Electrical Engineering and Power Engineering

Application of an advanced objective function to minimize active power losses

D.O. Danylchenko — 2025-01-28

Purpose of the work. The improvement of the method for optimizing active power losses in networks using dynamic control of capacitor bank parameters, taking into account the variability of generation and loads. Research methods. Analysis of an electrical system modeled in MATLAB using elements of renewable energy sources and capacitor banks. The study of optimizing active power losses is carried out by using an improved objective function that includes the multifactorial nature of the system and certain restrictions. A comparison of active losses and their changes in the presence of renewable energy sources and capacitor banks in the electrical network is carried out.

Results obtained. The obtained modeling results demonstrate the practical applicability of the proposed method for reducing active losses in the system. This, in turn, leads to a reduction in costs for network operation and maintenance, a reduction in energy losses, and an improvement in the quality of energy supply. Reducing active losses contributes to increasing the economic efficiency of the power system.

Modeling in MATLAB/Simulink provides the ability to conduct analysis to assess the behavior of the system under various operating conditions, such as peak loads or sharp fluctuations in generation. This allows to ensure the flexibility and adaptability of the power system to real operating conditions.

The results obtained also contribute to solving sustainable development problems, as they ensure effective integration of RES without deteriorating the stability and parameters of the network.

Scientific novelty. A comprehensive modeling of the power system operation is proposed, taking into account the dynamic control of capacitor units and the integration of renewable energy sources (RES), which allows to assess the effectiveness of various compensation measures and their impact on active losses. The scientific novelty lies in creating a model that takes into account the variable nature of the load, transmission line parameters and unstable RES generation, providing a comprehensive approach to optimizing the operation of the power system.

Practical value. Improving the objective function to minimize active power losses by adding capacitor banks to the generation function, changing the generation of renewable energy sources, and changing the load of the PV system (active and reactive), this allowed a more accurate assessment of the impact of reactive power and RES integration on active losses, and increased the efficiency of power system management by taking into account the real operating conditions of the system (load and generation dynamics).

Method for identifying a connection with a metering defect among multiple connections on a single busbar section

A.V. Voloshko — 2025-01-28

Purpose. The purpose of this work is to develop a methodology for identifying a defective connection on a single medium- or low-voltage busbar section among several parallel connections.

Methodology. As is known, from three to two dozen connections can be powered simultaneously from the busbar section of the main step-down substation with a higher voltage of 35÷154 kV, a dead-end substation with a medium voltage of 10 (6) kV or a transformer substation with a voltage of 10 (6)/0.4 kV.A metering device defect on one of these connections can only be detected using the balance method (where a metering device, usually for commercial purposes, is installed at the busbar section input, and each outgoing connection from the busbar section is also equipped with an electricity meter). The search for a defective metering device is carried out by inspecting all metering devices for each connection. Among them, the defective device is identified. However, this procedure often takes a significant amount of time, requires the implementation of organizational and technical measures when working in operational electrical installations, and can lead to emergency disconnections of connections due to voltage circuit shorting or current circuit breaking caused by incorrect or erroneous actions of personnel.

Findings. Four main types of defects in accounting schemes are identified. It is shown that the imbalance between commercial and technical accounting can be used to identify defects in the tire section. Criteria for the rapid identification of defective connections based on statistical methods such as correlation analysis and one-factor analysis of variance are developed.

Originality. In contrast to the existing approach, the sequence is proposed and the criteria for finding a connection with a metering defect are developed using the analytical method. As a result, it will be necessary to replace the metering device or device only at one connection connected to the busbar section with a defect in the metering circuits. The analytical method is based on the processing of metering data and the calculation of several statistical coefficients.

Practical value. The proposed methodology enables the rapid identification of a defective metering device using an analytical method. It ensures fast and accurate detection of defective connections on the busbar section, helping to avoid emergency situations and energy losses. This makes the methodology valuable for industrial enterprises with high energy consumption.

Optimization of energy use during routing of transportation of grain elevator

V.A. Mardziavko — 2025-01-28

The purpose of the work. The purpose of this work is to create a mathematical model and justify the algorithm for minimizing energy consumption during grain transportation in the elevator complex by optimizing the transportation route.

Research methods. An analytical research method was applied to study existing approaches to route optimization and energy minimization algorithms. A mathematical method is applied to formalize the problem of minimizing energy consumption in the elevator complex. An algorithmic method was used to develop and adapt algorithms, such as the salesman's problem, to the specifics of grain transportation.

Obtained results. The obtained results showed that the implementation of the algorithm for optimizing the grain transportation route based on the criterion of minimizing energy consumption can significantly reduce the total energy consumption of the elevator complex. The developed mathematical model and algorithm based on the Salesman's problem allows to describe and explain the provision of efficient route selection that passes through all necessary nodes only once, with minimal energy costs. A system of logical equations that takes into account the state of nodes, overload, speed and direction of movement will ensure its effectiveness in reducing energy consumption.

