facial Angles Using Radon Transform, Mohamad Amin Bakhshali, Mousa Shamsi

Turkish Journal of Electrical Engineering and Computer Sciences

Analysis of human facial images has become increasingly important due to its numerous applications. In this regard, extracting facial parameters is vital and various studies have been done in this field. Using these methods, different facial parameters such as the location of eyebrows, eye length, and nose angles are extracted. In this article, a robust and automatic method is introduced for determining facial angles from profile view images using the Radon transform. The Radon transform is a type of linear integration along a specific direction and angles play an important role in its performance. The proposed algorithm not only has …


Effect Of Nonuniform Varying Delay On The Rate Of Convergence In Averaging-Based Consensus, Onur Ci̇han, Mehmet Akar Jan 2015

Effect Of Nonuniform Varying Delay On The Rate Of Convergence In Averaging-Based Consensus, Onur Ci̇han, Mehmet Akar

Turkish Journal of Electrical Engineering and Computer Sciences

This paper discusses the effect of nonuniform varying communication delay on distributed consensus algorithms in discrete time. After introducing the delayed mathematical model, we first investigate the ergodicity of the delayed system using the properties of scrambling matrices. Subsequently, the effect of nonuniform varying delay on convergence is examined. It is shown theoretically that nonuniform delay is not detrimental to the convergence rate of the algorithm for directed acyclic graphs. The results are also illustrated with several numerical examples.


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 …


Energy Management Of Solar Car In Circuit Race, Erkan Atmaca Jan 2015

Energy Management Of Solar Car In Circuit Race, Erkan Atmaca

Turkish Journal of Electrical Engineering and Computer Sciences

This study develops an optimal driving strategy for solar car on a track with nonzero gradients and sharp corners. This strategy consists of finding the racing line and the speed profile that minimizes the lap time with a given amount of energy. The problem is formulated in proper form for a commercial nonlinear optimization software program. The track is modeled into segments identified by their spatial coordinates on its own surface. The speed-distance behavior of the vehicle is linearized at each segment. The constraints set by the brushless DC motor, battery, and circuit are formulated accordingly. This is the motor …


Decode-And-Forward Relaying Based On Orthogonal Complementary Codes, Refi̇k Çağlar Kizilirmak Jan 2015

Decode-And-Forward Relaying Based On Orthogonal Complementary Codes, Refi̇k Çağlar Kizilirmak

Turkish Journal of Electrical Engineering and Computer Sciences

In this note, we propose a full-duplex decode-and-forward cooperative diversity scheme based on code division with orthogonal complementary codes. We consider a simple case in which a single user is assisted by a single relay to achieve cooperative diversity. When the cooperation is full-duplex, the operational delay of the relay makes the channel asynchronous and this may cause multiple-access interference (MAI) between the user and relay. The orthogonal complementary codes have perfect autocorrelation and cross-correlation properties that provide MAI-free operation in asynchronous channels. In the proposed scheme, the user and relay terminals spread their messages with complementary codes and the …


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 …


Semiconductor Laser Beam Bending, Remzi̇ Yildirim, Fati̇h Vehbi̇ Çelebi̇ Jan 2015

Semiconductor Laser Beam Bending, Remzi̇ Yildirim, Fati̇h Vehbi̇ Çelebi̇

Turkish Journal of Electrical Engineering and Computer Sciences

This study is about a single-component cylindrical structured lens with a gradient curve that was used for bending laser beams. It operates under atmospheric conditions and bends the laser beam independently of temperature, pressure, polarity, polarization, magnetic field, electric field, radioactivity, and gravity. A single-piece cylindrical lens that can bend laser beams was developed. Lenses are made of transparent, tinted, or colored glass and are used to undermine or absorb the energy of laser beams. This study is not a work of a plasma filamentation, nor is related to a self-accelerating wave packet. Rather, it focuses on bending the laser …


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 …


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 …


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. …


An Implementable Approach In Order To Model A Nonideal Incremental Encoder In Speed Measurement Studies, Mahdi Maaref, Alireza Rezazadeh Jan 2015

An Implementable Approach In Order To Model A Nonideal Incremental Encoder In Speed Measurement Studies, Mahdi Maaref, Alireza Rezazadeh

