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Open AccessEditorial

Preface and Statement of Peer-Review: The 6th International Conference on Communications, Information, Electronic and Energy Systems (CIEES 2025)

by Teodor Iliev, Ivaylo Stoyanov and Grigor Mihaylov

Eng. Proc. 2026, 122(1), 30; https://doi.org/10.3390/engproc2026122030 - 30 Jan 2026

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Abstract

The conference is aimed to provide an international forum for researchers, academics, people in industry, and students to address recent research results and to present and discuss their ideas, theories, technologies, systems, tools, applications, works in progress and experiences on all theoretical and [...] Read more.

The conference is aimed to provide an international forum for researchers, academics, people in industry, and students to address recent research results and to present and discuss their ideas, theories, technologies, systems, tools, applications, works in progress and experiences on all theoretical and practical issues arising in telecommunications, electronics, signal processing and applications, information technologies, energy, automotive and industrial engineering. Full article

(This article belongs to the Proceedings of The 6th International Conference on Communications, Information, Electronic and Energy Systems)

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14 pages, 1359 KB

Open AccessProceeding Paper

Non-Parametric Model for Curvature Classification of Departure Flight Trajectory Segments

by Lucija Žužić, Ivan Štajduhar, Jonatan Lerga and Renato Filjar

Eng. Proc. 2026, 122(1), 1; https://doi.org/10.3390/engproc2026122001 - 13 Jan 2026

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Abstract

This study introduces a novel approach for classifying flight trajectory curvature, focusing on early-stage flight characteristics to detect anomalies and deviations. The method intentionally avoids direct coordinate data and instead leverages a combination of trajectory-derived and meteorological features. This research analysed 9849 departure [...] Read more.

This study introduces a novel approach for classifying flight trajectory curvature, focusing on early-stage flight characteristics to detect anomalies and deviations. The method intentionally avoids direct coordinate data and instead leverages a combination of trajectory-derived and meteorological features. This research analysed 9849 departure flight trajectories originating from 14 different airports. Two distinct trajectory classes were established through manual visual inspection, differentiated by curvature patterns. This categorisation formed the ground truth for evaluating trained machine learning (ML) classifiers from different families. The comparative analysis demonstrates that the Random Forest (RF) algorithm provides the most effective classification model. RF excels at summarising complex trajectory information and identifying non-linear relationships within the early-flight data. A key contribution of this work is the validation of specific predictors. The theoretical definitions of direction change (using vector values to capture dynamic movement) and diffusion distance (using scalar values to represent static displacement) proved highly effective. Their selection as primary predictors is supported by their ability to represent the essential static and dynamic properties of the trajectory, enabling the model to accurately classify flight paths and potential deviations before the flight is complete. This approach offers significant potential for enhancing real-time air traffic monitoring and safety systems. Full article

(This article belongs to the Proceedings of The 6th International Conference on Communications, Information, Electronic and Energy Systems)

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12 pages, 3547 KB

Open AccessProceeding Paper

A Study on Fuzzy PID Controllers with a Parallel Structure for Electro-Hydraulic Servo System Control

by Georgi Mihalev, Stanimir Yordanov, Krasimir Ormandzhiev, Stefan Ivanov and Hristina Stoycheva

Eng. Proc. 2026, 122(1), 2; https://doi.org/10.3390/engproc2026122002 - 14 Jan 2026

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Abstract

This paper presents the design of a fuzzy PID controller with a parallel structure for controlling an electro-hydraulic servo system. The main factors affecting control performance in electro-hydraulic systems are discussed in detail. The proposed fuzzy controller features a specific structure obtained through [...] Read more.

This paper presents the design of a fuzzy PID controller with a parallel structure for controlling an electro-hydraulic servo system. The main factors affecting control performance in electro-hydraulic systems are discussed in detail. The proposed fuzzy controller features a specific structure obtained through a coefficient transfer approach from a classical PID controller, enabling seamless integration of the fuzzy logic component and simplifying the tuning process. Relevant mathematical equations and dependencies are provided. The closed-loop system’s stability is analyzed using the BIBO (Bounded Input, Bounded Output) criterion. The designed controller is implemented in the MATLAB/Simulink 2019 environment and tested using a real-time measurement and control system. Graphical results are presented, illustrating the performance of the closed-loop system under step and sinusoidal reference signals. The obtained results confirm the qualities and proper tuning of the implemented controller. Full article

(This article belongs to the Proceedings of The 6th International Conference on Communications, Information, Electronic and Energy Systems)

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12 pages, 2700 KB

Open AccessProceeding Paper

A Low-Cost and Reliable IoT-Based NFT Hydroponics System Using ESP32 and MING Stack

by Tolga Demir and İhsan Çiçek

Eng. Proc. 2026, 122(1), 3; https://doi.org/10.3390/engproc2026122003 - 14 Jan 2026

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Abstract

This paper presents the design and implementation of an IoT-based automation system for indoor hydroponic plant cultivation using the Nutrient Film Technique. The system employs an ESP32-based controller with multiple sensors and actuators. These enable real-time monitoring and control of pH, TDS, temperature, [...] Read more.

This paper presents the design and implementation of an IoT-based automation system for indoor hydroponic plant cultivation using the Nutrient Film Technique. The system employs an ESP32-based controller with multiple sensors and actuators. These enable real-time monitoring and control of pH, TDS, temperature, humidity, light, tank level, and flow conditions. A modular five-layer architecture was developed. It combines the MING stack, which includes MQTT communication, InfluxDB time-series storage, Node-RED flow processing, and Grafana visualization. The system also includes a Flutter-based mobile app for remote access. Key features include temperature-compensated calibration, hysteresis-based control algorithms, dual-mode operation, TLS/ACL security, and automated alarm mechanisms. These features enhance reliability and safety. Experimental results showed stable pH/TDS regulation, dependable actuator and alarm responses, and secure long-term data logging. The proposed open-source and low-cost platform is scalable. It provides a solution for small-scale producers and urban farming, bridging the gap between academic prototypes and production-grade smart agriculture systems. In comparison to related works that mainly focus on monitoring, this study advances the state of the art. It combines continuous time-series logging, secure communication, flow verification, and integrated safety mechanisms to provide a reproducible testbed for future smart agriculture research. Full article

(This article belongs to the Proceedings of The 6th International Conference on Communications, Information, Electronic and Energy Systems)

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10 pages, 2382 KB

Open AccessProceeding Paper

Integrated Potential for Wind and Solar Energy in the Context of Sustainable Development of the Coastal Regions of Bulgaria

by Rositsa Velichkova, Iskra Simova, Elitsa Gieva, Angel Aleksandrov and Aleksandar Stanilov

Eng. Proc. 2026, 122(1), 4; https://doi.org/10.3390/engproc2026122004 - 14 Jan 2026

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Abstract

This study presents a comparative analysis of the potential for combined use of wind and solar energy in nine key coastal settlements on the Bulgarian Black Sea coast—Shabla, Balchik, Varna, Byala, Obzor, Nesebar, Burgas, Primorsko, and Tsarevo—selected for their diverse geographical and meteorological [...] Read more.

