Yazar "Kahveci, Hakan" seçeneğine göre listele

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    Double adaptive power allocation strategy in electric vehicles with battery/supercapacitor hybrid energy storage system
    (Wiley, 2022) Corapsiz, Muhammed Resit; Kahveci, Hakan
    This paper proposes a new energy management strategy (EMS) for electric vehicles (EVs) with battery/supercapacitor hybrid energy storage systems (HESS). Firstly, the battery/supercapacitor HESS configuration and obtaining the load current from the driving cycle are comprehensively explained. Secondly, fixed and adaptive frequency-based (AFB) EMS are discussed in detail. In the proposed method, the current demanded by the load is separated into low and high-frequency components with the help of an adaptive low-pass filter (A-LPF). In addition, adaptive battery current (ABC) is generated according to the supercapacitor (SC) state of charge (SoC), and a double adaptive power allocation strategy is performed. The proposed method is compared with the AFB-EMS for load currents, load powers, DC link voltages, filter cut-off frequencies, battery, and SC SoCs on the UDDS driving cycle. When the obtained results were evaluated together, it was observed that the proposed method completed the driving cycle with a higher battery SoC and realized the adaptive cut-off frequency in a narrower band.
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    The effect of various industrial dust particles on the performance of photovoltaic panels in Turkey
    (Springer Heidelberg, 2023) Gungor, Okan; Kahveci, Hakan; Gokce, H. Suleyman
    The accumulation of dust is one of the main causes of power loss in photovoltaic (PV) farms, and the effect of dust particles' size and chemistry on system performance is often overlooked. This study has focused on a comprehensive analysis of the effect of different dust particles collected from common industrial production facilities in Turkey on the performance of PV panels in the indoor laboratory environment. The collected dust samples were analyzed to determine the dust sample particles' chemical properties, size, character, and topography. The data for dust samples at different weights with changes in maximum power point (MPP) of PV panel has been collected using the artificial solar irradiation source system. Thus, the mathematical correlations (R-2 >= 0.965) between the PV panel Thevenin resistance (RTH), fill factor (FF), MPP, and pollution rate were obtained using these collected data and particle swarm optimization (PSO). According to the results of the obtained mathematical correlations, marble dust is 2.3, 3.4, and 4.2 times less polluting than cement, fly ash, and silica fume, respectively. Additionally, it was observed that smaller dust particles block more light than larger ones of the same weight and reduce MPP, FF while increasing the R-TH.
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    Novel PV Array Reconfiguration and Integration with a Maximum Power Point Tracking Algorithm: RMPPT
    (Springer Heidelberg, 2023) Gungor, Okan; Kahveci, Hakan
    Partial shading significantly impacts the output power of photovoltaic (PV) arrays. This issue can be addressed by reconfiguring connections or positions of modules within the PV array. However, reconfiguration approaches present some drawbacks including the requirements of manual effort, complex algorithms, difficulty in implementation, and switching matrices that increase power losses. To overcome these issues, we present a low-cost and easily implemented reconfiguration method with integration into a maximum power point tracking (MPPT) algorithm for a PV array. We denote our MPPT approach as reconfigurable MPPT (RMPPT), and verify its applicability using a particle swarm optimization (PSO) algorithm, namely the reconfigurable PSO. Consequently, this approach has enhanced the output power of the PV array by at least 7.2% compared to PNO (perturb and observe) and PSO-based MPPT under realistic weather conditions.
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    An overview of frequency-based power split strategies in electric vehicles with battery/supercapacitor hybrid energy storage system
    (Wiley, 2023) Corapsiz, Muhammed Resit; Kahveci, Hakan
    Energy management in hybrid energy storage systems (HESSs) consisting of battery and supercapacitor packages has an essential role in the efficient and safe use of energy storage devices. In the mentioned HESSs, with frequency separation-based energy management, the source with slow dynamics (eg, batteries) is supported by other sources with fast dynamics (eg, supercapacitors). To realize power sharing in the battery/supercapacitor HESS, the load current is divided into low- and high-frequency components and supplied/allocated from energy storage devices. This review touches on the historical development of electric vehicles and includes extensive information about the battery and supercapacitor. It also comprehensively analyzes frequency separation-based power allocation strategies for battery/supercapacitors HESS. These strategies were investigated in detail regarding their features, advantages, and restrictions. In addition, interconnection circuit topologies and control techniques used in frequency-based power allocation were explained comprehensively. As a result, this study will serve as a guide on frequency-based power separation principles in HESS.
