Browsing by Author "Genc, Naci"

Now showing 1 - 19 of 19

Analysis of Passive Filters for Pv Inverters Under Variable Irradiances
(Ieee, 2019) Karaca, Muhammet; Mamizadeh, Ali; Genc, Naci; Sular, Adem
In this study, passive filters used for photovoltaic (PV) inverters producing different values of power under variable irradiation were analyzed. The use of passive filters is essential to obtain a sinusoidal output voltage with a low harmonic content at the output of PV inverters. For this reason, L-type, L-C and L-C-L type passive filters were designed for PV inverters operating with Maximum Power Point Tracking (MPPT) and Total Harmonic Distortion (THD) analyzes were performed under the same conditions. In addition, the behavior of these filters in PV inverters operating at different irradiations and therefore at different power ratings was observed and compared. In the study, Perturb and Observation (P&O) MPPT technique is used for PV inverter and classical PI controller is used for output voltage control. After the related design studies, the whole circuit with a rated power of 1kW was simulated in the Matlab/Simulink program and the results were compared.
Design and Application of Pem Fuel Cell-Based Cascade Boost Converter
(Springer, 2019) Kocaarslan, Ilhan; Kart, Sude; Genc, Naci; Uzmus, Hasan
This paper presents average sliding current controller (ASCC) for the proton membrane exchange fuel cell (PEMFC)-based DC-DC cascade boost converter under different source and load conditions. PEMFC which has variable voltage and current can be used in a lot of applications with a wide operating range in low temperatures. However, as the PEMFC produces low nonlinear voltage, this lower nonlinear voltage value needs to be increased as a linear voltage with an appropriate power electronics converter. Therefore, this paper proposes DC-DC cascade boost converter which has a higher voltage gain for PEMFC stack. First, a classical PI controller was applied to regulate the output voltage. Then, the current of the PEMFC-based DC-DC cascade boost converter was controlled via ASCC by using output of the voltage controller. After analyzing the dynamic model of the PEMFC-based DC-DC cascade boost converter via MATLAB/Simulink program, the experimental results of the controlled PEMFC-based DC-DC cascade boost converter are observed and discussed.
Design and Simulation of Active Direct Current Filter for High Voltage Direct Current Transmission Systems
(Gazi Univ, Fac Engineering Architecture, 2016) Akdemir, Murat; Yildirim, Selcuk; Genc, Naci
In this paper, firstly, a monopolar High Voltage Direct Current (HVDC) transmission system model has been formed. Series, parallel and series-parallel active direct current filter designs were carried out to suppress harmonics caused by the converters in this HVDC transmission system. Simulations of the designed HVDC transmission system using these filter were carried out in MATLAB Simulink. Waveforms and total harmonic distortion (THD) values of load current and voltage were obtained in this transmission system model for filtered and unfiltered conditions. Harmonics in the load voltage and current were suppressed to a large extent by active direct current filter used in the HVDC transmission system. Furthermore, THD values for current and voltage were obtained significantly below 5%. According to these results, designed active direct current filters which have simple structure and not complex controller offer significant advantages.
Dsp Based Hybrid Control Method for Pv Systems
(Gazi Univ, Fac Engineering Architecture, 2023) Uzmus, Hasan; Genc, Naci; Celik, Mehmet Ali
Purpose: In this study, it is aimed to control the output voltage and current of the DC/DC boost converter faster with PI and ASM controllers, respectively, while PV panels are forced to harvest maximum power with the P&O MPPT control method. Theory and Methods: In this study, perturb and observation maximum power point tracking (P&O MPPT) control method was used to harvest maximum power from solar energy with PV panel. Conventional PI and average sliding mode (ASM) controllers were utilized for voltage and current control, respectively. The proposed hybrid control method was obtained by cascading P&O MPPT, PI, ASM controllers. MPPT and conventional PI controllers were cascaded in order to obtain an output voltage that does not change according to irradiation and load. A reference voltage was generated with MPPT for PI controller to control the output voltage. The reference current for ASMC was generated by cascaded MPPT-PI controllers. ASM controller was utilized for increasing the speed of the controller and controlling current. The process was depicted in Figure A. Results: The simulation and experimental results were compatible. There was no oscillation and chattering at output of the system. The proposed hybrid control method is quite fast. Conclusion: The simulation and experimental results clearly indicate that the proposed hybrid control method is quite satisfactory. This hybrid control method can be used for on-grid, off-grid and hybrid PV systems.
