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https://hdl.handle.net/20.500.12684/6781

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Harmonic analysis and passive power filter design for a medium voltage power system according to IEEE standards
(Sila Science, 2012) Ertay, Muhammed Mustafa; Duru, H. Tarık
Harmonic current and voltage distortions on plant distribution systems are becoming an increasingly serious problem as sources of harmonic currents increase. Passive power filters have been commonly used to limit the harmonic currents in distribution systems. In this paper firstly harmonic analysis of an industrial system has been done. After the analysis, passive power filter design for limitation of current harmonics and power factor correction is realized taking into consideration IEEE 519-1992 and IEEE Std 18 (TM)-2002 standards. Effectiveness of designed single tuned filters in reducing the harmonic distortions is investigated through computer simulations. Simulation studies have been performed in Matlab-Simulink environment
Gravitational Search Algorithm for Economic Dispatch with Valve-Point Effects
(Praise Worthy Prize Srl, 2010) Duman, Serhat; Güvenç, Uğur; Yörükeren, Nuran
In recent years, various heuristic optimization methods have been proposed to solve Economic Dispatch (ED) problem in power systems. This paper presents the well-known power system ED problem solution considering valve-point effect by a new optimization algorithm called as Gravitational Search Algorithm (GSA). The proposed approach has been applied to various test systems with incremental fuel cost function taking into account the valve-point effects. The results shows that performance of the proposed approach reveal the efficiently and robustness when compared results of other optimization algorithms reported in literature. Copyright (c) 2010 Praise Worthy Prize S.r.l. - All rights reserved.
Fuzzy adaptive anisotropic filter for medical images
(Wiley, 2010) Demirci, Recep
An adaptive anisotropic diffusion filter for images is proposed in this paper. First, the gradient of an image was calculated by a novel fuzzy-rule-based gradient operator. Accordingly, the centre of gravity of a histogram of the gradient image was estimated and it was assigned as an edge threshold. In conventional anisotropic filters, the conduction coefficients have to be selected by an operator. However, in this study, the centre of gravity of the histogram was assigned as the conduction coefficient of the anisotropic filter. Consequently, an adaptive anisotropic image filter which automatically sets its conduction coefficient without user intervention was developed. The image filter achieved was tested with various medical images.
DETERMINATION OF THE CONDITIONS OF OPTIMAL OPERATION IN POWER SYSTEMS USING GENETIC ALGORITHM
(Gazi Univ, Fac Engineering Architecture, 2009) Öztürk, Ali; Duman, Serhat
In this study, optimum operating conditions in electric power systems are determined by using Genetic Algorithm (GA), which is one of the optimization methods. Main objective of the work is determination of the voltage amplitude values of the load buses that ensure active power losses in transmission line will be minimum. A five-buses system is considered as an example and the operating voltage values of the load buses are calculated for this system using both GA and Newton-Raphson (NR) power flow method. Using these values, Static VAR Compensation (SVC) and reactive power compensation are implemented. Results show that it will be economically and energy-providently if the operating conditions are determined using GA, since the active power loss is minimized.
The Simulation Study and Dynamic Analysis of Unified Power Flow Controller for Industrial and Educational Purposes
(Kaunas Univ Technology, 2012) Ertay, Muhammed Mustafa; Aydoğmuş, Zafer
M. M. Ertay, Z. Aydogmus. The Simulation Study and Dynamic Analysis of Unified Power Flow Controller for Industrial and Educational Purposes // Electronics and Electrical Engineering. - Kaunas: Technologija, 2012. - No. 5(121). - P. 109-114. Unified Power Flow Controller (UPFC) is versatile and one of the advanced FACTS devices. In this study, dynamic analysis of UPFC is realized by MATLAB-Simulink simulation. For this purpose, a simulation model is presented that enable to be analysed of effects of device to power system in detail. Simulation model is a based on shunt current injection and series voltage injection. UPFC system dynamic model is based on a d-q synchronous reference frame. Developed simulation model enables to be analyzed effects of UPFC and the other converter based FACTS devices (STATCOM, SSSC,IPFC) to power system very simply. Besides, it can be used for education purpose in graduate studies which is about converter based FACTS devices. On the other hand, it can be used for industrial purpose in terms of power system engineers' investigations of effects of UPFC to power system. Simulated UPFC system consists of a load, UPFC and a power system with two machines. In simulation studies, functions of UPFC such as terminal voltage regulation and automatic power flow control is analysed and results are presented in case of graphics. Ill. 17, bibl. 18 (in English; abstracts in English and Lithuanian).
