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Articles 4291 - 4320 of 10319
Full-Text Articles in Physical Sciences and Mathematics
Application Of Singular Value Decomposition Algorithm For Implementing Power Amplifier Linearizer, Rajbir Kaur, Manjeet Singh Patterh
Application Of Singular Value Decomposition Algorithm For Implementing Power Amplifier Linearizer, Rajbir Kaur, Manjeet Singh Patterh
Turkish Journal of Electrical Engineering and Computer Sciences
A power amplifier (PA) is an integral component of all base stations in wireless communication systems and is used for converting DC power supply into radio frequency output power, but PAs are highly nonlinear. To achieve high power conversion efficiency, the PA is operated near saturation, which causes intermodulation products and hence results in nonlinear distortion. Digital predistortion (DPD) is a technique used to compensate for the nonlinear distortion without compromising its efficiency. Fourth Generation Long Term Evolution (4G LTE) systems use a carrier aggregation scheme to combine separate available bandwidths to deliver high data speeds. In this paper the …
Exploiting Kernel-Based Feature Weighting And Instance Clustering To Transfer Knowledge Across Domains, Jafar Tahmoresnezhad, Sattar Hashemi
Exploiting Kernel-Based Feature Weighting And Instance Clustering To Transfer Knowledge Across Domains, Jafar Tahmoresnezhad, Sattar Hashemi
Turkish Journal of Electrical Engineering and Computer Sciences
Learning invariant features across domains is of vital importance to unsupervised domain adaptation, where classifiers trained on the training examples (source domain) need to adapt to a different set of test examples (target domain) in which no labeled examples are available. In this paper, we propose a novel approach to find the invariant features in the original space and transfer the knowledge across domains. We extract invariant features of input data by a kernel-based feature weighting approach, which exploits distribution difference and instance clustering to find desired features. The proposed method is called the kernel-based feature weighting (KFW) approach and …
Design And Walking Pattern Generation Of A Biped Robot, Tolga Olcay, Ahmet Özkurt
Design And Walking Pattern Generation Of A Biped Robot, Tolga Olcay, Ahmet Özkurt
Turkish Journal of Electrical Engineering and Computer Sciences
This paper presents the design of a biped robot, the walking trajectory generation method, and experimental results about biped walking. Walking trajectory generation is one of the deterministic factors in walking robot applications. Different approaches for stable walking trajectory are worked on in robotic research. The linear inverted pendulum model (LIPM) is an effective method used with the zero moment point (ZMP) criteria. Biped robot trunk and feet moving patterns are generated depending on these fundamental methods. In this study, generated trajectories were tested by a 12 degree of freedom (DOF) biped robot RUBI built at Dokuz Eylül University. In …
Full Occlusion Handling For Pedestrian Tracking Via Hybrid System, Xiaoyu Zhang, Shiqiang Hu, Huanlong Zhang, Xing Hu
Full Occlusion Handling For Pedestrian Tracking Via Hybrid System, Xiaoyu Zhang, Shiqiang Hu, Huanlong Zhang, Xing Hu
Turkish Journal of Electrical Engineering and Computer Sciences
Occlusion and lack of visibility even in sparse crowd scenes make it difficult to track individual pedestrians correctly and consistently, particularly in a single view. We present a novel pedestrian tracking approach that connects tracking with reidentification to locate and maintain the identity of certain people who may be occluded for a long time. First, two models are constructed. One model tracks the pedestrian and trains a classifier, while the other model reidentifies the pedestrian of interest from detection results with the trained classifier. Secondly, we design a set of transition rules for model switching. Finally, the two models work …
A Novel Wound Field Flux Switching Machine With Salient Pole Rotor And Nonoverlapping Windings, Faisal Khan, Erwan Sulaiman, Md Zarafi Ahmad
A Novel Wound Field Flux Switching Machine With Salient Pole Rotor And Nonoverlapping Windings, Faisal Khan, Erwan Sulaiman, Md Zarafi Ahmad
Turkish Journal of Electrical Engineering and Computer Sciences
