WoS İndeksli Yayınlar Koleksiyonu

Permanent URI for this collectionhttps://hdl.handle.net/20.500.12573/394

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Author: search.filters.author.Tekgun, Burak

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Now showing 1 - 10 of 25
  • Article
    An Adaptation Mechanism of Model Reference Adaptive System Based on Variable Structure Control for Online Parameter Estimation of IPMSM
    (Wiley, 2026-01) Tekgun, Burak; Barut, Murat; Ates, Ertugrul
    This study introduces stator currents-based model reference adaptive system (MRAS) estimators that employ variable structured control (VSC) in the adaptation mechanism to enable the online estimation of stator resistance and permanent magnet (PM) flux in interior permanent magnet synchronous motors (IPMSMs). These MRAS estimators estimate stator resistance and PM flux by analysing the error between the stator currents measured as the reference model and the stator currents generated by the adaptive model. The performance of the proposed estimators is assessed through simulation studies. Furthermore, the proposed approach is compared to a conventional MRAS employing a fixed-gain proportional-integral (PI) controller. Simulation results and error analyses indicate that the VSC-based MRAS algorithms outperform traditional PI-based MRAS in terms of accuracy and reliability. Additionally, the proposed method eliminates the reliance on a fixed-gain PI controller, a common component in conventional MRAS systems.
  • Article
    Comparative Analysis of Modulation Shapes on Laser Diode Performance with a High-Efficiency LLC Resonant Converter Driver
    (Wiley, 2026-02-06) Yigit, Hayri; Rifat boynuegri, Ali; Tekgun, Burak; Rifat Boynuegri, Ali
    High-power laser diodes (LDs) are key components in laser-based wireless power transfer (WPT) systems, where end-to-end efficiency is one of the most critical performance metrics. This study investigates the driving performance of an LD powered by a high-efficiency LLC resonant converter under three distinct excitation waveforms-sinusoidal, triangular, and rectified-sine-using a MATLAB/SIMULINK model and an experimental setup designed to reproduce real-world operating conditions. Each waveform is synthesized through frequency modulation of a full-bridge inverter stage and filtered at the output. The analysis examines the impact of modulation shape on output current ripple, converter efficiency, and overall LD efficiency. Experimental validation confirms the simulation trends, underscoring the trade-offs between waveform smoothness, implementation complexity, and efficiency. Beyond confirming that constant-current operation yields the highest LD efficiency, this study explicitly quantifies how low-frequency current ripple induced by different modulation waveforms propagates through the LLC resonant converter, alters RMS current stress, and translates into measurable efficiency degradation at both the driver and LD levels. By experimentally correlating waveform symmetry, ripple magnitude, and loss mechanisms, the work establishes practical design boundaries for waveform-modulated laser drivers in WPT systems.
  • Conference Object
    Structural Integrity Analysis of a Two-Pole Synchronous Reluctance Machine With Non-Circular Shaft
    (IEEE, 2023-06-14) Tekgun, Didem; Tekgun, Burak; Alan, Irfan
    This paper investigates the structural strength of a 6-inch diameter, two-pole, 4 kW line start synchronous reluctance machine (LS-SynRM) designed with a new non-circular shaft structure that serves as a pump motor. Flux paths on the rotor are widened while narrowing down the shaft of the motor on the q- axis to improve the motor efficiency. By using this method, a wider path is created for the flux in the d-axis. As a result, the inductance in the d-axis, the ratio of inductance between the d-axis and q-axis (referred to as saliency ratio), and the difference in inductance between the d-axis and q-axis are all amplified. To evaluate the structural strength of the machine, a series of analyses are conducted, including modal, harmonic, and static examination on the rotor using ANSYS Structural. The findings indicate that to prevent redundant deformations and undesirable vibrations because of resonance, the maximum safe limit for shaft size reduction is determined as 8 mm.
  • Conference Object
    Citation - WoS: 1
    Citation - Scopus: 5
    Sliding Mode Control of a Switched Reluctance Motor Drive With Four-Switch Bi-Directional DC-DC Converter for Torque Ripple Minimization
    (Institute of Electrical and Electronics Engineers Inc., 2020-09) Ates, Ertugrul; Tekgun, Burak; Ablay, Günyaz
    In this paper, a method to drive switched reluctance motors (SRM) with a modular four-switch bidirectional DC-DC converter and an H-bridge is proposed. The DC-DC converter operates as a buck or a boost converter with constant frequency to control each phase current while the H-bridge inverter switches only twice in a period to adjust the polarity of the phase voltage. Sliding mode control is designed to have fast and robust current control in the DC-DC converter. The sliding surface equation which is derived for all operation modes including buck and boost modes in motoring and regenerating conditions is defined with the estimated inductor current. The proposed drive system eliminates the bulk DC-capacitors and allows one to adjust the bus voltage individually for all phases. Moreover, the proposed system topology works with only one high-frequency switching device in the DC-DC conversion stage rather than two in conventional drives which provides a simpler current control and reduced switching losses. © 2020 Elsevier B.V., All rights reserved.
  • Conference Object
    Citation - WoS: 1
    Sliding Mode Control of a Switched Reluctance Motor Drive With Four-Switch Bi-Directional Dc-Dc Converter for Torque Ripple Minimization
    (IEEE, 2020-09) Ates, Ertugrul; Tekgun, Burak; Ablay, Gunyaz
    In this paper, a method to drive switched reluctance motors (SRM) with a modular four-switch bi-directional DC-DC converter and an H-bridge is proposed. The DC-DC converter operates as a buck or a boost converter with constant frequency to control each phase current while the H-bridge inverter switches only twice in a period to adjust the polarity of the phase voltage. Sliding mode control is designed to have fast and robust current control in the DC-DC converter. The sliding surface equation which is derived for all operation modes including buck and boost modes in motoring and regenerating conditions is defined with the estimated inductor current. The proposed drive system eliminates the bulk DC-capacitors and allows one to adjust the bus voltage individually for all phases. Moreover, the proposed system topology works with only one high-frequency switching device in the DC-DC conversion stage rather than two in conventional drives which provides a simpler current control and reduced switching losses.
