Видання НТУ "ХПІ"
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Документ Порівняльна оцінка вентильних комплектів двофазного і трифазного тягових асинхронних електроприводів(Національний технічний університет "Харківський політехнічний інститут", 2004) Хворост, Микола Васильович; Чумак, Володимир Анатолійович; Панасенко, Надія МиколаївнаРозглянуті питання, пов'язані з можливістю використання в тягових електропередачах електрорухомого складу двофазного частотно-регульованого асинхронного електроприводу. Проаналізовані силові схеми двофазного і трифазного асинхронного електроприводу з вузлами захисту від короткого замикання двигуна при відмовах в інверторі напруги на предмет сталої потужності їх вентильних комплектів.Документ Performance investigations of five-level reduced switches count Η-bridge multilevel inverter(Національний технічний університет "Харківський політехнічний інститут", 2023) Parimalasundar, Ezhilvannan; Muthukaruppasamy, S.; Dharmaprakash, R.; Suresh, KrishnanThis research paper describes a simple five-level single-phase pulse-width modulated inverter topology for photovoltaic grid applications. Multilevel inverters, as opposed to conventional two-level inverters, include more than two levels of voltage while using multiple power switches and lower-level DC voltage levels as input to produce high power, easier, and less modified oscillating voltage. The H-bridge multilevel inverter seems to have a relatively simple circuit design, needs minimal power switching elements, and provides higher efficiency among various types of topologies for multi-level inverters that are presently accessible. Nevertheless, using more than one DC source for more than three voltage levels and switching and conduction losses, which primarily arise in major power switches, continue to be a barrier. The novelty of the proposed work consists of compact modular inverter configuration to connect a photovoltaic system to the grid with fewer switches. Purpose. The proposed system aims to decrease the number of switches, overall harmonic distortions, and power loss. By producing distortion-free sinusoidal output voltage as the level count rises while lowering power losses, the constituted optimizes power quality without the need for passive filters. Methods. The proposed topology is implemented in MATLAB/Simulink with gating pulses and various pulse width modulation technique. Results. With conventional topology, total harmonic distortion, power switches, output voltage, current, power losses, and the number of DC sources are investigated. Practical value. The proposed topology has proven to be extremely useful for deploying photovoltaic-based stand-alone multilevel inverters in grid applications.Документ Активний випрямляч з фіксованою частотою модуляції та векторною системою управління в режимі двонаправленого потоку енергії(Національний технічний університет "Харківський політехнічний інститут", 2023) Крилов, Денис Сергійович; Холод, Ольга ІгорівнаВ статті розглянуто роботу активного випрямляча-джерела напруги, що працює з фіксованою частотою модуляції в режимі двонаправленого потоку енергії, запропоновано нову структуру векторної системи управління, та отримано характеристики роботи схеми в широкому діапазоні зміни величини та знаку вихідної потужності. Розглянуті фізичні передумови функціонування силової схеми АВДН, запропонованої авторами векторної системи управління та принципи формування діючих усереди ні неї сигналів в складі частотного перетворювача середньої потужності. Показано переваги нової системи управління над існуючими та отримано залежності, що демонструють коректність застосування запропонованих у статті технічних рішень. Результати математичного моделювання показали, що АВДН, який працює з фіксованою частотою модуляції та запропонованою системою управління, дозволяє підтримувати задане значення вихідної напруги та близький до синусоїди струм мережі живлення при нульовому споживанні реактивної потужності в усталеному режимі в широкому діапазоні зміни параметрів схеми та величини і знаку потужності навантаження.Документ Investigation of efficient multilevel inverter for photovoltaic energy system and electric vehicle applications(Національний технічний університет "Харківський політехнічний інститут", 2023) Parimalasundar, Ezhilvannan; Jayanthi, Ramalingam; Suresh, Krishnan; Sindhuja, RamachandranThis research presents a simple single-phase pulse-width modulated 7-level inverter topology for renewable system which allows home-grid applications with electric vehicle charging. Although multilevel inverters have appealing qualities, their vast range of application is limited by the use of more switches in the traditional arrangement. As a result, a novel symmetrical 7-level inverter is proposed, which has the fewest number of unidirectional switches with gate circuits, providing the lowest switching losses, conduction losses, total harmonic distortion and higher efficiency than conventional topology. The novelty of the proposed work consists of a novel modular inverter structure for photovoltaic energy system and electric vehicle applications with fewer numbers of switches