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Articles 4981 - 5010 of 13043

Full-Text Articles in Computer Engineering

A Ga-Based Adaptive Mechanism For Sensorless Vector Control Of Induction Motor Drives For Urban Electric Vehicles, Asma Boulmane, Youssef Zidani, Driss Belkhayat, Marouane Bouchouirbat Jan 2020

A Ga-Based Adaptive Mechanism For Sensorless Vector Control Of Induction Motor Drives For Urban Electric Vehicles, Asma Boulmane, Youssef Zidani, Driss Belkhayat, Marouane Bouchouirbat

Turkish Journal of Electrical Engineering and Computer Sciences

Induction motors are more attractive to car manufacturers because they are more robust and more cost effective to maintain in comparison with other types of electric machines. The evolution of their control makes them more efficient and less expensive. However, a new control technique known as sensorless control is being used to simplify the implementation of electric machines in electric vehicles. This technique involves replacing the flux and speed sensors with an observer. The estimation of these elements is based on the measurement of currents and voltages. The main purpose of the present study is to design a novel robust …


Experimental And Predicted Xlpe Cable Insulation Properties Under Uvradiation, Abdallah Hedir, Ali Bechouche, Mustapha Moudoud, Madjid Teguar, Omar Lamrous, Sebastien Rondot Jan 2020

Experimental And Predicted Xlpe Cable Insulation Properties Under Uvradiation, Abdallah Hedir, Ali Bechouche, Mustapha Moudoud, Madjid Teguar, Omar Lamrous, Sebastien Rondot

Turkish Journal of Electrical Engineering and Computer Sciences

This paper deals with the behavior of the crosslinked polyethylene (XLPE) used as high-voltage power cable insulation under ultraviolet (UV) radiations. For this, XLPE samples have been irradiated for 240 h using low-pressure vapor fluorescent lamps. Electrical (surface and volume resistivities), mechanical (tensile strength, elongation at break and surface hardness) and physical (weight loss, water absorption, work of water adhesion and contact angle) tests have been first carried out. Experimental results show that the XLPE characteristics are affected by UV radiation. Indeed, a decline in surface resistivity, mechanical properties, and contact angle, and an increase in the water retention amount …


Plane Wave Diffraction By Strip With An Integral Boundary Condition, Kami̇l Karaçuha, Vasil Tabatadze, Eldar Ismailovich Veliev Jan 2020

Plane Wave Diffraction By Strip With An Integral Boundary Condition, Kami̇l Karaçuha, Vasil Tabatadze, Eldar Ismailovich Veliev

Turkish Journal of Electrical Engineering and Computer Sciences

In this article, a new solution method is proposed for plane wave diffraction by a strip. On the surface of the strip, an integral boundary condition is used. The impedance of the strip is investigated. The theoretical and numerical analyses show that there is a relation between the complex-valued fractional order of the integral boundary condition and properties of the material such as the impedance. As a further study, the total radar cross-section is investigated using the proposed method.


Facest: Feedback-Assisted Estimation Of End-To-End Capacity In Ip-Basedcommunication Networks, Fati̇h Abut Jan 2020

Facest: Feedback-Assisted Estimation Of End-To-End Capacity In Ip-Basedcommunication Networks, Fati̇h Abut

Turkish Journal of Electrical Engineering and Computer Sciences

The end-to-end capacity, defined as the maximal transmission rate of the weakest link on the entire path between two end hosts, plays an important role in efficient network design and management. Although various capacity estimation tools have been proposed in the literature, there is still uncertainty in their accuracy and reliability when they are used in today's IP-based communication networks. The main reason for this is that all current capacity estimation tools only yield a potential candidate for an acceptable estimate, without being aware of its reliability level. In this study, we propose a new feedback-assisted end-to-end capacity estimation (FACEST) …


Deep Reinforcement Learning For Acceptance Strategy In Bilateral Negotiations, Yousef Razeghi, Celal Ozan Berk Yavuz, Reyhan Aydoğan Jan 2020