Dynamic Behaviour Analysis of Anfis Based Mppt Controller for Standalone Photovoltaic Systems
(int Journal Renewable Energy Research, 2020) Haji, Dilovan; Genc, Naci
This paper proposes dynamic behavior analysis of Adaptive Neuro Fuzzy Inference System (ANFIS) based Maximum Power Point Tracking (MPPT) controller for a standalone photovoltaic (PV) system under various weather conditions such as different level of irradiance and temperature. Also, the dynamic behavior analysis of the system has been done by using different MPPT techniques which are ANFIS, Perturb and Observation (P&O) and Fuzzy Logic Controller (FLC). Based upon the results, the ANFIS based MPPT controller can track the maximum power point faster than other suggested controllers under various weather circumstances. It also observed that the intelligent based MPPT algorithms have lower rippling in power compared with conventional P&O algorithm. In addition, the dynamic behavior analysis of proposed MPPT controller shows that the system could stay operating at MPP during changes occurring to the load by changing PV voltage and current to extract the desired maximum power.
Exergetic Performance Analysis of a Solar Power System (Sps) in a High Plateau
(inderscience Enterprises Ltd, 2017) Genc, Naci; Mert, Suha Orcum; Reis, Alper
In this study, a comprehensive exergy analysis was applied to a solar power system (SPS) located in the city of Van, Turkey. Van was always known as a sun city throughout history with the name of TUSBA. It has an average of 300 sunny days a year, an altitude of 1727 m, and an average daily temperature of 9.85 degrees C. Considering how the need for sustainable and renewable energy sources -and knowledge over them - constantly increases, this SPS was built to reveal the true solar potential of the campus area of Yuzuncu Yil University of the city of Van, hopefully as a precursor for further large-scale SPS constructions in the region. A daily analysis considering energy production and global radiation was applied to the system in 2013 for 365 days. It was found that the yearly exergy efficiency of the system was 10% and total electrical energy production was 31,038.95 kWh, averaging 1763.5 kWh/kWp yearly.
Experimental Verification of an Improved Soft-Switching Cascade Boost Converter
(Elsevier Science Sa, 2017) Genc, Naci; Koc, Yavuz
A soft switching cascade DC-DC boost converter is proposed in this paper. The proposed cascade single switch converter has a higher step-up voltage gain and a wider turn-of period compared to classical boost converters, which tend to have a problem of narrow turn-of periods at higher output voltages. To reduce the switching losses, an auxiliary circuit was also added to the converter. It has a simple structure with only one main switch, one auxiliary switch and the minimum number of diodes. The proposed soft switching method enables the main switch to turn on at zero-voltage-transition (ZVT) and turn off at zero-voltage-switching (ZVS). Furthermore, the auxiliary switch and diodes are soft-switched thanks to this method. All semiconductor components operate under soft-switching, safe from any additional voltage and current stresses. The study presents the design considerations for the proposed converter, along with principle operations of the topology in a single switching period. Finally, experimental results, which were obtained on a laboratory prototype rated at300 W, are also presented in the paper. The results show that the proposed cascade boost converter can be operated successfully in soft-switching operation for a variety of input voltages and a relatively wider load range, even at higher voltage outputs. (C) 2017 Elsevier B.V. All rights reserved.
Experimental Verification of Interleaved Hybrid Dc/Dc Boost Converter
(Springer Heidelberg, 2022) Celik, M. Ali; Genc, Naci; Uzmus, Hasan
In this study, an improved interleaved hybrid DC/DC boost converter used for high-power applications with high voltage gain was proposed. The proposed DC/DC boost converter increases low-input voltage to the desired high-output voltage with a wide duty cycle range through the hybrid structure, thereby prolonging the lifetime of the proposed converter by decreasing the current on circuit components. An extra filter for input current ripples is unnecessary. The proposed converter is less complex and has easier control than the converters used for high voltage gain. The proposed converter was operated when the duty cycle (d) was larger and smaller than 0.5. It was also analyzed theoretically, and the average- and small-signal circuits were obtained to show its stability. The proposed converter was controlled with the conventional control method by using a modern digital signal processor TMS320F28379D board. The proposed converter and its controller were operated under different conditions.
