http://hdl.handle.net/2117/3420 2013-05-24T22:43:05Z http://hdl.handle.net/2117/17127 Title: Salinity effect on the corona onset for a 765 kV AC substation connector Authors: Hernández Guiteras, Joan; Riba Ruiz, Jordi-Roger; Sanllehi, Josep; Bosch Tous, Ricardo Abstract: Outdoor substations placed in coastal areas are affected by saline environments. In the technical literature it is found extensive information regarding insulations problems in presence of saline environments [1]. The accumulation of salts and other contaminants promotes the onset of partial discharges on the devices subjected to very high voltages. Insulators are also affected by this phenomenon. While rainfall has a cleaning effect on the insulator surface, humidity enhances the corrosion effect and degrades the performance of insulation [2], favouring onset conditions for partial discharge. Corrosion due to saline environments or dirt increases the roughness of the insulator surface, thus facilitating the appearance of partial discharges [3]. It is well known that the air pollution has a great impact on metals corrosion. Chloride ions are common in coastal environments, because seawater acts as a source of air mineralization. Deposition of chloride ions on metal surfaces intensifies metallic corrosion, thus degrading the conductor surface [4]. In this work the behaviour of a 765 kVRMS AC (line-to-line voltage) outdoor substation connector is analyzed when operating under both dry conditions and under wet saline environments by means of three-dimensional finite elements simulations (3D-FEM). FEM simulations show that the electric field strength in the connector surroundings does not exceed the electric breakdown strength for air under clean and dry atmospheric conditions when energized at its rated voltage, 765 kVRMS AC (line-to-line). These results are corroborated by means of experimental measurements carried out in a high-voltage laboratory. Both, the laboratory tests and the 3D-FEM simulations performed in this study concluded that the corona onset voltage is approximately 980 kVRMS AC (line-to-line voltage). Additionally, 3D-FEM simulations allow detecting the connector weakest points regarding to electrical stress. Hence, this software allows redesigning the connector geometry to optimize its performance, thus minimizing the corona occurrence risk and their associated unwanted effects. Additionally, FEM simulations performed under a saline atmosphere were carried out by including a thin conductive saline moisture layer acting as a wetting film on the connector surface. Results revealed that saline environments worsen the connector behaviour, thus favouring corona onset conditions and their related effects.Outdoor substations placed in coastal areas are affected by saline environments. In the technical literature it is found extensive information regarding insulations problems in presence of saline environments [1]. The accumulation of salts and other contaminants promotes the onset of partial discharges on the devices subjected to very high voltages. Insulators are also affected by this phenomenon. While rainfall has a cleaning effect on the insulator surface, humidity enhances the corrosion effect and degrades the performance of insulation [2], favouring onset conditions for partial discharge. Corrosion due to saline environments or dirt increases the roughness of the insulator surface, thus facilitating the appearance of partial discharges [3]. It is well known that the air pollution has a great impact on metals corrosion. Chloride ions are common in coastal environments, because seawater acts as a source of air mineralization. Deposition of chloride ions on metal surfaces intensifies metallic corrosion, thus degrading the conductor surface [4]. In this work the behaviour of a 765 kVRMS AC (line-to-line voltage) outdoor substation connector is analyzed when operating under both dry conditions and under wet saline environments by means of three-dimensional finite elements simulations (3D-FEM). FEM simulations show that the electric field strength in the connector surroundings does not exceed the electric breakdown strength for air under clean and dry atmospheric conditions when energized at its rated voltage, 765 kVRMS AC (line-to-line). These results are corroborated by means of experimental measurements carried out in a high-voltage laboratory. Both, the laboratory tests and the 3D-FEM simulations performed in this study concluded that the corona onset voltage is approximately 980 kVRMS AC (line-to-line voltage). Additionally, 3D-FEM simulations allow detecting the connector weakest points regarding to electrical stress. Hence, this software allows redesigning the connector geometry to optimize its performance, thus minimizing the corona occurrence risk and their associated unwanted effects. Additionally, FEM simulations performed under a saline atmosphere were carried out by including a thin conductive saline moisture layer acting as a wetting film on the connector surface. Results revealed that saline environments worsen the connector behaviour, thus favouring corona onset conditions and their related effects. 