This study presents a comparative analysis of the potential for combined use of wind and solar energy in nine key coastal settlements on the Bulgarian Black Sea coast—Shabla, Balchik, Varna, Byala, Obzor, Nesebar, Burgas, Primorsko, and Tsarevo—selected for their diverse geographical and meteorological characteristics. The study evaluates the feasibility of implementing hybrid renewable energy systems by analyzing the average annual solar radiation and wind velocity for each location. A methodology based on physical and technical parameters is applied to determine the required installed capacity of photovoltaic systems to meet the average annual household electricity consumption of 6000 kWh. Concurrently, wind energy potential is assessed through theoretical and practical models using two turbine sizes (3 m and 6 m in diameter), which represent small-scale residential wind applications. Full article

(This article belongs to the Proceedings of The 6th International Conference on Communications, Information, Electronic and Energy Systems)

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9 pages, 1778 KB

Open AccessProceeding Paper

Simple Experimental Evaluation of a Quantum Computer via Tomography and GHz States

by Darin Peev and Yordan Sivkov

Eng. Proc. 2026, 122(1), 5; https://doi.org/10.3390/engproc2026122005 - 14 Jan 2026

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Abstract

This paper presents a simple experimental method for evaluating a superconducting quantum processor through two-qubit quantum state tomography and generalized GHZ-state benchmarking. The goal is to provide an accessible procedure for assessing hardware fidelity and entanglement capability. The method was demonstrated using IBM’s [...] Read more.

This paper presents a simple experimental method for evaluating a superconducting quantum processor through two-qubit quantum state tomography and generalized GHZ-state benchmarking. The goal is to provide an accessible procedure for assessing hardware fidelity and entanglement capability. The method was demonstrated using IBM’s 127-qubit ibm_brisbane device, where each Bell state was prepared and reconstructed from 10,000 shots, and the resulting fidelities were compared to Qiskit Aer simulations. The method further examines multi-qubit GHZ states to gauge scalability. The main advantages are its simplicity, reproducibility on free IBM Quantum hardware, and its suitability for entry-level experimentation and performance evaluation. Full article

(This article belongs to the Proceedings of The 6th International Conference on Communications, Information, Electronic and Energy Systems)

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10 pages, 1995 KB

Open AccessProceeding Paper

Methodology for Selecting an Electric Pump and Battery Pack for a Low-Thrust LRE: Computational Simulation Study

by Kenzhebek Myrzabekov, Kuanysh Alipbayev, Akylbek Bapyshev, Zhandos Kozhabek, Nazgul Kaliyeva and Makpal Nogaibayeva

Eng. Proc. 2026, 122(1), 6; https://doi.org/10.3390/engproc2026122006 - 14 Jan 2026

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Abstract

The paper offers a practical method for selecting an electric pump and battery pack for low-thrust liquid rocket engines. The approach combines 0D/1D modeling of hydraulic, electromechanical, and thermal subsystems in a single environment and is supplemented by sensitivity analysis, correlation analysis, and [...] Read more.

The paper offers a practical method for selecting an electric pump and battery pack for low-thrust liquid rocket engines. The approach combines 0D/1D modeling of hydraulic, electromechanical, and thermal subsystems in a single environment and is supplemented by sensitivity analysis, correlation analysis, and Monte Carlo simulation with N = 3000 iterations to verify the stability of the estimates. The methodology has been tested on mission profiles in the 5–50 kN thrust range and shows that the electric pump scheme is most effective at low thrusts, while an increase in thrust leads to a disproportionate increase in energy and thermal loads and narrows the scope of applicability. The determining factors remain the hydraulic efficiency of the pump η_pump and the oxidizer pressure; electrical parameters such as bus voltage and internal battery resistance have less influence and become noticeable at high power levels. Modeling confirms the stability of the obtained estimates; at a thrust of 20 kN, the spread of the battery block mass is close to ±10%. The proposed methodology provides quantitative guidelines in the early stages of design and helps to justify the scope of application of electric pump liquid rocket engines; expansion beyond low thrust requires progress in battery technologies. Full article

(This article belongs to the Proceedings of The 6th International Conference on Communications, Information, Electronic and Energy Systems)

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10 pages, 492 KB

Open AccessProceeding Paper

Precision Localization of Autonomous Vehicles in Urban Environments: An Experimental Study with RFID Markers

by Svetozar Stefanov, Valentina Markova and Miroslav Markov

Eng. Proc. 2026, 122(1), 7; https://doi.org/10.3390/engproc2026122007 - 14 Jan 2026

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Abstract

This paper presents an experimental study validating the feasibility of Radio Frequency Identification (RFID) marker systems as a complementary solution for autonomous vehicle (AV) localization in Global Navigation Satellite System (GNSS)-degraded urban environments. A novel synchronized dynamic testbed featuring hardware-level integration with wheel [...] Read more.

