Performance Improvement Of Three-Phase Self-Excited Induction Generator Feeding Induction Motor Load,
2015
TÜBİTAK
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 …
Transient Stability Analysis Of Vsc Hvdc Transmission With Power Injection On The Dc-Link,
2015
TÜBİTAK
Transient Stability Analysis Of Vsc Hvdc Transmission With Power Injection On The Dc-Link, Agha Francis Nnachi, Josiah Munda, Dan Valentine Nicolae, Augustin Mabwe Mpanda
Turkish Journal of Electrical Engineering and Computer Sciences
The utilization of a DC-link transmission corridor of embedded VSC HVDC for a DC power injection from renewable energy sources to increase the power flow capability and AC network stability support is a promising technology. However, DC faults on the DC transmission line are likely to threaten the system's operation and stability, especially when the DC power injection exceeds certain limits. A DC single line-to-earth fault is the most likely fault scenario and its effect on the VSC HVDC operation will depend on the earth-loop impedance. Adding an injection point on the DC-link will reduce the earth-loop impedance, hence imposing …
Integration Of Wind Power For Optimal Power System Black-Start Restoration,
2015
TÜBİTAK
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, …
Supercapacitor Energy Storage Based-Upqc To Enhance Ride-Through Capability Of Wind Turbine Generators,
2015
TÜBİTAK
Supercapacitor Energy Storage Based-Upqc To Enhance Ride-Through Capability Of Wind Turbine Generators, Gangatharan Sivasankar, Velu Suresh Kumar
Turkish Journal of Electrical Engineering and Computer Sciences
The recent advancement in electric energy storage technologies provides an opportunity of using energy storage systems to address the issues of grid-integrated wind energy conversion systems. This paper proposes a novel configuration of a unified power quality conditioner (UPQC) with a supercapacitor-based short-term energy storage system for managing wind power intermittency during grid faults. The STATCOM-like compensation device can compensate only current related issues. The dynamic voltage restorer can compensate voltage-related issues but it can contribute only 50{\%} voltage due to converter rating limitations. Moreover, real power handling capabilities of these devices are very poor. This new UPQC scheme can …
Renewable Energy Integration In Smart Grids-Multicriteria Assessment Using The Fuzzy Analytical Hierarchy Process,
2015
TÜBİTAK
Renewable Energy Integration In Smart Grids-Multicriteria Assessment Using The Fuzzy Analytical Hierarchy Process, Aleksandar Janjic, Suzana Savic, Lazar Velimirovic, Vesna Nikolic
Turkish Journal of Electrical Engineering and Computer Sciences
Unlike the traditional way of efficiency assessment of renewable energy sources integration, the smart grid concept is introducing new goals and objectives regarding increased use of renewable electricity sources, grid security, energy conservation, energy efficiency, and deregulated energy market. Possible benefits brought by renewable sources integration are evaluated by the degree of the approach to the ideal smart grid. In this paper, fuzzy analytical hierarchy process methodology for the integration efficiency has been proposed, taking into account the presence of multiple criteria of both qualitative and quantitative nature, different performance indicators, and the uncertain environment of the smart grid. The …
Capacity Allocation Of Hybrid Solar-Wind Energy System Based On Discrete Probabilistic Method,
2015
TÜBİTAK
Capacity Allocation Of Hybrid Solar-Wind Energy System Based On Discrete Probabilistic Method, Chengjin Ye, Minxiang Huang
Turkish Journal of Electrical Engineering and Computer Sciences
Complementary renewable energies like wind and solar power may be more sufficient to satisfy reliability requirements. This paper proposes a quantitative capacity allocation method of a hybrid wind and solar energy system. First, discrete probability distributions are established to model the random factors including the volatility of power outputs and the failure of components. Then a multiobjective optimization model is formulated with objectives of minimization of the total investment, the nodal voltages violating limits probability, and power supply inadequacy probability. For the purpose of fast probability computing with a satisfactory precision degree, an innovative probabilistic load flow algorithm is introduced, …
Frequency-Adaptive Grid-Virtual-Flux Synchronization By Multiple Second-Order Generalized Integrators Under Distorted Grid Conditions, Yingjie Wang, Haiyuan Liu, Xuelong Han, Kangan Wang
Turkish Journal of Electrical Engineering and Computer Sciences
With some of the intermittent new energy and large nonlinear loads, grid voltage unbalance, harmonics, and frequency deviation are increasing year by year. The voltage source converter (VSC) is seriously affected by the various unexpected factors, and the presence of grid impedance makes the situation worse. In order to make the VSC track the nonideal grid quickly and accurately, this paper proposes a frequency-adaptive grid-virtual-flux synchronization by multiple second-order generalized integrators (MSOGI-GVFS). Key expressions of the MSOGI-GVFS and its frequency response characteristics are described in this paper. A second-order generalized integrator configured as a quadrature signal generator generates a specific-frequency …