Deep Reinforcement Learning For Acceptance Strategy In Bilateral Negotiations, Yousef Razeghi, Celal Ozan Berk Yavuz, Reyhan Aydoğan

Turkish Journal of Electrical Engineering and Computer Sciences

This paper introduces an acceptance strategy based on reinforcement learning for automated bilateral negotiation, where negotiating agents bargain on multiple issues in a variety of negotiation scenarios. Several acceptance strategies based on predefined rules have been introduced in the automated negotiation literature. Those rules mostly rely on some heuristics, which take time and/or utility into account. For some negotiation settings, an acceptance strategy solely based on a negotiation deadline might perform well; however, it might fail in another setting. Instead of following predefined acceptance rules, this paper presents an acceptance strategy that aims to learn whether to accept its opponent's …


Zeki: Unsupervised Zero-Day Exploit Kit Intelligence, Emre Süren Jan 2020

Zeki: Unsupervised Zero-Day Exploit Kit Intelligence, Emre Süren

Turkish Journal of Electrical Engineering and Computer Sciences

Over the last few years, exploit kits (EKs) have become the de facto medium for large-scale spread of malware. Drive-by download is the leading method that is widely used by EK flavors to exploit web-based client-side vulnerabilities. Their principal goal is to infect the victim's system with a malware. In addition, EK families evolve quickly, where they port zero-day exploits for brand new vulnerabilities that were never seen before and for which no patch exists. In this paper, we propose a novel approach for categorizing malware infection incidents conducted through EKs by leveraging the inherent "overall URL patterns" in the …


Multiplicative-Additive Despeckling In Sar Images, Gülay Aksoy, Fati̇h Nar Jan 2020

Multiplicative-Additive Despeckling In Sar Images, Gülay Aksoy, Fati̇h Nar

Turkish Journal of Electrical Engineering and Computer Sciences

Visual and automatic analyses using synthetic aperture radar (SAR) images are challenging because of inherently formed speckle noise. Thus, reducing speckle noise in SAR images is an important research area for SAR image analysis. During speckle noise reduction, homogeneous regions should be smoothed while details such as edges and point scatterers need to be preserved. General speckle noise model contains gamma distributed multiplicative part which is dominant and Gaussian distributed additive part which is in low amount and mostly neglected in literature. In this study, a novel sparsity-driven speckle reduction method is proposed that takes both multiplicative noise model and …


Bases Of Polymatroids And Problems On Graphs, Hakan Kutucu Jan 2020

Bases Of Polymatroids And Problems On Graphs, Hakan Kutucu

Turkish Journal of Electrical Engineering and Computer Sciences

In the paper, we present new theorems to show that a Hamiltonian path and circuit on an undirected graph can be formulated in terms of bases of polymatroids or extended polymatroids associated with submodular functions defined on subsets of the node-set of a given graph. In this way, we give a new formulation of the well-known traveling salesman problem including constraints in these terms. The main result in the paper states that using a special base of the polymatroid, a Hamiltonian path on an undirected graph can be solved effectively. Since the determination of a Hamiltonian circuit can be reduced …


Harmonic Reduction Of Svc With System Integrated Apf, Yan Xuhui, Wang Feng, Mahmood Ul Hassan, Muhammad Humayun Jan 2020

Harmonic Reduction Of Svc With System Integrated Apf, Yan Xuhui, Wang Feng, Mahmood Ul Hassan, Muhammad Humayun

Turkish Journal of Electrical Engineering and Computer Sciences

Static var compensators (svcs) are widely used to compensate for reactive power in a system. The hybrid active power filter (hapf) in combination with svc has extensively been studied in the literature to reduce harmonics generated by the svc. This study proposes a new topology of svc for three-phase systems based on a three-phase thyristor-control reactor (tcr). The harmonics generated by the tcr are minimized by an active power filter (apf), which can be realized by a reduced resonant capacitor size. A control strategy comprising feedback and feedforward control is employed to achieve good harmonic reduction and fast transient response. …


