Browsing by Author "Taşkin S."
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Item An application of denoising based on wavelet transform for temperature signals of the alternators in a passenger coach(2008) Taşkin S.; Akinci T.Ç.; Şeker S.This paper deals with a passenger coach alternators. In this study, temperature variations, which are depended on load conditions of alternators in a passenger coach, have been investigated using the wavelet transform based denoising and statistical methods. To obtain real road data from the bus alternators, the bus was driven 456 km on the roadway in Turkey. During the collecting alternators data, interior lighting lambs on/off locations, air conditioner operation position, bus headlights situations and other electrical/electronic devices on/off positions have been considered. MATLAB program was used for the signal analysis of the alternators.Item Analysis of vibration signals related to fuel tank in a passenger coach; [Bi̇r yolcu otobüsünün yakit deposununa i̇li̇şki̇n ti̇treşi̇m si̇nyalleri̇ ni̇n anali̇zi̇](2008) Şeker S.; Taşkin S.; Akinci T.Ç.In this study, the data which was taken from accelerometer located in vertical direction to fuel tank chassis of a traveler bus has been analyzed. Firstly vibration signal related to the endurance of the connection has been observed as a raw data on the time-frequency plane and then it has been passed from a critical frequency 20 Hz low pass filter and power spectrum changes have been observed. After this, critical frequency value whose peak value is about 11 Hz has been forced mechanically to the construction which consists of fuel tank has been determined. In addition, it was determined that 11 Hz emerged at about 244th second on the time scale and it has been observed that big amplitude has also been created by this frequency on the time serial. ©2008 IEEE.Item Design and simulation of a lqg robust controller for an electrical power system(2008) Oǧuz Y.; Erdal H.; Taşkin S.LQG robust controller, electrical power system, modeling, Matlab/Simulink. This paper describes a LQG robust controller for the load frequency control of an electrical power system. The controller is used in order to achieve robust stability and good dynamic performance against the variation of power system parameters and its load. The application of the proposed LQG robust control scheme is implemented through the simulation of a single area power system model. The proposed robust controller for power systems stability is designed using Matlab/Simulink program. Simulation results confirm the performance of the proposed controller for the electrical power system.Item Detection of static eccentricity for permanent magnet synchronous motors using the coherence analysis(2010) Akar M.; Taşkin S.; Şeker S.; Cankaya I.This paper reports on work to detect the static eccentricity faults for permanent magnet synchronous motor (PMSM) using spectral analysis methods. Measurements are carried out by the collecting the stator current and voltage, torque and speed for healthy and faulty cases of the motor. Static eccentricity case is formed by changing the rotor position in the mannner of sliding the shaft on a horizontal axis. As a result of the spectral analysis for the motor currents, side band effects appeared at around the fundamental frequency are determined as a most important indicator of the eccentricity. In addition to this determination, the eccentricity problem is observed from the torque and rotor speed data comparing with each others as well as current and voltage variations. © TÜBİTAK.Item Power plants monitoring for reverse power flow evaluation(Istanbul University, 2010) Taşkin S.Power plant generators are important components of an electrical energy system. They should be constantly monitored and protected in order to maintain the quality and reliability of the power supply. Otherwise, generators may occur in case of faults or incorrect operation. One of them is reverse power condition. Reverse power flow can be cause important problems if it is not considered in the protection system design. The objective of this study is to investigate of the reverse power condition of the power plants generators. For this purpose, reverse power data are collected from a cogeneration power plant generators protection relays. The relays are able to detect disturbances and when these occurs, all digital and analogical signals are stored in its memory, including the pre-fault, fault and post-fault intervals. Hence, the reverse power data, which are collected during the transition case from abnormal condition of the generators to motoring mode, present current, voltage, active and reactive power data as well as frequency variations, are analyzed for two generators.Item Analysis of issues for implementing e-learning: The student perspective(2012) Akaslan D.; Law E.L.-C.; Taşkin S.Integration of e-learning into campus-based institutions is a challenging issue. A number of key issues and questions clearly need to be solved and answered before any attempt for implementing e-learning is taken. The purpose of this paper is hence to investigate how to implement e-learning in the higher education institutions (HEI) associated with the subject of electricity in Turkey, considering the student perspective. For this reason, a web-based survey has been conducted to measure the extent to which the representative students in the Turkish HEI are ready for e-learning and to investigate their perspectives on issues for implementing e-learning. Two techniques were used: an online questionnaire with close-and open-ended items and semi-structured online interviews. 704 responses were analysed. At the end of the questionnaire, respondents were invited to participate in a semi-structured interview. 