Scientific news. The scientific novelty of the work consists in the development of an algorithm for choosing the optimal grain transportation route based on the minimization of energy consumption, which integrates the mathematical model of the co-traveler problem with Miller-Tucker-Zemlin conditions for the exclusion of subcycles. For the first time, a system of logic equations was proposed, which takes into account the condition of the nodes, the direction of movement, the speed and the absence of overloading. The algorithm also optimizes transportation time, which ensures increased energy efficiency and productivity of automated elevator systems.

Practical value. The practical value of the research lies in the possibility of introducing the developed algorithm into the automated control systems of elevator complexes to increase energy efficiency and optimize work. The proposed methodology facilitates the automated selection of routes with minimal energy consumption, whilst accounting for the technical characteristics of the equipment and the prevailing operating conditions. This contributes to the reduction of the total cost of electricity, increasing the productivity and reliability of the system, ensuring economic benefit and stable operation of the transport infrastructure.

Approaches in modeling electrical energy conversion systems in hybrid vehicles

O.V. Vasylenko — 2025-01-28

Purpose. Selection of adequate software and development of a modeling methodology for economical multi-domain simulation of the power distribution and conversion system, taking into account the control system for modern vehicles, in particular, for a hybrid electric vehicle with a fuel cell (HEV).

Methodology. The main research method is mathematical modeling; for the structural synthesis of the model of the power conversion system and comparative analysis of programs, heuristic decision-making methods based on the comparison of variant metrics were used.

Findings. A method of decomposition of HEV from the point of view of the scope of application of existing programs for modeling its subsystems is proposed. Subsystems from blocks of such a structural scheme are suitable for research using single-domain modeling programs. The prospects of the computer-aided design in electronics (ECAD) programs for multi-domain HEV modeling are shown, since the central and main conversion unit is the electronic domain. Based on the selected software metrics, the choice of programs for modeling the power conversion system is justified, with the possibility of organizing model interfaces to ensure multi-domain modeling and correct export-import of models when transitioning between abstraction levels. The sequential use of selected computer-aided engineering (CAE) and ECAD programs is proposed, with the transfer of information about the model and simulation results. This is capable of providing both optimal synthesis of the Automatic Control System based on the Phase Margin criterion with the study of the stability zone according to the Solution map, and in-depth analysis of the energy performance of the power stage of the converters. To test the method, a parallel topology of the power system with a block of supercapacitors, a boost-type converter in voltage control mode and a promising Four-Switch Bidirectional Buck-Boost converter in current control mode were selected. To increase the stability of the system, it is proposed to use a Type3 controller, which combines the capabilities of a compensator and a modulator.

Originality. A new approach to modeling the HEV energy subsystem is proposed, which takes into account the multi-domain nature of the system and requires its consideration, first, as an Automatic Control System at the macro level in the CAE program SmartCtrl, with a preliminary expansion of its library by synthesizing Transfer Functions in the ECAD program PSIM, and a subsequent return to the micro level for analyzing energy characteristics and parametric optimization of converters together with control systems at the level of electrical circuits in PSIM. Based on the analysis of the capabilities of the programs for modeling the components of the HEV aggregate system, a variant of the structural diagram of the model of the energy subsystem is proposed, taking into account the possibilities of adequate application of "single-domain" programs and the prospects for their use for multi-domain modeling of HEV are shown. A specific set of program metrics is determined for a reasonable choice of software when studying such systems.

Practical value. The presented method of sequential modeling of the energy system in the complex of automated engineering and automated design programs SmartCtrl+PSIM from Altair Group with mutual data exchange provides a comprehensive analysis and optimization of the characteristics of this subsystem of modern vehicles.

Development of a digital twin prototype of a robotic device for motion reproduction in space

D.O. Bilka — 2025-01-28

Purpose. To develop a prototype of a digital twin for a robotic device capable of reproducing an object's motion in real time with high accuracy.

Methodology. To achieve the objective, the following methods were employed: integration of ESP8266 NodeMCU v3 and Arduino Uno R4 Wi-Fi microcontrollers with an MPU6050 sensor, firmware development using the C++ programming language in the Arduino IDE environment, creation of server-side software using PHP scripts and a MySQL database, and the development of an interactive data visualization system in Unity. Additionally, methods for data filtering and calibration were applied to ensure accuracy.

Findings. A digital twin prototype was developed, which accurately reproduces the movements of a physical object based on data from MPU6050 sensors. The system ensures reliable data collection and transmission from the microcontroller to the server without significant losses or distortions. The data is successfully stored in the MySQL database and is available for further analysis and visualization via interactive 3D models in Unity. Implemented mechanisms for data integrity verification and connection stability provide high reliability of the system over extended periods.

Originality. A novel approach to developing a digital twin has been proposed, integrating ESP8266 and Arduino Uno R4 Wi-Fi microcontrollers with an MPU6050 sensor for data collection and processing, employing real-time filtering and calibration algorithms to enhance data accuracy.

Practical value. The developed prototype of the digital twin for a robotic device expands the possibilities for studying and researching digital twin technologies in robotics.