This paper presents an experimental study validating the feasibility of Radio Frequency Identification (RFID) marker systems as a complementary solution for autonomous vehicle (AV) localization in Global Navigation Satellite System (GNSS)-degraded urban environments. A novel synchronized dynamic testbed featuring hardware-level integration with wheel revolution tracking enables precise correlation of RFID marker reads with vehicle angular position. Experimental results demonstrate that multi-antenna configurations achieve consistently high read success rates (up to 99.6% at 0.5 m distance), sub-meter localization accuracy (~55 cm marker spacing), and reliable performance at average urban speeds (36 km/h simulated velocity). Spatial diversity from four strategically positioned antennas overcomes multipath interference and orientation challenges inherent to high-speed RFID reading. Processing latency remains well within the 58 ms time budget critical for autonomous navigation. These findings validate RFID’s potential for smart road infrastructure integration and demonstrate a scalable, cost-effective solution for enhancing AV safety and decision-making capabilities through contextual information transmission. Full article

(This article belongs to the Proceedings of The 6th International Conference on Communications, Information, Electronic and Energy Systems)

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9 pages, 955 KB

Open AccessProceeding Paper

LiDAR-Based 3D Mapping Approach for Estimating Tree Carbon Stock: A University Campus Case Study

by Abdul Samed Kaya, Aybuke Buksur, Yasemin Burcak and Hidir Duzkaya

Eng. Proc. 2026, 122(1), 8; https://doi.org/10.3390/engproc2026122008 - 15 Jan 2026

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Abstract

This study aims to develop and demonstrate a low-cost LiDAR-based 3D mapping approach for estimating tree carbon stock in university campuses. Unlike conventional field-based measurements, which are labor-intensive and error-prone, the proposed system integrates a 2D LiDAR sensor with a servo motor and [...] Read more.

This study aims to develop and demonstrate a low-cost LiDAR-based 3D mapping approach for estimating tree carbon stock in university campuses. Unlike conventional field-based measurements, which are labor-intensive and error-prone, the proposed system integrates a 2D LiDAR sensor with a servo motor and odometry data to generate three-dimensional point clouds of trees. From these data, key biometric parameters such as diameter at breast height (DBH) and total height are automatically extracted and incorporated into species-specific and generalized allometric equations, in line with IPCC 2006/2019 guidelines, to estimate above-ground biomass, below-ground biomass, and total carbon storage. The experimental study is conducted over approximately 70,000 m² of green space at Gazi University, Ankara, where six dominant species have been identified, including Cedrus libani, Pinus nigra, Platanus orientalis, and Ailanthus altissima. Results revealed a total carbon stock of 16.82 t C, corresponding to 61.66 t CO₂eq. Among species, Cedrus libani (29,468.86 kg C) and Ailanthus altissima (13,544.83 kg C) showed the highest contributions, while Picea orientalis accounted for the lowest. The findings confirm that the proposed system offers a reliable, portable, cost-effective alternative to professional LiDAR scanners. This approach supports sustainable campus management and highlights the broader applicability of low-cost LiDAR technologies for urban carbon accounting and climate change mitigation strategies. Full article

(This article belongs to the Proceedings of The 6th International Conference on Communications, Information, Electronic and Energy Systems)

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11 pages, 3899 KB

Open AccessProceeding Paper

Computation of Conduction and Displacement Current Densities in Modelled Human Organs near an Overhead Transmission Line

by Cvetanka Bilbiloska, Elena Todorova, Bojan Glushica and Andrijana Kuhar

Eng. Proc. 2026, 122(1), 9; https://doi.org/10.3390/engproc2026122009 - 15 Jan 2026

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Abstract

This study employs numerical simulations to analyse current densities in modelled human organs originating from extremely low frequency (ELF) electromagnetic fields emanating from a 110 kV single-circuit high-voltage transmission line. Exposure to these ELF fields gives rise to both conduction and displacement currents [...] Read more.

This study employs numerical simulations to analyse current densities in modelled human organs originating from extremely low frequency (ELF) electromagnetic fields emanating from a 110 kV single-circuit high-voltage transmission line. Exposure to these ELF fields gives rise to both conduction and displacement currents within the human body, potentially perturbing endogenous bioelectric currents and raising concerns of health risks. Using CST Studio Suite 2018 software, a three-dimensional multipart ellipsoidal anatomical model is developed to analyse these phenomena. Although displacement currents have lower magnitudes than conduction currents, they contribute significantly to the total current density and must therefore be included in rigorous safety assessments. Simulation results indicate that the current density values remain below the basic restrictions of the International Commission on Non-Ionizing Radiation Protection. Full article

(This article belongs to the Proceedings of The 6th International Conference on Communications, Information, Electronic and Energy Systems)

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10 pages, 2128 KB

Open AccessProceeding Paper

Artificial Neural Network Model for Predicting the Characteristics of a Solar Vacuum Tube System for Domestic Hot Water Heating

by Mariyana Sestrimska, Nikolay Komitov and Margarita Terziyska

Eng. Proc. 2026, 122(1), 10; https://doi.org/10.3390/engproc2026122010 - 15 Jan 2026

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Abstract

The use of different energy sources for heating and year-round domestic water heating is driven by the European Union’s increasingly strict environmental and climate requirements. For this reason, consumers are seeking alternatives and show growing interest in implementing installations that utilize solar energy. [...] Read more.

The use of different energy sources for heating and year-round domestic water heating is driven by the European Union’s increasingly strict environmental and climate requirements. For this reason, consumers are seeking alternatives and show growing interest in implementing installations that utilize solar energy. Modern households typically employ at least two different energy sources for this purpose. In practice, these are hybrid installations that, depending on the season, can operate with one, two, or more energy sources. The system examined in this paper is of this type, comprising a pellet boiler, solar vacuum tubes, and electric heaters. Managing such a system is complex, and based on the conducted studies, process optimization can be pursued. This report presents an artificial neural network (ANN) model developed to predict the behavior of a real solar installation for domestic hot water heating during the summer season. This study aims, through the obtained model, to forecast the system’s performance during transitional periods such as autumn and spring, thereby enabling more efficient control. Full article

(This article belongs to the Proceedings of The 6th International Conference on Communications, Information, Electronic and Energy Systems)

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7 pages, 1304 KB

Open AccessProceeding Paper

Study of the Effect of Higher-Order Harmonics on the Frequency Response Analysis of Series Resonant Converter

by Dimitar Spirov, Angel Lichev, Vasil Mihov, Yasen Madankov and Hristo Vargov

Eng. Proc. 2026, 122(1), 11; https://doi.org/10.3390/engproc2026122011 - 15 Jan 2026

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Abstract

This paper presents an investigation of the influence of higher-order harmonics on the frequency-response characteristics of a full-bridge series-resonant DC-DC converter. A Fourier series-based analytical method is developed to include these harmonics, providing a more accurate representation of voltage and current waveforms within [...] Read more.

