Ahmet Teke | American Association for the Advancement of Science (AAAS) (original) (raw)

Papers by Ahmet Teke

This paper proposes to estimate the electrical characteristics and maximum power point of a photo... more This paper proposes to estimate the electrical characteristics and maximum power point of a photovoltaic (PV) panel under variable environmental conditions in banlurfa region (southeast of Turkey). Variable environment conditions cause to change of current, voltage and maximum power point (MPP) of PV panels. Under any environmental conditions there is a unique MPP for PV panels, to increase efficiency and reduce cost of energy systems, it is need to determine the maximum power point and electrical characteristics of PV panels. The Artificial Neural Network (ANN) is an improved structure that neurobiologically inspires brain functioning, to determine the effects of all parameters on system, ANN Cascade-forward backpropagation and feed-forward backpropagation algorithm have been used, the installed system performed in banlurfa region and the detailed performance tests have been performed in MATLAB simulation program. The proposed system is the first study by means of installing in ban...

Bitkiler iyi bir gelisim icin isiga gereksinim duyarlar. Bitki gelisiminde ihtiyac duyulan isigin... more Bitkiler iyi bir gelisim icin isiga gereksinim duyarlar. Bitki gelisiminde ihtiyac duyulan isigin kaynagi gunes veya yapay isiklardir. Son donemlerde LED (Light Emitting Diode-Isik Yayan Diyotlar) teknolojisi ile daha ucuz ve bitkinin fotosentetik aktivitesinin yogun oldugu isiklanma saglanabilmektedir. Bu calismada LED lambalarin domates bitkisinin (Lycopersicon esculentum L.) gelisimi uzerine etkisi incelenmistir. Deneme, ozel olarak planlanmis alcak plastik tunellerde yurutulmustur. Bitkilerinin yetistirildigi tunellerde isik kaynagi olarak; 1). Dogal gunes isigi (kontrol grubu), 2). Gunduz saatlerinde gunes isigi, gunes battiktan sonra ise kirmizi-turuncu isik veren LED lambalar (623nm) kullanilmistir. LED’lerin tuketecegi enerji ise gunes paneli sistemi araciligiyla saglanmistir. Arastirmada, bitki boyu (cm), yaprak sayisi (adet), cicek sayisi (adet), kok bogazi kalinligi (mm), govde kalinligi (mm), yaprak kalinligi (mm) toplam bitki agirligi (g), kok agirligi (g), biomas agirl...

Horticultura Brasileira, 2015

Journal of Sustainable Development of Energy, Water and Environment Systems, 2019

Electrical energy forecasting is crucial for efficient, reliable, and economic operations of hosp... more Electrical energy forecasting is crucial for efficient, reliable, and economic operations of hospitals due to serving 365 days a year, 24/7, and they require round-the-clock energy. An accurate prediction of energy consumption is particularly required for energy management, maintenance scheduling, and future renewable investment planning of large facilities. The main objective of this study is to forecast electrical energy demand by performing and comparing well-known techniques, which are frequently applied to short-term electrical energy forecasting problem in the literature, such as multiple linear regression as a statistical technique and artificial intelligence techniques including artificial neural networks containing multilayer perceptron neural networks and radial basis function networks, and support vector machines through a case study of a regional hospital in the medium-term horizon. In this study, a state-of-the-art literature review of medium-term electrical energy forecasting, data set information, fundamentals of statistical and artificial intelligence techniques, analyses for aforementioned methodologies, and the obtained results are described meticulously. Consequently, support vector machines model with a Gaussian kernel has the best validation performance, and the study revealed that seasonality has a dominant influence on forecasting performance. Hence heating, ventilation, and airconditioning systems cover the major part of electrical energy consumption of the regional hospital. Besides historical electrical energy consumption, outdoor mean temperature and calendar variables play a significant role in achieving accurate results. Furthermore, the study also unveiled that the number of patients is steady over the years with only small deviations and have no significant influence on medium-term electrical energy forecasting.

