Yazarlar
- Cuce, Erdem(25)
- Cuce, Pinar Mert(20)
- Tozlu, Alperen(17)
- Karaali, Rabi(11)
- Guclu, Tamer(10)
- Kahveci, Hakan(7)
- Özahi, Emrah(6)
- Keven, Arzu(5)
- Çorapsız, Muhammed Reşit(5)
- Bayram, Ozkan(4)
- Ceviz, Mehmet Akif(4)
- Igman, Erdal(4)
- Imamoglu, Ilyas Kays(4)
- Isik, Cem(4)
- Karaali, R.(4)
- Kosunalp, Selahattin(4)
- Köksal, Hüseyin(4)
- Ongan, Serdar(4)
- Ozel, Faruk(4)
- Ozel, Sultan Suleyman(4)
- Tozlu, A.(4)
- Abusoglu, Aysegul(3)
- Abuşoğlu, Ayşegül(3)
- Güngör, Okan(3)
- Korkmaz, Şadan(3)
- Kus, Mahmut(3)
- Kuziboev, Bekhzod(3)
- Pat, Suat(3)
- Sari, Fahriye(3)
- Simsek, Onder(3)
- Uyar, Mehmet(3)
- Çakir, Uǧur(3)
- Çomakli, Kemal(3)
- Özen, Soner(3)
- Şenay, Volkan(3)
- Abuşoǧlu, A.(2)
- Afshari, Faraz(2)
- Aloui, F(2)
- Arslantürk, Cihat(2)
- Atabani, A.E.(2)
Yayınlar
- MakaleAçık Erişim2022Scopus SJRQ1Techno-economic assessment of a synthetic fuel production facility by hydrogenation of CO2 captured from biogas
Tozlu, Alperen
In this study, a thermodynamic and economic analysis of a synthetic fuel production facility by utilizing the hydrogenation of CO2 captured from biogas is carried out. It is aimed to produce methanol, a synthetic fuel by hydrogenation of carbon dioxide. A PEM electrolyzer driven by grid-tie solar PV modules is used to supply the hydrogen need of methanol. The CO2 is captured from biogas produced in an actual wastewater treatment plant by a water washing unit which is a method of biogas purification. The required power which is generated by PV panels, in order to produce methanol, is found to be 2923 kW. Herein, the electricity consumption of 2875 kW, which is the main part of the total electricity generation, belongs to the PEM system. As a result of the study, the daily methanol production is found to be as 1674 kg. The electricity, hydrogen and methanol production costs are found to be $ 0.043 kWh−1, $ 3.156 kg−1, and $ 0.693 kg−1, respectively. Solar availability, methanol yield from the reactor, and PEM overpotentials are significant factors effecting the product cost. The results of the study presents feasible methanol production costs with reasonable investment requirements. Moreover, the efficiency of the cogeneration plant could be increased via enriching the biogas while emissions are reduced.
AtıfScopus34WoS32OpenAlex37
İncele - MakaleAçık Erişim2022Scopus SJRQ1Double adaptive power allocation strategy in electric vehicles with battery/supercapacitor hybrid energy storage system
Çorapsız, Muhammed Reşit; 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.
AtıfScopus14WoS12OpenAlex14İncele - MakaleAçık Erişim2022Scopus SJRQ3Performance Analysis of Buck-Boost and SEPIC Converter for Commutation Torque Ripple Minimization in BLDC Motors
Çorapsız, Muhammed Reşit; 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.
