Elektronika ir Elektrotechnika https://eejournal.ktu.lt/index.php/elt <div>ELEKTRONIKA IR ELEKTROTECHNIKA is&nbsp;a peer-reviewed bimonthly research journal of Kaunas University of Technology.</div> <p>The research journal ELEKTRONIKA IR ELEKTROTECHNIKA publishes previously unpublished manuscripts that will have a high impact in the field of electronics and electrical engineering. It targets not only certain field specialists, but the wider public also.</p> Kaunas University of Technology en-US Elektronika ir Elektrotechnika 1392-1215 <p>Authors retain copyright and grant the journal the right of the first publication with the paper simultaneously licensed under the <a href="https://creativecommons.org/licenses/by/4.0/" target="_blank" rel="noopener">Creative Commons Attribution 4.0&nbsp;(CC BY 4.0)</a> licence.</p> <p>Authors are allowed to enter into separate, additional contractual arrangements for the non-exclusive distribution of the paper published in the journal with an acknowledgement of the initial publication in the journal.</p> <p>Copyright terms are indicated in the Republic of Lithuania Law on <a href="https://e-seimas.lrs.lt/portal/legalAct/lt/TAD/5f13b560b2b511e59010bea026bdb259?jfwid=9tq147ogj" target="_blank" rel="noopener">Copyright and Related Rights, Articles 4-37</a>.</p> Second-Order Fast Terminal Sliding Mode Control for MPPT of PMSG-based Wind Energy Conversion System https://eejournal.ktu.lt/index.php/elt/article/view/25762 <p>This article proposes a new maximum power point tracking (MPPT) controller based on voltage-mode Second-Order Fast Terminal Sliding Mode Control (SO-FTSMC) to obtain better performance in the power extraction from Permanent Magnet Synchronous Generator (PMSG)-based Wind Energy Conversion System (WECS). The major objective of the study is the design of SO-FTSMC that can ensure the operation of the system in maximum power reference with higher efficiency, less steady-state error, and voltage fluctuation. Maximum power references are determined by mechanical sensorless MPPT approach. The small-scale WECS configuration incorporates wind turbine, PMSG, uncontrolled rectifier, boost converter, and MPPT controller. SO-FTSMC method has not been performed before as a voltage regulator in such a topology. The proposed controller has been validated for two different wind speed test scenarios in simulation environment, which can be applied effectively to PMSG-based WECS. Moreover, Conventional SMC (C-SMC) is created and then performance of controllers is compared in these wind speed scenarios according to maximum extracted average power, output voltage fluctuation, and voltage error in steady-state, MPPT efficiency, and performance indices. Obtained results indicate that proposed SO-FTSMC-based MPPT controller achieves superior performance.</p> Emre Hasan Dursun Ahmet Afsin Kulaksiz Copyright (c) 2020 Elektronika ir Elektrotechnika 2020-08-07 2020-08-07 26 4 39 45 10.5755/j01.eie.26.4.25762 An Adaptive Protection Technique for Smart Distribution Network https://eejournal.ktu.lt/index.php/elt/article/view/25778 <p>The future distribution networks (DNs), commonly known as the smart grid is expected to be reliable, efficient, and can accommodate renewable energy resources. The smart distribution network has to withstand the technical challenges related to the integration of distributed generations (DGs). Among these technical challenges, protection malfunctioning with the increased integration of DGs is one of the important issues, which requires a great concern. Thus, a protection philosophy, which can suit the future smart grid requirements with respect to increased integration of DGs, has to be devised. In this paper, an adaptive protection technique, which is based on the characteristics of fault-current and load-current variation, is proposed. In the proposed method, intelligent electronic devices (IEDs) monitor the status of circuit breakers (CBs) and DGs. If any status change occurs, the calculation and relay agents are triggered to update the IEDs. DigSILENT PowerFactory is used to verify the suggested philosophy. Especially DigSILENT Programming Language (DPL) is used to model the adaptive protection. The solar power plant in the Antalya vicinity in Turkey is used to verify the proposed method. The results of the simulation study show the correct operation and effectiveness of the proposed method.