Yazar "Kabalci Y." seçeneğine göre listele
Listeleniyor 1 - 8 / 8
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe A comparative simulation study on the performance of LDPC coded communication systems over Weibull fading channels(Universidad Nacional Autonoma de Mexico, Centro de Ciencias Aplicadas y Desarrollo Tecnologico, 2016) Develi I.; Kabalci Y.The Weibull distribution is a useful statistical model that can be used to describe the multipath fading in nowadays wireless communication environments. In this paper, the bit error rate (BER) performance of Low-Density Parity-Check (LDPC) coded communication systems using different decoding rules is presented over Weibull fading channels by means of comparative computer simulations. It is shown that, especially for the case of the Belief Propagation (BP) decoding rule, significant performance improvement can be achieved in comparison with uncoded transmission when the channel is assumed to have Weibull fading. © 2016 Universidad Nacional Autónoma de México, Centro de Ciencias Aplicadas y Desarrollo Tecnológico.Öğe A modified ABC algorithm approach for power system harmonic estimation problems(Elsevier Ltd, 2018) Kabalci Y.; Kockanat S.; Kabalci E.Electrical harmonic is an important issue on power quality of electrical systems. Therefore, estimation of power harmonics are essential to design filters to be utilized in electrical power systems for reducing harmonics and their effects on the electrical power systems. In this study, a power system harmonic estimation solution based on modified artificial bee colony (MABC) algorithm have been proposed. The proposed method in this study is different from other hybrid techniques previously reported ones since estimation processes are mainly focused on decreasing computational complexity and time. In order to provide more accurate and comprehensive estimation results for the proposed method, two different experiments are investigated. Obtained results by the performed experiments showed that the proposed harmonic estimator provides several advantages such as offering very low computational time, more accurate estimation of amplitude and phase values for all conditions and low complexity. © 2017 Elsevier B.V.Öğe Hybrid Microgrid System Design with Renewable Energy Sources(Institute of Electrical and Electronics Engineers Inc., 2018) Kabalci E.; Irgan H.; Kabalci Y.This study presents both a hybrid microgrid system design with renewable energy and their control methods, analysis result. This renewable energy resources (RES) consist of 33kW PVs, 100kW fuel cell stack and a 50kW wind turbine with permanent magnet synchronous generator (PMSG). PV plant includes the PV arrays and DC-DC boost converter. Fuel cell plant includes the fuel cell stacks and DC-DC boost converter. The wind energy plant contains the wind turbine, PMSG, uncontrolled rectifier and DC-DC boost converter. The boost converter connected to PV plant has been controlled by using incremental conductance maximum power point tracking algorithm (IC-MPPT A). Both the boost converters of the wind energy system and fuel cell system have been operated with PI controllers. The switching element of all boost converters is M OSFE T. The switching frequency for boost converters of the wind energy system and fuel cell system is 30 kHz and 50 kHz for boost converter connected PV array. The hybrid microgrid has been coupled on 1000V DC-bus bar. 400V/120 kV transformer and 120 kV, 50 Hz AC supply have been used to create the grid model. To convert from DC to AC, as the topology, full bridge inverter circuit has been used and IGBT has selected as the switching element. Phase locked loop (PLL) algorithm has been used as a control for the AC voltage generated at the inverter output to be the same phase, frequency and amplitude with the grid. The system has been operated under the various operating conditions such as wind speed and solar irradiation. And despite these variables, the desired results have been obtained from the system. © 2018 IEEE.Öğe Hybrid precoding for mmWave massive MIMO systems with generalized triangular decomposition(Institute of Electrical and Electronics Engineers Inc., 2018) Kabalci Y.; Arslan H.Hybrid precoding schemes have recently gained a great attention for millimeter wave (mmWave) massive multiple-input-multiple-output (massive MIMO) communication systems because of offered cost and low-power consumption advantages. The singular value decomposition (SVD) method which is exploited in the design of hybrid precoding causes several problems on system design, especially on bit allocation, precoding and equalizing processes. On the other hand, the previous works show that generalized triangular decomposition (GTD) method can present asymptotically optimal performance in conventional MIMO systems. In the light of this, we propose the use of GTD method for designing hybrid precoding operating in mmWave massive MIMO systems. The proposed design is analyzed via performed simulation studies including different system configurations. Moreover, the archived results are compared with the standard orthogonal matching pursuit (OMP) algorithm based hybrid precoding scheme. The simulation results show that the proposed hybrid precoding scheme can reach up to the performance of optimal precoding scheme. © 2018 IEEE.