AtıfScopus5WoS2OpenAlex3İncele - MakaleAçık Erişim2022Scopus SJRQ3Exergy analyses of two and three stage cryogenic cycles
Atasbak, Musa; Keven, Arzu; Karaali, Rabi
Cryogenics has an important influence on industry and science. In this study, optimum working conditions are obtained by applying exergy analysis and local optimization methods to two- and three-stage vapor compression cascade cryogenic cycle. The first and second laws of thermodynamics, exergy analysis, and local optimization methods are applied to the two- and three-stage cascade cryogenic cycle. By considering the needs and demands, it is possible to create new cycles by adding new devices and/or new stages to these cycles. The results of the optimum operating conditions are obtained for the two- and three-stage vapor compression cascade cryogenic cycle. It is seen that to achieve high COP values and high efficiency; it is necessary to reduce the compression ratio of the compressor as much as the fluid allows. For the two-stage cycle, the minimum total work required for cryogenic cooling is around P 7 = 2,400 kPa. The COP value is 0.30 between P 7 = 2,400 and 2,800 kPa, and the maximum exergy efficiency is obtained around 0.235. It is seen operating the first-stage compressor at high pressures increases the total losses of the entire cycle from 7,500 to 18,550 kW. The increase in total exergy losses is around 247%, and operating the first-stage compressor at high pressures increases the exergy efficiency of the entire cycle. The increase in total exergy efficiency is around 160%. When the second-stage compressor is operated at low pressure, the COP value increases by 2%, the exergy efficiency increases by 20%, and the exergy losses decrease by around 40%.
AtıfScopus6WoS3OpenAlex9İncele - MakaleAçık Erişim2022Scopus SJRQ2Assessment of waste-to-energy potential of ELT management: An actual case study for Erzincan
Güngör, Osman; Tozlu, Alperen; Arslantürk, Cihat
End-of-life tires (ELTs) and their decomposition are becoming a major environmental issue in the local region as a result of economic and technological challenges. Despite this, ELT management is gaining popularity as an advanced function for treating tires to obtain char, oil, and gas products using pyrolysis. The main goal of this article is to integrate data from an actual recycling plant with the activities of pyrolysis products and their physical properties in the literature. This article presents energy potentials and basic applications of pyrolysis products as well as advances in the current situation in ELT management in the world. Accordingly, an existing ELT management in Erzincan, Turkey is explained in detail by considering the available energy recovery and material treatment activities. In this plant, which has an installed power capacity of 12 MW, approximately 25 tons of pyrolytic oil, 10.7 tons of pyrolytic gas, 24 tons of carbon black and, 10.4 tons of steel are produced daily. The calorific values of carbon black and pyrolytic oil for the products leaving the pyrolysis plant are close to the values in the literature, which is promising. In the plant, the overall thermal efficiency of the system and the engine is found to be 26.34% and 51.24%, respectively. On the other hand, to supply additional power to the plant utilizing exhaust gas discharged to the atmosphere, some thermodynamic models can be developed; additionally, more rational values can be obtained through thermoeconomic and optimization.
AtıfScopus1WoS2OpenAlex3İncele - MakaleAçık Erişim2022Scopus SJRQ1Thermoeconomic analysis of a low-temperature waste-energy assisted power and hydrogen plant at off-NG grid region
Tozlu, Alperen; Kayabasi, Erhan; Ozcan, Hasan
In this study, thermoeconomic analysis of a CO2 power cycle and PEM hydrogen system using ultra-low temperature waste heat from a milk production facility is conducted. In the transcritical CO2 cycle, low-temperature LNG evaporation is used for cooling the condenser to increase the temperature difference enabling low temperature waste heat use. In addition, a PEM electrolyzer produces hydrogen to reduce the LNG requirement at the plant. A CO2-water exchanger has been designed to recover the pasteurized water's excess heat and evaporate the CO2 using Simcenter-Flomaster software. The inlet mass flow rates and outlet temperatures of the heat exchanger were optimized by performing thermoecomic analysis, and the thermal and economic performance of the facility was examined. The power cycle has 14% higher efficiency when LNG is used as the heat sink compared to ambient temperature condensation with an electricity production cost range at 0.05–0.11 $/kWh, and the hydrogen generation cost is between $2.6–5.20 kg−1. It is found that the plant could only be economically feasible when less than 50% of the power produced is used for hydrogen generation. Consequently, the proposed system can co-generate power and on-demand hydrogen in off-NG grid regions with reasonable investment and product costs.