A flux switching machine (FSM) with a segmented rotor and nonoverlapping windings is an attractive alternative for driving high torque density applications. However, a rotor with segments makes the motor less robust as well as difficult to be assembled, while a FSM with salient rotor and overlapping windings inherits high copper losses and less efficiency due to high coil volume. In this paper, a novel structure of FSM with nonoverlapping windings and salient rotor is proposed, making it different from the 10Slot-8Pole segmental and salient rotor FSM. Several design parameters defined in the rotor, armature coil, and field excitation coil …
Design And Analysis Of A Reduced Ultrawideband Band-Notched Band-Pass Filter, Navid Daryasafar, Mojtaba Tangaki, Mohammad Naser Moghaddasi, Ramezanali Sadeghzade
Design And Analysis Of A Reduced Ultrawideband Band-Notched Band-Pass Filter, Navid Daryasafar, Mojtaba Tangaki, Mohammad Naser Moghaddasi, Ramezanali Sadeghzade
Turkish Journal of Electrical Engineering and Computer Sciences
In this paper we intend to design a reduced ultrawideband band-pass filter using new models of coupled transmission lines. In this paper, by providing a new model of resonators, the bandwidth of band-pass filters (which are among the most crucial elements in communication systems) will be moderately increased, while their size and volume decreases. According to the change of their equations and consequent changes in basic parameters of these models, optimization and dependency among these parameters and also the frequency response of these filters will be developed to utilize notches in the pass-band, and a reduced ultrawideband band-pass filter with …
Protein Fold Classification With Grow-And-Learn Network, Özlem Polat, Zümray Dokur
Protein Fold Classification With Grow-And-Learn Network, Özlem Polat, Zümray Dokur
Turkish Journal of Electrical Engineering and Computer Sciences
Protein fold classification is an important subject in computational biology and a compelling work from the point of machine learning. To deal with such a challenging problem, in this study, we propose a solution method for the classification of protein folds using Grow-and-Learn (GAL) neural network together with one-versus-others (OvO) method. To classify the most common 27 protein folds, 125 dimensional data, constituted by the physicochemical properties of amino acids, are used. The study is conducted on a database including 694 proteins: 311 of these proteins are used for training and 383 of them for testing. Overall, the classification system …
Lambda Optimization Of Constraint Violating Units In Short-Term Thermal Unit Commitment Using Modified Dynamic Programming, Logavani Kandasamy, Senthil Kumar Selvaraj
Lambda Optimization Of Constraint Violating Units In Short-Term Thermal Unit Commitment Using Modified Dynamic Programming, Logavani Kandasamy, Senthil Kumar Selvaraj
Turkish Journal of Electrical Engineering and Computer Sciences
This paper presents a new approach with a three-stage optimization algorithm for the least-cost optimal solution of the unit commitment problem. In the proposed work, the optimal schedule is obtained by optimizing the lambda operator for the states that violate the inequality constraints. The objective of the work is to minimize the fuel cost when subjected to various constraints such as load balance, minimum up/down time, ramp limit, and spinning reserve. This method of committing the units yields the least-cost solution when applied to the IEEE 10-unit systems and 7-unit Indian utility practical systems scheduled for 24 h and the …
Tunable Microstrip Dual-Band Bandpass Filter For Wlan Applications, Abbas Rezaei, Leila Noori
Tunable Microstrip Dual-Band Bandpass Filter For Wlan Applications, Abbas Rezaei, Leila Noori
Turkish Journal of Electrical Engineering and Computer Sciences
In this paper, based on a new stub-loaded open loop resonator, a compact microstrip dual-band bandpass filter is presented. The proposed filter is designed using two stub-loaded open loop resonators to create two pass bands at 2.39 GHz and 5.7 GHz for multimode wireless LANs applications. Two high impedance sections are used in the main loops and the internal stubs are two low impedance microstrip cells. A method is presented to control the mode resonance frequencies. By increasing the internal stubs' dimensions, the resonance frequencies are adjusted without size increment. The proposed filter has a good performance. The insertion losses …