</p> Abdulfetah Shobole Mustafa Baysal Mohammed Wadi Mehmet Rida Tur Copyright (c) 2020 Elektronika ir Elektrotechnika 2020-08-07 2020-08-07 26 4 46 56 10.5755/j01.eie.26.4.25778 Editorial Board https://eejournal.ktu.lt/index.php/elt/article/view/27460 Elektronika ir Elektrotechnika Copyright (c) 2020 Elektronika ir Elektrotechnika 2020-08-07 2020-08-07 26 4 2 3 A Development of a Capacitive Voltage Divider for High Voltage Measurement as Part of a Combined Current and Voltage Sensor https://eejournal.ktu.lt/index.php/elt/article/view/25888 <p>This article deals with the development of capacitive voltage divider for high voltage measurements and presents a method of analysis and optimization of its parameters. This divider is a part of a combined voltage and current sensor for measurements in high voltage power networks. The sensor allows continuous monitoring of the network distribution status and performs a quick diagnosis and location of possible network failures. Deployment of these devices will support semi-autonomous control of power networks and it can be considered as a step from traditional power grids toward smart grids. This is a worldwide trend connected with increasing number of renewable energy sources and plug-in electric vehicles as described in. In this way, it contributes to the reliability of the distribution network. Together with automated control techniques and fault location methods, it enables its self-healing capability. The following characteristics required for the sensor include: current measurement error up to 2&nbsp;%, voltage measurement error up to 0.5&nbsp;%, and power measurement error up to 5&nbsp;%. At the same time, it is necessary that the sensor is cost-effective - relatively cheap. There were selected capacitors made in series production for the capacitive divider designing. The capacitive voltage divider was tested in terms of time and temperature stability; the results are described in the paper. Then, the method of mathematical correction of a temperature dependence of the capacitive voltage divider was suggested and tested.</p> Roman Hrbac Vaclav Kolar Mikolaj Bartlomiejczyk Tomas Mlcak Petr Orsag Jakub Vanc Copyright (c) 2020 Elektronika ir Elektrotechnika 2020-08-07 2020-08-07 26 4 25 31 10.5755/j01.eie.26.4.25888 Exposure of Underground Cable Intrusion Detection System to Transient Disturbances Caused by Nearby Lightning Strikes https://eejournal.ktu.lt/index.php/elt/article/view/25847 <p>Electronic systems with extensive underground cable installations are endangered by damage or interference during lightning as a result of current and voltage surges induced in the installations. The paper presents the study on the lightning threat to the electronic intrusion detection system based on underground cable sensors during a nearby lightning strike to the pole of the lighting system installed in parallel with the sensory cables. In the extensive intrusion detection system working in a network composed of several controller-sensor-terminator units, a problem arises whether the neighbouring units should or should not be connected galvanically <strong>&nbsp;</strong>in order the system is less vulnerable to the effects of a lightning electromagnetic pulse. The problem is complex since the threat level may depend on many factors, i.e. the point of the strike, the lightning current, soil parameters, and configurations of the affected systems. The problem has been studied using numerical simulations based on the electromagnetic field theory and method of moments. The results show that the isolated configuration, i.e. without the galvanic continuity between the units, may be better as far as relatively low soil resistivity and low steepness of the lightning current waveform are considered.