AtıfScopus6WoS6OpenAlex8İncele - MakaleYalnız künye2022Scopus SJRQ1High-speed treatment of low strength domestic wastewater for irrigation water production in pilot-scale classical, moving bed and fixed bed hybrid MBRs
Tuluk, Banu; Yildiz, Ergun; Nuhoglu, Alper; Tataroglu, Numan Suadi; Gulluce, Ekrem; Cengiz, Ibrahim; Degermenci, Nejdet; Angin, Ilker
To evaluate the treatability of domestic wastewater under conditions of low hydraulic retention time and high organic loadings, 3 pilot-scale automatically controlled membrane bioreactors (MBRs) as classical (C-MBR), moving bed (MB-MBR), and fixed bed (FB-MBR) were established and operated for a total of 268 days. Established pilot plants were compared in terms of treatment performance, membrane fouling, irrigation water criteria, and power consumption values. Results obtained have shown that all three systems were able to achieve more than 93% removal of chemical oxygen demand (COD) in an average hydraulic retention time (HRT) of 1 hour, and MB-MBR and FB-MBR were superior in terms of total nitrogen (TN) and total phosphorus (TP) removals. It has been determined that MB-MBR and FB-MBR are also advantageous in terms of power consumption. Especially it has been found that FB-MBR can produce better quality irrigation water with 40% lower power consumption than C-MBR under the same conditions. It was concluded that biofilm-supported hybrid systems could be a practical application in the fight against increasing water scarcity and global warming, both in obtaining clean water with less power consumption and in protecting human and environmental health.
AtıfScopus16WoS11OpenAlex17İncele - Derleme MakaleAçık Erişim2021Investigation of Shale Gas Reserves in The World and A Case Study for Electricity Production from Shale Gas in Turkey
Oztekin, Erman Kadir; Tozlu, Alperen
Shale gas reserves, which is globally accepted as unconventional gas resource, scattered around the world and can be used in order to meet the growing energy needs due to limited amounts of conventional resources. Since notable effort has to be put in order to investigate and drill shale gas resources the early decision has to be made carefully, especially considering the economic benefits. Several factors must be considered including the known technically recoverable shale gas amount at the selected region, current technology to drill the shale source and the amount of investment before the extraction of shale gas. In this study, global underground shale gas amount and recent discoveries as well as the potential shale gas areas in Turkey are presented. Benefits of using shale gas for electricity generation and common methods being used during shale gas extraction are studied along with gas and liquid flow mechanisms. At the end, general overview of separation and utilization of shale gas components is schematically presented. In the case study, the potential of electricity generation in the SE Anatolia region in Turkey is estimated with only using methane obtained from the shale gas purification process at the power generation step. According to the estimations, 3337.8 MW electric power may be generated for 50~55 years, at the appropriate gas engine by using 8.5 billion cubic meter shale gas annually.
- MakaleAçık Erişim2021Strategy Development for the Applicability of Photovoltaic Systems in Hospitality Enterprises using SWOT Analysis and AHP Method: The Case of Sinop Province
Alcan, Yalçın; Esmer, Yusuf; Alcan, Özlem
Strategy is the way to achieve the objective or goal. In this context, strategies are developed and attempted to be implemented in order to achieve certain objectives or goals in each enterprise or sector. In this study, by combining SWOT analysis and AHP method, a strategy was developed to use the photovoltaic systems in hospitality enterprises. For this purpose, in the study, based on the relevant literature, a research has been conducted on the applicability of photovoltaic systems in the hospitality enterprises in Sinop. In the research, SWOT analysis was carried out for managers, experts and related academicians to identify the strengths and weaknesses of photovoltaic systems and opportunities and threats to these systems. 4 strategies were developed using the data obtained from the SWOT analysis, and then the most suitable one was tried to be determined by AHP method. As a result of the research, it has been determined that the most suitable strategy for the applicability of photovoltaic systems for hospitality enterprises in Sinop province is carrying out studies for photovoltaic systems to be an alternative energy source in the tourism sector.
