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A control scheme employing an adaptive hysteresis current controller and an uncomplicated reference current generator for a single-phase shunt active power lter
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Klasik gerilim ve akim kaynakli inverterlere alternatif olarak ortaya cikan empedans kaynakli inverterler (Z-Kaynakli Inverter), ustun ozelliklerinden dolayi guc kosullandirma devrelerinde siklikla tercih edilmektedir. Empedans kaynakli... more
Klasik gerilim ve akim kaynakli inverterlere alternatif olarak ortaya cikan empedans kaynakli inverterler (Z-Kaynakli Inverter), ustun ozelliklerinden dolayi guc kosullandirma devrelerinde siklikla tercih edilmektedir. Empedans kaynakli inverterler, geleneksel inverterlerin sahip oldugu kavramsal ve teorik sinirlamalari ortadan kaldirarak gelismis bir guc donusum konsepti saglar. Empedans kaynakli inverter devresi, anahtarlama elemanlarinin bulundugu guc katini giriste bulunan besleme katina baglayan bir cift kondansator ve bobinden meydana gelen ozel bir empedans agina sahiptir. Son yillarda empedans kaynakli inverterlere kiyasla daha yuksek verime sahip yari empedans kaynakli inverter topolojisi ortaya konmustur. Bu calismada, yari empedans kaynakli inverterde farkli darbe genislik modulasyon (PWM) kontrol tekniklerinin gerilim kazancina ve cikis akim sinyalinin harmonik acidan kalitesine etkisi incelenmistir. Basit yukseltici kontrol, maksimum yukseltici kontrol, 3. harmonik ilav...
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beslemeli paralel rezonans devreli bir inverterin Pspice programı kullanılarak simülasyonu ve prototip tasarımı pratik olarak gerçekleştirilmiştir. İnverter devresinde iki yönlü gerilim anahtarı olarak MOSFET kullanılmıştır. İndüksiyonlu ısıtma sistemi, ısıtma işlemi boyunca açık çevrimmore
In this study, single-phase, bridge type, a current-source inverter which contains a parallel resonant circuit for the induction heating applications has been simulated using Pspice program, and the prototype design was practically... more
In this study, single-phase, bridge type, a current-source inverter which contains a parallel resonant circuit for the induction heating applications has been simulated using Pspice program, and the prototype design was practically carried out. In inverter circuit, MOSFET which act as the bidirectional voltage switches are used. Induction heating system is operated in an open-loop throughout the heating cycle. The experimental results are compared with the results of Pspice simulation program and, the results seen that in accordance with each other.
Nowadays, power LEDs are widely used in the lighting sector due to their extensive lifetime, durability and high efficiency compared to the traditional lighting sources. As power LEDs draw high currents, they need special driver circuits.... more
Nowadays, power LEDs are widely used in the lighting sector due to their extensive lifetime, durability and high efficiency compared to the traditional lighting sources. As power LEDs draw high currents, they need special driver circuits. These circuits include AC-DC converters drawing harmonic current from the grid and decreasing the power factor. These converters can be replaced by AC-DC converters with active PFC. Therefore, the power factor is approximated to unity and power quality can be improved by drawing sinusoidal currents with reduced harmonic content. In this study, two flyback type circuits with internal and external PFC, which correct the input power factor and drive the power LEDs after reducing the harmonic content of the current drawn from grid, were designed and implemented. As a result of the experiments involving 20 W power LED, for power LED driver with external PFC, power factor and THD values were found as 0.93 and 31.1%, respectively. For the circuit with int...
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Bu calismada, induksiyonlu isitma uygulamalari icin tek fazli, kopru tipi, akim beslemeli paralel rezonans devreli bir inverterin Pspice programi kullanilarak simulasyonu ve prototip tasarimi pratik olarak gerceklestirilmistir. Inverter... more
Bu calismada, induksiyonlu isitma uygulamalari icin tek fazli, kopru tipi, akim beslemeli paralel rezonans devreli bir inverterin Pspice programi kullanilarak simulasyonu ve prototip tasarimi pratik olarak gerceklestirilmistir. Inverter devresinde iki yonlu gerilim anahtari olarak MOSFET kullanilmistir. Induksiyonlu isitma sistemi, isitma islemi boyunca acik cevrim modunda calistirilmistir. Deneysel sonuclar, Pspice simulasyon programindan elde edilen sonuclarla karsilastirilmis ve sonuclarin birbiriyle uyum icinde oldugu gorulmustur.