Quasi-Physical Modeling Of Robot Irb 120 Using Simscape Multibody For Dynamicand Control Simulation, Truc Le Ngoc, Tung Lam Nguyen Jan 2020

Quasi-Physical Modeling Of Robot Irb 120 Using Simscape Multibody For Dynamicand Control Simulation, Truc Le Ngoc, Tung Lam Nguyen

Turkish Journal of Electrical Engineering and Computer Sciences

The mathematical model of robot that is used to design control algorithms is mostly reused in numerical simulations as a virtual plant. The use of same model for both control design and simulation tasks makes the outcome idealized. Consequently, the effectiveness and feasibility of designed control methodologies when applied in practice seem to be questionable. The paper presents the quasi-physical modeling of a 6-DOF robot using MATLAB/Simscape Multibody for dynamic and control simulation. The bodies of the robot are assembled into a physical network with connections that represent physical domains. The dynamical manners of the quasi-physical model are close to …


Performance Analysis Of A Fuzzy Disparity Selector For Stereo Matching Of Imagesegments Under Radiometric Variations, Akhil Appu Shetty, Vadakekara Itty George, Chempi Gurudas Nayak, Raviraj Shetty Jan 2020

Performance Analysis Of A Fuzzy Disparity Selector For Stereo Matching Of Imagesegments Under Radiometric Variations, Akhil Appu Shetty, Vadakekara Itty George, Chempi Gurudas Nayak, Raviraj Shetty

Turkish Journal of Electrical Engineering and Computer Sciences

Stereo matching algorithms generate disparity maps, which contain the depth information of the environment, from two or more images of a scene taken from different viewpoints. The process of obtaining dense disparity maps is a problem which is still being actively researched. The presence of radiometric differences in the images only further complicates the stereo matching problem. In the present research work, the images are initially split into small patches of pixels, such that pixels in each patch have similar intensities. The authors attempt to study the effect of the parameters, namely, tuning parameter `?? and the number of segments, …


Improvement Of The Distribution Network State Estimation With Increase Ofaccurate Information And Using A Two-Step Method, Karim Amiri, Rasool Kazemzadeh Jan 2020

Improvement Of The Distribution Network State Estimation With Increase Ofaccurate Information And Using A Two-Step Method, Karim Amiri, Rasool Kazemzadeh

Turkish Journal of Electrical Engineering and Computer Sciences

Distribution networks (DNs) are gradually changing and this makes their control and utilization complicated. State estimation (SE) plays a significant role in active distribution networks. The performance of the energy management center in modern distribution networks is highly dependent on the results obtained from the SE. In the present study, considering the shortage of measurements in the DN, a two-step state estimation method with a new network reduction process (NRP) is proposed. In the proposed method, a new NRP is used in a two-step state estimation method to improve the performance of SE in a DN. Obtaining accurate initial information …


An Efficient Reliability Simulation Tool For Lifetime-Aware Analog Circuit Synthesis, Engi̇n Afacan Jan 2020

An Efficient Reliability Simulation Tool For Lifetime-Aware Analog Circuit Synthesis, Engi̇n Afacan

Turkish Journal of Electrical Engineering and Computer Sciences

Time-dependent degradation (aging) has become more severe in modern CMOS technologies. Therefore, it is highly critical to capture the variation effects and design reliable circuits against aging. Simulation of time-dependent variations is quite complicated since the degradation is a function of time, where the step count of simulation directly affects the accuracy and the efficiency of the analysis. Commercial simulator tools use a constant step count during reliability simulations, in which choosing a large step count degrades the efficiency whereas keeping it small may result in accuracy problems. To overcome this bottleneck, a couple of different approaches have been proposed …