Turkish Journal of Electrical Engineering and Computer Sciences

Incremental encoders have attracted significant attention to measure motor speed worldwide. Due to the advantages of incremental encoders a noticeable percentage of Servo system drives have been built based on these sensors. The nonideality of encoders, especially mechanical misalignments, is one of their most important problems, affecting the precision of calculations. In the current paper we present an analytical formula to model the nonideal incremental encoder and calculate both the frequency and magnitude of vibrations due to this nonideality. Moreover, a nonideality identity parameter of the encoder is defined. This parameter can be used for quality assurance purposes. Moreover, it …


A New High-Performance Current-Mode Fuzzy Membership Function Circuit And Its Application, Turgay Temel Jan 2015

A New High-Performance Current-Mode Fuzzy Membership Function Circuit And Its Application, Turgay Temel

Turkish Journal of Electrical Engineering and Computer Sciences

A new current-mode fuzzy-membership function circuit is proposed. The circuit has a very compact and simple architecture based on the simultaneous use of winner- and loser-take-all topologies. The circuit has also the advantage of easily adjusting generated membership function characteristics such as center or mean and width with a straightforward application of respective input currents. It is shown that the new circuit outperforms previous counterparts in terms of speed, power consumption, layout area, and robustness to variations in design parameters and errors. As an application, a fuzzy-classifier is designed with a new membership circuit as a seven fuzzy level controller.


Fuzzy Sliding Mode Control Applied To A Doubly Fed Induction Generator For Wind Turbines, Sid Ahmed El Mehdi Ardjoun, Mohamed Abid Jan 2015

Fuzzy Sliding Mode Control Applied To A Doubly Fed Induction Generator For Wind Turbines, Sid Ahmed El Mehdi Ardjoun, Mohamed Abid

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper an indirect vector control using fuzzy sliding mode control is proposed for a double-fed induction generator (DFIG), applied for a wind energy conversion system in variable speed. The objective is to independently control the active and reactive power generated by the DFIG, which is decoupled by the orientation of the flux. The sliding mode control finds its strongest justification for the problem concerning the use of a robust nonlinear control law for the model uncertainties. As far as the fuzzy mode control is concerned, it aims at reducing the chattering effect. The obtained results show the increasing …


Model-Reference Sliding Mode Control Of A Three-Phase Four-Leg Voltage Source Inverter For Stand-Alone Distributed Generation Systems, Ayhan Özdemi̇r, İrfan Yazici, Zeki̇ye Erdem Jan 2015

Model-Reference Sliding Mode Control Of A Three-Phase Four-Leg Voltage Source Inverter For Stand-Alone Distributed Generation Systems, Ayhan Özdemi̇r, İrfan Yazici, Zeki̇ye Erdem

Turkish Journal of Electrical Engineering and Computer Sciences

This paper proposes a discrete-time model-reference sliding mode control of three-phase four-leg voltage source inverters for stand-alone distributed generation systems. Three-phase four-leg voltage source inverters (VSIs) are used in a broad area. A discrete-time model-reference sliding mode controller, having superior advantages such as insensitivity to external disturbances, system parameter variations, and modeling errors, is applied to control the output voltage of three-phase four-leg VSIs. As a new study, the discrete-time model-reference sliding mode control with a supplemented output feedback integral controller is proposed so that the controlled output voltages of the VSI tracks the input reference signal. The controller is …


Performance Analysis Of A 500-Kwp Grid-Connected Solar Photovoltaic Power Plant In Kahramanmaraş, Şaban Yilmaz, Hasan Riza Özçalik Jan 2015

Performance Analysis Of A 500-Kwp Grid-Connected Solar Photovoltaic Power Plant In Kahramanmaraş, Şaban Yilmaz, Hasan Riza Özçalik

Turkish Journal of Electrical Engineering and Computer Sciences

In today's world, the daily need for and cost of energy sources increase and this forces industrial institutions to seek for new ways to generate their own energy. The developments in photovoltaic systems have recently drawn attention in the business world. Although their installation costs are high, they are environmentally friendly and profitable investments in the long run. The cost analysis of a large-scale photovoltaic generator in the climatic conditions of Kahramanmara\c{s} will lead the way to new investments. In this study, the modeling and cost analysis of an on-grid photovoltaic generator of 500 kW, which was installed to provide …


Integration Of Wind Power For Optimal Power System Black-Start Restoration, Amany El Zonkoly Jan 2015

Integration Of Wind Power For Optimal Power System Black-Start Restoration, Amany El Zonkoly

