Intelligent fuzzy back-stepping observer design based induction motor robust nonlinear sensorless control

Introduction. 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.Вступ. Алгоритм керування асинхронним двигуном (АД) багато в чому залежить від його параметрів; тому будь-яка зміна цих параметрів (особливо опору ротора) неминуче призводить до поширення помилок. Щоб уникнути цієї проблеми, дослідники пропонують щось більше, ніж просто рішення: вони запропонували управління змінною структурою (VSC), адаптивні спостерігачі, такі як адаптивна система еталонної моделі, розширений спостерігач Люенбергера (ELO) та розширений фільтр Калмана (EKF); ці рішення зменшують передбачувані помилки за потоком та швидкістю. Новизною цієї статті є те, що спостерігач швидкості моделі використовує оцінені струми та напруги як змінні стани; ми розробляємо його за допомогою коректора зворотного зв'язку помилки. Непряме управління з полю ротора (IRFOC) використовує правильне значення швидкості; у нашому дослідженні ми покращуємо роботу спостерігача, використовуючи керування ковзним режимом (SM) зі зворотним кроком. Мета. Генерувати імпульси інвертора широтно-імпульсної модуляції, які швидко зменшують помилку, викликану змінами параметрів. Методи. Для досягнення цієї мети ми розробляємо дослідження двох різних лінійних спостерігачів, що використовуються для високопродуктивного приводу VSC АД, стійкого до змін швидкості та моменту навантаження. По-перше, ми представляємо трирівневий інвертор, вибраний для живлення АД; ми представляємо його моделювання та метод управління, закінчуючи експериментальною платформою, що демонструє його вихідний сигнал. Представлена блок-схема IRFOC; ми аналізуємо за допомогою математичних рівнянь різні етапи моделювання, наочно демонструючи теорію розв'язки та безсенсорний метод керування. У дослідженні описані два типи спостерігачів, ELO та EKF, для оцінки швидкості та крутного моменту АД. Далі ми оптимізуємо перехідну реакцію, використовуючи нечітку логіку, яка допомагає системі генерувати коефіцієнти посилення ПІ-регулятора. Обидва з двох спостерігачів передаються контролером струму SM, зближення структур SM-ELO та SM-EKF гарантується за рахунок зведення до нуля помилки між фактичним та спостережуваним струмами. Результати. Наведено результати, що показують ефективність запропонованих схем

Smart current control of the wind energy conversion system based permanent magnet synchronous generator using predictive and hysteresis model