63 accepted the invitation, but only 33 of them actually attended the interview. Based on the findings derived from the interviews, we develop a model to illustrate what principles are needed for implementing e-learning in the respective institutions. Overall, our findings show that e-learning is perceived as a solution for resolving some issues and it brings some innovation in the respective institutions in Turkey; and that it should be integrated into campus-based education and training via the blended learning approach. © 2012 IEEE.Item Coherence analysis on thermal effect for power cables under different environmental conditions(2014) Taşkin S.; Şeker S.S.; Kalenderli O.; Karahan M.There are 2 important aspects of this research; these are the experimental study and the data analysis, which are based on coherence analysis. In this study, a low-voltage power cable is tested under 2 different environments, air and water, and the variations in temperature are measured for the conductor, the sheath parts of the cable, and the environment. The recorded test data are analyzed using such as coherence analysis. This in turn provides the means to determine the relationship among the sheath, conductor, and the environment. In conclusion, high correlated peaks in the frequency domain are used to determine the temperature effect. © TÜBİTAK.Item INVERTED DECOUPLING PID CONTROLLER DESIGN FOR A MIMO SYSTEM(Yildiz Technical University, 2019) Üstüner M.A.; Taşkin S.Eliminating loop interaction is a critical issue in the control of Multi Input Multi Output (MIMO) systems. In this study, an experimental setup, Festo Didactic MPS-PA, is used as MIMO system. Inverted decoupling PID method is applied to the system to eliminate the loop interactions of MIMO system. For this purpose, firstly, the system is modelled. Then, decoupler blocks are designed to eliminate the loop interactions. Finally, the modelled system is simulated, and experiments are performed on the real system. The effect of inverted decoupling PID control on the system performance and the effect of classical PID control on the system performance are compared. © 2019 Yildiz Technical University. All Rights Reserved.Item MODELING AND ANALYSIS OF SINGLE-PHASE INDUCTION MOTOR DRIVE FOR VARIABLE CAPACITY CONTROL OF A REFRIGERATOR COMPRESSOR(Yildiz Technical University, 2020) Önceler A.A.; Taşkin S.A refrigeration system with single-phase induction motor compressor is used to operate the cooling process at constant speed and On/Off control mode. Using a motor driver with this system allows us to utilize variable speed control algorithms, and gives many opportunities to improve energy efficiency. This paper presents developed model simulation results of a single-phase induction motor drive to improve energy efficiency for a refrigerator compressor motor. For this aim, firstly, a household refrigerator compressor and a compatible drive system are determined to obtain the model of the system. Based on the catalog values of a selected real compressor, a model is created. Then, the developed model simulation results are verified with the real compressor data. In the drive system model, scalar control, single-phase full bridge inverter topology and unipolar sinusoidal pulse width modulation methods are employed. Finally, total harmonic distortion and energy consumption of a single-phase induction motor which is driven by the developed driver model are measured. Energy consumption values of the conventional and variable-speed cooling systems which are available in the market are compared with the developed model. © 2020 Yildiz Technical University. All Rights Reserved.Item Modeling and validation of the thermoelectric generator with considering the change of the Seebeck effect and internal resistance(Turkiye Klinikleri, 2022) Üstüner M.A.; Mamur H.; Taşkin S.Thermoelectric generators (TEGs) produce power in direct proportion to the temperature difference between their surfaces. The Seebeck coefficient and internal resistance of the thermoelements (TEs) that make up the TEGs change depending on the temperature change. In simulation studies, it is seen that these two values are kept constant. However, this situation prevents approaching the data of TEG in real applications. In this study, a TEG Simulink/MATLAB ® model has been developed to capture real TEG module data, which considers changing of both the Seebeck coefficient and the internal resistance depending on the temperature difference change. To achieve this aim, a commercially available TEG data used in also academic studies has been used. A boost converter with a perturb and observe (P&O) maximum power point tracker (MPPT) algorithm has been designed to maximize the TEG power. The TEG Simulink/MATLAB ® model data are compared with commercially available TEG data at different temperatures. The error between the actual values and the simulation results, and the mean absolute percent errors (MAPEs) are calculated. The open circuit voltage and short circuit current error rates of the designed TEG module are 0.125% and 0.256%, respectively. The MAPE values of the designed model are 0.5104%, 0.7837%, and 2.0952% for 30 ◦C, 50 ◦C, and 80 ◦C cold surface temperatures, respectively. In addition, simulations are made in order to see the effect of temperature-dependent parameters in a TEG system built using the designed model. While the simulations made with the designed model give realistic results, with the simulations made with constant coefficients, up to 2.63% more power is obtained than the capacity of the system, contrary to reality. Simulation and validated results show that this new TEG Simulink/MATLAB ® model gives more realistic results. © TÜBİTAK.