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  Problemele energeticii regionale

E-Journal N1(57)2023



1 Hybrid Reactive Power Compensator with Adaptation of the Operation of the Control System to the Parameters of the Mains Voltage
Authors: Goolak S.1, Tkachenko V.1 Kyrychenko M.2, Kozlov S.3 1State University of Infrastructure and Technologies Kyiv, Ukraine 2Kyiv National University of Construction and Architecture Kyiv, Ukraine 3National Technical University «Kharkiv Polytechnic Institute» Kharkiv, Ukraine
  Abstract: The aim of the work is to develop a model of a hybrid reactive power compensator with adaptation of the control system to the parameters of the voltage supply. The task was achieved by applying the control algorithm for the operation of the control system of the active part of the reactive power compensator, which is based on the regression analysis method. The traction drive of the AC electric locomotive VL-80K, which is operated on the railways of the Ukraine, was chosen as the object of study. The simulation of the traction drive operation was carried out for a traction drive with and without a reactive power compensator, for cases where the process of changing the voltage in the catenary was a stationary deterministic process and for the case when this process was a non-stationary non-deterministic process. The most important result is the development of a block diagram of the control system for the active part of the reactive power compensator based on the implementation of the Levinson-Durbin linear prediction algorithm. The significance of the results obtained lies in the possibility of the proposed control scheme for the active part of the compensator to adapt the operation of the compensator to the voltage parameters of the catenary, that is, to the actual operating conditions of the electric locomotive.
  Keywords: active power, reactive power, apparent power, reactive power compensation, traction drive, electric locomotive, control system.
2 Development of the Experimental Stand for Studying and Testing Digital Protection Terminals
Authors: Shabovta M., Besarab O., Plis V. Odessa National Polytechnic University Odessa, Ukraine
  Abstract: However, the approach to designing laboratory stands for training students and electrical per-sonnel on the specifics of using digital protections in most cases has remained the same, which does not allow for fully realizing their potential. The purpose of the work is to improve the qual-ity of the knowledge and practical skills received by students in the work with digital protection blocks. To achieve the goal, a specialized laboratory stand for testing digital security terminals has been developed. The stand consists of a mathematical model of the protected object, imple-mented in the form of a computer program and hardware, which allows real-time conversion of changes in model mode parameters into physical signals transmitted to the digital protection de-vice. The stand provides the terminal feedback with the model, which makes it possible to study the protection behavior in the characteristic operating modes of the protected element. The pro-tection of the "line-transformer" block using the Siprotec 4 7SJ6 Siemens terminal is considered. It is possible to calculate the protection operation parameters, configure the digital protection device, and also check the correct operation of the protections by automatically simulating nor-mal and emergency operation modes of the protected object. The software and hardware of the stand makes it easy to expand its capabilities by adding new models of power system objects and other digital protection devices. The equipment used in the developed stand does not require significant capital investments, which makes this approach accessible to higher educational insti-tutions.
  Keywords: digital security terminal, experimental stand, crate system, analog-to-digital converter; digital-to-analogue converter.
3 Inter-Object Navigation of Unmanned Aerial Vehicles to Increase the Efficiency and Accuracy of Inspection of Power Lines
Authors: Tymochko O.1, Fustii V.2, Kolesnyk G.1, Olizarenko S.1, Kalashnyk G.1, Kulish R.1, Tymoschuk O.3, Galinskji D.1 1Flight Academy of the National Aviation University Kropyvnytskyi, Ukraine 2Kharkiv National Air Force University named after Ivan Kozhedub Kharkiv, Ukraine 3State University of Infrastructure and Technology Kyiv, Ukraine
  Abstract: The purpose of the work is to improve the accuracy and efficiency of a power line section inspection for a fault detection using unmanned aerial vehicles. The goal was achieved by using a unified computing and measurement platform on multicopter and aircraft drones and by simplifying the interaction between them and by using the inter-object navigation sensors. The most significant results were the development of a method of route planning by drones over different parts of the power grid and a method of inter-object navigation. The drone route planning problem was represented by a multi-agent variation of the classical traveling salesman problem and was solved by the ant colony method. The method of inter-object navigation was distinguished by the representation of the power grid topology by high and low intensity graphs, involving a different number and types of drones in the inspection process. The application of the developed methods made it possible to increase the accuracy of power line inspections by 27-73%, and the efficiency by 2-8 times. Solving the problem of multi-criteria optimization of the drone team flight route planning made it possible to reduce the cost of monitoring critical infrastructure facilities while improving its efficiency and accuracy. Thus, the conducted research has shown the effectiveness of the proposed approach for the monitoring of power facilities, route selection, number and composition of search teams. The direction for further research is to improve the ant algorithm.