2012-12-13T10:52:45Z http://hdl.handle.net/2117/13043 Title: Sistemas internos de garantía de la calidad (SIGC): necesidad y reto Authors: Carral Mahia, Eva Mª; Pérez Gracia, María de la Vega; Codinas, Xavier; López López, José; García Alzórriz, Juan Antonio; Buenestado Caballero, Pablo; Torres Cámara, Ricardo; Martínez Sánchez, Joan; Velasco Quesada, Guillermo Abstract: La Escuela Universitaria de Ingeniería Técnica Industrial de Barcelona (EUETIB) está diseñando su SIGC propio, teniendo en cuenta las características del centro, las directrices de la Universidad Politécnica de Cataluña y de las agencias de calidad, la formación que se requiere para sus estudiantes y los resultados que se observan en otros centros de éste y de otros países en los que ya se han implantado los sistemas de calidad. En una época de crisis y de cambios, en la que las titulaciones deben adaptarse al Espacio Europeo de Educación Superior (EEES), el diseño de un sistema de calidad deviene una necesidad y un reto para la EUETIB. 2011-07-26T08:01:13Z http://hdl.handle.net/2117/13042 Title: Correlación entre la nota de ingreso a los estudios de grado de ámbito industrial y los resultados académicos obtenidos en el primer año de estudios de grado Authors: López López, José; Buenestado Caballero, Pablo; Pérez Gracia, María de la Vega; García Alzórriz, Juan Antonio; Torres Cámara, Ricardo; Martínez Sánchez, Joan; Velasco Quesada, Guillermo Abstract: El presente trabajo estudia la relación de la nota de acceso al centro con las calificaciones académicas obtenidas por los estudiantes de primer curso de Grado una vez transcurrido el primer año de implantación en la Escuela Universitaria de Ingeniería Técnica Industrial de Barcelona (EUETIB). En este trabajo se discute sobre los resultados obtenidos en función de la procedencia de los estudiantes, Bachillerato o Ciclos formativos de grado superior. 2011-07-26T07:45:33Z http://hdl.handle.net/2117/12366 Title: Analysis of transient behavior during starter compensated of asynchronous motors propellant in low-powered electric boats Authors: Bosch Tous, Ricardo; Casals Torrens, Pau; Grau-Mir, Ramón; Barsan, Eugen 2011-04-14T08:18:57Z http://hdl.handle.net/2117/6200 Title: Two Examples of Efficient Superconducting Cable Applications Authors: Romenade, Olivier; Granados, Xavier; Casals Torrens, Pau; Obradors i Berenguer, Francesc Xavier; Cascante, Santiago; Puig Molina, Teresa Abstract: Within the scope of the Supercable project granted by ENDESA, we have study some possible applications of the superconducting cable on linking of sub-stations. One of them considers the possibility to link two sub-stations at the medium voltage level (25 kV) by both, a standard set of copper cables and their equivalent superconducting cable. The second case establishes a comparison between a medium voltage superconducting link and the high voltage, 220= kV, counterpart. As in the first case, the energy and emissions savings are clearly coming from the lower impedance of the SC cable, in the second case the benefit is clearly due to the absence of transformers. Although superconducting cable benefits are not only related with efficiency or environmental impact, the higher efficiency could be an added value when considering a SC cable installation. 2010-01-22T12:23:29Z http://hdl.handle.net/2117/6112 Title: Optimización de la Prueba de Rigidez Dieléctrica para la Selección de Compuestos Aislantes para Cables de Energía Authors: González Parada, Adrián; Casals Torrens, Pau; Gómez Martínez, M.A.; Bosch Tous, Ricardo; Guzmán Cabrera, Rafael 2009-12-24T10:24:57Z http://hdl.handle.net/2117/6111 Title: Detección en Línea de Descargas Parciales en Accesorios de Cables de Media y Alta Tensión mediante Emisiones Acústicas Authors: Casals Torrens, Pau; Martínez Parada, Adrián; Bosch Tous, Ricardo 2009-12-24T10:00:37Z