Dynamic Optimal Management Of A Hybrid Microgrid Based On Weather Forecasts, Hamadi Bouaicha, Emily Craparo, Habib Dallagi, Samir Nejim Jan 2020

Dynamic Optimal Management Of A Hybrid Microgrid Based On Weather Forecasts, Hamadi Bouaicha, Emily Craparo, Habib Dallagi, Samir Nejim

Turkish Journal of Electrical Engineering and Computer Sciences

Hybrid microgrids containing both renewable and conventional power sources are becoming increasingly attractive for a variety of reasons. However, intermittency of renewable power production and uncertainty in future load prediction increase risks of electric grid instability and, by consequence, restrict the portion of renewable power production in microgrids. In order, to prefigure the upcoming renewable power production, particularly, wind power and photovoltaic power, we suggest using weather forecasts. In addition to illustrating short term renewable power prediction based on ensemble weather forecasts, this paper focuses on optimizing the management of distributed power generation, power storage, and power exchange with the …


Transmit Antenna Selection Schemes For Stbc-Sm, Belal Asaati, Ammar Abu Hudrouss Jan 2020

Transmit Antenna Selection Schemes For Stbc-Sm, Belal Asaati, Ammar Abu Hudrouss

Turkish Journal of Electrical Engineering and Computer Sciences

The coupling of space-time block codes (STBCs) with the spatial modulation (SM) scheme can introduce a spatial diversity to the SM systems. This paper presents antenna selection techniques to provide an additional coding gain with the space-time block coded spatial modulation (STBC-SM). Specifically, the selection of optimal transmit antenna elements at the transmitter to send a spatially modulated space-time block code is studied. This paper studies the effects of applying the capacity optimized antenna selection (COAS) algorithm with the STBC-SM. The COAS algorithm has a suboptimal performance with a trade-off between complexity and bit-error-rate (BER) enhancement. Simulation results for STBC-SM …


The Quantum Version Of The Shifted Power Method And Its Application Inquadratic Binary Optimization, Ammar Daşkin Jan 2020

The Quantum Version Of The Shifted Power Method And Its Application Inquadratic Binary Optimization, Ammar Daşkin

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, we present a direct quantum adaptation of the classical shifted power method. The method is very similar to the iterative phase estimation algorithm; however, it does not require any initial estimate of an eigenvector, and as in the classical case its convergence and the required number of iterations are directly related to the eigengap. If the amount of the gap is in the order of $1/poly(n)$, then the algorithm can converge to the dominant eigenvalue in $O(poly(n))$ time. The method can be potentially used for solving any eigenvalue related problem and finding minimum/maximum of a data set …


Passenger Scoring For Free-Pass Promotion In Public Transportation, Ufuk Demi̇r Alan, Derya Bi̇rant Jan 2020

Passenger Scoring For Free-Pass Promotion In Public Transportation, Ufuk Demi̇r Alan, Derya Bi̇rant

Turkish Journal of Electrical Engineering and Computer Sciences

The focus of promotions targeted to increase the use of public transportation concentrates on increasing the attractiveness of it, particularly by decreasing transportation fares. To serve that purpose, this paper proposes a novel passenger scoring model, namely RFLT (recency, frequency, loyalty, and time), for offering a free-pass promotion in public transportation. It presents the comparison results of RFLT and wRFLT (weighted version) using a real-world dataset obtained by a near field communication (NFC) mobile payment application. The experimental results show that the w-RFLT model provides a more balanced score distribution than the RFLT model, and the frequency parameter (F), among …


A Content-Based Recommender System For Choosing Universities, Miftahul Jannat Mokarrama, Sumi Khatun, Mohammad Shamsul Arefin Jan 2020

A Content-Based Recommender System For Choosing Universities, Miftahul Jannat Mokarrama, Sumi Khatun, Mohammad Shamsul Arefin

