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Full-Text Articles in Computer Sciences

Exploring The Use Of Plc Debugging Tools For Digital Forensic Investigations On Scada Systems, Tina Wu, Jason R.C. Nurse Jan 2015

Exploring The Use Of Plc Debugging Tools For Digital Forensic Investigations On Scada Systems, Tina Wu, Jason R.C. Nurse

Journal of Digital Forensics, Security and Law

The Stuxnet malware attack has provided strong evidence for the development of a forensic capability to aid in thorough post-incident investigations. Current live forensic tools are typically used to acquire and examine memory from computers running either Windows or Unix. This makes them incompatible with embedded devices found on SCADA systems that have their own bespoke operating system. Currently, only a limited number of forensics tools have been developed for SCADA systems, with no development of tools to acquire the program code from PLCs. In this paper, we explore this problem with two main hypotheses in mind. Our first hypothesis …


Forensic Acquisition Of Imvu: A Case Study, Robert Van Voorst, M-Tahar Kechadi, Nhien-An Le-Khac Jan 2015

Forensic Acquisition Of Imvu: A Case Study, Robert Van Voorst, M-Tahar Kechadi, Nhien-An Le-Khac

Journal of Digital Forensics, Security and Law

There are many applications available for personal computers and mobile devices that facilitate users in meeting potential partners. There is, however, a risk associated with the level of anonymity on using instant message applications, because there exists the potential for predators to attract and lure vulnerable users. Today Instant Messaging within a Virtual Universe (IMVU) combines custom avatars, chat or instant message (IM), community, content creation, commerce, and anonymity. IMVU is also being exploited by criminals to commit a wide variety of offenses. However, there are very few researches on digital forensic acquisition of IMVU applications. In this paper, we …


Tracking And Taxonomy Of Cyberlocker Link Sharers Based On Behavior Analysis, Xiao-Xi Fan, Kam-Pui Chow Jan 2015

Tracking And Taxonomy Of Cyberlocker Link Sharers Based On Behavior Analysis, Xiao-Xi Fan, Kam-Pui Chow

Journal of Digital Forensics, Security and Law

The growing popularity of cyberlocker service has led to significant impact on the Internet that it is considered as one of the biggest contributors to the global Internet traffic estimated to be illegally traded content. Due to the anonymity property of cyberlocker, it is difficult for investigators to track user identity directly on cyberlocker site. In order to find the potential relationships between cyberlocker users, we propose a framework to collect cyberlocker related data from public forums where cyberlocker users usually distribute cyberlocker links for others to download and identity information can be gathered easily. Different kinds of sharing behaviors …


A Survey Of Botnet Detection Techniques By Command And Control Infrastructure, Thomas S. Hyslip, Jason M. Pittman Jan 2015

A Survey Of Botnet Detection Techniques By Command And Control Infrastructure, Thomas S. Hyslip, Jason M. Pittman

Journal of Digital Forensics, Security and Law

Botnets have evolved to become one of the most serious threats to the Internet and there is substantial research on both botnets and botnet detection techniques. This survey reviewed the history of botnets and botnet detection techniques. The survey showed traditional botnet detection techniques rely on passive techniques, primarily honeypots, and that honeypots are not effective at detecting peer-to-peer and other decentralized botnets. Furthermore, the detection techniques aimed at decentralized and peer-to-peer botnets focus on detecting communications between the infected bots. Recent research has shown hierarchical clustering of flow data and machine learning are effective techniques for detecting botnet peer-to-peer …


Sparse Coding Based Dense Feature Representation Model For Hyperspectral Image Classification, Ender Oguslu, Guoqing Zhou, Zezhong Zheng, Khan Iftekharuddin, Jiang Li Jan 2015

Sparse Coding Based Dense Feature Representation Model For Hyperspectral Image Classification, Ender Oguslu, Guoqing Zhou, Zezhong Zheng, Khan Iftekharuddin, Jiang Li

Electrical & Computer Engineering Faculty Publications

We present a sparse coding based dense feature representation model (a preliminary version of the paper was presented at the SPIE Remote Sensing Conference, Dresden, Germany, 2013) for hyperspectral image (HSI) classification. The proposed method learns a new representation for each pixel in HSI through the following four steps: sub-band construction, dictionary learning, encoding, and feature selection. The new representation usually has a very high dimensionality requiring a large amount of computational resources. We applied the l1/lq regularized multiclass logistic regression technique to reduce the size of the new representation. We integrated the method with a linear …


Adaptive Graph Construction For Isomap Manifold Learning, Loc Tran, Zezhong Zheng, Guoquing Zhou, Jiang Li, Karen O. Egiazarian (Ed.), Sos S. Agaian (Ed.), Atanas P. Gotchev (Ed.) Jan 2015

Adaptive Graph Construction For Isomap Manifold Learning, Loc Tran, Zezhong Zheng, Guoquing Zhou, Jiang Li, Karen O. Egiazarian (Ed.), Sos S. Agaian (Ed.), Atanas P. Gotchev (Ed.)