  Keywords: power grid, navigation, unmanned aerial vehicle, accuracy, efficiency, monitoring, ant algorithm.
4 Hybrid Renewable Energy System with High Gain Modified Z-Source Boost Converter for Grid-Tied Appli
Authors: Sathish Ch.1, Chidambaram I.A.,1 Manikandan M.2 1Annamalai University, Tamilnadu, India 2Jyothishmathi Institute of Technology and Science, Telangana, India
  Abstract: In a hybrid renewable system, a conventional boost converter produces more losses at the time of the energy conversion process due to this, the performance of the hybrid system is reduced total harmonic distortion is increased, and the hybrid microgrid outcome is reduced. The main objective of the work enhancing the low DC voltage produced by the PV panel, a high gain Boost converter is utilized. The objectives of the work were achieved by a High Gain Modified Z-source Boost converter along with Modified Particle Swarm Optimized- Proportional Integral (MPSO-PI) controller employed in the energy conversion stage at Grid. It reduced power conversion stages and decreases the losses compared to existing Hybrid Grid-connected systems. A new 13-bus system is developed in this work for regulating the output voltage in distribution networks. The significance of our work lies in the design of an efficient microgrid system for grid-tied applications. High Gain Modified Z-source Boost converter along with Modified Particle Swarm Optimized- Proportional Integral (MPSO-PI) controller is employed to boost the voltage obtained from the PV system. A battery converter along with a bi-directional battery is connected to the DC link, to store energy generated by Hybrid Renewable Energy System (HRES) in excess amounts. The obtained DC link voltage is transferred to Three Phase VSI for the conversion of DC to AC voltage. Effective harmonic reduction is attained with the aid of an LC filter coupled to Three Phase grid, and the PI controller connected to Voltage Source Inverter(VSI) supports achieving effective grid synchronization. The proposed work was tested with 13 bus system through MATLAB Simulink.
  Keywords: hybrid renewable energy system, photovoltaic system, total harmonic distortion, 13 bus system, switched Z-source boost converter.
5 Investigation of Steady State Two-Phase Short Circuit Modes of Phase-Shifting Autotransformer with Hexagon Scheme and with Adjusting Autotransformer
Authors: Bosneaga V., Suslov V. Institute of Power Engineering of Technical University of Moldova, Kishinau, Republic of Moldova
  Abstract: The purpose of work is to investigate two - phase short-circuiting modes of new autotransformer FACT’s - type device and is intended for power systems flexible connection. The developed mathematical model contains the main phase-shifting and additional regulating autotransformers. The model allows studying of asymmetrical modes of such schemes, including the un-identical load connection in different phases of phase-shifting transformers. Visual vector diagrams of winding’s voltages, currents and relative magnetic fluxes of magnetic core legs for main and regulating autotransformers for the modes with two-phase short-circuiting with and without ground have been elaborated. It is shown that significant distortions of the polygon shape occurred. It is revealed that in two-phase short - circuiting mode without ground, and the loads identically connected in different phases, the relative magnetic fluxes of the legs of main and regulating autotransformers are asymmetrical, but their sum is zero, and the magnetic flux does not come out into surrounding space. Load currents in this mode contain only direct and reverse sequences components. When the load is un-identically connected in different phases, significant zero-sequence currents occur, and magnetic flux goes out into surrounding space. However, load currents do not contain symmetrical components of zero sequence. A similar analysis of two-phase short circuit modes with ground showed that even with the identical connection of the loads, there is zero sequence both in the magnetic fluxes and in the load currents. Moreover, zero sequence is present when the load is connected differently on the phases.
  Keywords: phase - shifting autotransformer, power systems flexible connection, two - phase short circuit, symmetrical components of currents, voltages, magnetic fluxes.
6 Balancing Properties of the Booster Transformer with the Longitudinal-Transverse Regulation
Authors: Zaitsev D., Golub I., Tirsu M., Caloshin D. Institute of Power Engineering of Technical University of Moldova, Kishinau, Republic of Moldova
  Abstract: The current development of the power industry involves various kinds of FACTS, being element of the Smart Grid and controlled by power electronics used for increasing the flexibility of electrical networks. Thus, the development and research of such devices are relevant. The study object is a controller belonging to the "Sen" family of transformers, which provides regulation of voltage and power flows in networks. The aim of the work is to study the balancing properties of booster transformer, which has an extended range and higher control accuracy in various modes. The goal was achieved during research carried out on the basis of structural simulation models. The most significant result was statement that the device under study has a pronounced per-phase balancing effect, which is preserved in various modes, including reverse ones. The main result can be consider that the proposed device, in comparison with the currently existing transformers of the "Sen" family, due to the extended range and accuracy of voltage regulation, allows using it when working, both for symmetrical and asymmetric loads. It is shown that the proposed technical solution provides ample opportunities for longitudinal-transverse phase-by-phase voltage regulation. Moreover, the deviations of parameters characterizing the quality of electricity, such as modules and voltage angles, do not go beyond the limits regulated by the requirements of the standard. The results obtained allowed us to conclude that this device can be used to solve the problem of coordinating the operation of two asymmetric systems in different operating modes.