Reliability Assessment Of A Standalone Wind-Conventional/Energy Storage System Using Probabilistic Production Simulation Method, Hossein Delavaripour, Behzad Mirzaeian Dehkordi
Turkish Journal of Electrical Engineering and Computer Sciences
This paper presents a reliability evaluation technique for a small standalone system including wind and conventional resources integrated with an energy storage system. A battery bank is considered as the energy storage system. The focus in this analysis is on the effect of battery modeling and its performance on system reliability. In this way, this paper presents an accurate model for the electrochemical batteries, which takes into account all the influential characteristics of the battery related to reliability studies, such as depth of charge, efficiency of charge, and rate of discharge. The proposed reliability evaluation method is based on the …
Speech Emotion Recognition Using Nonlinear Dynamics Features,
2015
TÜBİTAK
Speech Emotion Recognition Using Nonlinear Dynamics Features, Ali Shahzadi, Alireza Ahmadyfard, Ali Harimi, Khashayar Yaghmaie
Turkish Journal of Electrical Engineering and Computer Sciences
Recent developments in man--machine interaction have motivated researchers to recognize human emotion from speech signals. In this study, we propose using nonlinear dynamics features (NLDs) for emotion recognition. NLDs are extracted from the geometrical properties of the reconstructed phase space of speech signals. The traditional prosodic and spectral features are also used as a benchmark. The Fisher discriminant ratio acts as a filter to remove irrelevant features quickly. Then a wrapper method based on a genetic algorithm and support vector machine is employed to find the best feature subset that obtains the maximum recognition rate. The classification accuracy of the …
High-Speed Separation Of Anechoic Mixtures Of Speech Signals Using Fusion Of Iterative And Closed-Forms Separation Method,
2015
TÜBİTAK
High-Speed Separation Of Anechoic Mixtures Of Speech Signals Using Fusion Of Iterative And Closed-Forms Separation Method, Mahdi Mahdikhani, Mohammad Hosein Kahaei
Turkish Journal of Electrical Engineering and Computer Sciences
We introduce the fusion of iterative and closed-forms separation (FICS) method for high-speed separation of anechoic mixed speech signals. This method is performed in two stages: 1) iterative-form separation and 2) closed-form separation. This algorithm significantly improves the separation quality simply due to incorporating only some specific frequency bins into computations. We apply the FICS method to the frequency-domain independent component analysis (ICA) to evaluate its performance in increasing the signal separation speed for anechoic mixtures. Simulation results show that for speech signals and anechoic conditions, the proposed algorithm is on average 65 times faster than ICA while preserving the …
Comparison Of Clustering Techniques For Traffic Accident Detection,
2015
TÜBİTAK
Comparison Of Clustering Techniques For Traffic Accident Detection, Nejdet Doğru, Abdülhami̇t Subaşi
Turkish Journal of Electrical Engineering and Computer Sciences
Transportation infrastructure in intelligent transportation systems (ITSs) is complemented with information and communication technologies to achieve better passenger safety and reduced transportation time, fuel consumption, and vehicle wear and tear. This paper shows how data mining techniques are used in ITSs for accident detection and prevention on motorways. In traffic, vehicles show similar behavior to that of vehicles in closed neighborhoods. Vehicles that show different behaviors than neighbor vehicles in cases like accidents, inappropriate lane changes, and speeding can be considered as anomalies and detected. In this paper, a traffic accident is simulated and the effectiveness of different clustering techniques …
Grounded Capacitor-Based New Floating Inductor Simulators And A Stability Test,
2015
TÜBİTAK
Grounded Capacitor-Based New Floating Inductor Simulators And A Stability Test, Erkan Yuce, Sezai̇ Tokat, Hali̇l Alpaslan
Turkish Journal of Electrical Engineering and Computer Sciences
In this paper, two new floating inductor simulators (FISs), both using two differential difference current conveyors, are considered. The proposed FISs do not suffer from passive component matching constraints and employ a minimum number of passive elements. They use a grounded capacitor; accordingly, they are suitable for integrated circuit technology. They have good low- and high-frequency performances. Simulations are performed with the SPICE program to verify the claimed theory. Moreover, for the first FIS used in a second-order low-pass filter, a stability test is performed as an example.