Electrical & Computer Engineering Faculty Publications

Isomap is a classical manifold learning approach that preserves geodesic distance of nonlinear data sets. One of the main drawbacks of this method is that it is susceptible to leaking, where a shortcut appears between normally separated portions of a manifold. We propose an adaptive graph construction approach that is based upon the sparsity property of the ℓ1 norm. The ℓ1 enhanced graph construction method replaces k-nearest neighbors in the classical approach. The proposed algorithm is first tested on the data sets from the UCI data base repository which showed that the proposed approach performs better than …


A Comparative Study Of Two Prediction Models For Brain Tumor Progression, Deqi Zhou, Loc Tran, Jihong Wang, Jiang Li, Karen O. Egiazarian (Ed.), Sos S. Agaian (Ed.), Atanas P. Gotchev (Ed.) Jan 2015

A Comparative Study Of Two Prediction Models For Brain Tumor Progression, Deqi Zhou, Loc Tran, Jihong Wang, Jiang Li, Karen O. Egiazarian (Ed.), Sos S. Agaian (Ed.), Atanas P. Gotchev (Ed.)

Electrical & Computer Engineering Faculty Publications

MR diffusion tensor imaging (DTI) technique together with traditional T1 or T2 weighted MRI scans supplies rich information sources for brain cancer diagnoses. These images form large-scale, high-dimensional data sets. Due to the fact that significant correlations exist among these images, we assume low-dimensional geometry data structures (manifolds) are embedded in the high-dimensional space. Those manifolds might be hidden from radiologists because it is challenging for human experts to interpret high-dimensional data. Identification of the manifold is a critical step for successfully analyzing multimodal MR images.

We have developed various manifold learning algorithms (Tran et al. 2011; Tran et al. …


Resilient And Trustworthy Dynamic Data-Driven Application Systems (Dddas) Services For Crisis Management Environments, Youakim Badr, Salim Hariti, Youssif Al-Nashif, Erik Blasch Jan 2015

Resilient And Trustworthy Dynamic Data-Driven Application Systems (Dddas) Services For Crisis Management Environments, Youakim Badr, Salim Hariti, Youssif Al-Nashif, Erik Blasch

Electrical & Computer Engineering Faculty Publications

Future crisis management systems needresilient and trustworthy infrastructures to quickly develop reliable applications and processes, andensure end-to-end security, trust, and privacy. Due to the multiplicity and diversity of involved actors, volumes of data, and heterogeneity of shared information;crisis management systems tend to be highly vulnerable and subjectto unforeseen incidents. As a result, the dependability of crisis management systems can be at risk. This paper presents a cloud-based resilient and trustworthy infrastructure (known as rDaaS) to quickly develop secure crisis management systems. The rDaaS integrates the Dynamic Data-Driven Application Systems (DDDAS) paradigm into a service-oriented architecture over cloud technology and provides …


The Multimodal Brain Tumor Image Segmentation Benchmark (Brats), Bjoern H. Menze, Andras Jakab, Stefan Bauer, Jayashree Kalpathy-Cramer, Khan M. Iftekharuddin, Syed M.S. Reza Jan 2015

The Multimodal Brain Tumor Image Segmentation Benchmark (Brats), Bjoern H. Menze, Andras Jakab, Stefan Bauer, Jayashree Kalpathy-Cramer, Khan M. Iftekharuddin, Syed M.S. Reza

Electrical & Computer Engineering Faculty Publications

In this paper we report the set-up and results of the Multimodal Brain Tumor Image Segmentation Benchmark (BRATS) organized in conjunction with the MICCAI 2012 and 2013 conferences. Twenty state-of-the-art tumor segmentation algorithms were applied to a set of 65 multi-contrast MR scans of low-and high-grade glioma patients-manually annotated by up to four raters-and to 65 comparable scans generated using tumor image simulation software. Quantitative evaluations revealed considerable disagreement between the human raters in segmenting various tumor sub-regions (Dice scores in the range 74%-85%), illustrating the difficulty of this task. We found that different algorithms worked best for different sub-regions …