Truncation Thresholds: A Pair Of Spike Detection Thresholds Computed Using Truncated Probability Distributions, Murat Okatan, Mehmet Kocatürk
Truncation Thresholds: A Pair Of Spike Detection Thresholds Computed Using Truncated Probability Distributions, Murat Okatan, Mehmet Kocatürk
Turkish Journal of Electrical Engineering and Computer Sciences
We describe a method for computing a pair of spike detection thresholds, called `truncation thresholds', using truncated probability distributions, for extracellular recordings. In existing methods the threshold is usually set to a multiple of an estimate of the standard deviation of the noise in the recording, with the multiplication factor being chosen between 3 and 5 according to the researcher's preferences. Our method has the following advantages over these methods. First, because the standard deviation is usually estimated from the entire recording, which includes the spikes, it increases with firing rate. By contrast, truncation thresholds decrease in absolute value with …
Optimal Determination Of Island Boundaries Besides The Optimal Placement Of D-Statcom Devices And Dg Units, Sadeq Rabie, Hossein Afrakhte
Optimal Determination Of Island Boundaries Besides The Optimal Placement Of D-Statcom Devices And Dg Units, Sadeq Rabie, Hossein Afrakhte
Turkish Journal of Electrical Engineering and Computer Sciences
In this study, integration of three important concepts of distributed generation, D-FACTS devices, and microgrids are evaluated. The performance of a microgrid is dependent on its location, capacity, and placement of DG units and D-FACTS devices. In this paper a new method is proposed to simultaneously determine the optimal number, location, and capacity of DG units and D-STATCOM devices and optimal boundaries of electrical islands in the independent mode of microgrids. The main objective is to minimize the economic costs. The optimal locations of DG units and D-STATCOM devices should be determined to maximize the DG capacities with minimum loss …
New Static Output Feedback Stabilization And Multivariable Pid-Controller Design Methods For Unstable Linear Systems Via An Ilmi Optimization Approach, Mehmet Nur Alpaslan Parlakçi, Elbrus Caferov
New Static Output Feedback Stabilization And Multivariable Pid-Controller Design Methods For Unstable Linear Systems Via An Ilmi Optimization Approach, Mehmet Nur Alpaslan Parlakçi, Elbrus Caferov
Turkish Journal of Electrical Engineering and Computer Sciences
The design problem of a static output feedback controller and multivariable proportional-integral-derivative (PID) controller is investigated for linear time-invariant systems (LTI). First, the static output feedback stabilization problem is taken into consideration and then an iterative linear matrix inequality (ILMI) algorithm is developed for the synthesis of the controller. Second, choosing a multivariable PID control law, the whole system is transformed into a new augmented system represented in the form of a static output feedback control system. This method allows us to convert the multivariable PID controller design problem into a static output feedback synthesis problem. Thus, the proposed ILMI …
Neural Network Approach On Loss Minimization Control Of A Pmsm With Core Resistance Estimation, Hüseyi̇n Erdoğan, Mehmet Özdemi̇r
Neural Network Approach On Loss Minimization Control Of A Pmsm With Core Resistance Estimation, Hüseyi̇n Erdoğan, Mehmet Özdemi̇r
Turkish Journal of Electrical Engineering and Computer Sciences
Permanent magnet synchronous motors (PMSMs) are often used in industry for high-performance applications. Their key features are high power density, linear torque control capability, high efficiency, and fast dynamic response. Today, PMSMs are prevalent especially for their use in hybrid electric vehicles. Since operating the motor at high efficiency values is critically important for electric vehicles, as for all other applications, minimum loss control appears to be an inevitable requirement in PMSMs. In this study, a neural network-based intelligent minimum loss control technique is applied to a PMSM. It is shown by means of the results obtained that the total …