Dual Open-End Stator Winding Induction Machine Fed By Redundant Voltage Source Inverters,
2015
TÜBİTAK
Dual Open-End Stator Winding Induction Machine Fed By Redundant Voltage Source Inverters, Sami Guizani, Faouzi Ben Ammar
Turkish Journal of Electrical Engineering and Computer Sciences
In this paper, the authors propose the availability analysis of a dual open-end stator windings asynchronous machine. Each open-end stator winding is supplied by two PWM voltage source inverters. The active and passive redundancy of the inverters improves reliability, availability, and safety of the system since the loss of inverter losses does not stop the machine. Indeed, for active redundancy, in the case of failure of the inverter, the corresponding winding is disconnected and the other winding is supplied by the two healthy inverters. For passive redundancy, one winding is fed by two inverters and the two others are waiting; …
Analysis And Design Of An Interleaved Current-Fed High Step-Up Quasi-Resonant Dc-Dc Converter For Fuel Cell Applications,
2015
TÜBİTAK
Analysis And Design Of An Interleaved Current-Fed High Step-Up Quasi-Resonant Dc-Dc Converter For Fuel Cell Applications, Sina Salehi, Behrooz Vahidi, Jafar Milimonfared, Maghdad Taheri, Hadi Moradi
Turkish Journal of Electrical Engineering and Computer Sciences
This paper proposes a current-fed quasi-resonant converter with soft switching method. Input current ripple is reduced by employing two boost circuits at the input, which makes this converter appropriate for fuel cell application. Current stress on switches is reduced because of the resonance in switches, and also, as a result of zero voltage switching in switches, switching losses will be reduced in this proposed converter. In the output, the reverse recovery problem of diodes is alleviated by zero current switching, so there is no need for fast diodes anymore. The reduction of losses improves the efficiency, and in a wide …
The Simulation And Production Of Glow Plugs Based On Thermal Modeling,
2015
TÜBİTAK
The Simulation And Production Of Glow Plugs Based On Thermal Modeling, Mustafa Saci̇d Endi̇z, Muci̇z Özcan, Mehmet Aki̇f Eri̇şmi̇ş, Mustafa Yağci, Hi̇dayet Günay
Turkish Journal of Electrical Engineering and Computer Sciences
In this work, we present the thermal behavior of a glow plug examined with thermal impedance modeling. The circuit model is based on the analogy of thermal and electrical domains and expresses the glow plug used in diesel engines to preheat the air-diesel fuel mixture. In this study, the circuit design, implementation, and simulation of a glow plug for diesel engines are illustrated. In order to verify this thermal model, 2 different glow plugs are produced. The test results of the glow plugs produced in this study show complete agreement with the simulation results. It is thought that this circuit-based …
Impedance Modeling For Classification Of Flavored Green Teas,
2015
TÜBİTAK
Impedance Modeling For Classification Of Flavored Green Teas, Munendra Singh, Sunil Semwal, Ashavani Kumar, Shailendra Singh
Turkish Journal of Electrical Engineering and Computer Sciences
This paper proposes an electrical impedance model of flavored green teas. Typically, impedance data of flavored green teas, obtained by electrochemical impedance spectroscopy (EIS), fit into an equivalent circuit that represents the physical and chemical processes taking place in it. The total impedance of each flavor alone is not sufficient, but different values of impedance parameters in the electrical impedance model are responsible for better classification of flavored green teas. Successfully classified data on the basis of their flavors were obtained by different support vector machine (SVM) techniques with encouraging results. The results show that a linear SVM has better …
Bull Optimization Algorithm Based On Genetic Operators For Continuous Optimization Problems,
