2022 № 2 Електротехніка і Електромеханіка

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https://repository.kpi.kharkov.ua/handle/KhPI-Press/65914

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Вплив легувальної добавки на теплофізичні та реологічні властивості полімерної композиції, що не містить галогенів, для ізоляції та оболонок кабелів
(Національний технічний університет "Харківський політехнічний інститут", 2022) Золотарьов, Володимир Михайлович ; Чулєєва, Олена Володимирівна; Чулєєв, Володимир Леонідович; Кулешова, Тетяна Анатоліївна; Суслін, Микола Сергійович
Попит на вогнестійкі композиції, що не містять галогенів, для виготовлення пожежобезпечних проводів та кабелів безперервно зростає. Тому розробка цих матеріалів є актуальною проблемою. Метою статті є дослідження впливу легувальної добавки на теплофізичні та реологічні властивості композицій. Теплофізичні властивості визначено з використанням приладу TGA/DSC 1/1100 SF компанії METTLER TOLEDO. Реологічні дослідження полімерних матеріалів проведено методом капілярної віскозиметрії на приладі ИИРТАМ. Визначено вплив легувальної добавки на формування надмолекулярної структури наповнених полімерних композицій. Встановлено зниження ефективної в'язкості розплаву полімерної композиції в 6 разів зі зростанням швидкості зсуву в 40 разів при зміненні температури від 150 до 190 ° С. Швидкість зсуву полімерної композиції з легувальною добавкою зростає в 40 разів з підвищенням напруження зсуву в 9 разів. Результати досліджень дають можливість обґрунтовано підходити до розроблення ефективних технологічних процесів виготовлення ізоляції та оболонок силових кабелів.
Регулятори підвищувально-понижувального типу в режимі передавання максимальної потужності
(Національний технічний університет "Харківський політехнічний інститут", 2022) Ромашко, Володимир Якович; Батрак, Лариса Миколаївна; Абакумова, Олена Олегівна
Introduction. Switching DC voltage regulators are traditionally used to regulate and stabilize the voltage on the load. Due to the widespread use of non-traditional and renewable sources of electricity, there is a need to select from them the maximum possible amount of electricity. As is known, the maximum power from the power supply to the load will be transmitted provided that the output resistance of the source is equal to the load resistance. If this condition is not met, a matching switching regulator is switched on between the power supply and the load. Most often, for the purpose of matching, pulse regulators of step-up or step-down types are used. Problem. The operation of regulators in the matching mode has a number of features, in comparison with the modes of regulation and stabilization of the output voltage. Thus, since in the maximum power transmission mode the output resistance of the source and the resistance of the load are values of the same order, in any calculation the internal resistance of the source must be taken into account. There are works in which features of work of regulators of step-up and step-down types in a mode of transfer of the maximum power are analyzed. In addition to these types of pulse regulators, there are regulators of step-up/step-down types, which are relatively rarely used for this purpose. First of all it is connected with insufficiently studied abilities of work of such regulators in the specified mode. Goal. The aim of the work is to analyze the features of the operation of pulse regulators of stepup/step-down types in the mode of transmission of maximum power from the power supply to the load, as well as to determine the conditions under which it is possible and appropriate to work in this mode. Methodology. In the work, taking into account the internal resistance of the power supply, the regulation characteristics of the basic circuit of the pulse regulator of the step-up/stepdown type are analyzed. The conditions under which the transfer of maximum power from the power supply to the load is ensured are determined. Results. It is shown that the existing variants of the circuits of regulators of the step-up/step-down type can be obtained from the basic circuit by applying the rules of construction of dual electric circuits. Consequently, the basic calculated relations for such circuits can be obtained from the calculated relations of the basic circuit using the principle of duality. Originality. A method for determining and studying the regulation characteristics of pulse regulators, taking into account the internal resistance of the power supply. Practical value. The obtained results allow to determine the conditions under which it is possible and expedient to operate different circuits of regulators in the mode of transmission of maximum power from the power supply to the load. Based on these results, recommendations are given for selecting a suitable range for changing the relative time of the closed state of the controlled switch, depending on the type of power supply used, as well as the method of connecting the controlled switch in the regulator circuit.