This paper presents an investigation of the influence of higher-order harmonics on the frequency-response characteristics of a full-bridge series-resonant DC-DC converter. A Fourier series-based analytical method is developed to include these harmonics, providing a more accurate representation of voltage and current waveforms within the resonant tank, as well as in the converter input and output. The frequency characteristics, total harmonic distortion (THD) and ripple factors of the converter are derived for various quality factors and normalized frequencies using GNU Octave for computational modeling. The results reveal that the higher-order harmonics considerably affect the shape and amplitude of the resonant current, especially below the resonant frequency. Experimental validation using a laboratory prototype demonstrates good correlation with the theoretical predictions obtained by the Fourier series analysis, whereas the FHA method shows noticeable deviations. The proposed approach offers improved precision and can serve as a practical tool for the filter design and performance optimization of resonant power converters. Full article

(This article belongs to the Proceedings of The 6th International Conference on Communications, Information, Electronic and Energy Systems)

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12 pages, 2342 KB

Open AccessProceeding Paper

Study of the Influence of the Geometric Shape of Structural Elements on the Hydrodynamic Pattern in a Radial Precipitator

by Aleksandrina Bankova, Anastas Yangyozov, Stefan Tenev and Asparuh Atanasov

Eng. Proc. 2026, 122(1), 12; https://doi.org/10.3390/engproc2026122012 - 16 Jan 2026

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Abstract

Wastewater treatment facilities of a diameter of approximately 15 m or more provide the opportunity to process large volumes of stormwater. The current report investigates the operation of a stormwater radial precipitator, without an impeller, working with particles of various sizes. A distinguishing [...] Read more.

Wastewater treatment facilities of a diameter of approximately 15 m or more provide the opportunity to process large volumes of stormwater. The current report investigates the operation of a stormwater radial precipitator, without an impeller, working with particles of various sizes. A distinguishing feature is that the two-phase flow is solely gravity-driven, which leads to reduced energy requirements. This entails the necessity of a facility in which the linear and the local losses are minimized as much as possible. Linear losses can be reduced by decreasing the precipitator’s size. The initially proposed 15 m diameter proved to be ineffective since the sand only reached a certain zone and could not flow further to the outlet due to the insufficient energy. Therefore, it was necessary to reduce the size of the radial precipitator, which resulted in a shorter path for the sand particles and the water, which, in turn, reduced the linear resistance. As for the local losses, it turned out that many areas of the precipitator construction could be geometrically modified to significantly reduce the energy loss of the sand–water mixture. The boundary layer cannot be removed. However, it is possible the size and the number of vortex structures inside the settler to be reduced in order to create an optimal working environment. Full article

(This article belongs to the Proceedings of The 6th International Conference on Communications, Information, Electronic and Energy Systems)

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8 pages, 2326 KB

Open AccessProceeding Paper

Numerical Modelling of the Thermal State of a Cylinder Head

by Delyan Petkov and Simeon Iliev

Eng. Proc. 2026, 122(1), 13; https://doi.org/10.3390/engproc2026122013 - 15 Jan 2026

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Abstract

The presented work is part of a comprehensive study exploring the feasibility of spark-ignited engines operating on fuels enhanced with additives derived from renewable sources. The investigation focuses on understanding how these alternative fuel mixtures influence engine performance and durability. In particular, attention [...] Read more.

The presented work is part of a comprehensive study exploring the feasibility of spark-ignited engines operating on fuels enhanced with additives derived from renewable sources. The investigation focuses on understanding how these alternative fuel mixtures influence engine performance and durability. In particular, attention was given to the thermal behavior of the cylinder head during engine operation with gasoline–ethanol blends. The cylinder head was selected for detailed analysis because it is one of the most thermally stressed components in the engine, directly exposed to combustion heat and pressure. Understanding its thermal state is crucial for assessing the impact of renewable fuel additives on engine reliability, efficiency, and emission characteristics. This study aims to provide insights into optimizing engine design and fuel formulation to accommodate sustainable fuel alternatives while maintaining or improving engine operation under varying conditions. Full article

(This article belongs to the Proceedings of The 6th International Conference on Communications, Information, Electronic and Energy Systems)

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8 pages, 4189 KB

Open AccessProceeding Paper

Aerodynamic Analysis of Small-Scale Turbines with Complex 3D Blade Shape

by Anastas Yangyozov, Aleksandrina Bankova, Stefan Tenev and Asparuh Atanasov

Eng. Proc. 2026, 122(1), 14; https://doi.org/10.3390/engproc2026122014 - 16 Jan 2026

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Abstract

The paper presents a comprehensive aerodynamic analysis of toroidal blade turbines, proposing them as a novel approach to enhance efficiency in the conversion of airflow kinetic energy. The unique toroidal blade geometry allows for reduced vortex-induced losses and improved aerodynamic performance relative to [...] Read more.

The paper presents a comprehensive aerodynamic analysis of toroidal blade turbines, proposing them as a novel approach to enhance efficiency in the conversion of airflow kinetic energy. The unique toroidal blade geometry allows for reduced vortex-induced losses and improved aerodynamic performance relative to conventional blade configuration. The study encompasses crucial performance parameters, including the airflow velocity at the outlet of the aerodynamic channel, rotational speed of the turbine model, electrical current and voltage output, the electrical power produced by the generator, and the power coefficient. Explored are strategies for optimizing structure design to minimize losses and maximize the power coefficient. The findings reveal that toroidal blade designs can significantly increase the effectiveness of low-power turbines, establishing them as a promising alternative for renewable energy applications in both urban and rural environments. Full article

(This article belongs to the Proceedings of The 6th International Conference on Communications, Information, Electronic and Energy Systems)

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18 pages, 1310 KB

Open AccessProceeding Paper

Progress on Developing a Sustainable BESS Technical–Economic Model by Mapping the Latest Grid-Connected Installations in Bulgaria

by Dimitrina Koeva, Metodi Dimitrov and Vladimir Zinoviev

Eng. Proc. 2026, 122(1), 15; https://doi.org/10.3390/engproc2026122015 - 16 Jan 2026

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Abstract

The rapid construction and commissioning of battery energy storage system (BESS) installations, both standalone and combined with photovoltaic power plants (PVPPs), is rapidly reshaping the energy market. Mapping these latest iterations in the energy infrastructure allows for a detailed analysis of the effects [...] Read more.

