Електротехніка і Електромеханіка

Постійне посилання на розділhttps://repository.kpi.kharkov.ua/handle/KhPI-Press/62894

Журнал публікує оригінальні результати досліджень з аналітичного, чисельного та мультифізичного методів моделювання електрофізичних процесів в електротехнічних електромеханічних та електроенергетичних установках та системах, з розробки нових електротехнічних пристроїв і систем з поліпшеними техніко-економічними та екологічними показниками в таких сферах, як: теоретична електротехніка, інженерна електрофізика, техніка сильних електричних та магнітних полів, електричні машини та апарати, електротехнічні комплекси та системи, силова електроніка, електроізоляційна та кабельна техніка, електричний транспорт, електричні станції, мережі і системи, безпека електрообладнання.

Рік заснування: 2002. Періодичність: 6 разів на рік. ISSN 2074-272X (Print), ISSN 2309-3404 (Online).

Новини

Видання включене до Переліку наукових фахових видань України з технічних наук до найвищої категорії «А» згідно Наказу МОН України №1412 від 18.12.2018 р.

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Зараз показуємо 1 - 7 з 7

Intelligent fuzzy back-stepping observer design based induction motor robust nonlinear sensorless control
(Національний технічний університет "Харківський політехнічний інститут", 2024) Abed, Khoudir; Zine, Hamed Kamel Eddine
The control algorithm of Induction Motor (IM) is massively dependent on its parameters; so, any variation in these parameters (especially in rotor resistance) gives unavoidably error propagates. To avoid this problem, researches give more than solution, they have proposed Variable Structure Control (VSC), adaptive observers such as Model Reference Adaptive System, Extended Luenberger Observer (ELO) and the Extended Kalman Filter (EKF), these solutions reduce the estimated errors in flux and speed. As novelty in this paper, the model speed observer uses the estimated currents and voltages as state variables; we develop this one by an error feedback corrector. The Indirect Rotor Field Oriented Control (IRFOC) uses the correct observed value of speed; in our research, we improve the observer’s labour by using back-stepping Sliding Mode (SM) control. Purpose. To generate the pulse-width modulation inverter pulses which reduce the error due of parameters variations in very fast way. Methods. We develop for reach this goal an exploration of two different linear observers used for a high performance VSC IM drive that is robust against speed and load torque variations. Firstly, we present a three levels inverter chosen to supply the IM; we present its modelling and method of control, ending by an experiment platform to show its output signal. A block diagram of IRFOC was presented; we analyse with mathematic equations the deferent stages of modelling, showed clearly the decoupling theory and the sensorless technique of control. The study described two kinds of observers, ELO and EKF, to estimate IM speed and torque. By the next of that, we optimize the step response using the fuzzy logic, which helps the system to generate the PI controller gains. Both of the two observers are forward by SM current controller, the convergence of SM-ELO and SM-EKF structures is guaranteed by minimizing the error between actual and observed currents to zero. Results. Several results are given to show the effectiveness of proposed schemes.
Sliding mode approach for control and observation of a three phase AC-DC pulse-width modulation rectifier
(Національний технічний університет "Харківський політехнічний інститут", 2023) Sakri, Djamel; Laib, Hichem; Farhi, Salah Eddine; Golea, Noureddine
Introduction. For AC-DC conversion systems, the electrical systems typically use thyristor or diode bridge rectifiers, which have relatively poor performance. Nowadays, three-phase pulse-width modulation rectifiers are widely applied in various applications for their well-known intrinsic benefits, such as adjustable DC link voltage, unity power factor, bidirectional power flow and very low total harmonic distortion. Purpose. The objective of this work is to achieve better stability and dynamic performance using sliding mode strategy for control and observation. Methods. For that purpose, first a sliding mode controller is introduced on the DC-link side to ensure a fast and accurate response of the output load voltage. Then, the sliding mode approach is employed to control the quadrature and direct components of power to maintain the input power factor at unity. Finally, this approach is used to design two observers for grid voltage estimation and online variation of load resistance. To overcome the problem associated with the use of the classical low-pass filter, an adaptive compensation algorithm is used to compensate the attenuation of the amplitude and phase delay of the observed grid voltages. This algorithm is based on the use of the two low-pass filters in cascade and ensures the minimization of chattering. Results. Comparative studies have been carried out between sliding mode control method for controlling the three-phase AC-DC pulse-width modulation rectifier and other conventional techniques. The validation by simulation and the tests carried out gave very satisfactory results and proved the effectiveness and feasibility of the sliding mode for both control and observation of three phase pulse-width modulation rectifier.
Cascade sliding mode maximum power point tracking controller for photovoltaic systems
(Національний технічний університет "Харківський політехнічний інститут", 2023) Hessad, M. A.; Bouchama, Z.; Benaggoune, S.; Behih, K.