Fuzzy and P&o Based Mppt Controllers Under Different Conditions
(Ieee, 2018) Haji, Dilovan; Genc, Naci
This paper proposes different maximum power point tracking (MPPT) techniques under different conditions for standalone photovoltaic (PV) systems by using MATLAB/Simulink framework. The MPPT techniques include Fuzzy Logic Controller (FLC) which is compared with Perturb and Observation (P&O). Based upon the simulation results, the FLC based MPPT controller can track the maximum power point (MPP) faster than other suggested controller under various weather circumstances such as different level of irradiance and temperature. It also observed the intelligent based MPPT algorithms have lower rippling in power compared with conventional P&O algorithm.
Hybrid Resonant Inverter-Based Induction Heating Converter With Cfpdm
(Taylor & Francis Ltd, 2011) Genc, Naci
This article proposes a 50 kHz hybrid (series-parallel) resonant inverter-based induction heating (IH) converter which is controlled with commercial frequency pulse density modulation (CFPDM). Since the hybrid resonant inverter enhances the series resonant inverter performance due to short-circuit handling capability and current gain, it has been successfully employed in IH. High power conversion efficiency and wide output power range can be obtained using CFPDM. In addition, some harmonic current problems occurred in conventional pulse density modulation because of the resonant frequency of non-smoothing filter are eliminated via CFPDM. There is no need for the application of any additional switches or passive components in CFPDM. In this article, CFPDM hybrid resonant inverter-based IH converter is modelled and the analysis of the converter is presented in detail. The operation principle of CFPDM controller is shown. In addition, the advantages of hybrid resonant inverter and CFPDM are stated. The theoretical analysis is verified via simulation and experimental studies, which are in very good agreement.
Impacts of Wind Speed and Humidity on the Performance of Photovoltaic Module
(Ieee, 2019) Ayadi, Faten; Colak, Ilhami; Genc, Naci; Bulbul, Halil Ibrahim
Photovoltaic modules present the most considered renewable energy source for non-solated and rural areas, thanks to its several benefits. Thus, in order to ensure sufficient production of energy by solar cells, they should be in operation. However, they face some factors, during their production periods, which affect their efficiency. This study has focused on the impacts of Wind speed and Humidity on electric parameters of Photovoltaic Modules like serial and shunt resistances, Current, Voltage and Power as well as their performance. It has been explained that the efficiency of solar cells can be varied not only by the temperature and the irradiance, but also by the Humidity and the Wind speed. Their influences have been demonstrated theoretically. The aim of this study is to take into consideration the effects of these two factors mutually when the Photovoltaic modules are in operation.
Lyapunov Based Pi Controller for Pem Fuel Cell Based Boost Converter
(int Journal Renewable Energy Research, 2020) Kocaarslan, Ilhan; Kart, Sude; Altun, Yener; Genc, Naci
Proton Exchange Membrane Fuel Cell (PEMFC) which is an efficient renewable energy system has usage area in home and industrial applications. Since the generated voltage from PEMFC is low, the output voltage of it can be increased by using a boost converter. The boost converter fed by PEMFC can normally be controlled by the classical PI controller which parameters (K-P, K-i) are constant and do not depend on the circuit parameters. Therefore, these coefficients are non-adaptive at variable load situations. In this study, an improved controller is obtained by regulating the PI controller according to Lyapunov stability theorem. Then, this improved Lyapunov based PI controller is proposed for PEMFC based boost converter. In the proposed method, K-P and K-i parameters vary adaptively depending on the circuit parameters. Thus, the system works more stable and settling time of system's output voltage signal decreased compared to classical PI controller. The proposed method has been successfully tested in Matlab/Simulink environment.