The rapid construction and commissioning of battery energy storage system (BESS) installations, both standalone and combined with photovoltaic power plants (PVPPs), is rapidly reshaping the energy market. Mapping these latest iterations in the energy infrastructure allows for a detailed analysis of the effects they have on the grid, in correlation with the already abundant operational PPV. This paper will provide a list of all BESS installations commissioned between 1 January and 30 September 2025. Taking into consideration their grid-connection power, and respective battery capacity, along with their geographical location and co-located (or lack thereof) PVPPs, the following-up analysis aims to answer several key questions: how do these installations compare to one another in terms of power, capacity and distribution across Bulgaria; how do they affect the availability of electric power from PVPP, co-located or not, to the end consumers; and how does that shift in availability affect the profits, both for the BESS and PVPP owners, based on the shifting price of electricity? Full article

(This article belongs to the Proceedings of The 6th International Conference on Communications, Information, Electronic and Energy Systems)

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9 pages, 1768 KB

Open AccessProceeding Paper

A Low-Cost 3D Printed Piezoresistive Airflow Sensor for Biomedical and Industrial Applications

by Utkucan Tek, Mehmet Akif Nişancı and İhsan Çiçek

Eng. Proc. 2026, 122(1), 16; https://doi.org/10.3390/engproc2026122016 - 16 Jan 2026

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Abstract

Flow sensing is essential in biomedical engineering, industrial process control, and environmental monitoring. Conventional sensors, while accurate, are often constrained by high fabrication costs, complex processes, and limited design flexibility, restricting their use in disposable or rapidly customizable applications. This paper presents a [...] Read more.

Flow sensing is essential in biomedical engineering, industrial process control, and environmental monitoring. Conventional sensors, while accurate, are often constrained by high fabrication costs, complex processes, and limited design flexibility, restricting their use in disposable or rapidly customizable applications. This paper presents a novel ultra-low-cost airflow sensor fabricated entirely through fused deposition modeling 3D printing. The device employs a cantilever-based structure printed with PETg filament, followed by the deposition of a conductive ABS piezoresistive layer in a two-step process requiring no curing or post-processing. Experimental characterization reveals that the sensor operates in an ultra-low pressure range of 0.88–26.68 Pa, corresponding to flow velocities of 1.2–6.6 m/s. The sensor achieves a sensitivity of 967 Ω/Pa, a resolution of 9.27 Pa, and a detection limit of 83.27 Pa, with a total resistance change of approximately 51.5 kΩ. This kilo-ohm-scale response enables direct readout via a digital multimeter without requiring Wheatstone bridges or instrumentation amplifiers. The minimalist design, combined with sub-5 min fabrication time and material cost below $0.05, positions this sensor as an accessible platform for disposable, scalable, and resource-constrained flow monitoring applications in both biomedical and industrial contexts. Full article

(This article belongs to the Proceedings of The 6th International Conference on Communications, Information, Electronic and Energy Systems)

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12 pages, 2137 KB

Open AccessProceeding Paper

Analysis of the Two-Stage Phenomenon and Construction of the Theoretical Model for Metal Hydride Reactors

by Jing Wang, Fusheng Yang, Xinlong Zhao, Zaoxiao Zhang, Jasmina Grbović Novaković and Zhen Wu

Eng. Proc. 2026, 122(1), 17; https://doi.org/10.3390/engproc2026122017 - 16 Jan 2026

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Abstract

The metal hydride (MH) reactor serves as the core unit of hydrogen storage systems, with its reaction performance limited by heat transfer rates. Effective enhancement of reactor heat transfer performance can only be achieved through a fundamental understanding of the reactor’s hydrogen–thermal coupling [...] Read more.

The metal hydride (MH) reactor serves as the core unit of hydrogen storage systems, with its reaction performance limited by heat transfer rates. Effective enhancement of reactor heat transfer performance can only be achieved through a fundamental understanding of the reactor’s hydrogen–thermal coupling mechanism. The reaction process within the reactor typically exhibits two distinct stages, a characteristic frequently disregarded in previous theoretical models. Through numerical simulation and analysis, the two-stage phenomenon and its associated hydrogen–thermal coupling mechanism were first quantitatively investigated. Based on the assumptions of neglecting the first-stage reaction time and maintaining bed thermal equilibrium, a novel two-stage theoretical model (a quantitative analytical model) was developed. This model successfully characterizes the internal hydrogen–thermal coupling and reaction progress. Having been numerically validated, the new model achieves a prediction accuracy of 2% for reaction rates, significantly outperforming the original reaction front model’s 25.5% error margin. Full article

(This article belongs to the Proceedings of The 6th International Conference on Communications, Information, Electronic and Energy Systems)

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8 pages, 1720 KB

Open AccessProceeding Paper

The Impact of Thermal Power Plants on the Sustainability of the Energy System Under Conditions of Large-Scale RES Penetration

by Dimitrina Koeva and Dimitar Slavov

Eng. Proc. 2026, 122(1), 18; https://doi.org/10.3390/engproc2026122018 - 16 Jan 2026

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Abstract

It is crucial to understand the market structure and the formation of the electricity mix in the context of the increasingly widespread and global introduction of renewable energy sources as primary energy sources. Due to the cyclical nature of energy production from RES, [...] Read more.