THE EFFECT OF MARBLE CUTTING PROCESS WITH AND WITHOUT INVERTER ON ELECTRIC ENERGY
(Gazi Univ, Fac Engineering Architecture, 2010) Dusun, Mustafa; Çimen, Hasan
In this study, an inverter application was made in order to reduce the consumption of electrical energy in the marble cutting machines. The control parameter of the inverter was kept constant and amount of energy consumption were compared by changing of frequency parameters. Open loop V/f control technique was chosen as control method on the inverter. In active, reactive and specific energy occurred variations with changing of speed ratio. Also the experiments were done without inverter and the differences between two cases were investigated. In the light of these results the most efficient cutting range for consuming less energy in marble cutting machines was determined.
Supply power factor and load current harmonic performance improvement of three phase AC voltage controller
(Academic Journals, 2010) Saraçoğlu, Bilal
AC voltage controllers as power converters used in many application between power ranges from few watts up to fractions of megawatts, such as light dimmers, induction motor soft starter, industrial heating and cycloconverters. Overall efficiency of power system controlled by some advanced methods in power converters is very important which covers supply and load power factor, harmonic distortion at both supply and load side. One of these advanced methods that is best used is the conventional controller, with phase angle control (PAC) of thyristors and it is a known method in contolling AC voltage applied to specific loads. However, these controllers are found to create some problems whose main problems are introduction of high level low order harmonics in current at the load and supply side, poor supply power factor and also low efficiency. This paper presents a proposed three phase AC voltage contoller scheme which allows the application of extinction angle control (EAC) to overcome these problems. Also, a comparison is given between proposed and conventional controllers on the basis of simulation under this viewpoints. The improvements are obtained in terms of high supply power factor, low harmonic content in the load current and high efficiency by proposed controller on comparing to conventional controllers.
Robust Design of PID Controller for Power System Stabilization by Using Real Coded Genetic Algorithm
(Praise Worthy Prize Srl, 2010) Duman, Serhat; Öztürk, Ali
A real coded genetic algorithm based PID controller (RCGAPID) is presented in this paper to improve power system dynamic stability. The proposed RCGAPID parameters are optimized using real coded genetic algorithm (RCGA). The design problem of the proposed controller is formulated as an optimization problem and RCGA is employed to search for optimal PID controller parameters. Integral absolute error (IAE) and integral squared error (ISE) performance indexes have been used for the determination of the PID controller parameters in power systems stabilization. The performance of the proposed RCGAPID under various loading and small disturbance conditions are analyzed and compared in single machine infinite bus (SMIB) power system. Simulation results show the effectiveness and robustness of proposed controllers to improve the stability performance of power system. Copyright (C) 2010 Praise Worthy Prize S.r.l. - All rights reserved.
Reduction of Asynchronous Motor Loss by Heuristic Methods (PSO-GA)
(Kaunas Univ Technology, 2012) Doğan, M.; Dursun, Mustafa
M. Dogan, M. Dursun. Reduction of Asynchronous Motor Loss by Heuristic Methods (PSO-GA) // Electronics and Electrical Engineering. - Kaunas: Technologija, 2012. - No. 1(117). - P. 53-58. The purpose of this article is to compensate the loss of performance caused by asynchronous motor feed. It was aimed to increase inverter output quality in order to reduce voltage instability at the current output and to minimize the harmonics of the inverters used to feed the motor. Many studies have made use of various algorithms to realize the aim mentioned in the article. Particle Swarm Optimization and Genetic Algorithm methods of optimization were used in this article to increase the current output quality, to minimize harmonics and to increase motor performance. Ill. 8, bibl. 15, tabl. 2 (in English; abstracts in English and Lithuanian).
Reactive power optimization with artificial bee colony algorithm
(Academic Journals, 2010) Öztürk, Ali; Çobanlı, Serkan; Erdoğmuş, Pakize; Tosun, Salih
Reactive power optimization (RPO) is an important issue for providing the secure and economic run of the power systems. The importance of reactive power planning on economic profit and secure running has been increasing, because of the increasing fuel costs and investment funds. It is also quite important for an electric operator to provide voltage in a specified range for the customers. As such, RPO provides voltage control in power systems. Furthermore, it is used for decreasing active power loss and making better power coefficents. In this study, multi-objective RPO was used considering voltage deviations of buses, active power losses and reactive power generator costs. In this study, a new metaheuristic optimization method, which is an artificial bee colony (ABC), was used for the optimization. However, ABC was applied on ten bus system and the results were compared with the improving strength pareto evolutionary algorithm. It was observed that the system runs more effectively and economically with the results found with ABC.
