13 research outputs found
Control por histéresis para un inversor buck-dual conectado a la red
Single-phase inverters are widely used in different renewable energy applications. Although the full-bridge inverter is typically used, dual-buck inverters provide an important advantage, since they eliminate the shoot-through problems. However, solutions proposed in the literature require additional inductors, use linear controllers designed around an operation point, or cannot be used in grid-connected applications. This paper presents a hysteresis current control of a single-phase dual-buck full-bridge inverter for grid-connected active power injection. Includes the dynamical model in state variables, as well as analytical conditions to guarantee the evolution of the error dynamics in a set with boundaries defined by the designer. Moreover, the paper provides guidelines for the design of the dead band required for the transitions between the positive and negative semi-cycles (and vice-versa) of the grid voltage. Finally, simulation results validate the main features of the controller as well as the design of the dead band.Los inversores monofĂĄsicos son ampliamente usados en diferentes aplicaciones de energĂas renovables. Aunque tĂpicamente se usa el inversor de puente completo, el inversor buck-dual provee una ventaja importante porque elimina el problema de posibles cortos-circuitos. Sin embargo, las soluciones reportadas en la literatura requieren inductores adicionales, usan controladores lineales diseñados para un punto de operaciĂłn, o no se pueden usar en aplicaciones de conexiĂłn a la red. En este artĂculo se presenta un control por histĂ©resis para un inversor monofĂĄsico buck-dual de puente completo con conexiĂłn a la red para inyecciĂłn de corriente activa. En particular, se presenta el modelo matemĂĄtico en variables de estado y se obtienen condiciones analĂticas para garantizar la evoluciĂłn de la dinĂĄmica de error dentro de un conjunto con lĂmites establecido por el diseñador. AdemĂĄs, se discuten los elementos para diseñar la banda muerta requerida en la transiciĂłn entre los semi-ciclos positivos y negativos de la tensiĂłn de la red. Finalmente, los resultados de simulaciĂłn validan las principales caracterĂsticas del controlador propuesto, asĂ como el diseño de la banda muerta
Propiedades åcidas de óxidos mixtos (TiO2-SiO2 y ZrO2-SiO2) preparados por el método sol-gel
Synthesis of New Pentacyclo[5.4.0.02,6.03,10.05,9]undecane-8,11-dione (PCU) Cyanosilylated Derivatives Using Sulphated Zirconia and Hydrotalcite as Catalysts in Microwave-Assisted Reactions under Solvent Free Conditions
A comparison was made of the effectiveness of the functionalization reactions of pentacyclo[5.4.0.02,6.03,10.05,9]undecane-8,11-dione (PCU) using sulphated zirconia in protection-deprotection reactions and Mg/Al hydrotalcite in a cyanosilylation reaction, under classical thermal conditions and imposing microwave radiation; improved yields and reaction times were considered
Catalytic Deactivation of HY Zeolites in the Dehydration of Glycerol to Acrolein
The study of the deactivation of HY zeolites in the dehydration reaction of glycerol to acrolein has represented a challenge for the design of new catalysts. HY zeolites with SiO2/Al2O3 molar ratios between 3.5 and 80 were studied. The solids were characterized by XRD, N2 physisorption, SEM-EDXS, Raman and UV-vis spectroscopies, infrared spectroscopy of pyridine (FTIR-Py) and catalytic activity tests from 250 °C to 325 °C. It was found that the total amount of acid sites per unit area of catalyst decreased as the SiO2/Al2O3 molar ratio increased from 3.5 to 80, resulting in the decrease in the initial glycerol conversion. The initial acrolein selectivity was promoted with the increase of the BrÞnsted/Lewis acid sites ratio at any reaction temperature. The deactivation tests showed that the catalyst lifetime depended on the pore structure, improving with the presence of large surface areas as evidenced by the deactivation rate constants. The characterization of the deactivated catalysts by XRD, N2 physisorption and thermogravimetric analysis indicated that the deposition of coke resulted in the total obstruction of micropores and the partial blockage of mesopores. Moreover, the presence of large mesopores and surface areas allowed the amount of coke deposited at the catalyst surface to be reduced
Synthesis of New Pentacyclo[5.4.0.02,6.03,10.05,9]undecane-8,11-dione (PCU) Cyanosilylated Derivatives Using Sulphated Zirconia and Hydrotalcite as Catalysts in Microwave-Assisted Reactions under Solvent Free Conditions
One-domain approach for studying multiphase transport phenomena in biofilm growing systems
MĂșsica tradicional y popular en MĂ©xico. 77 Nueva Ăpoca (2005) enero-marzo. AntropologĂa. BoletĂn Oficial del Instituto Nacional de AntropologĂa e Historia
- El canto llano y el canto de Ăłrgano en la mĂșsica novohispana por Juan Manuel Lara CĂĄrdenas. - El cambio sonoro de la mĂșsica sacra. Algunos ejemplos entre los pueblos indĂgenas por Camilo RaxĂĄ Camacho Jurado. - âÂżQuiĂ©n soy yo para saber mĂĄs que los antepasados?â por Sergio Navarrete Pellicer. - Los contextos simbĂłlicos y sociales de la mĂșsica indĂgena del Noroeste de MĂ©xico por VĂctor Acevedo MartĂnez. - El mitote entre los pames de San Luis PotosĂ por MarĂa Eugenia Jurado. - Los sonidos del huentli. La mĂșsica de viento: su simbolismo, su funciĂłn ritual y terapĂ©utica entre los nahuas de Morelos por Ulises Julio Fierro Alonso. - La âinvenciĂłnâ de la mĂșsica indĂgena de MĂ©xico por Marina Alonso Bolaños. - El mariachi tradicional en contexto: la fiesta cora del âequinoccio de otoñoâ en Santa Teresa (Kueimarutse'e) por JesĂșs JĂĄuregui. - El corrido minero de la sierra por Daniela A. Gaxiola. - La mĂșsica popular en YucatĂĄn por Manuel Ălvarez Boada. - ÂżBruta, ciega y sordomuda?: relaciones de gĂ©nero e identidad en canciones populares comerciales por Alberto ZĂĄrate Rosales. - MĂșsica, mujeres y tĂ© de limĂłn: charla en una tarde lluviosa con Henrietta Yurchenco por BenjamĂn Muratalla. - A Spiral Way: una historia del fonĂłgrafo por Carlos Ruiz RodrĂguez
Habitabilidad y polĂtica de vivienda
En esta obra, en la que participan destacados investigadores y profesores, dedicados al estudio de la problemĂĄtica habitacional se presentan diferentes anĂĄlisis que permiten conocer cuales son las condiciones de habitabilidad y las caracterĂsticas de la actual polĂtica de vivienda de MĂ©xico.
En sus capĂtulos se abordan los principales desafĂos que enfrentan las familias mexicanas para acceder a una vivienda digna y decorosa y cuales son los retos econĂłmicos, polĂticos, territoriales, arquitectĂłnicos, ambientales, financieros y culturales de las formas de producciĂłn habitacional en MĂ©xico y en otros paĂses, en el marco de una sociedad global
Mexico ants: incidence and abundance along the NearcticâNeotropical interface
International audienceto explore different aspects of the population and community research of ants at different spatial scales, and to aid in the establishment of conservation policies and actions. There are no copyright restrictions. Please cite this data paper when using its data for publications or teaching events