Elektronika ir Elektrotechnika, 2019

A dynamic voltage compensator (DVC) technique is presented for the minimizing of the capacitance ... more A dynamic voltage compensator (DVC) technique is presented for the minimizing of the capacitance value of the interleaved power factor corrected (PFC) boost converter for the battery charger in electric vehicles. This technique is based on eliminating the ripple on the capacitor by creating a voltage in the opposite direction as well as the amount of ripple on the capacitor. With the proposed method, the capacitance value is reduced by approximately five times. Reducing the size of the capacitor also provides the use of film-capacitors with a longer life. The other contribution of this study is designing a faster and more stable fully-digital control system, instead of the commonly used analogue controller of interleaved PFC boost converter. A 3.3 kW interleaved PFC boost converter is designed to verify the effect of the designed dynamic voltage compensator and digital controller.

Çukurova Üniversitesi Mühendislik-Mimarlık Fakültesi Dergisi, 2015

DSTATCOM is one of the power conditioning devices that is used to mitigate power quality problems... more DSTATCOM is one of the power conditioning devices that is used to mitigate power quality problems in distribution systems. The overall performance of the DSTATCOM is strictly related with the proper selection of power circuit configuration and controller algorithm. The power circuit of DSTATCOM consists of dc link capacitor, inverter and passive filter. The control circuit of DSTATCOM consists of reference signal extraction, DC link voltage control, AC voltage control and switching signal generation. Compensating current reference signal is generally derived from the measured quantities by the use of the Instantaneous Symmetrical Component Theory (ISCT) and dq theory based method. A proportional-integral (PI) controller is generally used to maintain a constant voltage at the dc-link of a Voltage-Source Inverter (VSI). Furthermore, by connecting a delta connected inductor-capacitor-inductor (LCL) passive filter at inverter output, the high order harmonics generated by the DSTATCOM can be easily and effectively eliminated. This study presents the design procedures for power and control circuits of 300 kVA DSTATCOM in detail.

Iranica Journal of Energy & Environment, 2015

This paper examines the viability of a grid-connected hybrid energy system (HES) for domestic ele... more This paper examines the viability of a grid-connected hybrid energy system (HES) for domestic electricity generation in the developing world. It aims to determine the techno-economic benefits of operating a wind energy conversion system. The HES consists of the grid power supply, wind energy conversion, power electronics, and storage units. The grid supply unit incorporates a probabilitybased prediction technique. The wind energy system modelling is based on the piecewise third order polynomial, using wind turbine power profile supplied by the manufacturer. The formulated optimization problem was solved using a hybrid Genetic Algorithm and Pattern Search (h-GAPS) technique. The h-GAPS based approach constrains the generation and distribution of power to ensure efficient operation. Analysis performed for a typical residential area used meteorological data for six sites, which spread across Nigeria. Results showed that the proposed power system could bring benefits of cost saving and improve power reliability, but the range of financial benefits depends on the geographical coordinates. In particular, 10kW/5.40kWh capacity wind/battery system installed in Sokoto can deal with 95.4% of the total electricity demand, save more than 77% of electricity payments and increase the reliability by approximately 140%.

Çukurova Üniversitesi Mühendislik-Mimarlık Fakültesi Dergisi, 2015

The increasing demand for energy and the depletion of existing fossil fuel based resources have f... more The increasing demand for energy and the depletion of existing fossil fuel based resources have forced the countries to realize the efficient use of energy, energy saving applications and searching alternative energy sources. Using the energy efficiently and performing energy saving studies have great importance for developing countries like ours that are dependent on other countries to meet their energy needs. Hospitals generally consume 6% of total energy in the buildings. Heating, Ventilation and Air Conditioning (HVAC) systems are the significant part of electrical energy consumption at the hospitals. The airconditioning system is responsible for around 70% of total electricity consumption. Electric motors and lighting systems in a hospital represent approximately 19-21% of the total energy consumption. In this study, according to the detailed analysis on the lighting devices, electric motors and HVAC systems, the energy saving potentials and payback periods of these systems are estimated for a University Hospital.

