Browsing by Author "Adak, Suleyman"

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Fotovoltaik Hücre Tek Diyot Eşdeğer Devre Modelinin Parçalı Doğrusal Paralel Dal Modeli Kullanılarak Doğrusallaştırılması ve Dolum Faktörünün Bulunması
(2025) Adak, Suleyman
Bu makalede Fotovoltaik (PV) hücre tek diyot eşdeğer devre modelinin doğrusallaştırılması ve analizi yapılmıştır. PV hücresi eşdeğer devre modelindeki diyot elemanı doğrusal olmayan bir bileşendir. Doğrusal olmayan PV hücresi tek diyot modeli, parçalı doğrusal paralel dallar modeli kullanılarak doğrusallaştırılmıştır (PLPBM). Ayrıca PV hücresinin maksimum gücü ve doldurma faktörü (FF) eşdeğer devre parametrelerine göre belirlenmiştir. Bu analiz sürecinde Thevenin teoremi kullanıldı. Bu teoremin uygulanabilmesi için devrenin doğrusal bir karakteristiğe sahip olması gerekir. Uygulamada amaç, PV hücresinden maksimum gücü (Pmax) aktarmaktır. PV hücresinin bir diğer önemli parametresi FF'dir. FF, bir güneş PV hücresinin genel davranışını tanımlamak için kullanılır. Bu faktör solar PV hücresinin kalitesini belirlemek için kullanılır. FF, güneş pilinin kalitesi ve verimliliği hakkında bilgi sağlar. Düşük FF durumunda seri direncin değeri yüksek, paralel direncin değeri ise düşüktür. Tipik PV hücresinin FF'rü %50 ile %82 arasında değişir. Makalede yapılan analizde PV güneş pilinin FF %74 olarak bulunmuştur.
Fotovoltaik Sistemin Çıkış Gücünün Sıcaklık ve Işımaya Bağlı Matematiksel Modellemesi ve Simülasyonu
(2019) Yılmaz, Ahmet Serdar; Adak, Suleyman; Cangi, Hasan
Fotovoltaik (FV) sistemlerin çıkış gücü güneş ışınımı ve sıcaklık değerlerine bağlıdır. Bu makalede, FV sisteminin çıkış gücünün sıcaklık ve güneş ışınımına bağlı değişimi incelenmiştir. Ayrıca, bu çalışmada FV panellerinin yanında FV dizininin çalışma prensibi özetlemiştir. Şebekeden bağımsız FV sistem Matlab/simülasyon programı kullanılarak modellenmiş ve bu çalışmada detaylı çalışması gerçekleştirilmiştir. Ayrıca, farklı sıcaklık ve ışınım değerleri için FV sisteminin çıkış gücü analiz edilmiştir. FV panellerde kısmi gölgelenme durumları için sistemin simulink eşdeğeri oluşturuldu. Kısmi gölgeli durumlara ait IV ve P-V eğrileri bulundu. Sonuç olarak, FV sisteminin çıkış gücünün analitik ifadesi, Sosyal Bilimler İçin İstatistik Programı (SPSS) kullanılarak bulunmuştur.
Citation - WoS: 2
Citation - Scopus: 3
Control Strategy Evaluation for Reactive Power Management in Grid-Connected Photovoltaic Systems Under Varying Solar Conditions
(Nature Portfolio, 2025) Adak, Suleyman
Solar energy is environmentally friendly and one of the most significant renewable energy sources. This energy is a leading renewable energy source, contributing significantly to sustainable development goals. In grid-connected photovoltaic (PV) systems, reactive power management is essential for maintaining voltage stability and ensuring reliable operation. However, the influence of fluctuating solar irradiation (G) on reactive power (Q) behavior is often underrepresented in conventional inverter control strategies. This research addresses this gap by modeling the dependence of reactive power on solar irradiance using a data-driven curve-fitting approach. The methodology involves the acquisition of real-world operational data, preprocessing, selection of an appropriate analytical model, and validation of its performance. The findings indicate that reactive power increases under low irradiance conditions, primarily due to inverter behavior and grid voltage support requirements. The resulting analytical expression offers a practical framework for integrating irradiance-dependent reactive power control into inverter firmware or grid management software. The model performed with high accuracy with an R2 of 0.9955. This contribution enhances the ability of PV systems to respond dynamically to environmental changes, improving grid compatibility, operational efficiency, and voltage regulation in modern distributed energy networks.
Development of Ultra Fast Gate Driver Board for Silicon Carbide MOSFET Applications
(2025) Adak, Suleyman; Cangi, Hasan; Tepedelen, Halil; Eid, Bilal
Silicon Carbide (SiC) is increasingly utilized in high-temperature, high-power applications due to its exceptional properties, including high-temperature resistance, high electrical conductivity, and a wide bandgap. In this study, the development of an ultra-fast gate driver circuit for SiC MOSFETs, designed for AC/DC and DC/AC converter applications, is presented. SiC switching elements are widely preferred in modern power electronics for their capabilities, such as faster switching within a wide bandwidth (50–250 kHz), higher power density, and operation at elevated voltage levels (up to 1,200 V). The high bandgap energy of SiC enables efficient and reliable operation under demanding conditions. This study focuses on designing an optimized gate driver board that minimizes voltage spikes and noise, achieving a voltage overshoot below 10% and noise suppression of up to 15 dB during switching operations. The proposed design is particularly suited for applications in solar inverters and other high-frequency power electronics systems. Simulation and experimental results, including switching rise times under 20 ns and total harmonic distortion (THD) levels below 3%, validate the effectiveness of the proposed gate driver.