Improvement of voltage stability for grid connected solar photovoltaic systems using static synchronous compensator with recurrent neural network
(Національний технічний університет "Харківський політехнічний інститут", 2022) Praveen Kumar, Thota ; Ganapathy, Somaskandan; Manikandan, Mani
This article proposes a new control strategy for static synchronous compensator in utility grid system. The proposed photovoltaic fed static synchronous compensator is utilized along with recurrent neural network based reference voltage generation is presented in grid system network. The novelty of the proposed work consists in presenting a Landsman converter enhanced photovoltaic fed static synchronous compensator with recurrent neural network algorithm, to generate voltage and maintain the voltage-gain ratio. Methods. The proposed algorithm which provides sophisticated and cost-effective solution for utilization of adaptive neuro-fuzzy inference system as maximum power point tracking assures controlled output and supports the extraction of complete power from the photovoltaic panel. Grid is interconnected with solar power, voltage phase angle mismatch, harmonic and voltage instability may occur in the distribution grid. The proposed control technique strategy is validated using MATLAB/Simulink software and hardware model to analysis the working performances. Results. The results obtained show that the power quality issue, the proposed system to overcome through elimination of harmonics, reference current generation is necessary, which is accomplished by recurrent neural network. By recurrent neural network, the reference signal is generated more accurately and accordingly the pulses are generated for controlling the inverter. Originality. Compensation of power quality issues, grid stability and harmonic reduction in distribution network by using photovoltaic fed static synchronous compensator is utilized along with recurrent neural network controller. Practical value. The work concerns the comparative study and the application of static synchronous compensator with recurrent neural network controller to achieve a good performance control system of the distribution network system. This article presents a comparative study between the conventional static synchronous compensator, static synchronous compensator with recurrent neural network and hardware implementation with different load. The strategy based on the use of a static synchronous compensator with recurrent neural network algorithm for the control of the continuous voltage stability and harmonic for the distribution network-linear as well as non-linear loads in efficient manner. The study is validated by the simulation results based on MATLAB/Simulink software and hardware model.
An improved sliding mode control for reduction of harmonic currents in grid system connected with a wind turbine equipped by a doubly-fed induction generator
(Національний технічний університет "Харківський політехнічний інститут", 2022) Bouraghda, Skander; Sebaa, Karim; Bechouat, Mohcen ; Sedraoui, Moussa
The implementation of renewable energy resources into the electrical grid has increased significantly in recent years. Wind power is one of the existing resources. Presently, power electronics has become an indispensable tool in wind power plants. Problem. However the associated control usually has an impact on increasing the harmonic distortion, especially on the output voltage. Goal. This paper proposes a new sliding mode control strategy, applied on a rotor-side of a doubly-fed induction generator. The main goal is to meet the electrical power requirements, while responding to the power quality issues. Methodology. The wind energy conversion system must be able to not only track the maximum power point of the wind energy, but also to mitigate the harmonic currents caused by the non-linear loads. To achieve this goal, the power converters are driven by the proposed sliding mode control strategy. The corresponding two gains of the sliding surface are well selected using a particle swarm optimization algorithm. The particle swarm optimization algorithm solves a constrained optimization problem whose fitness function is a prior formulated as the sum of two mean square error criterions. The first criterion presents the tracking dynamic of the reference active power while the second one presents the tracking dynamic of the reference reactive power. The novelty lies in the implementation of the particle swarm optimization algorithm in conventional sliding mode control strategy, in which the proposed-improved sliding mode control strategy is developed. The wind energy conversion system control uses the principal of the vector oriented control to decouple the control of the active power from that of the reactive power. Results. The improved sliding mode control strategy is applied to control separately theses powers in the presence of non-linear loads. The energy assessment of this strategy is analysed using the wind energy conversion system model based on SimPower software. Originality. The obtained simulation results confirm the superiority of the proposed-improved sliding mode control strategy in terms of reference tracking dynamics and suppression of harmonic currents.
Equivalent cable harness method generalized for predicting the electromagnetic emission of twisted-wire pairs
(Національний технічний університет "Харківський політехнічний інститут", 2022) Bensiammar, Samir; Lefouili, Moussa; Belkhelfa, Soufiane
In this paper, the equivalent cable harness method is generalized for predicting the lectromagnetic emissions problems of twisted-wire pairs. The novelty of the proposed work consists in modeling of a multiconductor cable, in a simplified cable harness composed of a reduced number of equivalent conductors, each one is representing the behavior of one group of conductors of the initial cable. Purpose. This work is focused on the development and implementation of simplified simulations to study electromagnetic couplings on multiconductor cable. Methods. This method requires a four step procedure which is summarized as follows. Two different cases, of one end grounded and two ends grounded configurations can be analyzed. Results. The results had shown that the model complexity and computation time are significantly reduced, without, however, reducing the accuracy of the calculations.