  Keywords: balancing properties of control transformer, active and reactive power, voltage regulation.
7 Efficiency Increase in Liquefied Natural Gas Production at Motor Gas Filling Compressor Station using Propane-Butane Fraction pre- Extraction
Authors: Munts V.A., Lebedev M.S. Ural Federal University named after the first President of Russia B.N. Yeltsin Yekaterinburg, Russian Federation
  Abstract: Nowadays the production of liquefied natural gas including low-tonnage production is one of the most promising areas of modern energy. The development of measures to improve the quali-ty of a liquefied product and the efficiency of its production processes is an urgent scientific problem of great practical importance. The aim of the study is to develop an effective techno-logical scheme which allows improving the quality of liquefied natural gas produced at automo-bile gas filling compressor stations. The goal was achieved by performing an analysis of the ef-fectiveness of the natural gas components low-temperature separation process at a gas distribu-tion station before its liquefaction at the compressed natural gas filling station in order to obtain a product with a reduced content of heavy hydrocarbons, as well as through a practical study of the process of low-temperature separation of hydrocarbons at an operating liquefaction facility natural gas. According to these characteristics and conducted experimental studies, the effec-tiveness of the scheme for obtaining a propane-butane product in the process of liquefying natu-ral gas has been confirmed. An important result is also a new substance obtained during the ex-periments, which has the properties of degreasing. The significance of the results obtained lies in the possibility of their use in the design of subsequent facilities for the reduction and liquefac-tion of natural gas with a line for the production of propane-butane and the investigated degreas-ing agent.
  Keywords: : liquefied natural gas, liquefied hydrocarbon gas, gas distribution station, compressed natural gas refill station, separation, condensation.
8 Analysis of the Energy Efficiency of the Air Conditioning System Based on Absorption Refrigeration Machine with Connection of Heat Pump and Solar Collectors
Authors: Mereutsa E.V., Sukhikh A.A. National Research University «Moscow Power Engineering Institute» Moscow, 111250 Russian Federation
  Abstract: This article proposes and analyzes a circuit solution for providing heat supply to the generator of an absorption refrigeration machine (AHM) in centralized air conditioning systems using a heat pump unit (HPU) and solar collectors (SOL). Previously, such schemes have already been considered in the scientific works of Russian and foreign authors. The aim of the work is to propose new circuit solutions aimed at improving such systems, as well as confirming higher energy efficiency. This goal is achieved by solving the following problems: additional supply of the circuit with a common storage tank, operation of the absorption refrigeration machine generator and the condenser of the heat pump unit based on a common heat exchanger. Such a solution for the air conditioning complex based on an absorption refrigeration unit has been proposed for the first time. The most important results are the possibility of obtaining high values of the coefficient of performance, the possibility of achieving a number of technological advantages, increasing reliability and efficiency, as well as reducing the metal consumption of an absorption-type plant operating from solar collectors and a heat pump plant compared to similar systems. The significance of the obtained results lies in the fact that the use of a common storage tank and a combined heat exchanger (AHM generator / HPU heater) provides a significant increase in the coefficient of performance, a decrease in the metal consumption (reduction in costs) of the main equipment.
  Keywords: air conditioning, absorption, absorption refrigeration machine, heat pump unit, heat conversion coefficient, solar collector, cooling capacity, coefficient of performance.
9 Analysis of the Numerical Modeling Results of the Associated Petroleum Gas Combustion in the Convertible Chamber in a Micro Gas TPP
Authors: Matyunin O.O., Bachev N.L., Shilova A.A. Perm National Research Polytechnic University Perm, Russian Federation
  Abstract: When developing prospective gas turbine plants or converting existing ones for burning non-standard fuel gases, one of the main tasks is creation of low-emission combustion chambers with stable combustion. At the stage of sketch design, the parameters of recycling chambers are usually determined using engineering calculation methods. Methods of numerical modeling of the working process allow to clarify the obtained parameters and significantly reduce the costs of creating a combustion chamber thanks to the numerical experiment. The purpose of this work is to develop recommendations for converting existing combustion chambers of microgas-turbine power plants to utilize non-standard fuel gases. To achieve the goal, the problem of nu-merical modeling of the working process with and without a stepwise air supply to the combus-tion zone was solved. The most significant result of the conducted studies is provision of stable combustion due to the change in the medium speed along the combustion zone with stepwise air supply and due to intensification of the reverse currents zone from the swirler with continuous air supply. The significance of the obtained results is that the proposed recommendations for converting a low-emission combustion chamber from components (kerosene+air) to components (combined petroleum gas+air) while keeping the diameter and length of the chamber unchanged, with changing the location of only the side holes. In this work, a three-dimensional numerical model of turbulent combustion for utilizing associated petroleum gases was developed to take into account the real operational conditions in a two-zone combustion chamber and analyze the performance characteristics.