Predicting Scenarios For Successful Autodissemination Of Pyriproxyfen By Malaria Vectors From Their Resting Sites To Aquatic Habitats; Description And Simulation Analysis Of A Field-Parameterizable Model, Samson Sifael Kiware, George F. Corliss, Stephen Merrill, Dickson W. Lwetoijera, Gregor J. Devine, Silas Majambere, Gerry F. Killeen Jan 2015

Predicting Scenarios For Successful Autodissemination Of Pyriproxyfen By Malaria Vectors From Their Resting Sites To Aquatic Habitats; Description And Simulation Analysis Of A Field-Parameterizable Model, Samson Sifael Kiware, George F. Corliss, Stephen Merrill, Dickson W. Lwetoijera, Gregor J. Devine, Silas Majambere, Gerry F. Killeen

Electrical and Computer Engineering Faculty Research and Publications

Background

Large-cage experiments indicate pyriproxifen (PPF) can be transferred from resting sites to aquatic habitats by Anopheles arabiensis - malaria vector mosquitoes to inhibit emergence of their own offspring. PPF coverage is amplified twice: (1) partial coverage of resting sites with PPF contamination results in far higher contamination coverage of adult mosquitoes because they are mobile and use numerous resting sites per gonotrophic cycle, and (2) even greater contamination coverage of aquatic habitats results from accumulation of PPF from multiple oviposition events.

Methods and Findings

Deterministic mathematical models are described that use only field-measurable input parameters and capture the biological …


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 …


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.


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 …


Active Filter Solutions In Energy Systems, Sabi̇r Rüstemli̇, Mehmet Sai̇t Cengi̇z Jan 2015

Active Filter Solutions In Energy Systems, Sabi̇r Rüstemli̇, Mehmet Sai̇t Cengi̇z

Turkish Journal of Electrical Engineering and Computer Sciences

Recent developments in power electronics have increased the usage of nonlinear loads in energy systems. With increases in the usage of semiconductor-sourced nonlinear loads, the adverse effects of harmonics-sensitive loads (e.g., protection control circuits and circuit breakers) have also increased. Generally, the negative effects of harmonics in power systems include the following: increased power losses; motor, generator, and transformer overheating; faulty operation of measurement and protection systems; lifetime shortening of electrical components; and parallel and series resonance problems. Therefore, harmonics has become a serious problem in current power electronics systems. However, harmonics can be reduced, particularly through drainage using filters. …


Variable Charge/Discharge Time-Interval Control Strategy Of Bess For Wind Power Dispatch, Wei Chai, Zheng Li, Xu Cai Jan 2015

Variable Charge/Discharge Time-Interval Control Strategy Of Bess For Wind Power Dispatch, Wei Chai, Zheng Li, Xu Cai

Turkish Journal of Electrical Engineering and Computer Sciences

A variable charge/discharge time-interval ($T_{C/D})$ control strategy of a battery energy storage system (BESS) for wind power dispatch is proposed in this paper, aiming at: 1) extending the BESS life, 2) reducing the total BESS energy loss, and 3) increasing the dispatch tracking accuracy. A multifactor life model of a large-scale BESS containing four factors, charge/discharge rate, times, $T_{C/D}$, and temperature, is developed, which has taken into account the cell series/parallel effects and BESS operational characteristics. A comprehensive evaluation system including BESS aging level (BAL), energy loss index (ELI), and tracking inaccuracy index (TII) is proposed, and the relationships between …


Low-Cost Sliding Mode Control Of Wecs Based On Dfig With Stability Analysis, Abdelhak Djoudi, Hachemi Chekireb, El Madjid Berkouk, Seddik Bacha Jan 2015

Low-Cost Sliding Mode Control Of Wecs Based On Dfig With Stability Analysis, Abdelhak Djoudi, Hachemi Chekireb, El Madjid Berkouk, Seddik Bacha

Turkish Journal of Electrical Engineering and Computer Sciences

The aim of this work is to developing sliding mode control of active and reactive stator powers produced by a wind energy conversion system (WECS), based on doubly fed induction generator (DFIG). A flux estimation model and rotor current sensor are no longer required. The controller is developed from the DFIG nonlinear-coupled model. Moreover, the global stability and the DFIG states' boundedness when our low-cost sliding mode control is applied are established analytically. It is revealed that the $(dq)$ components of the rotor flux remain near their nominal values. Our approach is validated via simulation in the case of a …


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 …


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 …


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 Jan 2015

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 …


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 …


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 …


Group Control And Identification Of Residential Appliances Using A Nonintrusive Method, Sunil Semwal, Munendra Singh, Rai Sachindra Prasad Jan 2015