AtıfOpenAlex4TR Dizin2
İncele - MakaleAçık Erişim2021Scopus SJRQ1Photovoltaic performance of non-covalent functionalized single-layer graphene in dye-sensitized solar cells (DSSCs)
Igman, Erdal; Bayram, Ozkan; Mavi, Ahmet; Hasar, Ugur Cem; Simsek, Onder
In this study, it was aimed to fabricate new effective alternative counter electrodes (CEs) in dye-sensitized solar cells (DSSCs). For this purpose, firstly, single-layer graphene (SLG) thin films were grown by chemical vapor deposition (CVD) method. Then, these films were separately functionalized with 1,8-cineole (ppCin/SLG), D-Limonene (ppLim/SLG) and Thiophene (ppTh/SLG) by plasma polymerization. Number of layers in CVD-grown graphene determined by Raman, transmission electron microscope (TEM) and ultraviolet–visible (UV–Vis) spectroscopy. Chemical structures of plasma polymerised (pp) thin films were investigated by Fourier transform infrared (FTIR) spectroscopy. Photovoltaic parameters of DSSCs were calculated, and electrocatalytic properties of CEs were investigated by electrochemical impedance spectroscopy (EIS). Polymer functionalization greatly enhanced the electrical conductivity and electrocatalytic activity properties of graphene compared to that of SLG. The efficiencies of DSSCs with ppCin/SLG and ppLim/SLG CEs were 1.10% and 1.02%, respectively. As a result, the cell efficiencies of ppCin/SLG and ppLim/SLG could be as alternative materials to platinum (Pt) counter electrode.
AtıfScopus14WoS13OpenAlex14İncele - MakaleYalnız künye2021Scopus SJRQ2Thermodynamic feasibility analysis of a newly modified absorption power cycle running with LiBr-water
Tozlu, Alperen; Yosaf, Salem A.; Özcan, Hasan
This study thermodynamically evaluates a newly modified absorption power cycle (APC) working with Lithium Bromide–Water (LiBr-H2O) solution and compares it with the conventional Rankine, one-stage, and three-stage APC systems. An additional steam condenser is integrated to the conventional APC and part of pure water is extracted and pumped back to the high-pressure side without passing through the absorber of the cycle. In order to specify the best system parameters, parametric optimization of all configurations is evaluated. The Rankine cycle and the modified APC have better thermodynamic performances than those of the conventional and the three-stage APC at generator temperatures. The conventional APC is found to improve the cycle performance at low generator pressure. However, the efficiencies of this cycle start to decrease when generator pressure increases. In contrast, the Rankine cycle and the modified APC have larger working ranges of generator pressure.
AtıfScopus8WoS5OpenAlex7İncele - MakaleAçık Erişim2021Scopus SJRQ1Municipal solid waste-based district heating and electricity production: A case study
Tozlu, Alperen; Abusoglu, Aysegul; Ozahi, Emrah; Anvari-Moghaddam, Amjad
In this paper, municipal solid waste (MSW) based electricity production and district heating (DH) potential of Turkey are considered. Three MSW based waste-to-energy (WtE) scenarios is developed: (i) Scenario-I, a DH system integrated into a gas turbine power plant (GTPP), (ii) Scenario-II, a DH system integrated into an organic Rankine cycle (ORC), and (iii) Scenario-III, which is based solely on a DH system. As a result of the thermodynamic and thermoeconomic analyzes of these developed scenarios using an existing MSW-based cogeneration facility's actual operating data, the system with the most extended payback period (about 5 years) is found as the GTPP-DH system developed in Scenario-I, which also has the highest investment cost. On the other hand, the system with the shortest payback period (about 2 years) is found as the DH system developed in Scenario-III, which also has the lowest investment cost. Overall exergy efficiencies of the GTTP-DH, ORC-DH, and DH systems are found to be 41.86%, 16.15%, and 31.87%, respectively. When the developed WtE scenarios adapted to the pilot provinces selected from each geographical region of Turkey, it is found that the GTPP system developed in Scenario-I can increase the power generation capacity of MSW plants for each province by about 20%.