Introduction. Given the increasing demand for performance and efficiency of converters and power drives, the development of new control systems must take into account the real nature of these types of systems. Converters and dimmers power are nonlinear systems of a hybrid nature, including elements linear and nonlinear and a finite number of switching devices. Signals input for power converters are discrete signals that control the ‘opening and closing’ transitions of each component. Problem. In the multilevel inverters connected to grid, the switching frequency is the principal cause of harmonics and switching losses, which by nature, reduces the inverter’s efficiency. Purpose. For guarantee the satisfying quality of power transmitted to the electrical grid, while ensuring reduction of current ripples and output voltage harmonics. Novelty. This work proposes a new smart control, based on a predictive current control of the three level neutral point clamped inverter, used in Wind Energy Conversion System (WECS) connected to grid, based permanent magnet synchronous generator, powered by a hysteresis current control for the rectifier. This new formula guarantees handling with the influence of harmonics disturbances (similar current total harmonic distortion), voltage stress, switching losses, rise time, over or undershoot and settling time in WECS. Methods. The basic idea of this control is to choose the best switching state, of the power switches, which ameliorates the quality function, selected from order predictive current control of WECS. Results. Practical value. Several advantages in this intelligent method, such as the fast dynamic answer, the easy implementation of nonlinearities and it requires fewer calculations to choose the best switching state. In addition, an innovative algorithm is proposed to adjust the current ripples and output voltage harmonics of the WECS. The performances of the system were analyzed by simulation using MATLAB/Simulink.Вступ. Зважаючи на зростаючі вимоги до продуктивності та ефективності перетворювачів та силових приводів, при розробці нових систем керування необхідно враховувати реальну природу систем такого типу. Перетворювачі та регулятори потужності являють собою нелінійні системи гібридної природи, що включають лінійні та нелінійні елементи та кінцеве число комутаційних пристроїв. Вхідні сигнали для силових перетворювачів є дискретними сигналами, які керують переходами «відкриття та закриття» кожного компонента. Проблема. У багаторівневих інверторах, підключених до мережі, частота перемикання є основною причиною гармонік та втрат перемикання, що за своєю природою знижує ефективність інвертора. Мета. Гарантувати задовільну якість електроенергії, що передається в електричну мережу, при одночасному зниженні пульсацій струму та гармонік вихідної напруги. Новизна. У цій роботі пропонується новий інтелектуальний контроль, заснований на прогнозуючому керуванні струмом трирівневого інвертора з фіксованою нейтральною точкою, що використовується в системі перетворення енергії вітру (WECS), підключеної до мережі, на основі синхронного генератора з постійними магнітами, що живиться від керування струмом . Ця нова формула гарантує обробку з урахуванням впливу гармонічних перешкод (аналогічні загальні гармонічні спотворення струму), перенапруги, втрат перемикання, часу наростання, пере- чи недорегулювання, а також часу стабілізації WECS. Методи. Основна ідея цього управління полягає у виборі найкращого стану перемикання силових перемикачів, що покращує функцію якості, обрану з порядку прогнозуючого керування струмом WECS. Результати. Практична цінність. Цей інтелектуальний метод має кілька переваг, таких як швидка динамічна відповідь, простота реалізації нелінійностей і необхідність меншої кількості обчислень для вибору найкращого стану перемикання. Крім того, запропоновано інноваційний алгоритм регулювання пульсацій струму та гармонік вихідної напруги WECS. Характеристики системи проаналізовано шляхом моделювання з використанням MATLAB/Simulink

An efficient broadcasting routing protocol WAODV in mobile ad hoc networks

Information broadcasting in wireless network is a necessary building block for cooperative operations. However, the broadcasting causes increases the routing overhead. This paper brings together an array of tools of our adaptive protocol for information broadcasting in MANETs. The proposed protocol in this paper named WAODV (WAIT-AODV). This new adaptive routing discovery protocol for MANETs, lets in nodes to pick out a fantastic motion: both to retransmit receiving request route request (RREQ) messages, to discard, or to wait earlier than making any decision, which dynamically confgures the routing discovery feature to decide a gorgeous motion through the usage of neighbors’ knowledge. Simulations have been conducted to show the effectiveness of the using of techniques adaptive protocol for information broadcasting RREQ packet when integrated into ad hoc on-demand distance vector (AODV) routing protocols for MANET (which is based on simple flooding)

A Rare Case of Homicide by Dual Method-Strangulation with Cut Throat: A Case Report

Background: Homicide is killing of a human being by another human being. Various methods like strangulation, cut throat, stabbing etc may be used for homicide; however combination of two mechanisms is rare.Case Report: hereby we present a rare case with unexpected appearance of two different mechanisms of homicide applied over same region, wherein body of a female was referred to us with history of cut throat. Body of the deceased was found near her house with cut throat injuries over front of neck, on examination cut throat injuries were present over neck along with ligature mark intermingling with them.Conclusion: The present case represents an unexpected rare association of two methods of homicide, as in this case of strangulation followed by cut throat. Correct Interpretation of cause of death with its manner in such case is very important, which needs meticulous post-mortem examination along with proper correlation with other information

Epidemiology of Burn Deaths in Aurangabad Region, India

Background: Amongst all discoveries by men, barely few like cultivation of soil, speech and writing, have borne such significant developments as has finding out how to make fire. From the discovery of fire and its tremendous force, manufacturing, transportation and practically all phases of modern industrial life emerged out. Burns are injuries often produced by contact with dry heat, such as flame, radiation, or some solid heated material like metal or glass to the body.Methods: This study was conducted prospectively on 325 cases of death due to burns in the period from January 2010 to December 2010.Results: Hindu married females belonging to rural background were most common victims of burns. Maximum cases were observed in the evening with involvement of cooking apparatus most of the time.Conclusion: The present study has findings more or less consistent with the findings of the other Indian studies. Rising incidences of burns can be prevented by awareness and education about the hazards of fire and safety measures also upgrade of social and educational standards of population