Citation - WoS: 2
Citation - Scopus: 4
Analysis of Solar Inverter THD According to PWM's Carrier Frequency
(IEEE, 2015) Cangi, Hasan; Adak, Suleyman
Solar PV systems are usually used in the generation of power systems. Electricity produced in Photovoltaic systems in the form of direct current. In order to convert direct current to alternating current used converters, which are harmonic source. In this thesis study, output distortion currents of solar inverter t are analyzed for various PWM's carrier frequency. Analytical expressions related to obtained numerical results, which was found by curve fitting method. Simulations are implemented in MATLAB and Simulink software. R-L inductive load is implemented in hardware to show the effectiveness of the proposed system.
Citation - WoS: 26
Citation - Scopus: 28
Developed Analytical Expression for Current Harmonic Distortion of the Pv System's Inverter in Relation To the Solar Irradiance and Temperature
(Springer, 2021) Cangi, Hasan; Eid, Bilal; Yilmaz, Ahmet Serdar; Adak, Suleyman
This paper deals with modeling and simulation of the total harmonic distortion of the current (THDI) dispatched from the inverter and connected to nonlinear load. The change of THD(I)was examined in relation to the ambient temperature (T) and solar irradiance (G). The developed model is being used to extract parameters for a given THD(I)as a function of temperature and solar radiation. This study outlines the working principle of photovoltaic (PV) panel as well as PV array. Off-grid PV system is modeled by using Matlab/Simulink program, and detailed analytical study has been carried out in this work. The design, modeling and simulation of this study are performed from 50 up to 988 W/m(2)for solar irradiance. Harmonic components have negative effects on the steady-voltage stability of the PV system. Therefore, analytical expression is needed for steady-state stability analysis in order to reduce negative effects. Hence, two analytical expressions of THD(I)were obtained by two new different methods which are statistical package for the social sciences program and genetic expression programming. Eventually, two different methods have been verified by the Matlab/Simulink program in order to find out THD(I)and demonstrated the effectiveness of the proposed strategy. As a result of this study, it is observed that input current THDI of nonlinear load is too high at low irradiance. It is suggested that active harmonic filters should be used at low irradiance in order to produce better quality energy and avoid damages in the PV system.
Citation - WoS: 19
Citation - Scopus: 20
The Quality Problems at Low Irradiance in the Grid-Connected Photovoltaic Systems
(Springer, 2024) Adak, Suleyman; Cangi, Hasan
Solar photovoltaic (PV) energy is one of the most prominent topics that have attracted the attention of researchers in recent years. The use of solar energy is increasing rapidly in the world. Although using PV energy has various advantages, it has some disadvantages. Among these disadvantages, power factor (PF) and total harmonic distortion (THD) issues are discussed in this article. When solar PV systems are integrated into the grid, various power quality problems arise. In addition, due to low power quality and high harmonics, power system components overheat and start operating in undesirable regions; causes great damage. The magnitude of PF and THD is dependent on solar irradiation values. In order to determine how the power quality in the grid-connected solar system is affected by changes in solar irradiation (G), results for various irradiation situations are presented and analyzed. In addition, at low irradiance values, the amplitude of harmonic components and reactive power increases, whereas the power factor of the PV system decreases. Low power factor and high amplitude of harmonics cause the efficiency of the solar system to decrease. In this study, PF and THDI values were measured on a particular cloudy day for analysis. An analysis of the solar PV system was conducted using Matlab/simulation program to model the grid-connected PV system. Thus, the analytical expression of the PF and THDI, which are dependent on irradiation, was found with a new method by using the Statistical Package for the Social Sciences (SPSS) program and the curve fitting method. Obtaining the analytical expressions for both solar irradiation (G) and power factor (PF) used the SPSS program and also solar irradiation (G) and total harmonic distortion (THDI) used the MATLAB curve fitting method which contributed to the science comparing to the existing literature. It can be prevented the low power quality by using such these expressions at low solar irradiation cases.
Citation - WoS: 6
Citation - Scopus: 11
Power Factor Analysis of Grid-Connected Solar Inverter Under Different Irradiance Levels Throughout the Day
(MDPI, 2024) Adak, Suleyman
The power factor (PF) plays a crucial role in determining the quality of energy produced by grid-connected photovoltaic (PV) systems. When irradiation levels are high, typically during peak sunlight hours, the PV panels generate more electricity. In this scenario, the PF tends to be higher because the real power output closely matches the apparent power drawn from the grid. Whereas, when irradiation levels are low, such as during cloudy weather or nighttime, the PV panels produce less electricity. In these conditions, the power factor may decrease because the real power output diminishes compared to the apparent power drawn from the grid. This could be due to reduced efficiency or increased reactive power flow. PF decreases linearly at solar irradiance values lower than 220 (W/m2). At the same time, it approaches unity at higher solar irradiance values than 220 (W/m2). In this study, the variation of the power coefficient of the grid-connected PV solar system depending on solar irradiation was modeled and analyzed using MATLAB/Simulink 41016490. The analytical expression of the power factor depending on the change in solar irradiation was found using the curve fitting method.