2022 № 6 Електротехніка і Електромеханіка

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https://repository.kpi.kharkov.ua/handle/KhPI-Press/65918

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Зараз показуємо 1 - 11 з 11

On modeling and real-time simulation of a robust adaptive controller applied to a multicellular power converter
(Національний технічний університет "Харківський політехнічний інститут", 2022) Hamdi, Rihab; Hadri Hamida, Amel; Bennis, Ouafae
Introduction. This paper describes the simulation and the robustness assessment of a DC-DC power converter designed to interface a dual-battery conversion system. The adopted converter is a Buck unidirectional and non-isolated converter, composed of three cells interconnected in parallel and operating in continuous conduction mode. Purpose. In order to address the growing challenges of high switching frequencies, a more stable, efficient, and fixed-frequency-operating power system is desired. Originality. Conventional sliding mode controller suffers from high-frequency oscillation caused by practical limitations of system components and switching frequency variation. So, we have explored a soft-switching technology to deal with interface problems and switching losses, and we developed a procedure to choose the high-pass filter parameters in a sliding mode-controlled multicell converter. Methods. We suggest that the sliding mode is controlled by hysteresis bands as the excesses of the band. This delay in state exchanges gives a signal to control the switching frequency of the converter, which, in turn, produces a controlled trajectory. We are seeking an adaptive current control solution to address this issue and adapt a variable-bandwidth of the hysteresis modulation to mitigate nonlinearity in conventional sliding mode control, which struggles to set the switching frequency. Chatter problems are therefore avoided. A boundary layer-based control scheme allows multicell converters to operate with a fixed-switching-frequency.
Interactive artificial ecosystem algorithm for solving power management optimizations
(Національний технічний університет "Харківський політехнічний інститут", 2022) Mahdad, Belkacem; Srairi, Kamel
Introduction. Power planning and management of practical power systems considering the integration and coordination of various FACTS devices is a vital research area. Recently, several metaheuristic methods have been developed and applied to solve various optimization problems. Among these methods, an artificial ecosystem based optimization has been successfully proposed and applied to solve various industrial and planning problems. The novelty of the work consists in creating an interactive process search between diversification and intensification within the standard artificial ecosystem based optimization. The concept of the introduced variant is based on creating dynamic interaction between production operator and consumer operator during search process. Purpose. This paper introduces an interactive artificial ecosystem based optimization to solve with accuracy the multi objective power management optimization problems. Methods. The solution of the problem was carried out using MATLAB program and the developed package is based on combining the proposed metaheuristic method and the power flow tool based Newton-Raphson algorithm. Results. Obtained results confirmed that the proposed optimizer tool may be suitable to solve individually and simultaneously various objective functions such as the total fuel cost, the power losses and the voltage deviation.
Photovoltaic system faults diagnosis using discrete wavelet transform based artificial neural networks
(Національний технічний університет "Харківський політехнічний інститут", 2022) Bengharbi, Abdelkader Azzeddine; Laribi, Saadi Souad; Allaoui, Tayeb; Mimouni, Amina
Introduction. This research work focuses on the design and experimental validation of fault detection techniques in grid-connected solar photovoltaic system operating under Maximum Power Point Tracking mode and subjected to various operating conditions. Purpose. Six fault scenarios are considered in this study including partial shading, open circuit in the photovoltaic array, complete failure of one of the six IGBTs of the inverter and some parametric faults that may appear in controller of the boost converter. Methods. The fault detection technique developed in this work is based on artificial neural networks and uses discrete wavelet transform to extract the features for the identification of the underlying faults. By applying discrete wavelet transform, the time domain inverter output current is decomposed into different frequency bands, and then the root mean square values at each frequency band are used to train the neural network. Results. The proposed fault diagnosis method has been extensively tested on the above faults scenarios and proved to be very effective and extremely accurate under large variations in the irradiance and temperature.
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.
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, Krishnan
Introduction. 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.