Ecological insights and conservation imperatives for Laurus azorica in Morocco

The Azores laurel Laurus azorica (Seub.) Franco is a highly esteemed forest species in Morocco due to its medicinal and aromatic properties. However, the natural habitats of this species are increasingly scarce, resulting in its classification as a rare species. This study comprehensively investigates the autoecology, plant communities, and distribution patterns of L. azorica, aiming to discern the crucial ecological factors underpinning its survival and shed light on its conservation status. Field surveys, including floristic relevés and environmental characterization, were conducted to identify the primary plant communities hosting remnants of L. azorica. Fieldwork and ecological analysis reveal five distinct plant communities associated with L. azorica: low elevation thermophilic holm oak woodland, mesophilic mid-altitude holm oak woodland, Quercus faginea, deciduous broadleaf mountain and Cytisus balansae plant communities. The study emphasizes the importance of ecological requirements such as oceanic exposure, rainfall, temperature, and forest mull soils in creating suitable habitats for L. azorica populations. Currently, L. azorica populations in Morocco are represented by small trees, shrubs, or bushes, often exhibiting distorted and damaged structures due to unregulated pruning. Natural regeneration of the species is completely absent. The value chain associated with L. azorica is limited, involving informal harvesters, intermediary herbalist grocers, and final consumers, due to the lack of a legal framework for resource evaluation caused by its severe depletion. To secure the survival of L. azorica in Morocco, it is crucial to address gaps in legislation, intensify conservation efforts, and promote sustainable development practices. Protecting and restoring the natural habitats of the species, along with implementing responsible harvesting practices, are essential steps towards conserving this valuable forest species

SUBMICRON SIZED SINTERED ODS STEELS PREPARED BY HIGH EFFICIENT ATTRITION MILLING AND SPARK PLASMA SINTERING

RESUMECet article résume des résultats récents relatifs à l’élaboration et la caractérisation structurale et mécanique d’un acier renforcé à l'oxyde (nuance appelée souvent ROD/ODS). Trois poudres commerciales d'acier, deux poudres austénitiques et une poudre martensitique ont été utilisées comme matières d’étude. Une des poudres austénitiques a été utilisée pour l'étude morphologique lors du broyage humide. Le broyage à haute efficacité est sur la base de ce travail assurant l’obtention de grains nanostructurés. Les modifications morphologiques au cours des étapes de broyage ont été bien décrites. Il a été démontré que 4 heures de broyage en atmosphère humide sont suffisantes pour réaliser des poudres d'acier de dimensions submicroniques. Une dispersion efficace des nano-oxydes dans les aciers ROD/ODS a été obtenue en utilisant un broyage spécifique. On a proposé un procédé de broyage humide et sec combiné à des particules de céramique et d'acier. La méthode de frittage par étincelle (spark plasma sintering (SPS)) a été appliquée pour élaborer des aciers compacts à grains submicroniques. Des grains ayant une taille moyenne de 100 nm ont été observés par microscopie électronique à balayage (MEB) dans les aciers ROD/ODS austénitiques frittées. En comparaison, la microstructure de l’acier ROD/ODS martensitique frittée a donné des grains de tailles de 100 à 300 nm dans les deux cas de broyage sec et de broyage combiné (humide et sec).ABSTRACTThis paper summarizes recent results for preparation, structural and mechanical investigation of oxide dispersed strengthened steel (ODS). Three commercial steel powders, two austenitic steel and one martensitic powders have been used as starting materials. One of the austenitic powders was used for morphological study during wet milling. The high efficient attrition mills are on the basis of this work assuring grains with nanostructure. The morphological changes during milling steps have been described. It was demonstrated that 4 hours milling in wet atmosphere are enough to realize steel powders with submicron dimensions. An efficient dispersion of nanosized oxides in ODS steels was achieved by employing high efficiency attrition milling. A combined wet and dry milling process of fine ceramic and steel particles has been proposed. Spark Plasma Sintering (SPS) was applied to realize submicron grained steel compacts. Grains with 100 nm mean size have been observed by scanning electron microscopy (SEM) in sintered austenitic ODS. In comparison, the sintered martensitic dry and combined milled ODS microstructure consisted of grain sizes with 100-300 nm in each case.KEYWORDS: ODS Steel, Spark Plasma Sintering (SPS), attrition milling, Nano-oxides, structural and mechanical investigatio