Load Shedding Scheme Based On Frequency And Voltage Stability For An Islanding Operation Of A Distribution Network Connected To Mini-Hydro Generation, Norazliani Md Sapari, Hazlie Bin Mokhlis, Javed Ahmed Laghari, Ab Halim Abu Bakar, Hasmaini Mohamad, Mohd Rohaimi Mohd Dahalan
Load Shedding Scheme Based On Frequency And Voltage Stability For An Islanding Operation Of A Distribution Network Connected To Mini-Hydro Generation, Norazliani Md Sapari, Hazlie Bin Mokhlis, Javed Ahmed Laghari, Ab Halim Abu Bakar, Hasmaini Mohamad, Mohd Rohaimi Mohd Dahalan
Turkish Journal of Electrical Engineering and Computer Sciences
This paper presents a load shedding scheme (LSS) based on system frequency and voltage stability (VS). In the proposed scheme, the amount of power imbalance is determined using a rate of change of frequency, and the load shedding priority is carried out based on a VS index. The load with the highest tendency for voltage collapse (based on the index value) is given first priority to be shed. Thus, by shedding the most sensitive load, the distribution system can be saved from power collapse and then the system can return to its nominal state after load shedding. The proposed LSS …
Model-Based Fault Analysis Of A High-Voltage Circuit Breaker Operating Mechanism, Ali Forootani, Ali Akbar Afzalian, Ali Nadian Ghohmshe
Model-Based Fault Analysis Of A High-Voltage Circuit Breaker Operating Mechanism, Ali Forootani, Ali Akbar Afzalian, Ali Nadian Ghohmshe
Turkish Journal of Electrical Engineering and Computer Sciences
In this paper, a dynamic model is developed for high-voltage circuit breakers to extract fault features and causes. Lagrange's method is applied using geometric equations of mechanism components to write the model. Unlike previous approaches, the proposed method reveals and analyzes all types of circuit breaker operating mechanism faults. Early fault detection, which is a vital requirement of the fault diagnosis system, becomes feasible by keeping track of changes in the contact travel curve in the proposed model. Resulting faults in the travel curve are analyzed mathematically in order to find out the exact origin of the fault. Field test …
A Neuro-Fuzzy Controller For Grid-Connected Heavy-Duty Gas Turbine Power Plants, Mohamed Iqbal Mohamed Mustafa, Joseph Xavier Rayappan, Kanakaraj Jagannathan
A Neuro-Fuzzy Controller For Grid-Connected Heavy-Duty Gas Turbine Power Plants, Mohamed Iqbal Mohamed Mustafa, Joseph Xavier Rayappan, Kanakaraj Jagannathan
Turkish Journal of Electrical Engineering and Computer Sciences
Frequent load fluctuation and set-point variation may affect the stability of grid-connected heavy-duty gas turbine power plants. To overcome such problems, a novel neuro-fuzzy controller is proposed in this paper for single-shaft heavy-duty gas turbines ranging from 18.2 MW to 106.7 MW. A neuro-fuzzy controller was developed using a hybrid learning algorithm and the effectiveness of the controller for all heavy-duty gas turbine plants (5, 6, 7, and 9 series) is demonstrated against load disturbance and set-point variation in a grid-connected environment. Various time domain specifications and performance index criteria of the neuro-fuzzy controller are compared with that of a …
A Novel Approach For Extracting Ideal Exemplars By Clustering For Massivetime-Ordered Datasets, Ömer Faruk Ertuğrul
A Novel Approach For Extracting Ideal Exemplars By Clustering For Massivetime-Ordered Datasets, Ömer Faruk Ertuğrul
Turkish Journal of Electrical Engineering and Computer Sciences
The number and length of massive datasets have increased day by day and this yields more complex machine learning stages due to the high computational costs. To decrease the computational cost many methods were proposed in the literature such as data condensing, feature selection, and filtering. Although clustering methods are generally employed to divide samples into groups, another way of data condensing is by determining ideal exemplars (or prototypes), which can be used instead of the whole dataset. In this study, first the efficiency of traditional data condensing by clustering approach was confirmed according to obtained accuracies and condensing ratios …