40% of total world electricity consumption is approximately consumed by electric motors. Research... more 40% of total world electricity consumption is approximately consumed by electric motors. Researches show that, hospitals represent approximately 6% of total energy consumption in the utility buildings sector. Electric motors in a hospital represent approximately 19% of the total energy consumption. In this paper, the research papers and practical studies on energy efficiency and energy saving potentials on electric motors at the hospitals are presented. Under the following sections, the latest literatures including research articles, conferences, e-books, handbooks, company reports, web pages, MSc and PhD theses interested in energy efficiency, energy saving and energy management on electric motors are summarized. Payback period of some projects on electric motors are also presented.

Use of multilevel inverters is becoming more popular in the recent years. Various topologies and ... more Use of multilevel inverters is becoming more popular in the recent years. Various topologies and modulation methods have been reported for utility and drive applications in the recent literature. Hybrid multilevel structures are the new multilevel inverter topologies where the cascaded series inverters have different internal DC bus voltages and/or modulated quite differently. This paper introduces a novel switching signals generation (modulation) method for hybrid multilevel inverters. This method is new and based on reference signal tracking. The structure of modeled hybrid multilevel inverter and operating principles of the proposed method are presented. The proposed method is verified by computer simulations using PSCAD/EMTDC. The waveform and THD values are presented and analyzed, which prove the validity of the proposed method.

gazi university journal of science, 2011

Decrease in the cost of power electronic devices and improvement in the efficiency of both power ... more Decrease in the cost of power electronic devices and improvement in the efficiency of both power converters and energy storage components have increased the applicability of new technological solutions such as Custom Power (CP) and Flexible AC Transmission Systems (FACTS) Devices. Active Power Filter (APF) is one of the CP devices and can mitigate harmonics, reactive power and unbalanced load currents originating from load side. In this study, a comprehensive review of APF studies, the advantages and disadvantages of each presented techniques are presented. The study also helps the researchers to select the optimum control strategies and power circuit configuration for APF applications. Keywords: Active Power Filter, Power Quality, Literature Review, Custom Power. .

The increasing demand for energy and the depletion of existing fossil fuel based resources have f... more The increasing demand for energy and the depletion of existing fossil fuel based resources have forced the countries to realize the efficient use of energy, energy saving applications and searching alternative energy sources. Using the energy efficiently and performing energy saving studies have great importance for developing countries like ours that are dependent on other countries to meet their energy needs. Hospitals generally consume 6% of total energy in the buildings. Heating, Ventilation and Air Conditioning (HVAC) systems are the significant part of electrical energy consumption at the hospitals. The air-conditioning system is responsible for around 70% of total electricity consumption. Electric motors and lighting systems in a hospital represent approximately 19-21% of the total energy consumption. In this study, according to the detailed analysis on the lighting devices, electric motors and HVAC systems, the energy saving potentials and payback periods of these systems ar...

Ascending energy demand and vanishing nonrenewable energy resources have increased the prominence... more Ascending energy demand and vanishing nonrenewable energy resources have increased the prominence of energy efficiency nowadays. In order to accomplish an energy efficient future for the forthcoming generations of humanity, traditional devices possessing low efficiency should be altered with intelligent devices having high efficiency. Thanks to internet of things (IoT), conventional devices have been turned into intelligent devices which can be remotely accessed, monitored and controlled by utilizing ubiquitous sensor mechanisms. In this study, enhancement of a low-cost intelligent device (iDev) is targeted to develop in order to compute and store electrical energy consumption into a database by an embedded card named as Arduino which has the capability of measuring voltage, current, frequency and power factor for improving energy efficiency in buildings. When a classic device is connected to the enhanced iDev, the device is converted to an intelligent device that is remotely contro...