</p> Renata Markowska Copyright (c) 2020 Elektronika ir Elektrotechnika 2020-08-07 2020-08-07 26 4 11 17 10.5755/j01.eie.26.4.25847 Evaluation of GaN Power Transistor Switching Performance on Characteristics of Bidirectional DC-DC Converter https://eejournal.ktu.lt/index.php/elt/article/view/25782 <p>The paper deals with the experimental analysis of the switching performance of selected GaN (Galium Nitride) power transistor, whose use is then expected in bidirectional buck/boost DC-DC converter. The switching performance was evaluated through highly accurate and verified simulation models of GS61008P transistor from GaN systems. Experiments have been provided for a wide spectrum of switching frequency and load current in order to verify transistor performance. Then, based on the results, it was expected that high-frequency operation (above 500&nbsp;kHz) should not distort the efficiency performance of the designed bidirectional converter. This was confirmed after laboratory measurements of the efficiency of the proposed DC-DC converter, while operation under very high switching frequency was more effective compared to low-frequency operation. Over 95&nbsp;% of efficiency was achieved for both buck and boost mode (125&nbsp;W), even switching frequency was above 500&nbsp;kHz.</p> Michal Frivaldsky Jan Morgos Richard Zelnik Copyright (c) 2020 Elektronika ir Elektrotechnika 2020-08-07 2020-08-07 26 4 18 24 10.5755/j01.eie.26.4.25782 Dental Amalgam Influence on the Amount of Absorbed Energy from Mobile Phone https://eejournal.ktu.lt/index.php/elt/article/view/25811 <p>The topic of the research presented in this paper is numerical calculation and analysis of the electric field and Specific Absorption Rate (SAR) distributions in the vicinity of dental amalgam exposed to the radiation of mobile phone at the frequencies corresponding to 3G and 4G mobile networks. This is carried out by numerical solving of the electromagnetic propagation equation. The results related to different tissues and organs placed in the vicinity of dental amalgam and exposed to radiation are presented and analysed. In order to obtain the most accurate results, the realistic 3D model of human jaw has been created. A comparative analysis of models with and without dental amalgam has been carried out, with aim to determine the impact of amalgam on biological tissues in its vicinity. According to the obtained results, the maximum values of electric field strength and SAR are higher in the presence of dental amalgam. In both cases, maximum values are out of bounds of safety limits.</p> Nenad N. Cvetkovic Marko A. Dimitrijevic Dejan B. Jovanovic Dragana U. Zivaljevic Dragan D. Krasic Copyright (c) 2020 Elektronika ir Elektrotechnika 2020-08-07 2020-08-07 26 4 32 38 10.5755/j01.eie.26.4.25811 Reviewers https://eejournal.ktu.lt/index.php/elt/article/view/27462 Elektronika ir Elektrotechnika Copyright (c) 2020 Elektronika ir Elektrotechnika 2020-08-07 2020-08-07 26 4 79 79 Title https://eejournal.ktu.lt/index.php/elt/article/view/27459 Elektronika ir Elektrotechnika Copyright (c) 2020 Elektronika ir Elektrotechnika 2020-08-07 2020-08-07 26 4 1 1 Fuzzy Logic and Webster’s Optimal Cycle Based Decentralized Coordinated Adaptive Traffic Control Method https://eejournal.ktu.lt/index.php/elt/article/view/25959 <p>Traffic control systems for an urban traffic management play an important role in reducing congestion and the negative effects of social and economic aspects. In this paper, the coordinated control method for an arterial road network is proposed. The proposed method is based on fuzzy logic and Webster optimum cycle formula. It is a cyclic method, which means that all-feasible phases at the intersection are get at least a minimum green signal during each cycle. These minimum green times can be used for pedestrian crossing purposes. This method eliminates the starvation that occurs at minor roads due to the non-cyclic strategy. The proposed method is investigated in both coordinated and isolated circumstances. It is compared with non-optimized fixed time control and the cyclic backpressure strategy suggested in the literature. The cyclic backpressure strategy was selected due to its similarity with our proposed method. Based on the obtained results, the adaptive fuzzy logic and Webster based coordinated method outperforms the other methods in terms of the average of waiting time, travel time, travel speed, and queue lengths. In addition, the result achieved from a coordinated situation slightly superior that obtained from isolated situation, which means the proposed method provides good performance both in an isolated and coordinated situations.