Електротехнички факултет [Научни радови] / Faculty of Electrical Engineering [Scientific papers]
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- СтавкаRenewable Energy-Powered Traffic Signalization as a Step to Carbon-Neutral Cities (The Case ofWestern Balkans)(MDPI, 2023) Vukovic, Marko; Miskic, Miroslav; Kastelan, Ivan; Lale, Srdjan; Forcan, Miodrag; Vukovic, Goran; Ikic, MarkoGlobal warming and its negative effect on the environment pose a great threat to the future of mankind. In order to overcome these challenges, EU countries have set the target of becoming climate neutral by 2050, a path defined through the policies of the European Green Deal. The Republic of Serbia and Bosnia and Herzegovina also agreed upon the same goal through the endorsement of the Green Agenda for the Western Balkans. One of the means to achieve this goal is by increasing the share of renewable energy sources. In this paper, we analyze the feasibility, challenges, and potential issues of substituting conventional traffic light signalization with signalization based on renewable energy sources on a national scale. An ad hoc questionnaire was used to collect data from representatives of most of the municipalities in the Republic of Srpska entity in Bosnia and Herzegovina and representatives of the city of Novi Sad in Serbia. In the city of Novi Sad, personal interviews were also carried out to collect additional information. The results of this research show that the implementation of solar-powered traffic lights is economically and environmentally viable. These results will provide the basis for understanding the benefits and challenges in the case of the application of traffic light signalization based on renewable energy sources.
- СтавкаA robust control design for multi-input LTI systems using discrete-time arbitrary order sliding mode approach(Elsevier, 2024) Peruničić-Draženović, Branislava; Milosavljević, Čedomir; Huseinbegović, Senad; Veselić, Boban; Petronijević, MilutinThis paper proposes a robust digital sliding mode control design for multi-input linear systems that provides the closed-loop system dynamics of an arbitrary order having a specified feasible spectrum of poles. By appropriate selection of auxiliary outputs according to the controllability indices of the system, the system is decoupled into a set of subsystems. The number of these subsystems is equal to the number of control inputs. The desired dynamic of the considered system is achieved using discrete-time higher order sliding mode, where the discrete-time sliding mode of appropriate order is realized in each subsystem. The robustness is based on the fact that the previous values of the matched disturbances are directly reflected in the present value of the switching variables and it will be enhanced by using an estimator/compensator based on integral of sliding function. This control structure looks like discrete-time super-twisting control. Effectiveness of the proposed control is analyzed and its impact on the control system performances is derived. The proposed control approach is illustrated by simulation examples.
- СтавкаA Zonal Approach for Wide-Area Temporary Voltage Quality Assessment in a Smart Grid(MDPI, 2024) Forcan, Miodrag; Simović, Aleksandar; Jokić, Srđan; Forcan, JovanaWide-area voltage quality assessment represents one of the mandatory objectives for distribution system operators in the development of advanced distribution management systems supporting smart grid requirements. This paper introduces a zonal approach for wide-area temporary voltage quality evaluation in a distribution network. The concept of temporary voltage quality evaluation and assessment is recommended to incentivize active/online management of voltage quality issues. A decision support system based on simple deterministic rules is proposed for rating the voltage quality zones in a distribution network and making recommendations to the distribution system operator. Voltage RMS level, unbalance, and total harmonic distortion are considered voltage quality indices representing the inputs in the decision support system. Residential, commercial, and industrial load types are considered when setting the thresholds for voltage quality indices. The proposed zonal approach for the division of distribution networks in voltage quality zones is applied to the example of a typical European-type distribution network. The operation of a decision support system is tested using the developed distribution smart grid model. The following simulation case studies are conducted: loads with low power factors, manual voltage regulation at MV/LV transformers, unbalanced loads, integration of solar power plant, and nonlinear loads. The obtained simulation results reveal the benefits of the proposed voltage quality assessment approach. Cybersecurity challenges that may impact the proposed approach are addressed, including security vulnerabilities, data privacy, and resilience to cyber threats.