AtıfScopus16WoS15OpenAlex16İncele - MakaleAçık Erişim2021Scopus SJRQ1Thermoeconomic analysis of a hybrid cogeneration plant with use of near-surface geothermal sources in Turkey
Tozlu, Alperen; Gençaslan, Betül; Özcan, Hasan
In this study, thermodynamic and thermoeconomic analyses of systems that produce electricity and heat through the use and storage of solar energy and near-surface geothermal sources are carried out. Three different configurations, which are the organic Rankine cycle (ORC), cogeneration system (CGN) and hybrid system (HYB), are coupled to the parabolic trough collector (PTC) system. The systems are named PTC-ORC, PTC-CGN and PTC-HYB are conducted. The reference system called PTC-ORC only produces electrical energy with parabolic trough collectors and it does not have a thermal energy storage system, whereas in PTC-CGN, in addition to the cogeneration of electricity and heat, thermal energy storage is also available. Finally, thermodynamic and economic analyses are conducted in the PTC-HYB with the assistance of near-surface geothermal energy, which is widely available in Turkey. In this study, the actual data of Ankara Kızılcahamam near-surface geothermal fields are taken as the heat source for the hybrid system. These facilities, each producing 1 MW of electricity, are first optimized with the help of parametric studies, and exergoeconomic analysis is performed with respect to optimum thermal conditions. The electricity production costs of PTC-ORC, PTC-CGN and PTC-HYB are found to be 0.257 $/kWh, 0.448 $/kWh and 0.401 $/kWh, respectively. The study demonstrates that thermal energy storage brings extra costs, while near-surface geothermal sources may help decrease energy costs from renewables.
AtıfScopus15WoS13OpenAlex21İncele - MakaleAçık Erişim2021Scopus SJRQ1A comparative thermoeconomic analysis and optimization of two different combined cycles by utilizing waste heat source of an MSWPP
Ozahi, Emrah; Abusoglu, Aysegul; Tozlu, Alperen
In this paper, thermodynamic and thermoeconomic analysis as well as genetic algorithm optimization of two combined cycles, a gas turbine-organic Rankine cycle (GT-ORC) and a gas turbine-Kalina cycle (GT-KAL) are carried out. The novelty of this study is that the cycles are adapted to an actual solid waste power plant to generate additional power from the exhaust gas. Thus, the power generation capacity of the actual power plant can be raised by using the combined cycle. Due to this reason, besides the thermodynamic analysis of the cycles, thermoeconomic analyses and optimizations are also very important in order to improve the actual system capacity. The net power output of GT-ORC and GT-KAL are found to be 1.51 MW and 1.59 MW, respectively. The results obtained are seen to be reasonable when compared to the net power output of the power plant (5.66 MW). Another originality of this study is that the thermoeconomic results are improved by utilizing a multi-objective optimization method namely non-dominated sorting genetic algorithm method (NSGA-II). Thus, the two objectives, total power output and the total cost rate, at the design stage of the cycles are optimized and enhanced. Due to the optimization results, it is found that the net power output of the GT-ORC and GT-KAL are increased by 11.34% and 0.99%, respectively, while the total cost rates are decreased by 18.59% and 1.31%, respectively. GT-ORC with the net power output of 1.70 MW is seen to be more efficient as compared to GT-KAL which produces a net power output of 1.61 MW. However, the total and the capital cost rates of GT-ORC are found to be higher than those of GT-KAL.
