Yazar "Ozbay, Harun" seçeneğine göre listele

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    Comparison of regular and irregular 32 pulse density modulation patterns for induction heating
    (Wiley, 2021) Karafil, Akif; Ozbay, Harun; Oncu, Selim
    In this study, an induction heating (IH) application is carried out by transferring the maximum power extracted from photovoltaic (PV) panels to the stainless steel with the designed regular and irregular 32 pulse density modulation (PDM) controlled series resonant inverter. The main objective of this study is to analyse the changes in the system due to regular and irregular PDM patterns. Maximum power point tracker (MPPT) is used to control the output power at different solar irradiation values with varying PDM patterns. Regular and irregular PDM control methods are compared in terms of MPPT efficiency, cost, algorithm complexity, logic control structure and current/voltage stresses of the power switches. Zero current switching (ZCS) conditions are provided by using phase locked loop (PLL) technique at all power points of the PV system. The appropriate switching conditions are tracked continuously at resonant frequency, and therefore soft switching is realised. Perturb and observe (P&O) algorithm is used with the aim of tracking the maximum power in PV panels and high tracking efficiency is obtained with PDM-controlled P&O MPPT algorithm. ATMEL328P-AU microcontroller is used to control the inverter in the system.
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    Design and Analysis of Single-Phase Grid-Tied Inverter With PDM MPPT-Controlled Converter
    (Ieee-Inst Electrical Electronics Engineers Inc, 2020) Karafil, Akif; Ozbay, Harun; Oncu, Selim
    In this article, a novel method is presented for maximum power point tracker (MPPT) system to increase efficiency. For this purpose, maximum power obtained from photovoltaic (PV) panels by pulse density modulation (PDM)-controlled high-frequency series-resonant converter was transferred to grid by a single-phase inverter. The resonant converter and the single-phase inverter circuits used in the system were analyzed, designed, simulated, and implemented. The designed series-resonant converter was operated at resonant frequency for different solar radiation conditions using the PDM control technique, and therefore the maximum power point was tracked. Soft switching was achieved by continuously tracking the resonant frequency. Simulated and experimental results were presented for 600 W prototype by operating the MPPT converter over 100 kHz. The MPPT efficiency was obtained as 99 & x0025; and above. The maximum power tracking of the PV panels was achieved using the perturb and observe (P & O) algorithm with PDM technique. The generated PV power was transferred to the single-phase grid by an LCL-filtered inverter. Proportional integral controller was preferred in the control of single-phase grid-tied inverter.
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    Power Control of Resonant Converter MPPT by Pulse Density Modulation
    (Ieee, 2017) Karafil, Akif; Ozbay, Harun; Oncu, Selim
    This paper presents the simulation of series resonant converter system with proposed 32 pulse density modulation (PDM) patterns which transfer the electrical energy obtained from PV panels to load with high power density. Maximum power point tracking (MPPT) is achieved by deleting some control pulses. Therefore, zero current switching (ZCS) is achieved at 100 kHz resonant frequency. The average output power changes of series resonant converter are given according to the proposed 32 PDM patterns. Both the MPPT algorithm and the high frequency series resonant converter are controlled by TMS320F28335 DSP. In the 600 W PV system, soft switching condition is achieved by using the proposed 32 PDM technique.
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    Simulink Model of Parallel Resonant Inverter with DSP Based PLL Controller
    (Kaunas Univ Technology, 2015) Oncu, Selim; Ozbay, Harun
    Resonant converters can operate at high switching frequencies with low switching losses. However, in order to reduce switching losses resonant frequency has an important role in the design. In this study, a DSP based closed loop phase locked loop (PLL) control algorithm for parallel resonant inverter is designed and simulated with MATLAB/Simulink. The validity of the Simulink model of current source inverter is tested for different loads and gain values obtained from Jury's stability. The developed DSP controlled parallel resonant inverter tracks the resonant frequency and achieves soft switching.
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    Sliding mode PLL-PDM controller for induction heating system
    (Tubitak Scientific & Technological Research Council Turkey, 2021) Ozbay, Harun; Karafil, Akif; Oncu, Selim
    In this study, a sliding mode controlled phase locked loop (SMC-PLL) was developed for induction heating (IH) applications with a resonant inverter. PLL applications are widely used in induction heating applications to achieve zero voltage switching and zero current switching. In many PLL applications, the frequency tracking is too slow and unreliable. Therefore, a sliding mode controller was developed to provide robust and fast PLL. Furthermore, a pulse density modulation (PDM) control strategy was developed to work at the resonant frequency for all power levels. The PDM power control is a good solution for the design of high-frequency inverters because of a great reduction of switching losses and electromagnetic noise. The PDM pattern for the desired output power is determined according to the set temperature value of the work piece. The proposed system was simulated in PSIM and a 250-W laboratory prototype was implemented with operating frequency of 35-42 kHz.
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    SMC-DPC based active and reactive power control of grid-tied three phase inverter for PV systems
    (Pergamon-Elsevier Science Ltd, 2017) Ozbay, Harun; Oncu, Selim; Kesler, Metin
    In this paper, sliding mode control (SMC) direct power controller (DPC) based active and reactive power controller for three-phase grid-tied photovoltaic (PV) system is proposed. The proposed system consists of two main controllers: the DC/DC boost converter to track the possible maximum power from the PV panels and the grid-tied three-phase inverter. The Perturb and Observe (P&O) algorithm is used to transfer the maximum power from the PV panels. Control of the active and reactive powers is performed using the SMC-DPC strategy without any rotating coordinate transformations or phase angle tracking of the grid voltage. In addition, extra current control cycles are not used to simplify the system design and to increase transient performance. The fixed switching frequency is obtained by using space vector modulation (SVM). The proposed system provides very good results both in transient and steady states with the simple algorithms of P&O and SMC-DPC methods. Moreover, the results are evaluated by comparing the SMC-DPC method developed for MPPT and the traditional PI control method. The proposed controller method is achieved with TMS320F28335 DSP processor and the system is experimentally tested for 12 kW PV generation systems. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.