World Academy of Science, Engineering and Technology, International Journal of Social, Behavioral, Educational, Economic, Business and Industrial Engineering, 2014

Hospitals represent approximately 6% of total energy consumption in the utility buildings sector.... more Hospitals represent approximately 6% of total energy consumption in the utility buildings sector. Heating, Ventilation and Air Conditioning (HVAC) systems are the major part of electrical energy consumption at the hospitals. The air-conditioning system is responsible for around 70% of total electricity consumption. Electric motors and lighting systems in a hospital represent approximately 19% and 21% of the total energy consumption, respectively. In this paper, profiles of hospital energy end-use consumption and an overview of energy saving areas at the hospitals are presented. Keywords—Energy efficiency, energy saving, healthcare energy consumption, hospital.

International Journal of Scientific and Technological Research, 2018

Recently, renewable energy resources have gained importance as a result of increasing energy dema... more Recently, renewable energy resources have gained importance as a result of increasing energy demand and rapid depletion of fossil fuels. Most of renewable energy resources depend on sunlight in one way or another. Since the solar energy is sustainable, the sun can be considered as an abundant energy source. Photovoltaic (PV) modules are used to convert sunlight into electrical energy. The amount of produced energy may change according to efficiency of the type of PV module. In other respects, proper positioning of PV modules directly affects the yield of solar energy system. Solar tracking systems (STSs) are designed to track the sun in order to position the PV modules and to provide the highest efficiency. In this study, an Arduino microcontroller based vertical axis STS was implemented to obtain the maximum power by rotating the PV modules either left or right. Keywords : Solar tracking system, Arduino, Renewable energy.

The effects of power quality (PQ) disturbances on power utilities and power customers are increas... more The effects of power quality (PQ) disturbances on power utilities and power customers are increasing day by day with widespread use of power electronics devices. These disturbances should be detected rapid and accurate. Wavelet transform (WT) has become a popular method to detect, classify and analyze various types of PQ disturbances in power systems. In this study, the fundamentals of WT, its distinctions from Fourier transform and the results of an extensive literature review of published studies are presented. The results of the literature review reveal that the detection of PQ disturbances using WT is a very powerful method and has been used in PQ mitigation devices effectively (that is, Custom Power, Flexible AC Transmission System, Flexible, Reliable and Intelligent Energy Delivery System).

ÖZET Tek bir yakıt girdisi ile birden fazla enerji türünün eş zamanlı olarak birlikte üretildiği ... more ÖZET Tek bir yakıt girdisi ile birden fazla enerji türünün eş zamanlı olarak birlikte üretildiği gaz motorlu kojenerasyon ve trijenerasyon santrallerinin endüstriyel ve sosyal tesislerde sayılarının gün geçtikçe artması, bu santrallerin Türkiye enerji piyasasındaki rolünü güçlendirmektedir. Ayrıca, %80 verimlilik koşulunu yerine getiren ve sadece kendi ihtiyaçları doğrultusunda doğal gazdan elektrik üretmek isteyen tesislere lisans muafiyeti getirilmesi, biyogaz motorlu kojenerasyon ve trijenerasyon santrallerinde üretilen elektrik enerjisinin şebekeye satışında yenilenebilir enerji kaynaklarını destekleme mekanizması (YEKDEM) tarafından sağlanan kilovatsaat başına 13,3 ABD Dolar sent fiyatlı alım garantisi teşviki, içten yanmalı gaz motoru tahrikli santrallerin karbon salınımının az olması, devreye girme sürelerinin hızlı olması ve geri ödeme sürelerinin kısalığı, kojenerasyon ve trijenerasyon santrallerinin son dönemlerde ilgi odağı haline gelmesini sağlamıştır. Bu çalışmada, Türk...

20% of total world electricity consumption is approximately consumed by lighting. Researches show... more 20% of total world electricity consumption is approximately consumed by lighting. Researches show that, hospitals represent approximately 6% of total energy consumption in the utility buildings sector. Lighting systems in a hospital represents approximately 21% of the total energy consumption. In this paper, the research papers and practical studies on energy efficiency and energy saving potentials on lighting systems at the hospitals are presented. Under the following sections, the latest literatures including research articles, conferences, e-books, company reports, web pages, MSc and PhD theses interested in energy efficiency, energy saving and energy management on lighting systems are summarized. Payback period of some lighting projects are also presented.