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Günümüzde güç LED’leri, geleneksel aydınlatma kaynaklarına göre uzun ömür, dayanıklılık ve yüksek verimleri nedeni ile aydınlatma sektöründe yaygın olarak kullanılmaktadır. Güç LED’leri yüksek değerde akım çektiklerinden, özel sürücü... more
Günümüzde güç LED’leri, geleneksel aydınlatma kaynaklarına göre uzun ömür, dayanıklılık ve yüksek verimleri nedeni ile aydınlatma sektöründe yaygın olarak kullanılmaktadır. Güç LED’leri yüksek değerde akım çektiklerinden, özel sürücü devrelerine ihtiyaç duyarlar. Bu özel sürücü devreleri, girişlerinde şebekeden harmonikli akımlar çeken ve güç faktörünü düşüren AC-DC dönüştürücülere sahiptir. Bu dönüştürücüler yerine aktif Güç Faktörü Düzeltmeli (PFC)’li AC-DC dönüştürücüler kullanılarak şebekenin güç faktörü 1’e yaklaştırılır ve şebekeden harmonik içeriği azaltılmış sinüs’e yakın akımlar çekilerek güç kalitesi düzeltilebilir. Bu çalışmada, giriş güç faktörünü düzelten ve şebekeden çekilen akımların harmonik içeriğini azaltarak güç LED’lerini süren dahili PFC’li geri dönüşlü (flyback) tipi bir devre tasarlanmış ve pratik olarak gerçekleştirilmiştir. Yapılan deneysel çalışmalar sonucunda güç faktörü 0.97 ve Toplam Harmonik Bozulma (THD) %10.4 olarak bulunmuştur. Gerçekleştirilen sürüc...
In this study, direct AC/AC converters controlled with space vector modulation (SVM) method are modelled in Matlab&Simulink. Direct AC/AC converters produce directly the three-phase load voltages which have variable frequency and... more
In this study, direct AC/AC converters controlled with space vector modulation (SVM) method are modelled in Matlab&Simulink. Direct AC/AC converters produce directly the three-phase load voltages which have variable frequency and variable amplitude, without rectifying the fixed three-phase input voltages. Simulation results are analyzed for output voltages with various frequency and amplitude.
Research Interests: Engineering and IEEE
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Abstract—Matrix converter is a single-stage converter which directly connects a three-phase voltage source to a three-phase load without dc-link components. Therefore, any harmonic distortion and imbalance in input voltage directly... more
Abstract—Matrix converter is a single-stage converter which directly connects a three-phase voltage source to a three-phase load without dc-link components. Therefore, any harmonic distortion and imbalance in input voltage directly reflect to the output of the converter. Recently, many researchers have made an effort to cope with this problem. In this paper, under distorted input voltage conditions, behaviors of the MC controlled with Venturini method are analyzed and a PI controller based compensation method to prevent negative effects of input voltage is proposed. Since the proposed method is based on closed loop control of the output currents, it not only reduces the output harmonic contents but also ensures a stable control of the load currents. Some results are presented to prove the effectiveness of the proposed compensation technique. Index Terms—Matrix converter, ac-ac converter, Venturini method, distorted input voltage, compensation.
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Maximum power point tracking (MPPT) algorithms are used to force photovoltaic (PV) modules to operate at their maximum power points for all environmental conditions. In artificial neural network (ANN)-based algorithms, the maximum power... more
Maximum power point tracking (MPPT) algorithms are used to force photovoltaic (PV) modules to operate at their maximum power points for all environmental conditions. In artificial neural network (ANN)-based algorithms, the maximum power points are acquired by designing ANN models for PV modules. However, the parameters of PV modules are not always provided by the manufacturer and cannot be obtained readily by the user. Experimental measurements implemented in the overall PV system may be used to obtain the ANN dataset. One drawback of this method is that the generalization ability of the neural network usually degrades and some data reducing the effectiveness of the network may exist. A genetic algorithm can be used to automatically select the important data among all the inputs, resulting in a smaller and more effective dataset. In our study, a genetic algorithm is used to improve the MPPT efficiency of a PV system with induction motor drive by optimizing the input dataset for an A...