It is crucial to understand the market structure and the formation of the electricity mix in the context of the increasingly widespread and global introduction of renewable energy sources as primary energy sources. Due to the cyclical nature of energy production from RES, a long-term plan for seasonal storage is mandatory for smooth and effective energy transition. The stability of the energy system remains a key requirement, especially due to the dynamic changes in the generation, consumption, and pricing of energy resources. This article aims to present the concept that, in the absence of a properly structured and balanced market, thermal power plants prove to be flexible and reliable power sources that can be quickly integrated into the energy system at critical moments when maintaining the grid balance is difficult (such as during peak hours of solar generation). Full article

(This article belongs to the Proceedings of The 6th International Conference on Communications, Information, Electronic and Energy Systems)

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11 pages, 4436 KB

Open AccessProceeding Paper

SRGAN-Based Deep Learning Framework for Wind Turbine Damage Detection from Sentinel-2 Imagery

by Kübra Çakır, Onur Elma and Murat Kuzlu

Eng. Proc. 2026, 122(1), 19; https://doi.org/10.3390/engproc2026122019 - 19 Jan 2026

Viewed by 198

Abstract

The operational reliability of wind turbines is critical for sustainable energy production in smart grids. This study proposes a remote monitoring approach using perceptually enhanced satellite imagery. Sentinel-2 multispectral data (10 m resolution) has been processed with a Super-Resolution Generative Adversarial Network (SRGAN) [...] Read more.

The operational reliability of wind turbines is critical for sustainable energy production in smart grids. This study proposes a remote monitoring approach using perceptually enhanced satellite imagery. Sentinel-2 multispectral data (10 m resolution) has been processed with a Super-Resolution Generative Adversarial Network (SRGAN) to improve visual quality to a perceptual resolution of 30 cm. Although true spatial refinement is not achieved, the sharper structural details enhance classification accuracy. The data set comprises 15,000 images—10,000 SRGAN-enhanced and 5000 augmented through rotation, zoom in, increasing brightness, noise addition, and blurring. A custom Convolutional Neural Network (CNN) has been trained to classify turbines as damaged or intact, achieving 95% accuracy, a 0.99 ROC-AUC, and a 0.95 F1 score. These results demonstrate that perceptually sharpened satellite data can effectively support automated wind turbine damage detection and predictive maintenance. The proposed framework also lays the groundwork for broader real-time and multimodal monitoring and cost-efficient applications in renewable energy systems. Full article

(This article belongs to the Proceedings of The 6th International Conference on Communications, Information, Electronic and Energy Systems)

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11 pages, 1928 KB

Open AccessProceeding Paper

Development and Modeling of a Modular Ankle Prosthesis

by Yerkebulan Nurgizat, Abu-Alim Ayazbay, Arman Uzbekbayev, Nursultan Zhetenbayev, Kassymbek Ozhikenov and Gani Sergazin

Eng. Proc. 2026, 122(1), 20; https://doi.org/10.3390/engproc2026122020 - 19 Jan 2026

Viewed by 231

Abstract

This paper presents a low-cost, modular ankle–foot prosthesis that integrates an S-shaped compliant foot with a parallel spring–short-stroke actuator branch to balance energy return, impact attenuation, and rapid personalization. The design follows an FDM-oriented CAD/CAE workflow using PETG and interchangeable modules (foot, ankle [...] Read more.

This paper presents a low-cost, modular ankle–foot prosthesis that integrates an S-shaped compliant foot with a parallel spring–short-stroke actuator branch to balance energy return, impact attenuation, and rapid personalization. The design follows an FDM-oriented CAD/CAE workflow using PETG and interchangeable modules (foot, ankle unit, pylon adapter). Finite-element analyses of heel-strike, mid-stance, and toe-off load cases, supported by bench checks, show strain localization in intended flexural regions, a minimum safety factor of 15 for the housing, and peak-stress reduction after geometric refinements (increased transition radii and local ribs). The modular layout simplifies servicing and allows quick tuning of stiffness and damping without redesigning the load-bearing structure. The results indicate an engineeringly realistic path toward accessible prosthetics and provide a basis for subsequent upgrades toward semi-active control and sensor-assisted damping. Full article

(This article belongs to the Proceedings of The 6th International Conference on Communications, Information, Electronic and Energy Systems)

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10 pages, 1229 KB

Open AccessProceeding Paper

Electromagnetic Field Parameters in the Coverage Area of a Base Station

by Miroslav Tomov, Michail Malamatoudis, Dimitrios Kazolis, Konstantinos Tramantzas and Stanimir Sadinov

Eng. Proc. 2026, 122(1), 21; https://doi.org/10.3390/engproc2026122021 - 19 Jan 2026

Viewed by 190

Abstract

This paper presents an exploration of the electromagnetic field characteristics and parameters in the area of coverage of a particular base station, as well as the radio signal strength and the data speed values for optimal service. Although there are many investigations concerning [...] Read more.

This paper presents an exploration of the electromagnetic field characteristics and parameters in the area of coverage of a particular base station, as well as the radio signal strength and the data speed values for optimal service. Although there are many investigations concerning the influence of the electromagnetic field on the reactions of the people positioned in such areas and general impact on humans’ health, it is worth exploring some specific aspects of that problem. One of them is to focus the investigation on some particular radio frequency ranges. The second is to propose some practical consequences of the steps and ways to perform the measurements, with fast opportunity to collect the results and to compare them with identical measurements performed by different equipment or different algorithms for measurements. As a consequence, approaches should be developed to allow relatively accurate measurements of the electromagnetic background with devices more accessible to ordinary people instead of the expensive specialized measuring instruments used by specialists in this field. Such alternative methods of control of the electromagnetic flux radiation could help reliably to update the permissible parameters set in the existing regulations. Full article

(This article belongs to the Proceedings of The 6th International Conference on Communications, Information, Electronic and Energy Systems)

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11 pages, 3104 KB

Open AccessProceeding Paper

Application and Development of CAD/CAM Technologies in the Modern Metalworking Industry

by Fatima Sapundzhi, Deyan Vezyuv, Slavi Georgiev and Ivaylo Nikolaev

Eng. Proc. 2026, 122(1), 22; https://doi.org/10.3390/engproc2026122022 - 19 Jan 2026

Viewed by 365

Abstract

The purpose of this paper is to examine the application and development of CAD/CAM technologies in the modern metal cutting industry, with a focus on their role in increasing production accuracy, efficiency, and sustainability. The study presents an industrial case of laser cutting [...] Read more.