- СтавкаAn Assessment of Extrapolated Field Strengths Versus Distance, Measurement Time, and Induced Traffic From 5G Base Station in C-Band(Institute of Electrical and Electronics Engineers Inc., 2024) WALI, SANGIN QAHTAN; SALI, ADUWATI; ŠUKA, DARKO; AERTS, SAM; ALKURAYŞI, MOHAMMED; LI, LU; ISMAIL, ALYANI; HASHIM, FAZIRULHISYAM; ALSAIDOSH, YASSER A.; GIL JIMÉNEZ, VÍCTOR P.; RUTTNER, MANFRED; OSMAN, ANWAR FAIZDThis study evaluates the maximum theoretical exposure to radiofrequency (RF) electromagnetic fields (EMFs) from a Fifth-generation (5G) New Radio (NR) base station (BS) while using four commonly used mobile applications: YouTube for video streaming, WhatsApp for voice calls, Instagram for posting pictures and videos, and running a Video game. Three factors that might affect exposure, i.e., distance of the measurement positions from the BS, measurement time, and induced traffic, were examined. Exposure was assessed through both instantaneous and time-averaged extrapolated field strengths using the Maximum Power Extrapolation (MPE) method. The former was calculated for every measured SS-RSRP (Secondary Synchronization Reference Signal Received Power) power sample obtained with a sampling resolution of 1 second, whereas the latter was obtained using a 1-min moving average applied on the applications’ instantaneous extrapolated field strengths datasets. Regarding distance, two measurement positions (MPs) were selected: MP1 at 56 meters and MP2 at 170 meters. Next, considering the measurement time, all mobile application tests were initially set to run for 30 minutes at both MPs, whereas the video streaming test (YouTube) was run for an additional 150 minutes to investigate the temporal evolution of field strengths. Considering the traffic, throughput data vs. both instantaneous and time-averaged extrapolated field strengths were observed for all four mobile applications. In addition, at MP1, a 30-minute test without a User Equipment (UE) device was conducted to analyze exposure levels in the absence of induced traffic. The findings indicated that the estimated field strengths for mobile applications varied. It was observed that distance and time had a more significant impact than the volume of data traffic generated (throughput).
- СтавкаNovel tuning rules for PIDC controllers in automatic voltage regulation systems under constraints on robustness and sensitivity to measurement noise(ELSEVIER, 2024) Bošković, Marko Č.; Šekara, Tomislav B.; Stojić, Djordje M.; Rapaić, Milan R.This paper presents a novel analytical method for designing the Proportional-Integral-Derivative controller with serial Compensator (PIDC) for automatic voltage regulation (AVR). The primary focus of this method is to address constraints related to robustness and sensitivity to measurement noise. The key concept behind this proposed design method lies in selecting a specific complementary sensitivity function, which is determined by two adjustable parameters, λ affecting performance and N primarily affecting robustness to measurement noise. The ultimate goal of the PIDC controller design is to achieve enhanced rejection of load disturbances and ensure satisfactory reference tracking. The method proposed in this paper offers a combination of flexibility and simplicity, providing new analytical tuning formulas for PIDC controller based on a pair of adjustable parameters affecting the trade-off between performance and robustness. The paper thoroughly analyzes the dependencies of performance and robustness indices on the design parameters, elucidating the associated trade-offs in detail. A comparative analysis with respect to two recently proposed optimal design methods has been performed in a simulation setting. Subsequently, the effectiveness of the proposed analytical method has been experimentally validated using a small-scale synchronous generator in a laboratory setting. The application of the proposed approach, resulting in enhanced suppression of disturbances is improved, as evidenced by improvements in the Integral of Absolute Error (IAE). Additionally, the proposed design method demonstrated robustness against uncertainties in the plant model and the measurement noise.