The Modified Mppt for Pv System With Interleaved Hybrid Dc-To Boost Converter
(Taylor & Francis inc, 2023) Uzmus, Hasan; Genc, Naci; Celik, M. Ali
A modified maximum power point tracking control technic for an off-grid photovoltaic system which include the interleaved hybrid DC-to-DC boost converter was presented in this paper. The input voltage was predicted by measured one branch current of the proposed hybrid DC-to-DC boost converter. The proposed control technic consists of maximum power point tracking with the predicted input voltage and PI controller. Thanks to the proposed control technic, the photovoltaic panel was forced to operate at maximum power point and the output voltage of the proposed converter ensured the desired value despite the varying input power. In addition, the interleaved hybrid DC-to-DC boost converter was increased the low output DC voltage of photovoltaic panel to the desired high voltage value and the stresses on the circuit elements was decreased by reducing the input current ripples. As a conclusion, the total cost of the proposed system is reduced by eliminating the sensing of the input voltage and the service lifespan of the proposed system is extended by using the interleave hybrid DC-to-DC boost converter. The simulation and experimental results of the proposed system were obtained by using MATLAB/Simulink and 400 W DSP TMS320F28379D based porotype, respectively.
Multi-Period Prediction of Solar Radiation Using Arma and Arima Models
(Elsevier Science Bv, 2015) Colak, Ilhami; Yesilbudak, Mehmet; Genc, Naci; Bayindir, Ramazan
Due to the variations in weather conditions, solar power integration to the electricity grid at a high penetration rate can cause a threat for the grid stability. Therefore, it is required to predict the solar radiation parameter in order to ensure the quality and the security of the grid. In this study, initially, a 1-h time series model belong to the solar radiation parameter is created for multi-period predictions. Afterwards, autoregressive moving average (ARMA) and autoregressive integrated moving average (ARIMA) models are compared in terms of the goodness-of-fit value produced by the log-likelihood function. As a result of determining the best statistical models in multi-period predictions, one-period, two-period and three-period ahead predictions are carried out for the solar radiation parameter in a comprehensive way. Many feasible comparisons have been made for the solar radiation prediction.
A Novel Application of Naive Bayes Classifier in Photovoltaic Energy Prediction
(Ieee, 2017) Bayindir, Ramazan; Yesilbudak, Mehmet; Colak, Medine; Genc, Naci
Solar energy is one of the most affordable and clean renewable energy source in the world. Hence, the solar energy prediction is an inevitable requirement in order to get the maximum solar energy during the day time and to increase the efficiency of solar energy systems. For this purpose, this paper predicts the daily total energy generation of an installed photovoltaic system using the Naive Bayes classifier. In the prediction process, one-year historical dataset including daily average temperature, daily total sunshine duration, daily total global solar radiation and daily total photovoltaic energy generation parameters are used as the categorical-valued attributes. By means of the Naive Bayes application, the sensitivity and the accuracy measures are improved for the photovoltaic energy prediction and the effects of other solar attributes on the photovoltaic energy generation are evaluated.
Performance Analysis of Interleaved Single-Phase Rectifier Using Different Current Control Methods
(Gazi Univ, Fac Engineering Architecture, 2014) Karik, Fatih; Iskender, Ires; Karaarslan, Ahmet; Genc, Naci
In this study, a comprehensive performance analysis of power factor correction control methods are presented for an interleaved single-phase rectifier operating under continuous conduction mode. The control of interleaved converter is achieved using proportional-integral control, average sliding control and predictive current control methods to obtain unity power factor and lower total harmonic distortion of input current. The interleaved power factor correction converters have many advantages in increasing power density, reducing input current ripple and RMS current of the boost capacitor, reducing filter volume, and cutting down the cost of materials. The analysis of the interleaved converter is presented and verified exactly by simulations and experimental carried out on 1 kW power and 50 kHz switching frequency. The performance of the current control methods for the interleaved converter is investigated by Matlab/Simulink program for different cases of operation such as change in input voltage and load. It is observed from the analysis that predictive current control method is more suitable than the others because it doesn't need sense current.