Turkish Journal of Electrical Engineering and Computer Sciences

Recommender system (RS) is a knowledge discovery and decision-making system that has been extensively used in a myriad of applications to assist people in making distinct choices from vast sources. This paper proposes a recommendation system that will help the prospective students of Bangladesh in choosing the most suitable private universities for getting admission. Since selecting the best private university does not depend merely on a few criteria or choices and making a decision considering all those criteria is not an easy task, a recommendation system can be of great assistance in this scenario for the prospective students. In this …


Improving Performance Of Indoor Localization Using Compressive Sensing Andnormal Hedge Algorithm, Saeid Hassanhosseini, Mohammad Reza Taban, Jamshid Abouei, Arash Mohammadi Jan 2020

Improving Performance Of Indoor Localization Using Compressive Sensing Andnormal Hedge Algorithm, Saeid Hassanhosseini, Mohammad Reza Taban, Jamshid Abouei, Arash Mohammadi

Turkish Journal of Electrical Engineering and Computer Sciences

Accurate indoor localization technologies are currently in high demand in wireless sensor networks, which strongly drive the development of various wireless applications including healthcare monitoring, patient tracking and endoscopic capsule localization. The precise position determination requires exact estimation of the time varying characteristics of wireless channels. In this paper, we address this issue and propose a three-phased scheme, which employs an optimal single stage TDOA/FDOA/AOA indoor localization based on spatial sparsity. The first contribution is to formulate the received unknown signals from the emitter as a compressive sensing problem. Then, we solve an $\ell_1$ minimization problem to localize the emitter's …


Replica Bias Circuit For Common-Source Amplifier, Burak Kelleci̇ Jan 2020

Replica Bias Circuit For Common-Source Amplifier, Burak Kelleci̇

Turkish Journal of Electrical Engineering and Computer Sciences

A replica bias circuit to set the current of common-source amplifier to reduce the gain variations across process, voltage, and temperature (PVT) changes is proposed. The gain of a common-source amplifier is set by the load resistor and transistor transconductance which is set proportional to a resistor using a constant-gm bias circuit. The success of constant-gm biasing depends on the accuracy of copying of generated current to the transistor. The leakage current at the transistor gate due to the electrostatic discharge protection diodes prevents the matching of the common source transistor current to the constant-gm circuit current. A low-power replica …


A Random Subspace Based Conic Functions Ensemble Classifier, Emre Çi̇men Jan 2020

A Random Subspace Based Conic Functions Ensemble Classifier, Emre Çi̇men

Turkish Journal of Electrical Engineering and Computer Sciences

Classifiers overfit when the data dimensionality ratio to the number of samples is high in a dataset. This problem makes a classification model unreliable. When the overfitting problem occurs, one can achieve high accuracy in the training; however, test accuracy occurs significantly less than training accuracy. The random subspace method is a practical approach to overcome the overfitting problem. In random subspace methods, the classification algorithm selects a random subset of the features and trains a classifier function trained with the selected features. The classification algorithm repeats the process multiple times, and eventually obtains an ensemble of classifier functions. Conic …


A 88 $\Mu W$ Digital Phase-Domain Gfsk Demodulator Compatible With Low-If And Zero-If Receiver With Preamble Detection For Ble, Shen Jie Ung, Ab Al-Hadi Ab Rahman Jan 2020

A 88 $\Mu W$ Digital Phase-Domain Gfsk Demodulator Compatible With Low-If And Zero-If Receiver With Preamble Detection For Ble, Shen Jie Ung, Ab Al-Hadi Ab Rahman

Turkish Journal of Electrical Engineering and Computer Sciences

Unlike conventional analog-to-digital converter (ADC), phase-domain ADC (Ph-ADC) is more power efficient for the implementation of fully digital Gaussian frequency shift keying (GFSK) demodulator in bluetooth low energy (BLE). Besides, Ph-ADC based demodulator is flexible to pair with low-IF and zero-IF receiver, opposed to limiter based demodulator that work with low-IF receiver only. Yet, currently reported Ph-ADC based demodulator lack of preamble detection for BLE which will be used as symbol clock synchronization. In this work, a Ph-ADC based demodulator is proposed with the feature of preamble detection on BLE's packet. The detected preamble is used for symbol clock recovery …