Renewable and Sustainable Energy Reviews

This paper proposes to estimate the electrical characteristics and maximum power point of a photo... more This paper proposes to estimate the electrical characteristics and maximum power point of a photovoltaic (PV) panel under variable environmental conditions in banlurfa region (southeast of Turkey). Variable environment conditions cause to change of current, voltage and maximum power point (MPP) of PV panels. Under any environmental conditions there is a unique MPP for PV panels, to increase efficiency and reduce cost of energy systems, it is need to determine the maximum power point and electrical characteristics of PV panels. The Artificial Neural Network (ANN) is an improved structure that neurobiologically inspires brain functioning, to determine the effects of all parameters on system, ANN Cascade-forward backpropagation and feed-forward backpropagation algorithm have been used, the installed system performed in banlurfa region and the detailed performance tests have been performed in MATLAB simulation program. The proposed system is the first study by means of installing in ban...

Bitkiler iyi bir gelisim icin isiga gereksinim duyarlar. Bitki gelisiminde ihtiyac duyulan isigin... more Bitkiler iyi bir gelisim icin isiga gereksinim duyarlar. Bitki gelisiminde ihtiyac duyulan isigin kaynagi gunes veya yapay isiklardir. Son donemlerde LED (Light Emitting Diode-Isik Yayan Diyotlar) teknolojisi ile daha ucuz ve bitkinin fotosentetik aktivitesinin yogun oldugu isiklanma saglanabilmektedir. Bu calismada LED lambalarin domates bitkisinin (Lycopersicon esculentum L.) gelisimi uzerine etkisi incelenmistir. Deneme, ozel olarak planlanmis alcak plastik tunellerde yurutulmustur. Bitkilerinin yetistirildigi tunellerde isik kaynagi olarak; 1). Dogal gunes isigi (kontrol grubu), 2). Gunduz saatlerinde gunes isigi, gunes battiktan sonra ise kirmizi-turuncu isik veren LED lambalar (623nm) kullanilmistir. LED’lerin tuketecegi enerji ise gunes paneli sistemi araciligiyla saglanmistir. Arastirmada, bitki boyu (cm), yaprak sayisi (adet), cicek sayisi (adet), kok bogazi kalinligi (mm), govde kalinligi (mm), yaprak kalinligi (mm) toplam bitki agirligi (g), kok agirligi (g), biomas agirl...

Horticultura Brasileira, 2015

Journal of Sustainable Development of Energy, Water and Environment Systems, 2019

Electrical energy forecasting is crucial for efficient, reliable, and economic operations of hosp... more Electrical energy forecasting is crucial for efficient, reliable, and economic operations of hospitals due to serving 365 days a year, 24/7, and they require round-the-clock energy. An accurate prediction of energy consumption is particularly required for energy management, maintenance scheduling, and future renewable investment planning of large facilities. The main objective of this study is to forecast electrical energy demand by performing and comparing well-known techniques, which are frequently applied to short-term electrical energy forecasting problem in the literature, such as multiple linear regression as a statistical technique and artificial intelligence techniques including artificial neural networks containing multilayer perceptron neural networks and radial basis function networks, and support vector machines through a case study of a regional hospital in the medium-term horizon. In this study, a state-of-the-art literature review of medium-term electrical energy forecasting, data set information, fundamentals of statistical and artificial intelligence techniques, analyses for aforementioned methodologies, and the obtained results are described meticulously. Consequently, support vector machines model with a Gaussian kernel has the best validation performance, and the study revealed that seasonality has a dominant influence on forecasting performance. Hence heating, ventilation, and airconditioning systems cover the major part of electrical energy consumption of the regional hospital. Besides historical electrical energy consumption, outdoor mean temperature and calendar variables play a significant role in achieving accurate results. Furthermore, the study also unveiled that the number of patients is steady over the years with only small deviations and have no significant influence on medium-term electrical energy forecasting.