Introduction. Constant increases in power consumption by both industrial and individual users may cause depletion of fossil fuels and environmental pollution, and hence there is a growing interest in clean and renewable energy resources. Photovoltaic power generation systems are playing an important role as a clean power electricity source in meeting future electricity demands. Problem. All photovoltaic systems have two problems; the first one being the very low electric-power generation efficiency, especially under low-irradiation states; the second resides in the interdependence of the amount of the electric power generated by solar arrays and the ever changing weather conditions. Load mismatch can occur under these weather varying conditions such that maximum power is not extracted and delivered to the load. This issue constitutes the so-called maximum power point tracking problem. Aim. Many methods have been developed to determine the maximum power point under all conditions. There are various methods, in most of them based on the well-known principle of perturb and observe. In this method, the operating point oscillates at a certain amplitude, no matter whether the maximum power point is reached or not. That is, this oscillation remains even in the steady state after reaching the maximum power point, which leads to power loss. This is an essential drawback of the previous method. In this paper, a cascade sliding mode maximum power point tracking control for a photovoltaic system is proposed to overcome above mentioned problems. Methodology. The photovoltaic system is mainly composed of a solar array, DC/DC boost converter, cascade sliding mode controller, and an output load. Two sliding mode control design strategies are joined to construct the proposed controller. The primary sliding mode algorithm is designed for maximum power point searching, i.e., to track the output reference voltage of the solar array. This voltage is used to manipulate the setpoint of the secondary sliding mode controller, which is used via the DC-DC boost converter to achieve maximum power output. Results. This novel approach provides a good transient response, a low tracking error and a very fast reaction against the solar radiation and photovoltaic cell temperature variations. The simulation results demonstrate the effectiveness of the proposed approach in the presence of environmental disturbances.
Efficiency enhancement strategy implementation in hybrid electric vehicles using sliding mode control
(Національний технічний університет "Харківський політехнічний інститут", 2023) Ibrar, Anas; Ahmad, Sohaira; Safdar, Ayla; Haroon, Nazo
Introduction. Hybrid electric vehicles are offering the most economically viable choices in today's automotive industry, providing best solutions for a very high fuel economy and low rate of emissions. The rapid progress and development of this industry has prompted progress of human beings from primitive level to a very high industrial society where mobility used to be a fundamental need. However, the use of large number of automobiles is causing serious damage to our environment and human life. At present most of the vehicles are relying on burning of hydrocarbons in order to achieve power of propulsion to drive wheels. Therefore, there is a need to employ clean and efficient vehicles like hybrid electric vehicles. Unfortunately, earlier control strategies of series hybrid electric vehicle fail to include load disturbances during the vehicle operation and some of the variations of the nonlinear parameters (e.g. stator's leakage inductance, resistance of winding etc.). The novelty of the proposed work is based on designing and implementing two robust sliding mode controllers (SMCs) on series hybrid electric vehicle to improve efficiency in terms of both speed and torque respectively. The basic idea is to let the engine operate only when necessary keeping in view the state of charge of battery. Purpose. In proposed scheme, both performance of engine and generator is being controlled, one sliding mode controllers is controlling engine speed and the other one is controlling generator torque, and results are then compared using 1-SMC and 2-SMC's. Method. The series hybrid electric vehicle powertrain considered in this work consists of a battery bank and an engine-generator set which is referred to as the auxiliary power unit, traction motor, and power electronic circuits to drive the generator and traction motor. The general strategy is based on the operation of the engine in its optimal efficiency region by considering the battery state of charge. Results .Mathematical models of engine and generator were taken into consideration in order to design sliding mode controllers both for engine speed and generator torque control. Vehicle was being tested on standard cycle. Results proved that, instead of using only one controller for engine speed, much better results are achieved by simultaneously using two sliding mode controllers, one controlling engine speed and other controlling generator torque.
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.
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.
Power quality improvement using ultra capacitor based dynamic voltage restorer with real twisting sliding mode control
(Національний технічний університет "Харківський політехнічний інститут", 2022) Shah, Muhammad Shahzaib; Mahmood, Tahir; Ullah, Mian Farhan
Power quality is a major problem in today's power system, since it may have an impact on customers and utilities. Problem. Power quality is important issue of financial consequences for utilities, their consumers and load apparatus vendors. Voltage sag/swell are the most significant and usually occurring power quality issues in a secondary distribution system for sensitive loads. Goal. Dynamic voltage restorer is a fast, flexible, effective and dynamic custom power device can be used to compensate voltage sag/swell with integration of energy storage. Ultra capacitors have ideal properties of great power density and low energy density for elimination of voltage sag/swell. Their performance is mostly determined by the control strategy established for switching of voltage source converters. Originality. In this research, a strategy for the voltage source converter of dynamic voltage restorer based on the real twisting sliding mode control and ultra capacitor is developed to correct the fault that successfully eliminates the impacts of voltage sag/swell. Methodology. Ultra capacitor along with real twisting sliding mode control gives the more robustness and faster response, with also increasing the compensation time of the dynamic voltage restorer. Testing environment. To evaluate the performance of the proposed control approach, the MATLAB / Simulink SimPower System tool box is employed. Practical values. According to Simulation results clearly shows that the ultra capacitor along with real twisting sliding mode control effectively eliminate the voltage sag/swell in a very short time of 2 ms as compared to IEEE standards that is 20 ms, with less than 5 % total harmonic distortion for sensitive loads as per Information Technology Industry Council Curve and SEMI-F-47 Standards.