Bibsqlqc: Brown Infomax Boosted Sql Query Clustering Algorithm To Detectanti-Patterns In The Query Log, Vinothsaravanan Ramakrishnan, Palanisamy Chenniappan Jan 2020

Bibsqlqc: Brown Infomax Boosted Sql Query Clustering Algorithm To Detectanti-Patterns In The Query Log, Vinothsaravanan Ramakrishnan, Palanisamy Chenniappan

Turkish Journal of Electrical Engineering and Computer Sciences

Discovery of antipatterns from arbitrary SQL query log depends on the static code analysis used to enhance the quality and performance of software applications. The existence of antipatterns reduces the quality and leads to redundant SQL statements. SQL log includes a large load on the database and it is difficult for an analyst to extract large patterns in a minimal time. Existing techniques which discover antipatterns in SQL query face a lot of innumerable challenges to discover the normal sequences of queries within the log. In order to discover the antipatterns in the log, an efficient technique called Brown infomax …


Disturbance Observer Based Control Of Twin Rotor Aerodynamic System, Hamid Ali, Ahsan Ali, Inam Ul-Hasan Shaikh Jan 2020

Disturbance Observer Based Control Of Twin Rotor Aerodynamic System, Hamid Ali, Ahsan Ali, Inam Ul-Hasan Shaikh

Turkish Journal of Electrical Engineering and Computer Sciences

Twin rotor aerodynamic system (TRAS) approximates the dynamics of helicopters and other vertical take off rotor crafts. The nonlinear nature with significant cross-coupling between the inputs and outputs of the main and tail rotors make the control of such system for either stabilization or reference tracking a challenging task. In this paper, the problem of disturbance rejection for TRAS is addressed by designing disturbance observers through $H_{\infty}$ based approach. The system is decoupled into main and tail rotors subsystems. For each subsystem, an inner loop disturbance observer is synthesized that provides disturbance rejection, whereas to ensure stability and performance an …


Net-Lda: A Novel Topic Modeling Method Based On Semantic Document Similarity, Eki̇n Eki̇nci̇, Sevi̇nç İlhan Omurca Jan 2020

Net-Lda: A Novel Topic Modeling Method Based On Semantic Document Similarity, Eki̇n Eki̇nci̇, Sevi̇nç İlhan Omurca

Turkish Journal of Electrical Engineering and Computer Sciences

Topic models, such as latent Dirichlet allocation (LDA), allow us to categorize each document based on the topics. It builds a document as a mixture of topics and a topic is modeled as a probability distribution over words. However, the key drawback of the traditional topic model is that it cannot handle the semantic knowledge hidden in the documents. Therefore, semantically related, coherent and meaningful topics cannot be obtained. However, semantic inference plays a significant role in topic modeling as well as in other text mining tasks. In this paper, in order to tackle this problem, a novel NET-LDA model …


Peri-Net: A Parameter Efficient Residual Inception Network For Medical Imagesegmentation, Fatmatülzehra Uslu, Cher Bass, Anil A. Bharath Jan 2020

Peri-Net: A Parameter Efficient Residual Inception Network For Medical Imagesegmentation, Fatmatülzehra Uslu, Cher Bass, Anil A. Bharath

Turkish Journal of Electrical Engineering and Computer Sciences

Recent developments in deep networks allow us to train networks with more parameters by yielding better performance given sufficient amount of data. However, we are still restricted with the availability of labelled data in medical image segmentation, where the problem is exacerbated with high intra- and intervariability of anatomical structures. In order to bypass this problem without compromising network performance, this study introduces a PERINet, which promises to achieve higher performance while being with smaller parameter count such as on the order of 0.8 million than its counterparts. The network benefits from rich features generated by our versions of inception …