Recovering the voltage dip analysis with STATCOM of DFIG in multi-machine wind farm
(Wydawnictwo Sigma-N O T Sp Z O O, 2012) Döşoğlu, Mehmet Kenan; Öztürk, Ali; Poyraz, Gökhan; Güvenç, Uğur
In this study, voltage dip analysis of the wind power plant that is connected to 6 MW Double Feed Induction Generator (DFIG) was performed. During the operation of Multi-machine wind farm that is connected to network adaptation between 10 MVAr STATCOM and system was provided. Purpose of this adaptation, 3-phase fault analysis is to be able and the elimination of problems that may occur with induction motor run-stop.
Optimal reactive power dispatch using a gravitational search algorithm
(Inst Engineering Technology-Iet, 2012) Duman, Serhat; Sönmez, Yusuf; Güvenç, Uğur; Yörükeren, Nuran
This study presents a gravitational search algorithm (GSA) for reactive power dispatch (RPD) problem. RPD is an optimisation problem that decreases grid congestion with one or more objective of minimising the active power loss for a fixed economic power schedule. The proposed algorithm is used to find the settings of control variables such as generator terminal voltages, transformer tap settings and reactive power output of the compensating devices, in order to active power losses minimisation in the transmission system. In this study, GSA is examined and tested on the standard IEEE 30-bus, 57-bus and 118-bus test systems with different test cases such as minimisation of active power losses, improvement of voltage profile and enhancement of voltage stability. To show the proposed algorithm of effectiveness and the obtained results are compared with those reported in the literature. Simulation results demonstrate the superiority and accuracy of the proposed algorithm, and considering the quality of the solution obtained, the proposed algorithm seems to be effective and robust to solve the RPD problem.
Optimal power flow using gravitational search algorithm
(Pergamon-Elsevier Science Ltd, 2012) Duman, Serhat; Güvenç, Uğur; Sönmez, Yusuf; Yörükeren, Nuran
In this paper, gravitational search algorithm (GSA) is proposed to find the optimal solution for optimal power flow (OPF) problem in a power system. The proposed approach is applied to determine the optimal settings of control variables of the OPF problem. The performance of the proposed approach examined and tested on the standard IEEE 30-bus and 57-bus test systems with different objective functions and is compared to other heuristic methods reported in the literature recently. Simulation results obtained from the proposed GSA approach indicate that GSA provides effective and robust high-quality solution for the OPF problem. (C) 2012 Elsevier Ltd. All rights reserved.
Investigation of the control voltage and reactive power in wind farm load bus by STATCOM and SVC
(Academic Journals, 2010) Öztürk, Ali; Döşoğlu, Kenan
In this study, the voltage stability of the bus load in various static and dynamic load systems that are fed by a wind farm has been examined. In the control of load voltage and reactive power, 10 MVAr static synchronous compensator (STATCOM) and static var compensator (SVC) is used. In the wind farm examined, double feed induction generator (DFIG) is used. In voltage and reactive power control, the results of time response and damping oscillation have been found using MATLAB / Simulink. The results achieved have proved that SVC and STATCOM yield good results when used in terms of voltage stability of the system.
Investigation of different load changes in wind farm by using FACTS devices
(Elsevier Sci Ltd, 2012) Döşoğlu, Mehmet Kenan; Öztürk, Ali
In this study, voltage, active power and reactive power variation of load bus were examined by Flexible AC Transmission Systems devices (FACTS) in grid-connected wind farm. In the system, FACTS devices, Static Synchronous Compensators (STATCOM), Static VAr Compensators (SVC), Static Synchronous Series Compensators (SSSC) and Thyristor Controlled Series Compensators (TCSC), were used. Also, dual feed induction generator (DFIG) was used as generator in the wind farm. This simulation study was done via Matlab/Simulink environment. According to different values of active and reactive loads at different times being attached to the system, shapes of load bus voltage, active power and reactive power variation were given, also the results were presented in tables. In the conclusion of this study, by means of FACTS devices that is used in the wind farm, instability was healed within a short time. (C) 2011 Elsevier Ltd. All rights reserved.