and compact in size. Purpose. The proposed system aims to reduce switch count, overall harmonic distortions, and power loss. There are no passive filters required, and the constituted optimizes power quality by producing distortion-free sinusoidal output voltage as the level count increases while reducing power losses. Methods. The proposed topology is implemented with MATLAB/Simulink, using gating pulses and various pulse-width modulation methodologies. Moreover, the proposed model also has been validated and compared to the hardware system. Results. Total harmonic distortion, number of power switches, output voltage, current, power losses and number of DC sources are investigated with conventional topology. Practical value. The proposed topology has proven to be extremely beneficial for implementing photovoltaic-based stand-alone multilevel inverter and electric vehicle charging applications.Документ MATLAB-Simulink environment based power quality improvement in photovoltaic system using multilevel inverter(Національний технічний університет "Харківський політехнічний інститут", 2023) Priyanka, G.; Surya Kumari, J.; Lenine, D.; Srinivasa Varma, P.; Sneha Madhuri, S.; Chandu, V.Introduction. In this world of technical advancement, conventional resources are at the stage of destruction. To avoid such problems, we are going to use an alternative energy source namely solar by photovoltaic effect. The demand for multilevel inverters increased as they are used for different dynamic (high) voltage and dynamic (high) power appliances as they are capable of producing the output wave shape with low total harmonic distortion. Novelty. A new multilevel inverter is used in adding a (bidirectional) two way switch in between the capacitor and a traditional H-bridge module. This produces a better sine wave. By series connection of these two H-bridge modules, nine levels output voltage including zero is possible. The purpose of the proposed topology is reduction in the number of switches and it gives the good result with comparatively less power loss when it is compared with the other normal basic traditional inverters of the same output quality. Methods. In this paper, sinusoidal pulse width modulation technique is used for the working of the switches in the multilevel inverter. The results are verified by using simulation and also experimental setup is done. From the results it is observed that the proposed topology with reduced number of switches gives lower electromagnetic interference, lower harmonic distortion. Practical value. The total harmonic distortion value in the simulation is 14.4 % and practically it is 13.8 %.Документ Fault diagnosis in a five-level multilevel inverter using an artificial neural network approach(Національний технічний університет "Харківський політехнічний інститут", 2023) Parimalasundar, Ezhilvannan; Senthil Kumar, Ramanathan; Chandrika, Vanitha Selvaraj; Suresh, KrishnanIntroduction. Cascaded H-bridge multilevel inverters (CHB-MLI) are becoming increasingly used in applications such as distribution systems, electrical traction systems, high voltage direct conversion systems, and many others. Despite the fact that multilevel inverters contain a large number of control switches, detecting a malfunction takes a significant amount of time. In the fault switch configurations diode included for freewheeling operation during open-fault condition. During short circuit fault conditions are carried out by the fuse, which can reveal the freewheeling current direction. The fault category can be identified independently and also failure of power switches harmed by the functioning and reliability of CHB-MLI. This paper investigates the effects and performance of open and short switching faults of multilevel inverters. Output voltage characteristics of 5 level MLI are frequently determined from distinctive switch faults with modulation index value of 0.85 is used during simulation analysis. In the simulation experiment for the modulation index value of 0.85, one second open and short circuit faults are created for the place of faulty switch. Fault is identified automatically by means of artificial neural network (ANN) technique using sinusoidal pulse width modulation based on distorted total harmonic distortion (THD) and managed by its own. The novelty of the proposed work consists of a fast Fourier transform (FFT) and ANN to identify faulty switch. Purpose. The proposed architecture is to identify faulty switch during open and short failures, which has to be reduced THD and make the system in reliable operation. Methods. The proposed topology is to be design and evaluate using MATLAB/Simulink platform. Results. Using the FFT and ANN approaches, the normal and faulty conditions of the MLI are explored, and the faulty switch is detected based on voltage changing patterns in the output. Practical value. The proposed topology has been very supportive for implementing non-conventional energy sources based multilevel inverter, which is connected to large demand in grid.