Time-Time Matrix Z-Score Vector-Based Fault Analysis Method For Series-Compensated Transmission Lines, Oveis Asgari Gashteroodkhani, Behrooz Vahidi, Aydin Zaboli
Time-Time Matrix Z-Score Vector-Based Fault Analysis Method For Series-Compensated Transmission Lines, Oveis Asgari Gashteroodkhani, Behrooz Vahidi, Aydin Zaboli
Turkish Journal of Electrical Engineering and Computer Sciences
In this paper, a novel protection method based on time-time (TT) transform for thyristor-controlled series-compensated lines is presented. First, current signals at both sides of the sending and receiving ends are retrieved and processed through time-time domain transform (TT-transform), and a TT-matrix is produced. A proposed index is then compared with a defined threshold (THD) in order to determine fault occurrence and faulted phases. Within less than three cycles of the fault inception, a tripping signal can be sent that is acceptable for the speed of digital relays. After faulted phase selection, considering the TT-matrix of the faulted phases of …
Late Fusion Of Facial Dynamics For Automatic Expression Recognition, Alessandra Bandrabur, Laura Florea, Cornel Florea, Matei Mancas
Late Fusion Of Facial Dynamics For Automatic Expression Recognition, Alessandra Bandrabur, Laura Florea, Cornel Florea, Matei Mancas
Turkish Journal of Electrical Engineering and Computer Sciences
Installment of a facial expression is associated with contractions and extensions of specific facial muscles. Noting that expression is about changes, we present a model for expression classification based on facial landmarks dynamics. Our model isolates the trajectory of facial fiducial points by wrapping them up in relevant features and discriminating among various alternatives with a machine learning classification system. The used features are geometric and temporal-based and the classification system is represented by a late fusion framework that combines several neural networks with binary responses. The proposed method is robust, being able to handle complex expression classes.
Hesitant Fuzzy Pairwise Comparison For Software Cost Estimation: A Case Study In Turkey, Ayfer Başar
Hesitant Fuzzy Pairwise Comparison For Software Cost Estimation: A Case Study In Turkey, Ayfer Başar
Turkish Journal of Electrical Engineering and Computer Sciences
Estimating the cost of software is a complex process for almost all engineering companies. Uncertainties about development method, design, estimation process, data, and processing affect the accuracy of estimation. Underestimation results in fewer resources being committed than the project really needs, an unrealistic schedule, and low quality outputs. On the other hand, overestimation wastes resources and causes loss of customer credit. Thus, choosing the appropriate cost estimation method is crucial. Studies in the literature emphasize the importance of empirical, analytical methods and expert judgement. Certain cost estimation techniques have been widely studied in the literature. However, there are limited studies …
A New Approach For Minimizing Torque Ripple In A Bldc Motor Drive With A Front End Ido Dc-Dc Converter, Ramya Amirthalingam, Balaji Mahadevan
A New Approach For Minimizing Torque Ripple In A Bldc Motor Drive With A Front End Ido Dc-Dc Converter, Ramya Amirthalingam, Balaji Mahadevan
Turkish Journal of Electrical Engineering and Computer Sciences
This paper proposes a front end integrated dual output (IDO) dc-dc converter for commutation torque ripple reduction in a permanent magnet brushless DC (BLDC) motor drive. The current ripple owed to the inductance and resistance of the motor during commutation instant results in torque ripple. In this work the dc link voltage of the converter is varied at commutation instants to minimize current ripple and hence torque ripple. The wider output range and faster response of the IDO converter make it a suitable choice as a front end converter for minimizing torque ripple. Simulation results validate the proposed converter for …
Multiphase Segmentation Based On New Signed Pressure Force Functions And One Level Set Function, Haider Ali, Noor Badshah, Ke Chen, Gulzar Ali Khan, Nosheen Zikria
Multiphase Segmentation Based On New Signed Pressure Force Functions And One Level Set Function, Haider Ali, Noor Badshah, Ke Chen, Gulzar Ali Khan, Nosheen Zikria
Turkish Journal of Electrical Engineering and Computer Sciences