An improved search ability of particle swarm optimization algorithm for tracking maximum power point under shading conditions
(Національний технічний університет "Харківський політехнічний інститут", 2022) Saeed, Hamdan; Mehmood, Tahir ; Khan, Fadia Ali ; Shah, Muhammad Shazaib; Ullah, Mian Farhan; Ali, Hamid
Extracting maximum possible power from solar energy is a hot topic of the day as other sources have become costly and lead to pollution. Problem. Dependency on sunlight for power generation makes it unfeasible to extract maximum power. Environmental conditions like shading, partial shading and weak shading are the major aspect due to which the output of photovoltaic systems is greatly affected. Partial shading is the most known issue. Goal. There have been many proposed techniques and algorithms to extract maximum output from solar resources by use of photovoltaic arrays but every technique has had some shortcomings that couldn’t serve the complete purpose. Methodology. Nature inspired algorithms have proven to be good to search global maximum in a partially shaded multipeak curve which includes particle swarm optimization, artificial bee colony algorithm, and flower pollination algorithm. Methods. Particle swarm optimization algorithm is best among these in finding global peaks with less oscillation around maximum power point, less complexity, and easy to implement nature. Particle swarm optimization algorithm has the disadvantage of having a long computational time and converging speed, particularly under strong shading conditions. Originality. In this paper, an improved opposition based particle swarm optimization algorithm is proposed to track the global maximum power point of a solar photovoltaic module. Simulation studies have been carried out in MATLAB/Simulink R2018a. Practical value. Simulation studies have proved that opposition based particle swarm optimization algorithm is more efficient, less complex, more robust, and more flexible and has better convergence speed than particle swarm optimization algorithm, perturb and observe algorithm, hill climbing algorithm, and incremental conductance algorithm.
Maximum power control of a wind generator with an energy storage system to fix the delivered power
(Національний технічний університет "Харківський політехнічний інститут", 2022) Boumassata, Abderraouf ; Kerdoun, Djallel; Oualah, Oussama
The power extracted from the wind turbine and delivered to the electrical network must be maximum and constant and the whole system should be have a good compromise between efficiency and cost. In order to attenuate this objective, a doubly fed induction machine, a cycloconverter, a maximum power point tracking algorithm and a flywheel energy storage system constitute a very interesting solution among many others that have been proposed. Novelty. The novelty of the proposed work is to use a doubly fed induction machine and a three pulses cycloconverter to reduce the cost and to integrate a flywheel energy storage system between the wind generator and the electrical network to maintain the constancy of the power sent to the network, following the instability of the wind. The proposed work uses a maximum power point tracking algorithm to capture the optimal power available in the wind in order to increase the efficiency of the system. Results. A detailed study of the proposed system is presented with the detailed dynamic modeling equations and simulation results are conducted to show the performance and the efficiency of the suggested work.
Passivity voltage based control of the boost power converter used in photovoltaic system
(Національний технічний університет "Харківський політехнічний інститут", 2022) Baazouzi, Kamel ; Bensalah, Abed Djebar; Drid, Said; Chrifi-Alaoui, Larbi
This paper presents a robust nonlinear control of the DC-DC boost converter feeding by a photovoltaic system based on the passivity control. The control law design uses the passivity approach. Novelty. The novelty consists in designing a control law for a photovoltaic system using a passivity approach based on energy shaping and associated with damping injection. Purpose. The purpose consists to develop a tool for design and optimize a control law of the photovoltaic system in order to improve its efficiency under some conditions such as the variations of the temperature, the irradiation and the parameters. Also, the control law design should be simple with a lower overshoot and a shorter settling time. Methods. This work uses the port Hamiltonian mathematical approach with minimization of the energy dissipation in boost converter of the photovoltaic system to illustrate the modification of energy and generate a specify duty cycle applied to the converter. Results. The results with MATLAB/SimPowerToolbox® have proven the robustness against parameter variations and effectiveness of the proposed control. Practical value. The experimental results, carried out using a dSPACE DS1104 system, are presented to show the feasibility and the robustness of the proposed control strategy against parameter variations.
The method of limitation of dynamic loads of nonlinear electromechanical systems under state vector robust control
(Національний технічний університет "Харківський політехнічний інститут", 2022) Kuznetsov, B. I.; Nikitina, T. B.; Bovdui, I. V.; Voloshko, O. V.; Kolomiets, V. V.; Kobilyanskiy, B. B.
Development of the method of limitation of dynamic loads of nonlinear electromechanical systems under state vector robust control. MethodologyLimitation of dynamic loads of nonlinear electromechanical systems is carried out using the minimum selector of choosing the minimum value of the control vector from formed with the help of local controllers and with the vector of maximum control values. Calculation of the gain coefficients of nonlinear robust controllers and observers are based on solutions of the Hamilton–Jacob–Isaacs equations. Results. The results of computer simulation of transitional processes of main roll drives of the rolling mill 950 of the Zaporozhye plant «Dnіprospetsstal» with limitation of dynamic loads are given. Originality. For the first time the method of limitation of dynamic loads of nonlinear electromechanical systems under state vector robust control based on minimum selector and nonlinear robust control of state variables which is needed limitation is developed. Practical value. Examples of transitional processes of main roll drives of the rolling mill 950 of the Zaporozhye plant «Dnіprospetsstal» with limitation of dynamic loads are given.

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