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Matrix converter is a single-stage converter which directly connects a three-phase voltage source to a three-phase load without dc-link components. Therefore, any harmonic distortion and imbalance in input voltage directly reflect to the... more
Matrix converter is a single-stage converter which directly connects a three-phase voltage source to a three-phase load without dc-link components. Therefore, any harmonic distortion and imbalance in input voltage directly reflect to the output of the converter. Recently, many researchers have made an effort to cope with this problem. In this paper, under distorted input voltage conditions, behaviors of the MC controlled with Venturini method are analyzed and a PI controller based compensation method to prevent negative effects of input voltage is proposed. Since the proposed method is based on closed loop control of the output currents, it not only reduces the output harmonic contents but also ensures a stable control of the load currents. Some results are presented to prove the effectiveness of the proposed compensation technique.
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The encoders are electromechanical devices that give information about the angular position and the number of turns of the shaft, which they are connected. These devices are divided into digital or analogue according to output types. On... more
The encoders are electromechanical devices that give information about the angular position and the number of turns of the shaft, which they are connected. These devices are divided into digital or analogue according to output types. On digital outputs, the output can be binary coded, gray coded or pulsed. The frequency (M) or period (T) method produces accurate results in pulse-output encoders. However, these methods alone cannot give accurate results in some encoder types, which are saw tooth type encoders that produce analogue outputs in different shapes. In this study, a new method was proposed, which reduces the relative error ratio too much below 1 % in an absolute encoder that produces an analogue output ranging from 0 V to 5 V according to the angular position of the shaft. Unlike in the studies in the literature, M method and Analog Digital Converter (ADC) were used together. Thanks to this proposed method (M + ADC), it is possible to increase the measurement accuracy of th...
Matrix converters have the most compact and efficient AC-AC converter structure due to the lack of the DC intermediate components. The matrix converter makes a single-stage conversion directly connecting any terminal of voltage source to... more
Matrix converters have the most compact and efficient AC-AC converter structure due to the lack of the DC intermediate components. The matrix converter makes a single-stage conversion directly connecting any terminal of voltage source to any terminal of load. This outstanding feature leads to some problems that must be overcome under the distorted input voltage conditions. A matrix converter has low immunity to power source disturbances, because it has no DC intermediate circuit. Any disturbance in the power source creates a negative effect on the load of the matrix converter and on the current drawn from the source. In this study, a novel compensation method, which provides immunity against input voltage disturbances, is suggested for the matrix converter. The suggested method has a hybrid structure, which includes both feedforward and fuzzy logic controller based feedback methods. The effectiveness and accuracy of the suggested new hybrid compensation approach are proved by the va...
In this study, a test setup was designed for three- and/or four-wheeled electric mobility scooter models used by disabled or old people. This system is composed of a test platform that enables measurement of vehicular velocity, a data... more
In this study, a test setup was designed for three- and/or four-wheeled electric mobility scooter models used by disabled or old people. This system is composed of a test platform that enables measurement of vehicular velocity, a data acquisition card, and an interface prepared in the C# program. Using the data acquisition card that was designed, seven quantities, namely, battery and motor currents, battery and motor terminal voltages, wheel speed in revolution per minute, and ambient and motor temperatures, were measured instantaneously during the test procedure and transferred to a computer via a USB device. Using these data that were transferred, motor speed in revolution per minute, torque generated by the motor, motor shaft power, motor and driver efficiency, instantaneous velocity of the vehicle, and total distance covered information obtained from the moment the vehicle began to be used were computed in real time throughout the experiment in the interface prepared in the C#, ...
Empedans kaynaklı mikroinverter, geleneksel gerilim kaynaklı inverterlerin kavramsal ve teorik sınırlamalarını ortadan kaldırır ve yeni bir güç dönüştürme konsepti sağlar. Bu çalışmada, son zamanlarda... more
Empedans kaynaklı mikroinverter, geleneksel gerilim kaynaklı inverterlerin kavramsal ve teorik sınırlamalarını ortadan kaldırır ve yeni bir güç dönüştürme konsepti sağlar. Bu çalışmada, son zamanlarda giderek yaygınlaşan ve fotovoltaik sistemlerde kullanılan empedans kaynaklı bir mikroinverter devresinin bilgisayar ortamında Matlab/Simulink yardımıyla analizi yapılmıştır. Klasik inverterler ile arasında genel bir karşılaştırma yapıldıktan sonra farklı topolojilerin avantajları ve dezavantajlarına değinilmiştir. Empedans kaynaklı mikroinverter devrelerinin çalışma prensibi, kontrol yöntemi ve temel özellikleri açıklanmıştır. Empedans kaynaklı mikroinverter yapısının Matlab/Simulink ortamında benzetimi gerçekleştirilmiştir.