Turkish Journal of Electrical Engineering and Computer Sciences

Integration of wind farms into power systems may increase the risk of power system blackouts due to the uncertain nature of their output power. In the meantime, wind turbines have relatively short starting time when compared to non-black-start (NBS) generating units. For this reason, wind farms need to participate in power system restoration after blackouts. The decision of restoring a wind farm depends on its output power and the characteristics of the power system. The power system restoration should be accomplished as soon as possible. For complete power system restoration, three stages must be completed: generation restoration, transmission system restoration, …


New Three-Dimensional Space Vector Pulse Width Modulation Of Pv-Af System Based On The Gh$\Gamma $ Coordinate System, Juan Zhou, Malong Liu, Chen Wei, Chaoxu Gao, Xiaojie Wu Jan 2015

New Three-Dimensional Space Vector Pulse Width Modulation Of Pv-Af System Based On The Gh$\Gamma $ Coordinate System, Juan Zhou, Malong Liu, Chen Wei, Chaoxu Gao, Xiaojie Wu

Turkish Journal of Electrical Engineering and Computer Sciences

The photovoltaic power generation and active filter (PV-AF) system can realize photovoltaic grid-connected power regulation, and meanwhile it can also improve the power quality of power grid effectively. The four-leg grid-connected inverter has successfully been used in the three-phase four-wire system. In this paper, a three-dimensional space vector pulse width modulation (3D-SVPWM) method based on the gh$\gamma $ coordinate system for a four-leg inverter has been proposed. As the switching vectors of the four-leg inverter are in the three-dimensional space, it is difficult to realize the complex modulation process. In order to simplify the modulation process, the reference vector is …


Stability Preservation And Power Management In Autonomous Microgrids Using Adaptive Nonlinear Droop Scheme, Sara Nourollah, Abolfazl Pirayesh, Poria Astero Jan 2015

Stability Preservation And Power Management In Autonomous Microgrids Using Adaptive Nonlinear Droop Scheme, Sara Nourollah, Abolfazl Pirayesh, Poria Astero

Turkish Journal of Electrical Engineering and Computer Sciences

This paper proposes sharing active and reactive power in autonomous voltage source inverter (VSI)-based microgrids with no physical communication links. In decentralized VSI-based microgrids, when the demand or generation changes, the output voltage of distributed generation units and the frequency of the system will also change. This study presents a novel adaptive nonlinear droop (ANLD) scheme for preserving network stability, improving the system's dynamics, and controlling power sharing in multibus microgrids in a decentralized manner. Subcontrollers are modeled in a state space and combined together so that a complete dynamic model of the network can be developed. Note that controller …


Performance Analysis Of A Low-Cost Current-Source 1-Ph Grid-Connected Pv Inverter, Gürhan Ertaşgin, Wen Liang Soong, Nesimi Ertugrul Jan 2015

Performance Analysis Of A Low-Cost Current-Source 1-Ph Grid-Connected Pv Inverter, Gürhan Ertaşgin, Wen Liang Soong, Nesimi Ertugrul

Turkish Journal of Electrical Engineering and Computer Sciences

This paper investigates the design and performance of a 150 W single-phase current-source grid-connected inverter topology that is based on a PV array and DC link inductor acting as a constant-current source. The inverter is implemented using a single boost switch, an H-bridge inverter, and a CL output filter. The inverter output current is simply controlled using the boost switch and open-loop or feedforward control. The dark I-V configuration is used to simulate two series PV modules. Comprehensive test results are obtained to validate the computer simulation results. Furthermore, the proposed inverter's ability to deliver a sinusoidal current to the …


Amorphous Core Transformers Efficiency Analysis In Turkish Electrical Distribution Systems, Fati̇h Işik, Yilmaz Uyaroğlu Jan 2015

Amorphous Core Transformers Efficiency Analysis In Turkish Electrical Distribution Systems, Fati̇h Işik, Yilmaz Uyaroğlu

Turkish Journal of Electrical Engineering and Computer Sciences

Transformers are an indispensable element in the transmission and distribution of electricity. While they are highly efficient, the increasing global demand for electrical energy has prompted efforts to improve their performance. No-load power losses constitute the majority of total losses within electrical energy distribution, especially when looking at load ratio. In recent years, some studies have found that no-load power losses of amorphous core transformers are less than those of laminated steel core transformers by as much as 60{\%} to 70{\%}. For this paper, we have manufactured an amorphous distribution transformer prototype rated 33 kV and 1 MVA. By quantifying …


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 …