  Keywords: combustion chamber, numerical modeling, emission of harmful substances, nitrogen oxides.
10 Heat Transfer Slot Matrix for Compact Rotary Heat Exchangers with Ultra-High Regeneration Ratio for Microturbines
Authors: Kostyukov A. V. Kosach L. A. Moscow Polytechnic University Moscow, Russian Federation
  Abstract: This paper considers the problem of the influence of distancing elements in slot matrix channels on the thermohydraulic characteristics of the matrix of a rotary heat exchanger having various values of the height of the slot channels. The following tasks were carried out: mathematical modeling of thermohydraulic processes in different slot channels having constant height along them (from 0.3 mm to 0.5 mm); analysis of the influence of the slit channels' height, the number of distancing elements in rows, the distance between rows and the total number of elements on the average value of the Nusselt number and on the pressure drop; analysis of the effect of changes in speed and temperature conditions on thermal and hydraulic characteristics. The most important results are the following facts: the influence of the relative location of the distancing elements on the thermohydraulic characteristics of the flow is negligible; changes in the tempera-ture and speed regime of the laminar flow practically does not affect the intensity of convection in the matrix channels; an increase in the height of the slot channel leads to a relatively small decrease in the average value of the Nusselt number. The significance of the results obtained is that they can be the basis for adjusting the methods of design calculations of rotary heat exchangers taking into account the decrease in thermal effi-ciency caused by the presence of distancing elements in the channels of their matrices. Recom-mendations can be made to minimize the number of distancing elements without considering their mutual location.
  Keywords: heat exchange, microturbine, regenerative heat exchanger, convection, Nusselt number, hydraulic loss.
11 The Use of Coplanar Transmission Lines for Protecting Receiving Antenna Systems from Powerful Electromagnetic Radiation in a Wide Frequency Range
Authors: Sotnikov O.1, Petrov K.2, Udovenko S.3, GnusovYu.4, RadchenkoV.4, Kaliakin S.4, Gromliuk K.5, Kyrychenko O.6 1 Kharkiv National University named after Ivan Kozhedub Kharkiv Air Force, Ukraine 2Kharkiv National University of Radio Electronics, Kharkiv, Ukraine 3Simon Kuznets Kharkiv National University of Economics, Kharkiv, Ukraine 4Kharkiv National University of Internal Affairs, Kharkiv, Ukraine 5 Military Institute of Telecommunications and Information Technologies named after Heroes of Kruty, Kiev, Ukraine 6 National Academy of the National Guard of Ukraine, Kharkiv, Ukraine
  Abstract: The goal of the work is to expand the frequency range of operation of coplanar waveguide transmission lines as broadband high-speed superconducting protection devices against powerful ultrashort electromagnetic radiation, and to apply them in antenna devices of radio electronic systems designed to ensure the reliable operation of critical infrastructure facilities. The aim is achieved by solving the following tasks: investigating the electrophysical properties of coplanar transmission lines, in particular, capacitance, surface and wave resistance in different phase states that arise under the influence of powerful electromagnetic radiation, and determining the main factors for effective protection in a wide frequency range, designing protective devices. The most important result is the establishment of the possibility of using coplanar transmission lines as protection devices in a wide frequency range up to 100 GHz, as well as the establishment of the dependence of their main characteristics on the design parameters of the superconducting protection device. The significance of the obtained results consists of solving a complex problem of providing protection of antenna systems against powerful ultrashort radiation by establishing an analytical relationship between the electrophysical parameters of coplanar waveguide transmission lines, which are in different phase states determined by the influence of powerful electromagnetic radiation, and their design parameters. The peculiarity of the obtained results is in the clarification of the dependence of the wave resistance of the coplanar waveguide transmission lines in superconducting, mixed, and normal phase states on the change of their active component of surface resistance, determined in turn by the design characteristics of the protective device. The difference from the known works lies in obtaining relationships for determining the wave resistance of protective devices in different phase states.
  Keywords: critical infrastructure facilities, antenna system, pulsed high-power ultrashort-duration electromagnetic radiation, protective device, coplanar strip transmission line.
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