AtıfScopus7WoS5OpenAlex11İncele - MakaleAçık Erişim2020İşletmelerin Finansal Performansının Veri Zarflama Analizi Yöntemiyle Tespit Edilmesi: Borsa İstanbul’da İşlem Gören Enerji İşletmelerine Yönelik Bir Uygulama
Ag, Aliriza; Kuloğlu, Eşref
Ekonomik ve sosyal kalkınmanın gerçekleştirilmesinde önemli faktörlerden birisi enerjidir. Özellikle sonyıllarda hızlı nüfus artışı ve sanayileşmeye bağlı olarak enerjiye olan ihtiyaç giderek artmıştır. Bununlabirlikte küreselleşmeye bağlı olarak işletmeler arasındaki rekabet gittikçe acımasız bir hal almıştır.Küresel rekabet ortamında işletmelerin hayatta kalabilmeleri ve tatmin edici bir kâr marjı elde edebilmeleri için kaynakları etkin bir biçimde kullanmaları, minimum girdi ile maksimum çıktı elde etmeleri vemaliyetleri minimum seviyeye çekerek etkin bir biçimde kontrol etmeleri gerekmektedir. Bu doğrultudaişletmelerde yapılacak olan etkinlik analizi küresel rekabet ortamında gerek işletmelerin performanslarının değerlendirilmesinde gerekse konumlarının belirlenmesinde önem arz etmektedir.Bu doğrultuda yapılan çalışmanın amacı, Veri Zarflama Analizi (VZA) yöntemi ile 2019 yılında Borsaİstanbul (BİST)’da işlem gören enerji işletmelerinin finansal performanslarını ve başka bir ifadeyleetkinliklerini ölçmektir. Bu amaç doğrultusunda, VZA yönteminin çıktı odaklı Charnes-Cooper-Rhodes(CCR) modeli ile 8 işletmenin etkinliği finansal tablolarından elde edilen 2 girdi ve 4 çıktı faktörükullanılarak ölçülmüştür. Çalışma sonucunda enerji piyasasında faaliyet gösteren 5 işletme etkin bulunmuştur. Son olarak, etkin olmayan işletmelerin etkinlik düzeylerini artırabilmeleri için referans almalarıgereken işletmeler belirlenmiş olup girdi ve çıktı değişkenleri ile ilgili gerekli potansiyel iyileştirme oranları tespit edilmiştir.
AtıfOpenAlex8TR Dizin12İncele - MakaleAçık Erişim2020Ranking alternative energy resources technology programsin turkey based on the methods of multi-criteria decisionmaking analysis
Teber, Ahmet; Karakaş, Ahmet
The diversity less among the Alternative Energy Resources Technology Programs (AERTPs) in Turkey makes giving the “proper” decision crucial by high school senior students. The literature review exhibits that there exists a need over the expectation for a ranking system of the two-year programs in vocational schools in Turkey so as identifying two-year programs compared to others. In this strategic decision context, it is especially important for the students to make a suitable decision associated with their higher education. Therefore, this study focuses on developing a specific ranking system of twoyear energy programs in Turkey. In order to classify the programs, the most important decision criteria should be required. In this aspect, a survey is applied to a hundred high school senior students to recognize which multi-criteria for selection of an energy program they pick. Thus, the survey makes this study is more applicable to build a foundation for a field-based ranking system in Turkey. In this regard, a framework for ranking of AERTPs during the academic year of 2019 in Turkey is accomplished using three methods of Multi-Criteria Decision Making Analysis including Analytic Hierarchy Process (AHP), Simple Multi-Attribute Rating Technique (SMART), and Technique for Order Preference by Similarity to Ideal Solution (TOPSIS).
AtıfOpenAlex1İncele - MakaleAçık Erişim2020An Experimental Study to Determine the Relationship Between Power Factor and Harmonic Distortion in Single-Phase AC Voltage Controller
Çorapsız, Muhammed Reşit; Kahveci, Hakan; Çorapsız, Muhammed Fatih
This paper deals with the determination of the relationship between the power factor and the harmonic distortion in a single-phase AC (SPAC) voltage controller. The aim of this study is to investigate the change of power factor (PF) and total harmonic distortion (THD) during different phase triggering angles (PTA). Firstly, the advantages of using thyristor instead of triac in single-phase AC voltage controllers operating at high frequencies are mentioned. Secondly, the power factor and total harmonic distortions for single-phase AC voltage controllers are theoretically examined. Finally, the relationship between power factor and total harmonic distortion are demonstrated by both simulation and experimental studies. However, it is monitored that, at lower output voltages, the power factor (PF) is pretty much reduced and total harmonic distortion (THD) is significantly increased.
