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• W2212131838 abstract "RESUME Pendant des decennies, les turbines a gaz ont ete des dispositifs importants et fiables dans les domaines de la production d'energie, de l'industrie petrochimique, et de l'aeronautique. Ces machines utilisent les compresseurs centrifuges et axiaux qui se degradent en presence d’instabilites aerodynamiques telles que le pompage et le decrochage tournant. Ces dernieres limitent la performance et peuvent causer des sollicitations mecaniques importantes, une reduction de la duree de vie, du bruit et des vibrations. De plus, dans les compresseurs axiaux a vitesse variable (CAVV), les variations de vitesse affectent la stabilite des systemes et peuvent entrainer le pompage et le decrochage tournant. Cela limite le taux de variation de vitesse et penalise la performance. Le travail presente dans cette these dresse premierement l'analyse de bifurcation du modele des CAVVs afin d’etudier l'impact de la dynamique de la vitesse sur la stabilite de points de fonctionnement efficaces. Ici, le taux de variation de vitesse (acceleration) est defini comme un nouveau parametre du modele et une analyse detaillee de bifurcation numerique est fournie. Les resultats des simulations dans le domaine temporel valident non seulement l'analyse de bifurcation, mais elargissent aussi nos connaissances sur la reponse transitoire du modele, qui est d’une importance majeure. L'analyse realisee revele que les variations de vitesse peuvent mener a un decrochage tournant entierement developpe ainsi qu’au decrochage temporaire mentionne precedemment. Les resultats montrent que les instabilites developpees dependent fortement du taux d'acceleration. L'impact des autres parametres du modele, les vitesses initiale et finale, et la contribution des modes du decrochage sont egalement etudies.Au niveau du controle, malgre toutes les realisations presentees, la conception d’une commande robuste meme pour des systemes de compression axiaux a vitesse constante demeure encore un probleme difficile. Ici, deux methodes de commande non lineaires: le controle par modes glissants et le controle par passivite sont proposees pour resoudre ce probleme de stabilite. Ces deux approches traitent de tous les aspects difficiles du sujet qui apparaissent dans la litterature : l'impact des perturbations externes, le manque de connaissance precise des parametres du modele, et l'absence d’un retour d’etat complet.---------- ABSTRACTFor decades, gas turbines have been important, widespread, and reliable devices in the field of power generation, petrochemical industry, and aeronautics. They employ centrifugal and axial compressors which suffer from aerodynamic instabilities, namely, surge and rotating stall. These performance limiting instabilities can cause component stress, lifespan reduction, noise, and vibration. Furthermore, in variable speed axial compressors (VSACs), speed variations affect the system stability and can lead to surge and rotating stall. This limits the rate of speed variations and results in important performance penalties. The present work firstly addresses the bifurcation analysis of VSACs’ model to investigate the impact of speed dynamics on the stability of efficient operating points. Here, the rate of speed variations (acceleration rate) is defined as a new parameter of the model and a detailed numerical bifurcation analysis is provided. The results of time-domain simulations not only validate the results of bifurcation analysis, but also broaden our knowledge about the transient response of the model, which is a matter of importance as well. The analysis reveals that speed variations can lead to a fully developed rotating stall as well as the previously reported temporary stall developments. The results show that the developed instabilities depend to a great extent on the acceleration rate. The impact of other key issues such as throttle gain, viscosity factor, initial speed, final speed, and the contribution of stall modes are also explored. From the control point of view, despite reported achievements, robust control design for compression systems remains a challenging problem. In this work, at first, two nonlinear approaches are proposed to tackle the stability problem of constant-speed axial compressors (CSACs). The first approach is a robust passivity-based control and the second one is a second order sliding mode control. The approaches tackle the challenging problems being addressed in the literature such as: the impact of external perturbations, the lack of detailed parameters knowledge, and the absence of full-state feedback. They drive the control from pressure and mass flow measurements and use throttle and close-coupled valve actuations. Finally, this study reports that these methods can be used in the case of VSACs by applying the required modifications to simultaneously control speed and instabilities. This simultaneous control design has been an open problem and the proposed method can improve the performance of VSACs." @default.
• W2212131838 created "2016-06-24" @default.
• W2212131838 creator A5016733993 @default.
• W2212131838 date "2014-08-01" @default.
• W2212131838 modified "2023-09-23" @default.
• W2212131838 title "MODEL ANALYSIS AND NONLINEAR CONTROL OF AIR COMPRESSORS" @default.