Öğe Multi-channel power line communication system design for hybrid renewables(2013) Kabalci E.; Kabalci Y.This study deals with a multi-channel power line communication infrastructure that is designed specifically for a hybrid renewable energy generation system. However, the proposed method can easily be adapted to any communication system that uses power line as a transmission channel. The modelled environment is based on carrying the various data acquired from a renewable energy test bed. The test bed is also a comprehensive modelling study itself where it is designed with wind turbine and solar energy plants. The generated voltage, current, and apparent power (S) of each energy plant are measured separately and are transmitted to monitoring centre over the power line. The modulators are located at the generation sites and acquired data are modulated with Quadrature Phase Shift Keying (QPSK) method. A QPSK modulated signal that carries 6-channel data is injected to power line and is transmitted to 25 km away monitoring centre. The demodulated data is calibrated to measured values and comparisons showed that the proposed system performs multi-channel power line communication successfully. The modelled communication system can also be used as a control system by transmitting any control data from grid side to renewables. © 2013 IEEE.Öğe Multiuser communications for broadband indoor power line channels using IDMA technology(2013) Bilim M.; Develi I.; Kabalci Y.Power line communication (PLC) systems are one of the most popular technologies for smart grids due to their cost efficiency. This paper presents bit error rate (BER) performance of traditional interleave-division multiple access (IDMA) systems over broadband (BB) indoor PLC channels. The BB PLC channels considered in this paper are proposed by Cañete and others. Subsequently, simulation results are carried out by using these different BB indoor PLC channel scenarios. © 2013 IEEE.Öğe Noise insensitive optimal harmonic estimator design with lightning search algorithm(Elsevier B.V., 2019) Kabalci Y.; Kabalci E.Electrical harmonics directly affect the power quality of electrical systems. In order to improve power quality of electrical systems, accurate estimation of electrical harmonics is crucial and essential. This paper presents a novel estimator design approach for harmonic estimation problems. The proposed harmonic estimator is based on lightning search algorithm (LSA) that is a powerful metaheuristic optimization method inspired of natural phenomenon of lightning. The performance of designed estimator has been comprehensively analyzed by considering time varying power signals that contain two well-known estimation problems in the literature. In addition, each of these problems are examined for three different levels of noise. Furthermore, performance of the designed estimator is compared with the previously reported estimators. The achieved estimation results for different case studies clearly indicated that the proposed LSA based harmonic estimator provides better estimation results in all experiments than that of our previous method based on modified artificial bee colony (MABC) optimization and other existing methods available in the literature. © 2019 Elsevier B.V.Öğe Proposal of an experimental data and image transmission system and its possible application for remote monitoring smart grids(Universidad Nacional Autonoma de Mexico, Centro de Ciencias Aplicadas y Desarrollo Tecnologico, 2017) Develi I.; Kabalci Y.This paper investigates the bit error rate (BER) and the peak signal-to-noise ratio (PSNR) performances of quasi-cyclic low-density parity-check (QC-LDPC) coded orthogonal frequency-division multiplexing (OFDM) systems over an actual power line communication (PLC) channel that are acquired by performing very long-term experimental measurements from the grid. The examined system is tested by changing system parameters such as code length, iteration number, coding rate and message type in detail. The results of this study show that the QC-LDPC coded OFDM system can be a possible solution for communication and remote monitoring purposes in smart grids. © 2017 Universidad Nacional Autónoma de México, Centro de Ciencias Aplicadas y Desarrollo Tecnológico