- MakaleAçık Erişim2020Voltage Control of Cuk Converter with PI and Fuzzy Logic Controller in Continuous Current Mode
Çorapsız, Muhammed Reşit; Çorapsız, Muhammed Fatih; Yilmaz, Mehmet
In today's energy systems, many equipment operates with Direct Current (DC) voltage. However, it is not always possible to obtain the voltage level required for the operation of these equipment from standard power supplies. For this reason, DC-DC converters are used to achieve the desired voltage values for equipment with different DC voltage levels. These converters are divided into three general categories, named Buck, Boost and Buck-Boost. The most preferred converter is the Cuk converter with low output ripple voltage, which can operate in both buck and boost modes. In this study, a detailed analysis of the Cuk converter, which is frequently used in Photovoltaic (PV) Panels was performed and different control methods of the output voltage were proposed. While performing this analysis, the dynamic model of the Cuk converter was created in which, Proportional-Integral (PI) and Fuzzy Logic (FL) are used to control the output voltage of the Cuk converter. The performances of both controllers were compared with respect to performance parameters such as steady state error, settling time and rise time. When the results obtained were evaluated as a whole, it was observed that FLC achieved the desired reference with less rise and settling time. In this study, modeling and controller applications of Cuk converter are realized by using MATLAB / SIMULINK program.
AtıfOpenAlex8İncele - MakaleYalnız künye2020Scopus SJRQ1Current–voltage analyses of Graphene-based structure onto Al2O3/p-Si using various methods
Efil, Esra; Kaymak, Nuriye; Seven, Elanur; Orhan, Elif Oz; Bayram, Ozkan; Ocak, Sema Bilge; Tataroglu, Adem
The present study's main purpose is to determine the current-voltage (I–V) performance of Graphene (Gr) based hetero nanostructure produced on Al2O3/p-Si. Graphene synthesis was carried out using the chemical vapor deposition (CVD) technique on Copper (Cu) foils used as a metal catalyst and transferred onto Al2O3/p-Si using the conventional transfer method. The I–V characteristics of this structure were measured in the dark environment, and the electrical properties of the Gr/Si structure were characterized at room temperature. The rectifying ratio (RR) of the structure was found to be about 103 at ± 3 V. The electrical properties of ideality factor (n), series resistance (Rs), and barrier height (Φb) were examined by using the theory of Thermionic Emission (TE), Norde's method, and Cheung's method. The values of Φb, which were calculated using Norde's method, Cheung's method, and the theory of thermionic emission (TE), were found to be 0.69 eV, 0.71 eV, and 0.68 eV, respectively. The ideality factor was found to be approximately 3.89 according to the theory of TE. The values of series resistance were also determined using the Norde's method and Cheung's two different parameters (dV/dln(I) and H(I)) found to be 9.60 kΩ, 9.12 kΩ, and 5.94 kΩ, respectively.
AtıfScopus25WoS25OpenAlex26İncele - MakaleAçık Erişim2020Scopus SJRQ2Experimental investigation of effects on performance, emissions and combustion parameters of biodiesel–diesel–butanol blends in a direct-injection CI engine
Örs, İlker; Sarıkoç, Selçuk; Atabani, A.E.; Ünalan, Sebahattin
This paper aims to asses and conduct a comparative analysis of fuel properties, performance, emissions and combustion characteristics of biodiesel produced from waste cooking oil (B100) as a cheap biodiesel feedstock, along with a binary blend of biodiesel–diesel (B20) and ternary blends of biodiesel–diesel–butanol as substitutions to diesel fuel. Although biodiesel and n-butanol have some negative impacts on engine performance parameters, they generally positively affect exhaust emission parameters compared to euro diesel. B100 caused an average reduction in brake power and exhaust gas temperature of 15.16% and 1.4%, respectively, although it increased brake specific fuel consumption on average by 14.09%, at full throttle under different engine load conditions. B100 decreased CO and HC emissions and smoke opacity by 65.4%, 61.07% and 54.94%, respectively. However, CO2 and NO emissions increased by 22.3% and 23.91%, respectively. Addition of n-butanol decreased some of the fuel thermo-physical properties such as density, viscosity and flash point. The average decreases in brake power when n-butanol was added were 6.17%, 7.49% and 11%, respectively, coupled with increases in specific fuel consumption of 6.25%, 8.96% and 14.29%, respectively. The addition of n-butanol decreased exhaust gas temperatures, CO, HC, NO and smoke emissions.
AtıfScopus41WoS33OpenAlex52İncele