Research Interests: Signal Processing, Global Positioning System, Parameter estimation, Kalman Filter, Navigation, and 14 moreMobile Robots, Computer Simulation, Kinematics, Robot kinematics, Sensor Fusion, Mobile Robot, Error Correction, Optimal Bayesian Estimation, Dead Reckoning, Extended Kalman Filter, White Noise, Navigation System, Global position ing system, and Positioning System
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Matrix converter is a single-stage converter which directly connects a three-phase voltage source to a three-phase load without dc-link components. Therefore, any harmonic distortion and imbalance in input voltage directly reflect to the... more
Matrix converter is a single-stage converter which directly connects a three-phase voltage source to a three-phase load without dc-link components. Therefore, any harmonic distortion and imbalance in input voltage directly reflect to the output of the converter. Recently, many researchers have made an effort to cope with this problem. In this paper, under distorted input voltage conditions, behaviors of the MC controlled with Venturini method are analyzed and a PI controller based compensation method to prevent negative effects of input voltage is proposed. Since the proposed method is based on closed loop control of the output currents, it not only reduces the output harmonic contents but also ensures a stable control of the load currents. Some results are presented to prove the effectiveness of the proposed compensation technique.
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In this study, an effective Real Coded Genetic Algorithm (GA) based optimal fuzzy controller is proposed. The fuzzy controller is used for sensorless speed control of a Brushless DC (BLDC) motor in DSP based application system. The... more
In this study, an effective Real Coded Genetic Algorithm (GA) based optimal fuzzy controller is proposed. The fuzzy controller is used for sensorless speed control of a Brushless DC (BLDC) motor in DSP based application system. The advantages of adopting a real coded GA for the design and optimization of fuzzy controllers, which have a great deal of design and optimization parameters, are analyzed. Having accomplished optimization of developed fuzzy control system, a multi-objective performance index has been defined and it has been used as an objective function to be minimized in the real coded GA. Thus, the system can obtain optimal design parameters in a short time without the need of an expert assistance. Convergence of the control system performance index and speed responses of the BLDC motor have been provided as a result of study. The obtained results indicate that there is close agreement between simulation and experimental results.
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Maximum power point tracking (MPPT) algorithms are used to force photovoltaic (PV) modules to operate at their maximum power points for all environmental conditions. In artificial neural network (ANN)-based algorithms, the maximum power... more
Maximum power point tracking (MPPT) algorithms are used to force photovoltaic (PV) modules to operate at their maximum power points for all environmental conditions. In artificial neural network (ANN)-based algorithms, the maximum power points are acquired by designing ANN models for PV modules. However, the parameters of PV modules are not always provided by the manufacturer and cannot be obtained readily by the user. Experimental measurements implemented in the overall PV system may be used to obtain the ANN dataset. One drawback of this method is that the generalization ability of the neural network usually degrades and some data reducing the effectiveness of the network may exist. A genetic algorithm can be used to automatically select the important data among all the inputs, resulting in a smaller and more effective dataset. In our study, a genetic algorithm is used to improve the MPPT efficiency of a PV system with induction motor drive by optimizing the input dataset for an A...
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In this paper, a simple control scheme of single-phase shunt active power filter for current harmonics and reactive power compensation of linear and non-linear loads, is proposed. Simplicity of the proposed control scheme is based on... more
In this paper, a simple control scheme of single-phase shunt active power filter for current harmonics and reactive power compensation of linear and non-linear loads, is proposed. Simplicity of the proposed control scheme is based on uncomplicated reference source current generation and fuzzy logic based dc bus voltage regulation methods. Thus, complex computations are not needed. To indicate reactive power
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Research Interests: Genetics, Neural Network, Genetic Algorithm, Brushless DC Motor, Maximum Power Point, and 12 moreHybrid Algorithm, Boost Converter, Digital Signal Processor, Maximum Power Point Tracking, Pv System, Levenberg Marquardt, Artificial Neural Network, Electrical And Electronic Engineering, Speed Control, LMS Algorithm, multi layer perceptron, and Proportional Integral Derivative (PID)
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Abstract—Matrix converter is a single-stage converter which directly connects a three-phase voltage source to a three-phase load without dc-link components. Therefore, any harmonic distortion and imbalance in input voltage directly... more
Abstract—Matrix converter is a single-stage converter which directly connects a three-phase voltage source to a three-phase load without dc-link components. Therefore, any harmonic distortion and imbalance in input voltage directly reflect to the output of the converter. Recently, many researchers have made an effort to cope with this problem. Inthis paper, under distorted input voltage conditions, behaviors of the MC