In this paper we propose a new model to detect multiple objects of various intensities in images having maximum, minimum, or middle-intensity background by evolving only one level set function. In this model, a new signed pressure force function based on novel generalized averages is used for segmentation of images with maximum or minimum intensity background. For images with middle-intensity backgrounds, which are indeed challenging for 2-phase models, we propose a new product generalized signed pressure force function. Finally, to give experimental and qualitative evidence, our model is tested on both synthetic and real images with the Jaccard similarity index. …
K-Nn-Based Classification Of Sleep Apnea Types Using Ecg, Oğuz Han Ti̇muş, Emi̇ne Doğru Bolat
K-Nn-Based Classification Of Sleep Apnea Types Using Ecg, Oğuz Han Ti̇muş, Emi̇ne Doğru Bolat
Turkish Journal of Electrical Engineering and Computer Sciences
Obstructive sleep apnea syndrome (OSAS) is a common sleep disorder that yields cardiovascular diseases, excessive daytime sleepiness, and poor quality of life if not treated. Classification of OSAS from electrocardiograms (ECGs) is a noninvasive method and much more affordable than traditional methods. This study proposes a pattern recognition system for automated apnea diagnosis based on heart rate variability (HRV) and ECG-derived respiratory signals. The k-nearest neighbor (k-NN) classifier has been used to develop the models for classifying the sleep apnea types. For comparison purposes, classification models based on multilayer perceptron, support vector machines, and C4.5 decision tree (C4.5 DT) have …
Fuzzy Support Vector Machine Based On Hyperbolas Optimized By The Quantum-Inspired Gravitational Search Algorithm, Feng Ni, Yuzhu He, Fei Jiang
Fuzzy Support Vector Machine Based On Hyperbolas Optimized By The Quantum-Inspired Gravitational Search Algorithm, Feng Ni, Yuzhu He, Fei Jiang
Turkish Journal of Electrical Engineering and Computer Sciences
Fuzzy support vector machines (FSVMs) are known for their excellent antinoise performance, but there is no general rule when the fuzzy membership function (FMF) is set up. A novel FSVM based on hyperbolas optimized by the quantum-inspired gravitational search algorithm (QGSH-FSVM) is proposed to handle this question. In the proposed QGSH-FSVM, the FMF is defined by two disparate hyperbolas, whose eccentricities are optimized by the quantum-inspired gravitational search algorithm. A variable called diversity, revealing the percentage of a sample in different classes, is proposed to distinguish outliers or noises from valid samples. Experimental results confirm that the QGSH-FSVM is able …
Constrained Control Allocation For Nonlinear Systems With Actuator Failures Or Faults, Saman Ebrahimi Boukani, Mohammad Javad Khosrowjerdi, Roya Amjadifard
Constrained Control Allocation For Nonlinear Systems With Actuator Failures Or Faults, Saman Ebrahimi Boukani, Mohammad Javad Khosrowjerdi, Roya Amjadifard
Turkish Journal of Electrical Engineering and Computer Sciences
In this paper, a combination of dynamic constrained control allocation with terminal sliding mode control is proposed for a general class of overactuated nonlinear systems with actuator faults/failures. First, the terminal sliding mode control is designed to converge the system tracking error to zero in a finite-time. Then a control allocation strategy is developed and will be solved by a Lyapunov method, which leads to a dynamic update law with finite-time convergence. This strategy satisfies input limits and when faults/failures occur in some of the actuators, the control signals are automatically redistributed among the healthy actuators. Simulation results on a …
Horizontal Directional Drilling Pilot Bore Simulation, Paulius Tervydis, Ruta Jankuniene
Horizontal Directional Drilling Pilot Bore Simulation, Paulius Tervydis, Ruta Jankuniene
Turkish Journal of Electrical Engineering and Computer Sciences
Various underground communications (water or gas supply systems, sewage, power lines) have been installed in recent years using trenchless technologies, i.e. horizontal directional drilling (HDD). This technique by its nature does not disturb the traffic and is environmentally friendly. One must be aware that, with HDD, pipeline building time is shortened. With respect to the above, HDD is especially effective in highly populated or industrial areas. However, it is necessary to ensure that HDD works, in order to prevent damage to installed underground facilities. The aim of this work is to propose a user-friendly and inexpensive simulation tool with required …