The purpose of this paper is to examine the application and development of CAD/CAM technologies in the modern metal cutting industry, with a focus on their role in increasing production accuracy, efficiency, and sustainability. The study presents an industrial case of laser cutting of AISI 304 stainless-steel sheets, in which two approaches are compared under identical material and technological parameters: conventional manual nesting and automatic nesting based on algorithms implemented in a CAD/CAM environment. The methodology evaluates both layouts using clear technical and economic indicators, including number of parts per sheet, material utilization, cutting time, weight of scrap, and cost per sheet. For the analyzed batch, automatic nesting increases the number of parts per sheet from 44 to 76 (≈73%), reduces the unused sheet area from 61% to 39%, and shortens the cutting time from 12 to 9 min (≈25%), which leads to a reduction in material waste by about 36% and cost savings of approximately 314 EUR per sheet. As a result, the process becomes more efficient and reliable, supporting sustainable and digital manufacturing goals. The findings confirm the importance of algorithmic optimization in CAD/CAM systems for enhancing industrial competitiveness, enabling effective resource management, and facilitating the transition towards Industry 5.0. Full article

(This article belongs to the Proceedings of The 6th International Conference on Communications, Information, Electronic and Energy Systems)

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14 pages, 2483 KB

Open AccessProceeding Paper

Fast Loss Estimation Framework for Current-Source Microinverters Using Hybrid Simulation Models

by Angel Marinov and Kaloyan Solenkov

Eng. Proc. 2026, 122(1), 23; https://doi.org/10.3390/engproc2026122023 - 19 Jan 2026

Viewed by 142

Abstract

A fast modelling framework is presented for loss estimation in current-source microinverters. The power stage is modelled with ideal switches and simplified magnetics to keep simulations lightweight, while dedicated estimators reconstruct core, conduction, and switching losses from simulated waveforms using Steinmetz-based and analytical [...] Read more.

A fast modelling framework is presented for loss estimation in current-source microinverters. The power stage is modelled with ideal switches and simplified magnetics to keep simulations lightweight, while dedicated estimators reconstruct core, conduction, and switching losses from simulated waveforms using Steinmetz-based and analytical models. The method is demonstrated on an interleaved active-clamp flyback with H-bridge unfolder but remains topology-agnostic and applicable to other current source (CS) DC/DC variants. Control includes maximum power point tracking (MPPT) with voltage-reference tracking, a PID loop, simplified grid synchronization, and peak-current regulation. Dynamic tests under irradiance and grid-voltage variations confirm stable operation and correct MPPT behaviour. A steady-state loss breakdown at 0.75 p.u. irradiance predicts ~97% overall efficiency, consistent with reported microinverter performance. The framework enables rapid design exploration and efficiency prediction without full device-level modelling, balancing accuracy and computational speed. Full article

(This article belongs to the Proceedings of The 6th International Conference on Communications, Information, Electronic and Energy Systems)

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9 pages, 860 KB

Open AccessProceeding Paper

LightGBM for Slice Recognition at 5G PHY and MAC Layers

by Rosy Altawil, Lucas Delolme, Vincent Audebert and Philippe Martins

Eng. Proc. 2026, 122(1), 24; https://doi.org/10.3390/engproc2026122024 - 20 Jan 2026

Viewed by 133

Abstract

Slicing functionality makes it possible for an operator to share a 5G physical infrastructure between several virtual networks operated by different institutions. The deployed slices can support a wide range of applications with conflicting QoS targets. The coexistence of these slices on top [...] Read more.

Slicing functionality makes it possible for an operator to share a 5G physical infrastructure between several virtual networks operated by different institutions. The deployed slices can support a wide range of applications with conflicting QoS targets. The coexistence of these slices on top of a common infrastructure is challenging and remains an open issue. Identifying traffic associated with a given type of slice is required to operate and control network resources in an efficient and secure way. This work proposes new algorithms operating at the physical and MAC layers. The solutions designed identify traffic generated by URLLC and eMBB slices by defining a new LightGBM framework. The algorithms can operate at the base station level in an O-RAN-type architecture. They provide a valuable input to radio resource management and traffic steering procedures. Full article

(This article belongs to the Proceedings of The 6th International Conference on Communications, Information, Electronic and Energy Systems)

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11 pages, 2695 KB

Open AccessProceeding Paper

Automatic Control of a Flywheel Actuator for Mobile Platform Stabilization

by Alina Fazylova, Kuanysh Alipbayev, Nazgul Kaliyeva, Yerkin Orazaly and Teodor Iliev

Eng. Proc. 2026, 122(1), 25; https://doi.org/10.3390/engproc2026122025 - 20 Jan 2026

Viewed by 148

Abstract

This paper presents the design, modeling and control of a flywheel actuator for mobile platform stabilization. A Lagrangian-based model couples platform mechanics with DC-motor electromechanics. Analytical calculations estimate natural frequencies, damping and actuator limits. Numerical simulations in Python 3.12 evaluate cascade and state-feedback [...] Read more.

This paper presents the design, modeling and control of a flywheel actuator for mobile platform stabilization. A Lagrangian-based model couples platform mechanics with DC-motor electromechanics. Analytical calculations estimate natural frequencies, damping and actuator limits. Numerical simulations in Python 3.12 evaluate cascade and state-feedback controllers for suppressing free oscillations and rejecting external disturbances. Additional studies examine filtering to improve measurement quality and unloading strategies to avoid actuator saturation. The results validate the proposed control architecture and demonstrate its applicability to robotic and energy systems operating under dynamic loads. Full article

(This article belongs to the Proceedings of The 6th International Conference on Communications, Information, Electronic and Energy Systems)

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10 pages, 16865 KB

Open AccessProceeding Paper

Predictive Load Balancing in Distributed Systems: A Comparative Study of Round Robin, Weighted Round Robin, and a Machine Learning Approach

by Elshan Rahimov and Tamerlan Aghayev

Eng. Proc. 2026, 122(1), 26; https://doi.org/10.3390/engproc2026122026 - 21 Jan 2026

Viewed by 326

Abstract

Load balancing is a widely adopted strategy in modern distributed systems because it distributes workloads across servers, mitigating overload and improving overall performance. However, the rapid growth of such systems has created a need for more adaptive strategies to ensure optimal utilization and [...] Read more.