  • Conference Object
    Citation - WoS: 1
    Citation - Scopus: 1
    Sensorless Position and Speed Control of IPMSM With Sliding Mode Observer and Voltage Signal Injection
    (IEEE, 2021) Ates, Ertugrul; Tekgun, Burak; Ablay, Gunyaz
    A sensorless control approach based on a sliding mode observer for predicting the rotor position and speed is studied in this work. For predicting the motor speed and position, the sliding mode observer followed by a phase locked loop is formulated by means of the back EMF model. The voltage signal injection method is utilized for accurate estimation in zero or low speed region. Numerical simulation results are provided for an 8-pole IPMSM, which shows that the motor speed and position in zero or low-speed region are accurately estimated with the designed observer and voltage signal injection approach.
  • Article
    Citation - WoS: 44
    Citation - Scopus: 58
    Real-Time Energy Management in an Off-Grid Smart Home: Flexible Demand Side Control With Electric Vehicle and Green Hydrogen Production
    (Pergamon-Elsevier Science Ltd, 2023-07) Boynuegri, Ali Rifat; Tekgun, Burak; Rifat Boynuegri, Ali
    A real-time energy management system for an off-grid smart home is presented in this paper. The primary energy sources for the system are wind turbine and photovoltaics, with a fuel cell serving as a supporting energy source. Surplus power is used to generate hydrogen through an electrolyzer. Data on renewable energy and load demand is gathered from a real smart home located in the Yildiz Technical University Smart Home Laboratory. The aim of the study is to reduce hydrogen consumption and effectively utilize surplus renewable energy by managing controllable loads with fuzzy logic controller, all while maintaining the user's comfort level. Load shifting and tuning are used to increase the demand supplied by renewable energy sources by 10.8% and 13.65% from wind turbines and photovoltaics, respectively. As a result, annual hydrogen consumption is reduced by 7.03%, and the average annual efficiency of the fuel cell increases by 4.6% & COPY; 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
  • Conference Object
    Citation - WoS: 2
    Citation - Scopus: 2
    LLC Laser Driver for Laser Wireless Power Transfer Application
    (IEEE, 2024-06-04) Yigit, Hayri; Boynuegri, A. Rifat; Tekgun, Burak
    Laser Wireless Power Transfer (LWPT) represents a cutting-edge technology for the long-range transmission of energy, distinguished by its capability for high-power transfer and adaptability to mobile applications. The effectiveness of this system is significantly tied to its transmitter component, comprising the Laser Diode (LD) and its associated driving circuitry. This research address to enhance system efficiency by introducing a specially designed LLC converter circuit, aimed at improving the overall efficiency of both the driver circuit and the LD driving process while minimizing current ripple. The proposed circuit underwent comprehensive simulation using MATLAB/SIMULINK, resulting in noteworthy outcomes that showcased an impressive efficiency of 98.44% within the LD driver circuit.
  • Conference Object
    Citation - WoS: 5
    Citation - Scopus: 5
    Investigation of the Effects of Multi-Layer Winding Structures in Two Pole Synchronous Reluctance Machines
    (IEEE, 2021-10-05) Tekgun, Didem; Cosdu, Muhammed Muhsin; Tekgun, Burak; Alan, Irfan; Muhsin Cosdu, Muhammed
    In this paper, a comparative study is performed between single, various double, and triple-layer winding structures to investigate the effects of the winding MMF harmonics and end winding length on the two-pole synchronous reluctance machines (SynRM). A two-step design approach is used including winding and geometry optimization using multi-objective differential evolution (MODE) algorithm. In the first stage, a Pareto front is obtained which determines the number of turns for each coil group for all winding configurations. Later in the second stage, three results are selected from the first stage to perform a geometric optimization to distinguish the effects of the THD and end winding length on the synchronous performance of a 4 kW two-pole SynRM. For the same average torque output, efficiency, mass, and the torque ripple of the selected designs are investigated and compared. Based on the analysis, it is concluded that rather than focusing on shortening the end winding length, reducing the MMF harmonics have a more positive effect on the machine performance as reduced harmonics resulted in efficiency improvement up to 2 points and torque ripple is reduced up to 8 points while having similar motor mass.
  • Article
    Citation - WoS: 1
    Citation - Scopus: 1
    Investigating the Tradeoff Between the MMF Distortion and End Turn Length of a 2-Pole Line Start SynRM Performance
    (Springer int Publ Ag, 2023-07-19) Tekgun, Didem; Cosdu, Muhammed M.; Tekgun, Burak; Alan, Irfan
    Conventional 2-pole AC machine windings have long end windings and generate harmonics, which increase losses and reduce torque density. This study investigates the performance tradeoff between the level of distortion (THD) in winding magneto-motive force (MMF) and end turn length on a 2-pole line start Synchronous Reluctance Machine (LS-SynRM) machine. A two-stage approach is used, winding and geometry optimization. Various multilayer winding configurations having unevenly distributed number of turns are investigated. First, the percentage of the turns in a coil group is optimized for minimum harmonics and end turn length for all structures. Second, geometric optimization is performed on selected winding configurations. Sixteen different configurations are optimized, and Pareto optimal solutions are obtained. Later, these solutions are graded with a new score-based assessment method to quantify the quality of the results. It is concluded that the designs having lower THD in winding MMF perform better than the designs with shorter end turns in terms of efficiency and torque density.