Axial Flux Pm Bldc Motor Design Methodology And Comparison With A Radial Flux Pm Bldc Motor, Ertuğrul Yeşi̇lbağ, Yasemi̇n Ertuğrul, Lale Ergene
Axial Flux Pm Bldc Motor Design Methodology And Comparison With A Radial Flux Pm Bldc Motor, Ertuğrul Yeşi̇lbağ, Yasemi̇n Ertuğrul, Lale Ergene
Turkish Journal of Electrical Engineering and Computer Sciences
The aim of this paper is to develop a methodology to design an axial flux permanent magnet brushless direct current (AFPM) motor for a washing machine and compare the results with a conventional radial flux permanent magnet brushless direct current (RFPM) motor with the same power ratings. The AFPM motor is designed based on the maximum power density for an optimum inner-to-outer diameter ratio by using the reference RFPM motor constraints, such as the same rated torque at the rated speed. Both motors use the same materials in terms of lamination, permanent magnet, and conductor. They both use ferrite magnets; …
Lossless Predictive Coding Of Electric Signal Waveforms, Krzysztof Duda
Lossless Predictive Coding Of Electric Signal Waveforms, Krzysztof Duda
Turkish Journal of Electrical Engineering and Computer Sciences
This paper describes a new predictive coding algorithm designed for lossless compression of electric signal waveforms. Prediction coefficients are obtained from the sinusoidal signal autoregressive model. Predictors for a single sinusoid and the sum of two and three sinusoids are considered. Integer-to-integer coding is obtained by the proper (i.e. reversible) quantization of computations. The proposed coding algorithm shows better performance than the commonly used 2nd order differences coding and linear prediction coding that is optimal in the least squares sense.
A Reduced-Order Observer Based On Stator Flux Estimation With Straightforward Parameter Identification For Sensorless Control Of Dfigs, Rahim Ajabi Farshbaf, Mohammad Reza Azizian, Vahid Eslampanah
A Reduced-Order Observer Based On Stator Flux Estimation With Straightforward Parameter Identification For Sensorless Control Of Dfigs, Rahim Ajabi Farshbaf, Mohammad Reza Azizian, Vahid Eslampanah
Turkish Journal of Electrical Engineering and Computer Sciences
This paper presents a new reducer-order observer for sensorless control of doubly fed induction generators (DFIGs), based on the Luenberger algorithm. Stable operation of the suggested observer is also considered in the design guidelines. Stator flux is selected as the state variable for the observer and its estimation error is used to correct the observer operation. The gain matrix of the proposed observer is calculated on the basis of flux error dynamics. The adaptation mechanism of the proposed observer is selected based on an estimation of rotor currents. A proportional integrator (PI) block is used in the structure of the …
Fault Location Determination For Transmission Lines With Different Series-Compensation Levels Using Transient Frequencies, Düzgün Akmaz, Mehmet Sali̇h Mami̇ş, Müslüm Arkan, Mehmet Emi̇n Tağluk
Fault Location Determination For Transmission Lines With Different Series-Compensation Levels Using Transient Frequencies, Düzgün Akmaz, Mehmet Sali̇h Mami̇ş, Müslüm Arkan, Mehmet Emi̇n Tağluk
Turkish Journal of Electrical Engineering and Computer Sciences
In this paper, based on the theory of traveling waves, the fault distances on long transmission lines with various series-compensation levels are determined using transient current and voltage frequencies. Transmission lines with series compensation are modeled using Alternative Transients Program software with frequency-dependent effects on the line included in the simulation. The transient current and voltage signals are obtained from the model. A fast Fourier transform is used for frequency-domain conversion and fault location is estimated from the frequencies of fault-generated harmonics in the transient spectrum. The algorithm is implemented in MATLAB. To investigate the effect of compensation on accuracy, …