Load balancing is a widely adopted strategy in modern distributed systems because it distributes workloads across servers, mitigating overload and improving overall performance. However, the rapid growth of such systems has created a need for more adaptive strategies to ensure optimal utilization and responsiveness of resources. Traditional algorithms such as Round Robin (RR) and Weighted Round Robin (WRR) assign requests without considering server states or request characteristics. We implement a machine learning (ML)–based predictive load balancer, forecasting the latency of a request based on the request itself and container parameters, specifically the average latency of the last 50 requests and the count of active requests, and evaluate it against RR and WRR. For the experiment, synthetic data were generated to replicate real-world requests by creating random URL and method combinations, attaching a task size in Million Instructions (MI), and distributing them among three containers with varying resources according to the load balancing strategies described above. Under the conditions tested, the ML approach achieved the worst performance, trailing both RR and WRR in terms of throughput and average latency, although the model accuracy was sufficiently high (R² = 0.8+). Post hoc analysis indicates that limited and occasionally stale runtime features caused the load balancer to direct all requests to a single container until the next statistics update, since that container was considered the ‘best’ during that interval. Full article

(This article belongs to the Proceedings of The 6th International Conference on Communications, Information, Electronic and Energy Systems)

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14 pages, 3779 KB

Open AccessProceeding Paper

Increasing Renewable Energy Penetration Using Energy Storage

by Alexandros Angeloudis, Angela Peraki, Yiannis Katsigiannis and Emmanuel Karapidakis

Eng. Proc. 2026, 122(1), 27; https://doi.org/10.3390/engproc2026122027 - 21 Jan 2026

Viewed by 192

Abstract

Greenhouse gas emissions are a primary contributor to climate change and the observed rise in global temperatures. To reduce these emissions, renewable energy sources (RESs) must replace fossil fuels in power generation. Because of the mismatch between production and demand, the increase in [...] Read more.

Greenhouse gas emissions are a primary contributor to climate change and the observed rise in global temperatures. To reduce these emissions, renewable energy sources (RESs) must replace fossil fuels in power generation. Because of the mismatch between production and demand, the increase in RES is limited. To address this phenomenon, the addition of renewable energy generation should be accompanied by storage systems. In this paper, the island of Crete is examined for various renewable energy generations and storage capacities using the PowerWorld Simulator software. Four main scenarios are studied in which the installed renewable energy generation is increased to reach substation limits. For every scenario, different renewable energy generation mixes are considered between wind farms and photovoltaics. Furthermore, for all sub-scenarios, different storage capacities are considered, ranging from 1.6 GWh to 12.8 GWh. This study proves that storage systems are mandatory to increase renewable energy penetration. In certain scenarios, a battery energy storage system can further increase renewable energy penetration from 6.15% to 28.07%. Although the battery energy storage system enhanced renewable penetration, increasing transmission line capacities should also be considered regarding the scenario. Full article

(This article belongs to the Proceedings of The 6th International Conference on Communications, Information, Electronic and Energy Systems)

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19 pages, 4026 KB

Open AccessProceeding Paper

Comparative SQP-GA-PSO Algorithms for Hierarchical Multi-Objective Optimization Design of Induction Motors

by Hung Vu Xuan

Eng. Proc. 2026, 122(1), 28; https://doi.org/10.3390/engproc2026122028 - 26 Jan 2026

Viewed by 231

Abstract

This paper presents the optimal design for a 30 kW, 3-phase squirrel-cage induction motor (IM). In this paper, three optimization algorithms are used for design optimization, namely, Particle Swarm Optimization Algorithm (PSO), genetic algorithm (GA), and Sequential Quadratic Programming (SQP). The optimal goals [...] Read more.

This paper presents the optimal design for a 30 kW, 3-phase squirrel-cage induction motor (IM). In this paper, three optimization algorithms are used for design optimization, namely, Particle Swarm Optimization Algorithm (PSO), genetic algorithm (GA), and Sequential Quadratic Programming (SQP). The optimal goals are maximum starting torque, efficiency, and minimum material cost. The result of the IM design optimization using three optimal methods is announced and compared. Additionally, computation time and the number of iterations of each algorithm are compared to find out the most suitable algorithm for the optimal design of an induction motor. In addition, this paper proposes a solution that permits us to find only one solution satisfying all the optimal criteria. Instead of using the conventional multi-objective optimization method that normally leads to a Pareto set with many optimal points at the same optimal level, we propose a hierarchical optimization method that experiences some mono-objective optimization and then builds a function representing the multi-objective optimization. Using this method, having a global optimal point can be obtained. Comparison of the optimal algorithms and multi-objective optimization methods has given broadened insight into optimal techniques for IMs. We have found that PSO is the best method for optimization design of IMs in terms of computation time and finding the global optimal point. Full article

(This article belongs to the Proceedings of The 6th International Conference on Communications, Information, Electronic and Energy Systems)

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8 pages, 3672 KB

Open AccessProceeding Paper

Diffraction Analysis of Two Semi-Submersible Platforms for Floating Offshore Wind Turbine Applications Using OrcaWave

by Olena Videnova, Nikita Dobin, Nick Markov, Silvia Kirilova and Rumen Kishev

Eng. Proc. 2026, 122(1), 29; https://doi.org/10.3390/engproc2026122029 - 26 Jan 2026

Viewed by 216

Abstract

This study presents a diffraction analysis of two semi-submersible platform configurations intended for floating offshore wind turbine applications. The first investigated configuration corresponds to a semi-submersible barge with a central moonpool, while the second configuration is a cross-shaped semi-submersible. Both hydrodynamic models were [...] Read more.

This study presents a diffraction analysis of two semi-submersible platform configurations intended for floating offshore wind turbine applications. The first investigated configuration corresponds to a semi-submersible barge with a central moonpool, while the second configuration is a cross-shaped semi-submersible. Both hydrodynamic models were developed and analyzed in OrcaWave. Simulations were performed for wave incidence directions ranging from 0° to 360°. The obtained hydrodynamic coefficients provide insights into the added mass, radiation damping, load response amplitude operators (RAOs) and two types of mean drift loads RAO of both platform types. The results highlight the influence of geometry and displacement on the diffraction performance, which is critical for the design of floating wind turbine support structures. Full article

(This article belongs to the Proceedings of The 6th International Conference on Communications, Information, Electronic and Energy Systems)

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