Elektrik ve Enerji Bölümü Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12514/174
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Article Citation - WoS: 26Citation - Scopus: 28Developed 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, SuleymanThis 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.Article Citation - WoS: 10Citation - Scopus: 12Development software program for finding photovoltaic cell open-circuit voltage and fill factor based on the photovoltaic cell one-diode equivalent circuit model(Springer, 2024) Adak, Süleyman; Cangi, HasanThe photovoltaic (PV) cell is the smallest building block of the PV solar system and produces voltages between 0.5 and 0.7 V. It acts as a current source in the equivalent circuit. The amount of radiation hitting the cell determines how much current it produces. The equivalent circuit of an ideal PV cell consists of a diode and a parallel current source. In order to express losses in applications, series and parallel resistance are added to the ideal equivalent circuit of the PV cell. There are many equivalent circuits in the literature for modeling the equivalent circuit of a PV cell. The single-diode equivalent circuit is the most widely used model because of its simplicity and ease of analysis. There are several methods available to estimate and analyze the parameters of PV cell models, such as Newton Raphson method, Lambert-W function, etc. In this study, the Newton Raphson method was used to find the equivalent circuit parameters of a PV cell. Fill factor is used to determine the quality of electricity generated by the photovoltaic cell. Open-circuit voltage is the maximum voltage value that the PV cell can transmit. The analysis of PV cell fill factor and open-circuit voltage was carried out using the developed software program. Then, the open-circuit voltage and fill factor were found using the software program prepared in MATLAB and given in Appendix.Article Citation - WoS: 4Güç sistemlerinde ünite tahsisi için döner rezerv gereksinimi optimal değerinin kayıp parametrelerin dikkate alınarak hesaplanması(Gazi Üniversitesi, 2019) Tür, Mehmet Rıda; Ay, Selim; Shobole, Abdulfetah; Wadi, MohammedDöner Rezerv, üretim kesintileri ve ani yük değişimleri gibi öngörülemeyen olaylara yanıt olarak sistem operatörleri tarafından kullanılan en önemli kaynaklardan biridir. Kullanılacak rezervlerin miktarını yüksek tutarak doğabilecek beklenmedik durumların sebep olduğu üretim kesintilerine karşı güç sistemini korumak mümkün olur, bu işlem karşısında yük atma işleminin uygulanma olasılığı azalır, fakat bu durumda rezerv sağlama oldukça yüksek bir maliyet ile sonuçlanır. Maliyeti düşürmek amacıyla rezerv miktarını düşük tutma durumunda ise olası kesinti ve arıza durumlarında sağlanamayan bir enerji söz konusu olur ve tüketiciler enerjisiz kalabilir. Bu iki durumu dengeleyici şekilde bir ekonomik incelemeye gerek duyulmaktadır. Geleneksel Ünite Tahsis formülasyonlarında, Döner Rezerv gereksinimini ayarlamak için en büyük çevrimiçi jeneratörün kapasitesi olarak belirleme yapan deterministik kriterler ile sabit bir rezerv miktarı benimsenir. Bu çalışmada, güç sisteminde tahsis edilmesi gerek Döner Rezerv gereksinimi, sağlanamayan enerji miktarı ve kayıp yük değeri gibi sosyo ekonomik parametreler dikkate alınarak elde edilir. Bu değer için fayda maliyet temeline dayalı bir yöntem ile hesaplama yapılmaktadır.Article Harmonics Mitigation of Stand‑Alone Photovoltaic System Using LC Passive Filter(Journal of Electrical Engineering & Technology, 2021) Adak, SüleymanThis article investigates modeling and simulation of the of-grid photovoltaic (PV) system, and elimination of harmonic components using an LC passive flter. Pulse width modulation (PWM) inverter is used to convert the direct current to alternating current. It is very important in terms of energy quality that the inverter output current total harmonic distortion (THDI) is below the value given by standards. Harmonic components have negatively efect on of-grid PV power system. THDI should be kept below a certain level in order to prevent damage to the equipment in the of-grid system and to ensure a higher quality energy fow to reduce the total harmonic distortion (THD) of the solar inverter output current; LC passive flter must be connected to the output of the PWM inverter. There are many types of passive flters for solar inverters. One of the most widely used flter types is the LC flter. LC flters are used in of-grid systems. LC flter is smaller in size and lower cost than other flters. But it is more complicated to determine the parameters of the LC flter. Therefore, in order for the system to remain in a steady state, the parameters must be accurately calculated and analyzed. In this study, the output power of the solar inverter, switching frequency, bus voltage etc. values were determined and LC flter parameters were calculated. Since high inductance values are used in LC flters, the voltage drop increases in these flters. To reduce the voltage drop, the DC bus voltage must be increased, which increases the switching losses. LC flter is connected between the inverter and the nonlinear load to flter the harmonic components produced by the DC/DC boost converter, DC/AC inverter and non-linear load. Matlab/Simulink program was used in Simulation and analysis of of-grid solar system. Solar inverter output current THD was measured as 91.55%. After the LC flter is connected to the system, this value has dropped to 2.62%.Article Citation - WoS: 17Citation - Scopus: 19The Quality Problems at Low Irradiance in the Grid-Connected Photovoltaic Systems(Springer, 2024) Adak, Suleyman; Cangi, HasanSolar 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.
