Видання НТУ "ХПІ"
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Документ Harmonics suppression in high-speed railway via single-phase traction converter with an LCL filter using fuzzy logic control strategy(Національний технічний університет "Харківський політехнічний інститут", 2024) Aissaoui, M.; Bouzeria, H.; Benidir, M.; Labed, M. A.The railway Traction Power Supply System (TPSS) encounters a common challenge related to high-frequency harmonic resonance, especially when employing AC-DC-AC traction drive systems in high-speed trains. This resonance issue arises when the harmonic elements introduced by the traction AC-DC converter on the grid side of trains align with the innate resonance frequency of the TPSS. The novelty the proposed work focuses on the challenges associated with resonance elevation and high-frequency harmonics in high-speed trains, while simultaneously enhancing energy quality. This is achieved by integrating a pulse-width-modulated converter on the grid side with a single-phase configuration and incorporating an LCL filter. Methodology. In order to optimize the system’s efficiency, a robust control system is employed, taking advantage of the capabilities of a fuzzy logic controller (FLC). The choice of the FLC is justified by its straight forward design and reliability, emphasizing the dedication to precise control, as fuzzy logic excels in handling complex, nonlinear systems. Through the use of linguistic variables and heuristic reasoning, the FLC adjusts to dynamic changes in the system, demonstrating its efficacy in enhancing both transient and steady-state responses. Practical value. A grid-side LCL filter-based converter was meticulously designed and rigorously simulated using the MATLAB/Simulink platform. The inclusion of advanced FLC in the system introduced a novel approach to control strategies, surpassing the traditional PI controller. Through a comprehensive comparative analysis, the simulation results showcased the remarkable efficacy of the proposed solution in an effectively mitigating high-frequency resonance within the TPSS. This outcome underscores the potential of FLC as a sophisticated control mechanism for enhancing the performance systems in railway applications, showcasing its superiority over conventional control methods. The study contributes in shedding light on innovative approaches for optimizing the control and efficiency of grid-side LCL filter-based converters in high-speed train systems.Документ Optimal hybrid photovoltaic distributed generation and distribution static synchronous compensators planning to minimize active power losses using adaptive acceleration coefficients particle swarm optimization algorithms(Національний технічний університет "Харківський політехнічний інститут", 2023) Labed, Mohamed Amir; Zellagui, Mohamed; Benidir, M.; Sekhane, Hocine; Tebbakh, NoureddineThe paper aims to identify the optimum size and location of photovoltaic distributed generation systems and distribution static synchronous compensators (DSTATCOMs) systems to minimize active power losses in the distribution network and enhance the voltage profile. The methodology employed in this article begins by thoroughly discussing various acceleration algorithms used in Particle Swarm Optimization (PSO) and their variations with each iteration. Subsequently, a range of PSO algorithms, each incorporating different variations of acceleration coefficients was verified to solve the problem of active power losses and voltage improvement. Simulation results attained on Standard IEEE-33 bus radial distribution network prove the efficiency of acceleration coefficients of PSO; it was evaluated and compared with other methods in the literature for improving the voltage profile and reducing active power. Originality. Consists in determining the most effective method among the various acceleration coefficients of PSO in terms of minimizing active power losses and enhancing the voltage profile, within the power system. Furthermore, demonstrates the superiority of the selected method over others for achieving significant improvements in power system efficiency. Practical value of this study lies on its ability to provide practical solutions for the optimal placement and sizing of distributed generation and DSTATCOMs. The proposed optimization method offers tangible benefits for power system operation and control. These findings have practical implications for power system planners, operators, and policymakers, enabling them to make informed decisions on the effective integration of distributed generation and DSTATCOM technologies.Документ 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 AmirIntroduction. 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.Документ Modelling and performance testing of a digital over-current relay enhanced designed model(Національний технічний університет "Харківський політехнічний інститут", 2022) Sekhane, Hocine; Labed, Djamel; Labed, Mohamed AmirThe over-current relay is widely used to protect distribution and transmission electrical systems against excessive currents occurring due to short circuit or overload conditions. Many works have been carried out in the field of models simulation design of digital over-current relays in the literature, but unfortunately many of them are more complex design models, have very slow execution time and only work in simple faults cases. Purpose. The purpose of this work is to present the performance of a modified and improved model of a digital over-current relay designed in Simulink/MATLAB environment with more simplified design, faster execution time, and able to operate under more complex fault conditions. Methodology. Before starting tests, modelling of over-current relay is presented in details, of which the basic logics of the proposed model to implement inverse and instantaneous characteristics are well explained. Afterwards, various tests are carried out for the performance analysis of the enhanced designed relay model in terms of: operating speed for eliminating faults that has arisen, ability to distinguish between a fault current and load starting current, capacity distinguish between real and temporary fault currents, the way to manage variable faults over time, and the degree of harmony between primary protection relay and back-up protection relay. Originality. The originality of our proposed work consists in the development and improvement of a digital over-current relay model designed in Simulink/MATLAB environment in such way that it becomes able to operate under new harsh test conditions. This developed designed model is implemented and applied in a 400V radial distribution power system with a load that causes a starting current. Results. The obtained values of simulation are compared with the theoretically calculated values and known existing models. The obtained results after various tests validate the good performance of our enhanced designed model.