Документ Power quality improvement by using photovoltaic based shunt active harmonic filter with Z-source inverter converter(Національний технічний університет "Харківський політехнічний інститут", 2022) Sai Thrinath, B. V. ; Prabhu, S.; Meghya Nayak, B.Introduction. The major source of energy for a long time has been fossil fuels, however this has its drawbacks because of their scarcity, exhaustibility, and impossibility of reusing them. Presently, a shunt active harmonic filter-equipped two-stage solar photovoltaic system is showing off its performance shunt active harmonic filter. The global power system has been impacted by current harmonics during the most modern industrial revolution. Novelty. The proposed work is innovative, by adopting the hysteresis modulation mode with Z-source inverter to enhance the performance of the system. Furthermore, the shunt active harmonic filter also get assists in this system for better improvement in the quality of power. Purpose. By incorporating an impedance source inverter and a photovoltaic shunt active harmonic filter methods, harmonic issues are mitigated. Methods. Load compensation is one of the services that the shunt active harmonic filter offers, in addition to harmonic compensation, power factor correction, and many other functions. The current pulse width modulation voltage source inverter method is more expensive, requires two converters owing to its two-stage conversion, has significant switching losses, and has a low rate of the reaction. The new model, in which the voltage source inverter is substituted out for a Z-source inverter converter, has been developed in order to address the problems of the existing system.Документ Performance investigation of modular multilevel inverter topologies for photovoltaic applications with minimal switches(Національний технічний університет "Харківський політехнічний інститут", 2022) Parimalasundar, Ezhilvannan; Kumar, Nathella Munirathnam Giri; Geetha, Prahalathan; Suresh, KrishnanIntroduction. In recent years, a growing variety of technical applications have necessitated the employment of more powerful equipment. Power electronics and megawatt power levels are required in far too many medium voltage motor drives and utility applications. It is challenging to incorporate a medium voltage grid with only one power semiconductor that has been extensively modified. As a result, in high power and medium voltage settings, multiple power converter structure has been offered as a solution. A multilevel converter has high power ratings while also allowing for the utilization of renewable energy sources. Renewable energy sources such as photovoltaic, wind, and fuel cells may be readily connected to a multilevel inverter topology for enhanced outcomes. The novelty of the proposed work consists of a novel modular inverter structure for solar applications that uses fewer switches. Purpose. The proposed architecture is to decrease the number of switches and Total Harmonic Distortions. There is no need for passive filters, and the proposed design enhances power quality by creating distortion-free sinusoidal output voltage as the level count grows while also lowering power losses.Документ Determination of the input filter parameters of the active rectifier with a fixed modulation frequency(Національний технічний університет "Харківський політехнічний інститут", 2022) Krylov, D. S.; Kholod, O. I.Development of a methodology for calculating the parameters of the active rectifier-voltage source input filter operating with a fixed modulation frequency to ensure electromagnetic compatibility with the supply network acceptable by standards at minimum values of the input inductance and checking its main characteristics on a mathematical model. Methodology. The authors have developed a methodology for calculating the parameters of the input filter of an active rectifier-voltage source. The calculation results are verified on the constructed mathematical model of a frequency converter, the scheme of which is an active rectifier and an autonomous voltage inverter. A series of experiments was carried out on a mathematical model to study the dependence of the total harmonic distortion of current and mains voltage on the value of the input inductance for various parameters of the input filter. Results. The structure and calculation procedure the input filter of an active rectifier operating with a fixed modulation frequency are proposed. The simulation results showed that the inclusion of a filter at the input of the active rectifier significantly improves its electromagnetic compatibility with the supply network in the entire range of variation of the input inductance of the circuit and makes it possible to achieve the values of the total harmonic distortion permissible by the norms. Originality. A structure and a calculation procedure the input filter of an active rectifier-voltage source operating with a fixed modulation frequency are proposed. Practical significance. The dependencies obtained in the article allow us to evaluate the relationship between the parameters of the filter elements and its characteristics among themselves and come to a compromise between them when designing a scheme for specific technical conditions.