</p> Muzamil Eltejani Mohammed Ali Akif Durdu Seyit Alperen Celtek Seyfettin Sinan Gultekin Copyright (c) 2020 Elektronika ir Elektrotechnika 2020-08-07 2020-08-07 26 4 57 64 10.5755/j01.eie.26.4.25959 A Packet Delivery Cost Analysis of a Flow-Enabled Proxy NEMO Scheme in a Distributed Mobility Anchoring Environment https://eejournal.ktu.lt/index.php/elt/article/view/27442 <p>DMM (Distributed Mobility Management) is a present elective worldview for creating a mobility management scheme to discourse the centralized issues in present IP-based mobile environments. The main reason is to enable these schemes to adapt to the present increment in the number of mobile operators, as well as mobile information traffic size, just as the pattern in the mobile Internet towards Industry 4.0 in a flat architecture. Until this point, the advancement of schemes dependent on the DMM-based method is still at fundamental phases in the Internet Engineering Task Force (IETF), as well as there is no present standard set up. With the point of taking advantage of utilizing different interfaces all at once, this paper proposes an enhanced Flow-enabled Proxy NEMO scheme in a Distributed Mobility Anchoring (FPNEMO-DMA) environment. Besides, a mathematical approach is advanced to assess the performance of the proposed FPNEMO-DMA scheme and benchmark with the existing Nemo Basic Support Protocol (NBSP) and Proxy NEMO.</p> Shayla Islam Mohammad Kamrul Hasan Aisha Hassan Abdalla Hashim Copyright (c) 2020 Elektronika ir Elektrotechnika 2020-08-07 2020-08-07 26 4 65 71 10.5755/j01.eie.26.4.27442 Improved Hybrid Precoder Design for Secure mmWave MIMO Communications https://eejournal.ktu.lt/index.php/elt/article/view/25857 <p>Key challenges of emerging mobile communication systems are to provide higher data rates, diverse device connectivity, low latency, higher system capacity, and low energy consumption. The communication systems exploiting the millimeter-wave (mmWave) band are realized to resolve thereof inevitable issues. However, security is considered as one of the challenging issues in mmWave communication in addition to unavoidable problems (e.g., propagation loss, penetration loss, and fading). This study aims to construct efficient secure hybrid precoder with low-resolution phase shifters that can protect legitimate information from eavesdropping by employing coordinated analog precoder and combiner algorithms and improve the secrecy rate. Moreover, in order to further enhance the secrecy rate, hybrid precoder are obtained using an efficient channel. This work compares its results with the recent approach reported in the literature, which indicates that our proposed model outperforms at high signal-to-noise ratio (SNR) values, while our model provides similar performance at low SNR values. Simulation studies also confirm the effectiveness of the proposed hybrid precoder to achieve maximum secrecy rate.</p> Yasin Kabalci Muhammad Ali Copyright (c) 2020 Elektronika ir Elektrotechnika 2020-08-07 2020-08-07 26 4 72 77 10.5755/j01.eie.26.4.25857 A Fractional-Order Sliding Mode Controller Design for Trajectory Tracking Control of An Unmanned Aerial Vehicle https://eejournal.ktu.lt/index.php/elt/article/view/25846 <p>In this paper, a fractional-order sliding mode controller (FOSMC) is designed and applied to a four rotor unmanned aerial vehicle (Quadrotor) to perform trajectory tracking for different time-varying references. Because quadrotor’s nonlinear system dynamics are effected by external disturbances and parameter variations easily, the FOSMC is used as a nonlinear controller and utilized its disturbance rejection characteristics to keep quadrotor on desired trajectory as well as overcome parameter variations. In order to indicate the priority of the FOSMC, an integer-order SMC (IOSMC) is also applied to quadrotor for the same references. The experimental results show that FOSMC is better than IOSMC in terms of error elimination and is good at dealing with parameter variations occurred while tracking the desired trajectory</p> Abdullah Basci Adnan Derdiyok Kaan Can Kamil Orman Copyright (c) 2020 Elektronika ir Elektrotechnika 2020-08-07 2020-08-07 26 4 4 10 10.5755/j01.eie.26.4.25846