Voltage control of DC-DC Three level Boost converter using TS Fuzzy PI controller

International audienceAppropriate control contributes essentially in the design of efficient DC-DC converters. With this intention, a study deals with the synthesis of a controller for DC-DC Three-level Boost converter (TLBC), has been addressed. The studied TLBC, known as nonlinear system, has been locally modeled using transfer function models. For instance, PI controllers were designed using the local models, and then they were combined using Takagi-Sugeno fuzzy (TSF) approach to form a TSF-PI controller. Simulation tests show the flexibility of the proposed controller, its rejection capability to different disturbances, and its ability to achieve the performance specification overall the wide operating range of the system

Влияние стратегий чтения на развитие понимания прочитанного

Основной целью исследования является изучение влияния стратегий чтения на понимание прочитанного. Для достижения цели было проведено исследование стратегий чтения, используемых студентами и их влияние на понимание прочитанного. Было опрошено 22 студента, обучающихся в Уральском федеральном университете. Результаты показали, что студенты используют различные стратегии чтения: сканирование, скимминг, чтение вслух, выделение грамматических структур, ответы на простые вопросы, поиск значений новых слов, перевод текстов на родной язык. Анализ полученных данных показывает, что учебные стратегии, используемые студентами для чтения на английском языке тесно связаны с уровнем понимания прочитанного, но не имеют системности.The main purpose of the study is to investigate the impact of reading strategies on reading comprehension achievements. A survey based on the questionnaire was conducted to identify learning strategies used by the learners and their impact on reading comprehension. A sample comprising of 22 students was selected from the Ural Federal University. The results indicated that students use variety of reading learning strategies including scanning, skimming, reading aloud, outlining grammatical structures, answering simple questions, looking for the meaning of new vocabulary and translating English texts in their mother language. The analysis of the data revealed that learning strategies adopted by students for reading English were strongly correlated with their performance in reading comprehension but not regular and systemic

New Ethylenediamine Crosslinked 2D-Cellulose Adsorbent for Nanoencapsulation Removal of Pb (II) and Cu (II) Heavy Metal Ions: Synthesis, Characterization Application, and RSM-Modeling

The main objective of the present work is to elaborate on a new eco-friendly and efficient adsorbent designated for aquatic micropollutants removal. However, the synthesis of the Ethylenediamine Crosslinked 2D-Cellulose green adsorbent was carried out successfully, by partial grafting of benzyl entities onto hydroxyl groups of HEC, and crosslinking with ethylenediamine ED. Further, the new ethylenediamine crosslinked 2D-Cellulose was used as a biosorbent for nanoencapsulation removal of copper and lead heavy metal ions from aqueous solutions. The proposal chemical structures of unmodified and modified materials were confirmed using FTIR, XRD, TGA, and SEM–EDX analysis. Furthermore, many parameters of the optimization for Pb (II) and Cu (II) in terms of removal efficiency including pH, adsorbent amount, and contact time were optimized by response surface methodology with a Box–Behnken design. Based on the desirability optimization with three factors, the maximal removal was 99.52% and 97.5% for Pb(II) and Cu(II), respectively and was obtained at pH = 5.94, 22.2 mg as the optimal adsorbent amount, and 21.53 min as contact time

Takagi-Sugeno Fuzzy Approach for PEM fuel cell system modeling

International audiencePEM fuel cell system modeling is a potential tool to design, analyze and predict its performances in different operating conditions. Many modeling approaches such as CFD, electrical equivalent circuit, empirical, semi-empirical and lumped parametric models have been applied to simulate PEMFC systems from the level of the MEA (membrane-electrodeassembly) unit cells up to full stack applications. In this paper, a new approach for a 5kW PEMFC system modeling is proposed. The FC system exhibits a nonlinear behavior captured from its experimental polarization curve. The latter is linearized around specific operation points. At each operating point, a local linear identified model that describes the behavior of the FC system at specific working conditions is developed. A data driven model based on Takagi Sugeno Fuzzy (TSF) approach is used to predict the global nonlinear behavior of the FC system for given operating conditions and driving inputs. In a controlled environment (stack temperature, humidity, and reactants pressure) the considered uncontrolled input for the system is the current load and the output is the voltage and electric power. The response of the proposed model is evaluated for different profiles of the load current. The developed model predicts the transitory behavior of the FC system accurately with a relative error of 0.4% and with a significant reduction in computational time making it suitable for integration and real time simulation of FCEV powertrains