2015
TÜBİTAK
Bull Optimization Algorithm Based On Genetic Operators For Continuous Optimization Problems, Oğuz Findik
Turkish Journal of Electrical Engineering and Computer Sciences
In this paper, the researcher proposes a new evolutionary optimization algorithm that depends on genetic operators such as crossover and mutation, referred to as the bull optimization algorithm (BOA). This new optimization algorithm is called the BOA because the best individual is used to produce offspring individuals. The selection algorithm used in the genetic algorithm (GA) is removed from the proposed algorithm. Instead of the selection algorithm, individuals initially produced attempt to achieve better individuals. In the proposed method, crossover operation is always performed by using the best individual. The mutation process is carried out by using individual positions. In …
Improving The Drain-Current Expression Of Bsim4 For Hot-Carrier Degradation Modeling That Is Suitable For Analog Applications,
2015
TÜBİTAK
Improving The Drain-Current Expression Of Bsim4 For Hot-Carrier Degradation Modeling That Is Suitable For Analog Applications, Gürsel Düzenli̇
Turkish Journal of Electrical Engineering and Computer Sciences
The reliability evaluation of MOS transistors is one of the most important subjects in device engineering and VLSI design. The down-scaling of device dimensions adversely affects device reliability and lifetime. Although different factors contribute to device reliability and lifetime, the most influential factor is hot-carrier degradation. Furthermore, hot-carrier degradation affects each application uniquely. In analog applications, hot-carrier degradation is more complex and diverse relative to digital applications. In this study, we improve the BSIM4 drain-current model to develop a hot-carrier degradation model that is suitable for both analog and digital applications. Our approach is readily applicable to all process technologies …
Multiagent-Based Simulation Of Simultaneous Electricity Market Auctions In Restructured Environment,
2015
TÜBİTAK
Multiagent-Based Simulation Of Simultaneous Electricity Market Auctions In Restructured Environment, Mohammad Farshad
Turkish Journal of Electrical Engineering and Computer Sciences
In the restructured environment of the power industry, various commodities such as energy and operating reserves may be provided through simultaneous auctions. Prediction of market players' behavior in the auctions and simulation of the markets' environment can assist market decision-makers in evaluating specific policies before enforcing them in the real environment. Considering effects of the energy and varieties of reserve markets and also their interactions in the simulations is of high importance, which leads to more realistic simulation results. In this paper, an approach based on a multiagent system is proposed for simulating the simultaneous energy, spinning reserve, and replacement …
A New Method For Segmentation Of Microscopic Images On Activated Sludge,
2015
TÜBİTAK
A New Method For Segmentation Of Microscopic Images On Activated Sludge, Hali̇me Boztoprak, Yüksel Özbay
Turkish Journal of Electrical Engineering and Computer Sciences
Activated sludge samples were taken from the Konya Wastewater Treatment Plant. Two hundred images for each sample were captured by a systematic examination of the slides. Segmentation of microscopic images is a challenging process due to lack of focus. Therefore, adjustment of the focus is required for every movement of the mobile stage. Because the mobile stage does not have the z axis, the focus cannot be adjusted. A new method that uses automatic segmentation of the captured images is developed for solving this problem. The proposed method is not dependent on image content, has minimal computation complexity, and is …