Fault tolerant control of a permanent magnet synchronous machine using multiple constraints Takagi-Sugeno approach
(Національний технічний університет "Харківський політехнічний інститут", 2022) Moussaoui, Lotfi; Aouaouda, Sabrina; Rouaibia, Reda
Introduction. Fault diagnosis, and fault tolerant control issues are becoming very important to ensure a good supervision of systems and guarantee the safety of human operators and equipments even if system complexity increases. Problem. In fact, the presence of faults in actuators, sensors and processes can lead to system performance degradation, system breakdown, economic loss, and even disastrous situations. Furthermore, Actuator saturation or control input saturation is probably the most usual nonlinearity encountered in control engineering because of the physical impossibility of applying unlimited control signals and/or safety constraints. Purpose. This article is dedicated to the problem of fault tolerant control for constrained nonlinear systems described by a Takagi-Sugeno model. One of the interests of this type of models is the possibility of extend some tools and methods from linear system case to the nonlinear one. The novelty of the work consists in developing a fault tolerant control algorithm for a nonlinear Permanent Magnet Synchronous Machine model using an observer based state-feedback control technique in order to enhance fault and state estimation despite actuator saturation and system disturbances. Methods. Indeed a sensor fault detection observer based residual generator is synthesized with a guaranteed L₂ performance to attenuate the external disturbances effect from one side and to maximize the residual sensitivity to faults from the other side. Based on Lyapunov function, design conditions are formulated in terms of Linear Matrix Inequalities to ensure stability of the global system. Practical value. A detailed study concerning nonlinear permanent magnet synchronous machine model, which is consolidated by simulation results, is conducted to show the used algorithm’s effectiveness guarantying fault estimation and reconfiguration of the control law to maintain stable performance even in the presence of actuator faults, external perturbation and the phenomenon of actuator saturation.
Fault detection and monitoring of solar photovoltaic panels using internet of things technology with fuzzy logic controller
(Національний технічний університет "Харківський політехнічний інститут", 2022) Shweta, Raj; Sivagnanam, Sivaramalingam; Kumar, Kevin Ark
Purpose. This article proposes a new control monitoring grid connected hybrid system. The proposed system, automatic detection or monitoring of fault occurrence in the photovoltaic application is extremely mandatory in the recent days since the system gets severely damaged by the occurrence of different faults, which in turn results in performance degradation and malfunctioning of the system. The novelty of the proposed work consists in presenting solar power monitoring and power control based Internet of things algorithm. In consideration to this viewpoint, the present study proposes the Internet of Things (IoT) based automatic fault detection approach, which is highly beneficial in preventing the system damage since it is capable enough to identify the emergence of fault on time without any complexities to generate Dc voltage and maintain the constant voltage for grid connected hybrid system. Methods. The proposed DC-DC Boost converter is employed in this system to maximize the photovoltaic output in an efficient manner whereas the Perturb and Observe algorithm is implemented to accomplish the process of maximum power point tracking irrespective of the changes in the climatic conditions and then the Arduino microcontroller is employed to analyse the faults in the system through different sensors. Eventually, the IoT based monitoring using fuzzy nonlinear autoregressive exogenous approach is implemented for classifying the faults in an efficient manner to provide accurate solution of fault occurrence for preventing the system from failure or damage.
Synthesis of an effective system of active shielding of the magnetic field of a power transmission line with a horizontal arrangement of wires using a single compensation winding
(Національний технічний університет "Харківський політехнічний інститут", 2022) Kuznetsov, B. I.; Nikitina, T. B.; Bovdui, I. V.; Voloshko, O. V.; Kolomiets, V. V.; Kobylianskyi, B. B.
Aim. The theoretical and experimental studies of the effectiveness of reducing the level of the magnetic field in two-storey cottage of the old building of a power transmission line with a horizontal arrangement of wires by means of active shielding with single compensation winding. Methodology Spatial location coordinates of the compensating winding and the current in the shielding winding were determined during the design of systems of active screening based on solution of the vector game, in whith the vector payoffs is calculated based on Biot-Savart's law. The solution of this vector game calculated based on algorithms of multi-swarm multi-agent optimization. Results The results of theoretical and experimental studies of the effectiveness of reducing the level of the magnetic field in two-storey cottage of the old building of a power transmission line with a horizontal arrangement of wires by means of active shielding with single compensation winding are presented. Originality. For the first time, the theoretical and experimental studies of the effectiveness of reducing the level of the magnetic field in two-storey cottage of the old building of a power transmission line with a horizontal arrangement of wires by means of active shielding with single compensation winding are considered. Practical value. From the point of view of the practical implementation it is shown the possibility to reduce the level of magnetic field in two-storey cottage of the old building from power transmission line with a horizontal arrangement of wires by means of active shielding with single compensation winding to the sanitary standards of Ukraine.
Optimal size and location of distributed generations in distribution networks using bald eagle search algorithm
(Національний технічний університет "Харківський політехнічний інститут", 2022) Tebbakh, Noureddine; Labed, Djamel; Labed, Mohamed Amir
Introduction. In the actual era, the integration of decentralized generation in radial distribution networks is becoming important for the reasons of their environmental and economic benefits. Purpose. This paper investigate the optimal size, location and kind of decentralized generation connected in radial distribution networks using a new optimization algorithm namely bald eagle search. Methods. The authors check the optimal allocation of two kinds of decentralized generation the first is operated at unity power factor and the second is operated at 0.95 power factor, a multi-objective functions are minimized based on reduction of voltage deviation index, active and reactive power losses, while taking into consideration several constraints. Results. Simulation results obtained on Standard IEEE-33 bus and IEEE-69 bus radial distribution networks demonstrate the performance and the efficiency of bald eagle search compared with the algorithms existing in literature and radial distribution networks performances are improved in terms of voltage profile and notably active and reactive power losses reduction, decentralized generation operated at 0.95 power factor are more perfect than those operated at unit power factor.