Elektronika ir Elektrotechnika, 2019

A dynamic voltage compensator (DVC) technique is presented for the minimizing of the capacitance ... more A dynamic voltage compensator (DVC) technique is presented for the minimizing of the capacitance value of the interleaved power factor corrected (PFC) boost converter for the battery charger in electric vehicles. This technique is based on eliminating the ripple on the capacitor by creating a voltage in the opposite direction as well as the amount of ripple on the capacitor. With the proposed method, the capacitance value is reduced by approximately five times. Reducing the size of the capacitor also provides the use of film-capacitors with a longer life. The other contribution of this study is designing a faster and more stable fully-digital control system, instead of the commonly used analogue controller of interleaved PFC boost converter. A 3.3 kW interleaved PFC boost converter is designed to verify the effect of the designed dynamic voltage compensator and digital controller.

Çukurova Üniversitesi Mühendislik-Mimarlık Fakültesi Dergisi, 2015

DSTATCOM is one of the power conditioning devices that is used to mitigate power quality problems... more DSTATCOM is one of the power conditioning devices that is used to mitigate power quality problems in distribution systems. The overall performance of the DSTATCOM is strictly related with the proper selection of power circuit configuration and controller algorithm. The power circuit of DSTATCOM consists of dc link capacitor, inverter and passive filter. The control circuit of DSTATCOM consists of reference signal extraction, DC link voltage control, AC voltage control and switching signal generation. Compensating current reference signal is generally derived from the measured quantities by the use of the Instantaneous Symmetrical Component Theory (ISCT) and dq theory based method. A proportional-integral (PI) controller is generally used to maintain a constant voltage at the dc-link of a Voltage-Source Inverter (VSI). Furthermore, by connecting a delta connected inductor-capacitor-inductor (LCL) passive filter at inverter output, the high order harmonics generated by the DSTATCOM can be easily and effectively eliminated. This study presents the design procedures for power and control circuits of 300 kVA DSTATCOM in detail.

Iranica Journal of Energy & Environment, 2015

This paper examines the viability of a grid-connected hybrid energy system (HES) for domestic ele... more This paper examines the viability of a grid-connected hybrid energy system (HES) for domestic electricity generation in the developing world. It aims to determine the techno-economic benefits of operating a wind energy conversion system. The HES consists of the grid power supply, wind energy conversion, power electronics, and storage units. The grid supply unit incorporates a probabilitybased prediction technique. The wind energy system modelling is based on the piecewise third order polynomial, using wind turbine power profile supplied by the manufacturer. The formulated optimization problem was solved using a hybrid Genetic Algorithm and Pattern Search (h-GAPS) technique. The h-GAPS based approach constrains the generation and distribution of power to ensure efficient operation. Analysis performed for a typical residential area used meteorological data for six sites, which spread across Nigeria. Results showed that the proposed power system could bring benefits of cost saving and improve power reliability, but the range of financial benefits depends on the geographical coordinates. In particular, 10kW/5.40kWh capacity wind/battery system installed in Sokoto can deal with 95.4% of the total electricity demand, save more than 77% of electricity payments and increase the reliability by approximately 140%.

Çukurova Üniversitesi Mühendislik-Mimarlık Fakültesi Dergisi, 2015

The increasing demand for energy and the depletion of existing fossil fuel based resources have f... more The increasing demand for energy and the depletion of existing fossil fuel based resources have forced the countries to realize the efficient use of energy, energy saving applications and searching alternative energy sources. Using the energy efficiently and performing energy saving studies have great importance for developing countries like ours that are dependent on other countries to meet their energy needs. Hospitals generally consume 6% of total energy in the buildings. Heating, Ventilation and Air Conditioning (HVAC) systems are the significant part of electrical energy consumption at the hospitals. The airconditioning system is responsible for around 70% of total electricity consumption. Electric motors and lighting systems in a hospital represent approximately 19-21% of the total energy consumption. In this study, according to the detailed analysis on the lighting devices, electric motors and HVAC systems, the energy saving potentials and payback periods of these systems are estimated for a University Hospital.