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    Performance Analysis of Buck-Boost and SEPIC Converter for Commutation Torque Ripple Minimization in BLDC Motors
    (Taylor & Francis Inc, 2022) Corapsiz, Muhammed Resit; Kahveci, Hakan
    This paper discusses comparative analysis of Buck-Boost and SEPIC (Single Ended Primary Inductance) converters used in DC link voltage control technique to reduce torque ripple in Brushless Direct Current Motors (BLDCM). The aim of this study is to prove the efficiency of the aforementioned two converters, which have been adopted in many studies to reduce torque ripples caused by commutation, on the same motor parameters. Although BLDCM has many advantages, ripples in the generated torque have limited the use of these motors in applications requiring precise speed and torque. In this study, BLDCM was analyzed exhaustive mathematically and electrically and the problem that caused commutation torque ripples was explained in detail. The DC link voltage control has been proposed to suppressing torque ripples in the BLDCM. In addition, the link voltages required for reducing the torque ripples were obtained separately via both the Buck-Boost and the SEPIC converters. These converter topologies are examined under certain speed and torque conditions and the results were compared. When the results are evaluated together, it was observed that both converters performed the very closely performance each other. However, the Buck-Boost converter produced the desired voltage levels with less oscillation than the SEPIC converter.
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    A study on Li-ion battery and supercapacitor design for hybrid energy storage systems
    (Wiley, 2023) Corapsiz, Muhammed Resit; Kahveci, Hakan
    This paper discusses a generic design of lithium-ion (Li-ion) batteries and supercapacitors, which are important sources for energy storage systems (ESS). The main contribution of this study is to compare the available and experimental models for batteries and supercapacitors operating under continuous charge or discharge conditions. Even though the available models show similar behavior to the experimental ones in short-term or pulsed discharge conditions, this situation may be different in continuous discharge conditions. For this purpose, the optimal electrical equivalent circuits of energy storage devices were constituted and modeled in the MATLAB/Simulink environment. Then, the electrical equivalent circuit parameters were approximately calculated with the help of dynamic equations. Finally, the model parameters were estimated using Nonlinear Least Squares Method (NLSM) and Trust Region Reflective Algorithm (TRRA). When the obtained results were evaluated together, it has been observed that the electrical equivalent circuit models (EECM) more accurately reveal the transient and steady states of energy storage devices compared to the available models, especially under continuous discharge conditions.
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    Tek Fazlı AA Gerilim Denetleyicilerde Güç Faktörü ve Harmonik Bozulma Arasındaki İlişkiyi Belirlemek için Deneysel Bir Çalışma
    (2020) Çorapsız, Muhammed Reşit; Kahveci, Hakan; Çorapsız, Muhammed Fatih
    Bu makale, tek fazlı bir AA (TFAA) gerilim kontrolörlerinde güç faktörü ile harmonik bozulma arasındakiilişkinin belirlenmesi ile ilgilidir. Bu çalışmanın amacı, farklı faz tetikleme açıları (FTA) sırasında güç faktörü(GF) ve toplam harmonik bozulmanın (THB) değişimini araştırmaktır. İlk olarak, yüksek frekanslarda çalışan tekfazlı AA gerilim denetleyicilerde triyak yerine tristör kullanmanın avantajlarından bahsedilmiştir. İkinci olarak,tek fazlı AA gerilim denetleyicileri için güç faktörü ve toplam harmonik bozulmalar teorik olarak incelenmiştir.Son olarak, güç faktörü ve toplam harmonik bozulma arasındaki ilişki hem benzetim hem de deneysel çalışmalarile gösterilmiştir. Bununla birlikte, düşük çıkış gerilimlerinde, güç faktörünün (GF) oldukça azaldığı ve toplamharmonik bozulmasının (THB) önemli ölçüde arttığı gözlenmiştir.