A Novel Control Technique for Voltage Balancing in Bipolar DC Microgrids

International audienceThe bipolar DC microgrid topology is characterized by three voltage levels and is able to transfer power more efficiently than a conventional DC microgrid. This paper proposes an advanced control strategy aiming to ensure the voltage balancing between the upper and lower terminals of a bipolar DC microgrid regardless of the distribution of loads. The proposed controller is based on the backstepping method, which is well known for its the robustness and the global asymptotic stability that can be guaranteed for the system. A particle swarm optimization algorithm has also been adopted for an optimal design of the proposed controller parameters. Simulation results in a Matlab/Simulink environment has been presented to verify the effectiveness and reliability of the proposed voltage-balancing controller

Simulation and Experimental Validation for Takagi-Sugeno Fuzzy-Based Li-ion Battery Model

International audienceThe significant growth in electric vehicles use has increased the demand for lithium-ion batteries. Battery modeling is vital for optimal and safe usage of batteries. In this paper, a novel battery model based on the Takagi-Sugeno fuzzy has been proposed. It has been demonstrated that the battery behavior is strongly dependent on its state of charge (SoC). As a result, the developed model takes into account the SoC effect, which can significantly improve the model accuracy. Simulation and experimental tests validated the pertinence of the proposed model. It has been also shown that the estimated battery internal voltage is identical to the experimental ones with a low root-mean-square error under different operating conditions. Overall, a model with high accuracy and reasonable computational time of a lithium-ion battery is created.&nbsp

Circuit magnétique des inductances couplées pour hacheur élévateur à phases parallèles tolérant aux défauts

National audience<div style=""&gt<font face="arial, helvetica"&gt<span style="font-size: 13px;"&gtLes véhicules électriques à pile à combustible (FCEVs) sont devenus une des alternatives les plus écologiques. La pile à combustible (PAC), étant la principale source d'énergie, est toujours associée à un convertisseur DC/DC pour adapter sa faible tension au bus de liaison DC. Afin de satisfaire les exigences imposées pour la conception des FCEVs, le convertisseur DC/DC doit garantir un rendement élevé, une densité de puissance élevée (poids, volume et coût réduits) et une haute fiabilité. L’utilisation des phases parallèles à inductances couplées est une meilleure combinaison pour améliorer les performances du convertisseur et ainsi prolonger la durée de vie de la PAC. Cependant, les noyaux magnétiques sont sensibles à la saturation en cas de perte d'une phase. Dans cette contribution, un dimensionnement des inductances couplées est proposé, afin de considérer la saturation, généralement négligée dans la littérature, dans le développement des contrôles tolérants aux défauts. La modélisation du circuit magnétique est validée sur le logiciel PLECS.</span&gt</font&gt<br&gt</div&g

Advanced cascade control strategy applied to an indirect hybrid solar-gas dryer: Numerical and experimental investigations

International audienceIn this paper, a cascade control strategy is applied to control the temperature inside a hybrid solar-gas dryer. In order to use the dryer even at night and in unfavorable weather conditions, the drying chamber is heated by two systems. The first one is the solar air heater and the second one is the gas heater. The solar collector heater is relatively slow compared to the gas heating system. Static and dynamic studies were established and haverevealed the nonlinear behavior of each dryer subsystem. The cascade control approach was developed to control the drying temperature at different setpoints in a temperature range of [50 °C, 90 °C] by managing the gas flow delivered to burners according to received solar energy. Simulation tests followed by experimental investigations have revealed that the proposed control strategy has been able to fulfill the desired dryer performances at different temperatures level, with apropitious steady-state error, reduced overshoot, and a fast transient settling time. Hence, for controlled temperatures at 60 °C, 70 °C, and 80 °C temperatures, the following performances were respectively obtained: a steady-state error of 0.5%, 0.28%, and 1.28%, an overshoot of 2.6%, 4.1%, and 2.5%, and a settling time of 20 min, 18 min, and 30 min. The developed control approach has shown also an effective perturbance rejection during the dryer operation. The proposed controltechnique and the manufactured kit can be easily integrated into hybrid dryers and it’s an adequate and compatible solution with solar dryers for a drying operation of wide agro-food products. This solution also makes it possible to optimize the energy consumption of the secondary source

Modeling and design of a solar-powered refrigerator for vaccines transportation in remote regions

International audienc