40% of total world electricity consumption is approximately consumed by electric motors. Research... more 40% of total world electricity consumption is approximately consumed by electric motors. Researches show that, hospitals represent approximately 6% of total energy consumption in the utility buildings sector. Electric motors in a hospital represent approximately 19% of the total energy consumption. In this paper, the research papers and practical studies on energy efficiency and energy saving potentials on electric motors at the hospitals are presented. Under the following sections, the latest literatures including research articles, conferences, e-books, handbooks, company reports, web pages, MSc and PhD theses interested in energy efficiency, energy saving and energy management on electric motors are summarized. Payback period of some projects on electric motors are also presented.

Use of multilevel inverters is becoming more popular in the recent years. Various topologies and ... more Use of multilevel inverters is becoming more popular in the recent years. Various topologies and modulation methods have been reported for utility and drive applications in the recent literature. Hybrid multilevel structures are the new multilevel inverter topologies where the cascaded series inverters have different internal DC bus voltages and/or modulated quite differently. This paper introduces a novel switching signals generation (modulation) method for hybrid multilevel inverters. This method is new and based on reference signal tracking. The structure of modeled hybrid multilevel inverter and operating principles of the proposed method are presented. The proposed method is verified by computer simulations using PSCAD/EMTDC. The waveform and THD values are presented and analyzed, which prove the validity of the proposed method.

gazi university journal of science, 2011

Decrease in the cost of power electronic devices and improvement in the efficiency of both power ... more Decrease in the cost of power electronic devices and improvement in the efficiency of both power converters and energy storage components have increased the applicability of new technological solutions such as Custom Power (CP) and Flexible AC Transmission Systems (FACTS) Devices. Active Power Filter (APF) is one of the CP devices and can mitigate harmonics, reactive power and unbalanced load currents originating from load side. In this study, a comprehensive review of APF studies, the advantages and disadvantages of each presented techniques are presented. The study also helps the researchers to select the optimum control strategies and power circuit configuration for APF applications. Keywords: Active Power Filter, Power Quality, Literature Review, Custom Power. .

The increasing demand for energy and the depletion of existing fossil fuel based resources have f... more The increasing demand for energy and the depletion of existing fossil fuel based resources have forced the countries to realize the efficient use of energy, energy saving applications and searching alternative energy sources. Using the energy efficiently and performing energy saving studies have great importance for developing countries like ours that are dependent on other countries to meet their energy needs. Hospitals generally consume 6% of total energy in the buildings. Heating, Ventilation and Air Conditioning (HVAC) systems are the significant part of electrical energy consumption at the hospitals. The air-conditioning system is responsible for around 70% of total electricity consumption. Electric motors and lighting systems in a hospital represent approximately 19-21% of the total energy consumption. In this study, according to the detailed analysis on the lighting devices, electric motors and HVAC systems, the energy saving potentials and payback periods of these systems ar...

Ascending energy demand and vanishing nonrenewable energy resources have increased the prominence... more Ascending energy demand and vanishing nonrenewable energy resources have increased the prominence of energy efficiency nowadays. In order to accomplish an energy efficient future for the forthcoming generations of humanity, traditional devices possessing low efficiency should be altered with intelligent devices having high efficiency. Thanks to internet of things (IoT), conventional devices have been turned into intelligent devices which can be remotely accessed, monitored and controlled by utilizing ubiquitous sensor mechanisms. In this study, enhancement of a low-cost intelligent device (iDev) is targeted to develop in order to compute and store electrical energy consumption into a database by an embedded card named as Arduino which has the capability of measuring voltage, current, frequency and power factor for improving energy efficiency in buildings. When a classic device is connected to the enhanced iDev, the device is converted to an intelligent device that is remotely contro...

World Academy of Science, Engineering and Technology, International Journal of Social, Behavioral, Educational, Economic, Business and Industrial Engineering, 2014

Hospitals represent approximately 6% of total energy consumption in the utility buildings sector.... more Hospitals represent approximately 6% of total energy consumption in the utility buildings sector. Heating, Ventilation and Air Conditioning (HVAC) systems are the major part of electrical energy consumption at the hospitals. The air-conditioning system is responsible for around 70% of total electricity consumption. Electric motors and lighting systems in a hospital represent approximately 19% and 21% of the total energy consumption, respectively. In this paper, profiles of hospital energy end-use consumption and an overview of energy saving areas at the hospitals are presented. Keywords—Energy efficiency, energy saving, healthcare energy consumption, hospital.