Heat and Mass Transfer Enhancement in Absorption of Vapor in Laminar Liquid Film by Adding Nano-Particles

In this paper, a numerical study was performed. The effect of nanoparticles on the absorption of vapor into a liquid film of lithium bromide aqueous solution flowing down over a cooled vertical channel is examined. The present model uses the numerical finite volume method to solve the parabolic governing equations for two-dimensional and laminar flow. In this model, the cooling water flows countercurrent to a solution of concentrated lithium bromide mixed with the nanoparticles. The water vapor is then absorbed at the interface of the absorbent film and diffused into the binary nanofluid (water-LiBr+nanoparticles). The numerical results indicate that the mass and heat transfer in binary nanofluids are enhanced more than that in base fluid and the highest absorption mass flux is observed by adding argent (Ag) nanoparticles. The results of the effects of operating conditions show that the effectiveness of the nanofluid becomes higher than that with the base fluid when the Reynolds number and inlet concentration are lower and when the inlet temperature solution and inlet pressure are higher

Disorganized Innervation and Neuronal Loss in the Inner Ear of Slitrk6-Deficient Mice

Slitrks are type I transmembrane proteins that share conserved leucine-rich repeat domains similar to those in the secreted axonal guidance molecule Slit. They also show similarities to Ntrk neurotrophin receptors in their carboxy-termini, sharing a conserved tyrosine residue. Among 6 Slitrk family genes in mammals, Slitrk6 has a unique expression pattern, with strong expression in the sensory epithelia of the inner ear. We generated Slitrk6-knockout mice and investigated the development of their auditory and vestibular sensory organs. Slitrk6-deficient mice showed pronounced reduction in the cochlear innervation. In the vestibule, the innervation to the posterior crista was often lost, reduced, or sometimes misguided. These defects were accompanied by the loss of neurons in the spiral and vestibular ganglia. Cochlear sensory epithelia from Slitrk6-knockout mice have reduced ability in promoting neurite outgrowth of spiral ganglion neurons. Indeed the Slitrk6-deficient inner ear showed a mild but significant decrease in the expression of Bdnf and Ntf3, both of which are essential for the innervation and survival of sensory neurons. In addition, the expression of Ntrk receptors, including their phosphorylated forms was decreased in Slitrk6-knockout cochlea. These results suggest that Slitrk6 promotes innervation and survival of inner ear sensory neurons by regulating the expression of trophic and/or tropic factors including neurotrophins from sensory epithelia

Stemness of the Organ of Corti Relates to the Epigenetic Status of Sox2 Enhancers

In the adult mammalian auditory epithelium, the organ of Corti, loss of sensory hair cells results in permanent hearing loss. The underlying cause for the lack of regenerative response is the depletion of otic progenitors in the cell pool of the sensory epithelium. Here, we show that an increase in the sequence-specific methylation of the otic Sox2 enhancers NOP1 and NOP2 is correlated with a reduced self-renewal potential in vivo and in vitro; additionally, the degree of methylation of NOP1 and NOP2 is correlated with the dedifferentiation potential of postmitotic supporting cells into otic stem cells. Thus, the stemness the organ of Corti is related to the epigenetic status of the otic Sox2 enhancers. These observations validate the continued exploration of treatment strategies for dedifferentiating or reprogramming of differentiated supporting cells into progenitors to regenerate the damaged organ of Corti