Automatic Generation Control of the Two Area Non-reheat Thermal Power System using Gravitational Search Algorithm
(Wydawnictwo Sigma-N O T Sp Z O O, 2012) Duman, Serhat; Yörükeren, Nuran
In this study, determination of the optimal proportional-integral-derivate (PID) parameters with Gravitational search algorithm (GSA) for automatic generation control (AGC) of the two area non-reheat thermal power system is proposed. GSA is applied to search for the optimal PID controller parameters to minimize various performance indexes. The designed PID controller with the proposed approach is simulated under variety of operating conditions. Simulation results are shown that dynamic performance of the two area non-reheat thermal power system is improved by the designed PID controller with the proposed approach.
Application of speed control of permanent magnet synchronous machine with PID and Fuzzy Logic Controller
(Sila Science, 2012) Doğan, Metin; Dursun, Mustafa
Permanent magnet synchronous motors (PMSM), so that the production of high power density and high torque for industrial applications, more and side with a wide range of applications. In this study was presented in the MATLAB / SIMULINK simulation environment of Permanent Magnet Synchronous Motor. PMSM has been driven with insulated gate bipolar transistors (IGBT) inverter as producing Pulse Width Modulation (PWM). Proportional-Integral-Derivative (PID) and fuzzy logic controllers for speed control with graphical analysis of the differences between them were made. It has been entered reference input for speed control of PMSM and is examined in approach to the reference input of output speed. it was seen that Permanent magnet synchronous motor speed control application of fuzzy logic controller given better results according to the other two controller.
AC Chopper Application and Benefits of Auxiliary Windings for PSC Motors
(Kaunas Univ Technology, 2013) Işık, Mehmet Fatih; Güvenç, Uğur; Yanmaz, Hilmi
In this work, a novel driver circuit is designed for permanent split capacitor motors (PSC). With this driver circuit, semi-conductive technology is used in place of cumulative winding for this type of motors that are particularly used in kitchen exhaust fans. Developed circuit is controlled via PWM method. IGBT transistors are used for the power circuit. An optocoupler driver is designed and used in order to drive and trigger these IGBT transistors. Due to this reason, this work includes an electronic AC/AC chopper application that provides energy conservation and noise reduction by removing cumulative winding in currently used asynchronous motors with cumulative auxiliary winding stators and shaded pole motors
Ekonomik Emisyon Yük Dağıtımı Problemi İçin Kaotik Yıldırım Arama Algoritması
(2018) Duman, Serhat; Yıldız, Bayram
Elektrik enerjisinin üretiminde kullanılan fosil yakıtlı kaynaklar çevre kirliliğine yolaçmaktadır. Bu nedenle, termal yakıtlı generatörlerde emisyon salınımının önemigiderek artmaktadır. Ekonomik emisyon yük dağıtımı problemi modern güçsistemlerinin en önemli doğrusal olmayan optimizasyon problemlerinden biridir.Yıldırım Arama Algoritması (YAA), ışık olayına dayalı lider yayılmamekanizmasından esinlenerek geliştirilen ve doğrusal olmayan optimizasyonproblemlerin çözümünde kullanılan sezgisel algoritmalardan biridir. Bu çalışmada,ekonomik emisyon yük dağıtımı problemi YAA ve kaotik YAA algoritmalarıkullanılarak çözülmüştür. Önerilen yaklaşımlar iki farklı test sistemine uygulanmışolup, benzetim çalışmalarından elde edilen sonuçlar literatürdeki diğer sonuçlarlakarşılaştırılmıştır. Önerilen yaklaşımın doğrusal olmayan mühendislik problemlerinçözümünde başarılı bir şekilde uygulandığı gösterilmiştir.
Genetik algoritma kullanılarak ekonomik dağıtım analizi: Türkiye uygulaması
(2009) Döşoğlu, Mehmet Kenan; Duman, Serhat; Öztürk, Ali
Dünyada üretilen elektrik enerjisinin büyük bir kısmını karşılayan termik santrallerin çalışma maliyetinin minimize edilmesi önemli rol oynamaktadır. Bununla birlikte termik yakıtlı santrallerin minimum ve maksimum aktif güç değerleri arasında çalışması istenilmektedir. Bu çalışmada, genetik algoritma (GA) kullanarak Türkiye’de bulunan 380 KV, 14 bara ve 6 adet termik santrallerin ekonomik yük dağıtım (EYD) analizi yapılmıştır. Yapılan analizde, genaratörlerin üretim kısıtlamaları, hat kayıpsız ve hat kayıplı durumları göz önünde bulundurularak sistemin toplam maliyetinin minimum olacak şekilde generatörlerin optimum çalışma koşulları belirlenmiştir.

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