International Journal of Scientific and Technological Research, 2018

Recently, renewable energy resources have gained importance as a result of increasing energy dema... more Recently, renewable energy resources have gained importance as a result of increasing energy demand and rapid depletion of fossil fuels. Most of renewable energy resources depend on sunlight in one way or another. Since the solar energy is sustainable, the sun can be considered as an abundant energy source. Photovoltaic (PV) modules are used to convert sunlight into electrical energy. The amount of produced energy may change according to efficiency of the type of PV module. In other respects, proper positioning of PV modules directly affects the yield of solar energy system. Solar tracking systems (STSs) are designed to track the sun in order to position the PV modules and to provide the highest efficiency. In this study, an Arduino microcontroller based vertical axis STS was implemented to obtain the maximum power by rotating the PV modules either left or right. Keywords : Solar tracking system, Arduino, Renewable energy.

The effects of power quality (PQ) disturbances on power utilities and power customers are increas... more The effects of power quality (PQ) disturbances on power utilities and power customers are increasing day by day with widespread use of power electronics devices. These disturbances should be detected rapid and accurate. Wavelet transform (WT) has become a popular method to detect, classify and analyze various types of PQ disturbances in power systems. In this study, the fundamentals of WT, its distinctions from Fourier transform and the results of an extensive literature review of published studies are presented. The results of the literature review reveal that the detection of PQ disturbances using WT is a very powerful method and has been used in PQ mitigation devices effectively (that is, Custom Power, Flexible AC Transmission System, Flexible, Reliable and Intelligent Energy Delivery System).

ÖZET Tek bir yakıt girdisi ile birden fazla enerji türünün eş zamanlı olarak birlikte üretildiği ... more ÖZET Tek bir yakıt girdisi ile birden fazla enerji türünün eş zamanlı olarak birlikte üretildiği gaz motorlu kojenerasyon ve trijenerasyon santrallerinin endüstriyel ve sosyal tesislerde sayılarının gün geçtikçe artması, bu santrallerin Türkiye enerji piyasasındaki rolünü güçlendirmektedir. Ayrıca, %80 verimlilik koşulunu yerine getiren ve sadece kendi ihtiyaçları doğrultusunda doğal gazdan elektrik üretmek isteyen tesislere lisans muafiyeti getirilmesi, biyogaz motorlu kojenerasyon ve trijenerasyon santrallerinde üretilen elektrik enerjisinin şebekeye satışında yenilenebilir enerji kaynaklarını destekleme mekanizması (YEKDEM) tarafından sağlanan kilovatsaat başına 13,3 ABD Dolar sent fiyatlı alım garantisi teşviki, içten yanmalı gaz motoru tahrikli santrallerin karbon salınımının az olması, devreye girme sürelerinin hızlı olması ve geri ödeme sürelerinin kısalığı, kojenerasyon ve trijenerasyon santrallerinin son dönemlerde ilgi odağı haline gelmesini sağlamıştır. Bu çalışmada, Türk...

20% of total world electricity consumption is approximately consumed by lighting. Researches show... more 20% of total world electricity consumption is approximately consumed by lighting. Researches show that, hospitals represent approximately 6% of total energy consumption in the utility buildings sector. Lighting systems in a hospital represents approximately 21% of the total energy consumption. In this paper, the research papers and practical studies on energy efficiency and energy saving potentials on lighting systems at the hospitals are presented. Under the following sections, the latest literatures including research articles, conferences, e-books, company reports, web pages, MSc and PhD theses interested in energy efficiency, energy saving and energy management on lighting systems are summarized. Payback period of some lighting projects are also presented.

Renewable and Sustainable Energy Reviews