Group Control And Identification Of Residential Appliances Using A Nonintrusive Method, Sunil Semwal, Munendra Singh, Rai Sachindra Prasad

Turkish Journal of Electrical Engineering and Computer Sciences

Identifying and controlling (ON/OFF) electrical appliance(s) from a remote location is an essential part of energy management. This motivated us to design a system that can collect the aggregate load signature from a single point, obtain the features, and finally identify the ON state of electrical appliance(s). The proposed disaggregation technique can be divided into two modules: the first part proposes an electrical installation system to disaggregate the appliance at the circuit level, whereas the second part consists of feature selection, dimension reduction, and classification algorithms. Load signatures of electrical appliances were combined with white Gaussian noise to analyze how …


Capacity Allocation Of Hybrid Solar-Wind Energy System Based On Discrete Probabilistic Method, Chengjin Ye, Minxiang Huang Jan 2015

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, …


An Economic And Environmental Analysis Of Biomass-Solar Hybrid System For The Textile Industry In India, Mahalakshmi Mahadevan, Latha Salai Jan 2015

An Economic And Environmental Analysis Of Biomass-Solar Hybrid System For The Textile Industry In India, Mahalakshmi Mahadevan, Latha Salai

Turkish Journal of Electrical Engineering and Computer Sciences

This paper focuses on the design and analysis of a hybrid biomass-solar photovoltaic system for the textile industry with the goal of minimizing the cost and greenhouse gas emissions. The feasibility analysis of the hybrid system is performed based on the resource availability and the power generation potential of the existing biomass power plant near the textile plant at T.Kallupatti in Tamil Nadu, India. The power plant located at the site (9.66$^{\circ}$N, 77.79$^{\circ}$E) has an average daily global horizontal irradiance of 4.86 kWh/m$^{2}$, which has been validated through NASA Surface Meteorology and Solar Energy data. The chosen site also has …


Frequency-Adaptive Grid-Virtual-Flux Synchronization By Multiple Second-Order Generalized Integrators Under Distorted Grid Conditions, Yingjie Wang, Haiyuan Liu, Xuelong Han, Kangan Wang Jan 2015

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 …


An Improved Incremental Conductance Based Mppt Approach For Pv Modules, Mustafa Engi̇n Başoğlu, Beki̇r Çakir Jan 2015

An Improved Incremental Conductance Based Mppt Approach For Pv Modules, Mustafa Engi̇n Başoğlu, Beki̇r Çakir

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a new maximum power point tracking (MPPT) method based on an incremental conductance (IC) algorithm, constant voltage, and look-up table approach. Convergence time, one of the indicators of MPPT quality, is considered for improving MPPT performance of photovoltaic (PV) modules. In this context, a novel hybrid MPPT approach has been proposed. This proposed method consists of three stages. In the first stage, the value of load resistance is calculated. Then the initial operation point of the PV module is determined by using the constant voltage method or look-up table approach. An IC algorithm is used in order …


Ray Tracing For Optimization Of Compound Parabolic Concentrators For Solar Collectors Of Enclosed Design, Vladimir Yurchenko, Eduard Yurchenko, Mehmet Çi̇ydem, Onat Totuk Jan 2015

Ray Tracing For Optimization Of Compound Parabolic Concentrators For Solar Collectors Of Enclosed Design, Vladimir Yurchenko, Eduard Yurchenko, Mehmet Çi̇ydem, Onat Totuk

Turkish Journal of Electrical Engineering and Computer Sciences

We present our developments in computer simulations and optimization of compound parabolic concentrators (CPCs) for solar heat collectors. Issues of both the optical and thermal optimization of CPC collectors of enclosed design are discussed. Ray tracing results for a CPC with a V-shaped absorber are presented. A range of optimal values for the apex angle of a V-shaped absorber is proposed for a CPC collector of typical design.


Supercapacitor Energy Storage Based-Upqc To Enhance Ride-Through Capability Of Wind Turbine Generators, Gangatharan Sivasankar, Velu Suresh Kumar Jan 2015

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 …


Reliability Assessment Of A Standalone Wind-Conventional/Energy Storage System Using Probabilistic Production Simulation Method, Hossein Delavaripour, Behzad Mirzaeian Dehkordi Jan 2015

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 …


Renewable Energy Integration In Smart Grids-Multicriteria Assessment Using The Fuzzy Analytical Hierarchy Process, Aleksandar Janjic, Suzana Savic, Lazar Velimirovic, Vesna Nikolic Jan 2015

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 …