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Документ Ameliorate direct power control of standalone wind energy generation system based on permanent magnet synchronous generator by using fuzzy logic control(Національний технічний університет "Харківський політехнічний інститут", 2020) Lebied, Rima; Lalalou, Rachid; Benalla, Hocine; Nebti, Khalil; Boukhechem, IsmailElectricity is a basic energy for life and its consumption increased so we need the discovery of new sources of energy such as wind energy .for thisameliorate the quality of generated wind energyby using the intelligent artificial control, this control is made to optimize the performance of three-phase PWM rectifier working.Документ Fuzzy maximum power point tracking compared to sliding mode technique for photovoltaic systems based on DC-DC boost converter(Національний технічний університет "Харківський політехнічний інститут", 2021) Nebti, Khalil; Lebied, RymaThis paper presents the amelioration of maximum power point tracking using fuzzy logic methods for photovoltaic system supplying a standalone system. Method. The main role of the maximum power tracking is to force the system for working at the maximum point for each change of meteorological conditions. The classic technique Perturb and Observe is more attractive due to its simple and high efficiency. Sliding mode is a non-linear control technique; characterised by robustness against the parameters change or disturbances, it gives a good maximum power operation under different conditions such as changing solar radiation and photovoltaic cell temperature. Novelty. Fuzzy logic tracking technique is treated. Fuzzy rules construction is based on Perturb and Observe behaviour when the appropriate disturbance step is produced in order to obtain a fast system with an acceptable precision. We use in our study 60 W photovoltaic panel associated to boost chopper converter in order to supply a standalone system. Results. As show in results figures using fuzzy maximum power point tracking the ameliorate performances especially the very low oscillation rate (nearly 0.6 W), and very acceptable response time 0.1 s.Документ A power quality enhanced for the wind turbine with sensorless direct power control under different input voltage conditions(Національний технічний університет "Харківський політехнічний інститут", 2021) Laggoun, Zakaria El Zair; Benalla, Hocine; Nebti, KhalilThe quality of electrical energy is essential during disturbances, at the level of power electronic devices will suffer serious operating problems causing dangerous damage. Aim. A new approach to direct power control without grid voltage sensor improves the quality and control of instantaneous active and reactive power converters. Methodology. First, the technique without network voltage sensor with a direct power control based on a switching table, which is a classic approach, is discussed and its performance is analyzed under increasing and decreasing load. In addition, the performance of the proposed technique is also analyzed under the same circumstances and their performance is compared. Originality. The new method consists of a nonlinear grid voltage modulated controller and a conventional controller which guarantees very good results in a polluted network. The proposed method is verified using MATLAB/Simulink. Results. The simulation results under different input voltage conditions show that the proposed method not only has good tracking performance in active and reactive power, but also reduces the current total harmonic distortion to 1.9 %, which is good lower than the requirement for network operation.Документ Power quality enhancement using active power filter five-level cascade H-bridge under unbalanced and distorted grid(Національний технічний університет "Харківський політехнічний інститут", 2023) Guergah, Manel; Nebti, Khalil; Rezgui, Salah Eddine; Benalla, Hocine; Ould-Abdeslam, Djaffar OuidIntroduction. To improve the power quality of a supply system, the total harmonic distortion (THD) is the most important parameter in the quantification of harmonics caused by nonlinear loads. In practice, it must be less than 5 %. The novelty of the proposed work consists in the use of a cascaded five level active filter, when the converter consisting of six H-bridge pairs, each one includes four transistors. Purpose. To increase the efficiency of this filter, two techniques for quantification of harmonic currents are proposed, first the PQ-theory which is simple but can only be used in case of a balanced grid, and second the synchronous reference frame theory (SFR-theory), which is capable of creating harmonic current not only in an unbalanced grid, but also in an unbalanced and distorted beam. Methods. Using the control techniques, the harmonic current is extracted from load current and considered as a reference. The constructed current should follow this reference. Results. The estimation of the active and reactive powers is based on the measurement of the currents crossing the load and the network voltages, these powers are used to determine the shape of the harmonic (reference) current. Using the PI regulator, the output current of the five-level inverter follows the reference current perfectly. The inverters output current is injected into the grid to eliminate harmonic currents. Practical value. In practice, the harmonic distortion rate THD is the most widely used criterion for criticizing the waveform of the currents and judging the quality of the energy involved. For currents on the source side, the THD is considered acceptable if it is less than 5 %, in our proposal the THD is 0.85 % with the PQ-theory and 2.34 % with SFR-theory, so it is optimal.