Controlling A Launch Vehicle At Exoatmospheric Flight Conditions Via Adaptivecontrol Allocation, Yildiray Yildiz Jan 2020

Controlling A Launch Vehicle At Exoatmospheric Flight Conditions Via Adaptivecontrol Allocation, Yildiray Yildiz

Turkish Journal of Electrical Engineering and Computer Sciences

The focus of this paper is the control of a reusable launch vehicle at exoatmospheric flight conditions, in the presence of actuator effectiveness uncertainty. Since during exoatmospheric flight, dynamic pressure is nonexistent, aerodynamic control surfaces cannot be used. Under these conditions, reaction control jet actuators can provide the necessary thrust to control the vehicle. Reaction control jets have only 2 states, namely, on and off, and continuous control inputs can be implemented with the help of pulse width modulation, which is also employed in this paper. A continuous controller is designed in the outer loop and a control allocator is …


A Secure And Energy-Efficient Opportunistic Routing Protocol With Void Avoidancefor Underwater Acoustic Sensor Networks, Varun Menon, Divya Midhunchakkaravarthy, Sonali John, Sunil Jacob, Amrit Mukherjee Jan 2020

A Secure And Energy-Efficient Opportunistic Routing Protocol With Void Avoidancefor Underwater Acoustic Sensor Networks, Varun Menon, Divya Midhunchakkaravarthy, Sonali John, Sunil Jacob, Amrit Mukherjee

Turkish Journal of Electrical Engineering and Computer Sciences

Recently, underwater acoustic sensor networks (UASNs) have gained wide attention due to their numerous applications in underwater surveillance, oil leakage detection, assisted navigation, and disaster prevention. With unique characteristics like increased propagation delay, constant mobility of sensor nodes, high error rate, and limitations in energy and interference, efficient routing of data packets from the source node to the destination is a major challenge in UASNs. Most of the protocols proposed for traditional sensor networks do not work well in UASNs. Although many protocols have been specifically proposed for underwater environments, the aim of most of them is to improve only …


Simplified Model Predictive Current Control Of Non-Sinusoidal Low Power Brushlessdc Machines, Alireza Lahooti Eshkevari, Hossein Torkaman Jan 2020

Simplified Model Predictive Current Control Of Non-Sinusoidal Low Power Brushlessdc Machines, Alireza Lahooti Eshkevari, Hossein Torkaman

Turkish Journal of Electrical Engineering and Computer Sciences

Several strategies have been proposed to control nonsinusoidal brushless DC machines (BLDCMs). However, high electromagnetic torque ripple and current overshoots occur in commutation times, which are significant problems of those strategies such as for hysteresis current controllers. This paper proposes a model predictive strategy to solve the above issues. It is simple and straightforward. Moreover, it reduces the motor torque ripple significantly and improves the response rate of the control system to the load torque variation in comparison with the conventional technique. The torque varies smoothly, and the performance of the system at commutation time is improved by eliminating the …


Partial Discharge Detection And Localization On The Medium Voltage Xlpe Cableswith Multiclass Support Vector Machines, Fati̇h Serttaş, Fati̇h Onur Hocaoğlu Jan 2020

Partial Discharge Detection And Localization On The Medium Voltage Xlpe Cableswith Multiclass Support Vector Machines, Fati̇h Serttaş, Fati̇h Onur Hocaoğlu

Turkish Journal of Electrical Engineering and Computer Sciences

In medium voltage cables, partial discharges (PD?s) are the major problems that trigger electrical insulation failures. Therefore, classification of PD source type and failure localization in medium voltage cables are significant issues of medium voltage engineering. Therefore, in this study, both detection and localization of PD are studied. As a first step, 4 different kind of defects are artificially generated at the same length of the same kind of medium voltage cross-linked polyethylene (XLPE) cables. Consequently, an experimental setup is built. During the experiments, different medium voltage levels are applied to the cables, then the PD signals are measured and …