• W2212131838 cites W135479180 @default.
• W2212131838 cites W1498887287 @default.
• W2212131838 cites W1535439667 @default.
• W2212131838 cites W1548148540 @default.
• W2212131838 cites W1590089162 @default.
• W2212131838 cites W1591387922 @default.
• W2212131838 cites W1596321532 @default.
• W2212131838 cites W1605165413 @default.
• W2212131838 cites W160832363 @default.
• W2212131838 cites W1629020967 @default.
• W2212131838 cites W164357479 @default.
• W2212131838 cites W1727056938 @default.
• W2212131838 cites W1965285013 @default.
• W2212131838 cites W1965623622 @default.
• W2212131838 cites W1968729257 @default.
• W2212131838 cites W1970313530 @default.
• W2212131838 cites W1973504195 @default.
• W2212131838 cites W1974161059 @default.
• W2212131838 cites W1977164028 @default.
• W2212131838 cites W1979442134 @default.
• W2212131838 cites W1980411718 @default.
• W2212131838 cites W1981717790 @default.
• W2212131838 cites W1985996685 @default.
• W2212131838 cites W1987447777 @default.
• W2212131838 cites W1988004841 @default.
• W2212131838 cites W1988368003 @default.
• W2212131838 cites W1997363221 @default.
• W2212131838 cites W2000167686 @default.
• W2212131838 cites W2000973087 @default.
• W2212131838 cites W2004333647 @default.
• W2212131838 cites W2004833170 @default.
• W2212131838 cites W2011987799 @default.
• W2212131838 cites W2012105651 @default.
• W2212131838 cites W2014695747 @default.
• W2212131838 cites W2022130059 @default.
• W2212131838 cites W2023963178 @default.
• W2212131838 cites W2025315488 @default.
• W2212131838 cites W2026245529 @default.
• W2212131838 cites W2026246097 @default.
• W2212131838 cites W2027905095 @default.
• W2212131838 cites W2028436424 @default.
• W2212131838 cites W2030276497 @default.
• W2212131838 cites W2031814859 @default.
• W2212131838 cites W2035531828 @default.
• W2212131838 cites W2047429583 @default.
• W2212131838 cites W2047614387 @default.
• W2212131838 cites W2048580032 @default.
• W2212131838 cites W2050361604 @default.
• W2212131838 cites W2051415525 @default.
• W2212131838 cites W2051820895 @default.
• W2212131838 cites W2055902526 @default.
• W2212131838 cites W2058782507 @default.
• W2212131838 cites W2061440515 @default.
• W2212131838 cites W2066442030 @default.
• W2212131838 cites W2067433675 @default.
• W2212131838 cites W2069039177 @default.
• W2212131838 cites W2073287583 @default.
• W2212131838 cites W2073571569 @default.
• W2212131838 cites W2075397786 @default.
• W2212131838 cites W2077976684 @default.
• W2212131838 cites W2078286552 @default.
• W2212131838 cites W2081215246 @default.
• W2212131838 cites W2081466062 @default.
• W2212131838 cites W2081696580 @default.
• W2212131838 cites W2082613595 @default.
• W2212131838 cites W2085084323 @default.
• W2212131838 cites W2085323716 @default.
• W2212131838 cites W2090167557 @default.
• W2212131838 cites W2090265588 @default.
• W2212131838 cites W2093365985 @default.
• W2212131838 cites W2093426824 @default.
• W2212131838 cites W2095007834 @default.
• W2212131838 cites W2097410403 @default.
• W2212131838 cites W2097585068 @default.
• W2212131838 cites W2098167057 @default.
• W2212131838 cites W2101509757 @default.
• W2212131838 cites W2102899117 @default.
• W2212131838 cites W2107636249 @default.
• W2212131838 cites W2107998946 @default.
• W2212131838 cites W2108357445 @default.
• W2212131838 cites W2109363900 @default.
• W2212131838 cites W2111699571 @default.
• W2212131838 cites W2112879260 @default.
• W2212131838 cites W2118615300 @default.
• W2212131838 cites W2118978029 @default.
• W2212131838 cites W2119085889 @default.
• W2212131838 cites W2119747972 @default.
• W2212131838 cites W2120068461 @default.
• W2212131838 cites W2123569008 @default.
• W2212131838 cites W2127786727 @default.
• W2212131838 cites W2128453050 @default.
• W2212131838 cites W2133409801 @default.
• W2212131838 cites W2138491388 @default.
• W2212131838 cites W2138788117 @default.

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