Planar Flyback Transformer Design for Pv Powered Led Illumination
(int Journal Renewable Energy Research, 2021) Mamizadeh, Ali; Mustafa, Bestoon Ahmed; Genc, Naci
Solar standalone LED lighting is becoming increasingly popular due to their economical, sustainability, simplicity and the low number of components. Designing of low volume and low weight driver decreases the price of LED drivers. Since the flyback converter has a low number of components, it is one of the most popular topologies for LED applications. The most important part of a flyback transformer or an inductor is the core. For the magnetic components, operation at high frequencies increases conductor losses due to skin and proximity effects. The use of planar transformers on printed circuit boards (PCB) can be an alleviate to this problem. With larger surface areas, planar transformers also provide better thermal performance than traditional wire-wound magnetic cores. Planar windings have different configurations. Optimal designing of core and winding reduce the losses of the transformer and inductors effectively. Therefore, this paper presents the design of a flyback planar transformer (PT) for photovoltaic (PV) powered LED illumination. The essential equations for designing of flyback PT are introduced and evaluated. The designed flyback PT was used in 50 W LED illumination driver powered by PV panel with a battery. In the proposed driver which was simulated by using MATLAB/Simulink program, the battery is charged via PV powered boost topology with Perturb Observation (P&O) MPPT method and an insulated H-bridge DC/DC converter.
Power Electronic Converters in Dc Microgrid
(Springer international Publishing Ag, 2020) Iskender, Ires; Genc, Naci
There are not many sustainable sources of energy other than renewable energy sources (RES), which are called solar, wind, water and various forms of biomass. Themost effectiveway to increase the use of renewable energy sources is to make use of renewable energy systems in villages, townships or small island-shaped districts where there are significant amounts of energy consumers. For this reason, the microgrid (MG) idea of small power system which is controllable, autonomous and balanced has been developed. Microgrids (MGs) playing a role of carrier for distributed generation resources (DGR), includes different distributed generation (DG) units, storage devices, energy converters, protection devices and load control devices. A MG generally includes renewable small power sources consisting of interconnected distributed energy sources with capacity of providing sufficient and sustained energy for a significant portion of the load. Different architecture types of MGs are presented in the literature. In recent years, the use of MGs being able to operate in two different modes depending on the island and grid-connected, has been expanded for DGR integration. Direct current (DC) microgrid has become an important subject of study in recent years as they have a more reliable and lower losses. A DC MG task distributes the DC power required by loads on a campus. Power generation in DC MG systems can be AC or DC; however, in most cases AC power supplies is converted to DC for distribution. The major advantage of DC microgridswhen compared toACsystems is its property of unidirectional power flow. This allows power control to be easily controlled by the power flow direction. In DC MG, the loads must be controllable to keep all loads at the DC range of the voltage in the default range and to regulate the voltage regulation. Besides voltage level and voltage regulation, the voltage ripple ratio should be kept as low as possible in DC microgrids. Therefore, power electronic converters are themost important part of the DC MG systems. There are although many studies published on MGs that control strategy and power electronic circuits make their important portions. It is obvious that the development of power electronic circuits and control methods has further enhanced the applicability of microgrids. In this study, the types, circuit structures and functions of power electronic converters used in DC microgrid are discussed. Power electronics converters used in DC MGs are grouped and evaluated according to their targets. These power electronic converters have been detailed in terms of AC-DC rectifiers, inverters (for AC loads) and DC-DC converter circuit types. The simulation results of some topologies have been evaluated.
Pv Power Based Duty Cycle Control of Quasi-Resonant Inverter for Induction Cooking
(Ieee, 2019) Sular, Adem; Mamizadeh, Ali; Genc, Naci; Karaca, Muhammet
In this study, photovoltaic (PV) power-based duty-cycle control is recommended for induction cooking (IC) topologies. The output power of the PV panels changes due to the change in solar irradiation. Based on this PV output power, variable duty-cycle control is recommended for single-switch quasi resonant inverter which is often used for IC applications. In the study, the output power is controlled by using the PV power value produced by MPPT to control the duty-cycle rate of the switch of the resonant inverter according to the variable input power, depending on the variable solar intensity and keeping the temperature and frequency constant. Thus, a quasi-resonant inverter is proposed which adjusts its own power increase or decrease according to the power change in the PV panel. This results in the batteries to be used in the system are allowed to have a longer life and constitute a significant financial gain. PV-powered single-switch quasi resonant inverter circuit with a rated power of 2kW was modeled in Matlab/Simulink environment and the results were presented.