Method of calculation of electromagnetic torque and energy losses of three-phase induction motors when powered by a regulated single-phase voltage
(Національний технічний університет "Харківський політехнічний інститут", 2022) Shurub, Yu. V.; Vasilenkov, V. Ye.; Tsitsyurskiy, Yu. L.
Single-phase power supply of induction motors is used in public utilities, in microclimate control systems for remote agricultural consumers, in water supply and pipeline transport systems, etc. In practice, there is the use of induction motors with three-phase stator winding in the conditions of single-phase power supply. Starting and operating capacitors are used to enable their operation when powered by a single-phase network. Problem. There are many fairly accurate methods for calculating the characteristics of an induction motor in asymmetric, including single-phase, modes of operation, but they are based on differential equations, which does not allow to obtain analytical expressions for preliminary analysis and synthesis of such systems. Goal. The purpose of this article is to develop the analytical method of definition of electromagnetic torque and energy losses of voltage-regulated three-phase induction motors working according to the scheme of single-phase inclusion with the phase-shifting capacitor. Methodology. The method is based on the theory of symmetric components and analysis of replacement schemes of induction machine in motor and generator modes. Results. The analysis of the obtained data shows that at a constant value of the phase-shifting capacitor capacity induction motor working according to the scheme of single-phase inclusion has a minimum of losses at one value of slip at different values of supply voltage. Therefore, if you keep this slip constant when the load changes, you can achieve a mode of minimizing losses at a constant value of the capacity, optimal for this slip. This shows that the thyristor voltage regulator can be used as an energy-saving element under variable load, while the capacitance of the phase-shifting capacitor can remain constant when changing the load in a wide range provided that this slip is stabilized. Originality. The developed method allows to obtain analytical expressions for comparative analysis of electromagnetic torque and energy losses of three-phase induction motors powered by a single-phase network at different values of the capacity of the phase-shifting capacitor, supply voltage for different variants of schemes for including three-phase induction motors in a single-phase network. Practical value. Based on the developed analytical method, the optimal parameters of phase-shifting capacitors and rational schemes for including three-phase induction motors in a single-phase network can be determined.
A high-frequency modeling of AC motor in a frequency range from 40 Hz to 110 MHz
(Національний технічний університет "Харківський політехнічний інститут", 2022) Miloudi, Houcine; Miloudi, Mohamed; Gourbi, Abdelkader; Bermaki, Mohammed Hamza; Bendaoud, Abdelber; Zeghoudi, Abdelhakim
Most electromagnetic compatibility models developed for the study of three-phase induction machines are generally valid for low and medium frequencies (<< 1 MHz). This frequency limit seems to be too restrictive for the overall study of conducted electromagnetic interference. In this paper, the model is using the proposed model and compared with experimental results in low and medium frequency. And then, the high-frequency modeling of induction motor is presented new method based on transfer function model. The proposed methodology is verified on an experimental and simulation, it’s suitable for prediction of the terminal overvoltage analysis and electromagnetic interference problems and common-mode and differential-mode currents. The novelty of the work consists to develop an improved high-frequency motor model based on transfer function to represent the motor high-frequency behavior for frequency-domain analyses in the frequency range from 40 Hz up to 110 MHz .The purpose of this work is to study the common-mode impedance and the differential-mode impedance of AC motor. The determination of these impedances is done for firstly both common and differential modes at low and medium frequency, and then common-mode and differential-mode characteristics at high frequency. Methods. For the study of the path of common-mode and differential-mode currents in typical AC motor (0.25 kW, 50 Hz) an identification method in high frequency for induction motor has been proposed based on the transfer function in differential-mode and common-mode configuration. The low and medium frequency model were presented in the first time based on equivalent circuit of electrical motor. Then, the common-mode and differential-mode impedances were defined in high frequency using asymptotic approach. This motor was studied by MATLAB Software for simulation and also experimental measurements. Results. All the simulations were performed using the mathematical model and the results obtained are validated by experimental measurements performed in the University of the Federal Armed Forces Hamburg in Germany. The obtained results of common-mode and differential-mode at low frequency, medium and high frequency are compared between simulation and experiment.

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