Interaction analysis in islanded power systems with HVDC interconnections

Postprint (published version

Stability and interaction analysis in islanded power systems including VSC-HVDC and LCC-HVDC power converters

Islanded power systems are often connected to larger mainland power systems using HVDC cables. These interconnections are used to import power at lower cost compared to local generation and improve the security of supply. The increase of HVDC interconnectors in islanded systems will allow the reduction of local synchronous generation, which might lead to new interaction and stability problems due to the low inertia and short-circuit power available in the system. Traditionally LCC-HVDC technology has been used to connect island grids, but recently VSCs are presented as an alternative solution that offers more controllability to the islanded grid. Therefore, in order to increase the power transfer to the islands multi-infeed hybrid HVSC systems with VSCs and LCCs might become a common solution. The introduction of VSCs in islanded systems will allow operations in weak grids, but possible interactions with LCCs must be analysed in detail. This paper introduces the potential interactions in multi-infeed HVDC systems with LCCs and VSCs. An initial benchmark model of an islanded power system with a LCC and a VSC-HVDC link is presented to analyse new interaction phenomena between the converters and the islanded AC grid. Simulation results in PSCAD/EMTDC are presented to validate the benchmark model for voltage stability and commutation failure analysis.Postprint (published version

Visual rehabilitation in post mild traumatic brain injury. Case-based review

Background: Traumatic brain injury (TBI) can cause visual dysfunction affecting binocularity, spatial orientation, posture, and balance. Currently, there are several options for treating manifested visual disturbances; vision therapy is one of the possible treatment options. Methods: A 14-year-old female fainted and sustained trauma to the upper-temporal part of her right eyebrow. The patient presented with eye pain, a decreased visual field, and blurred vision and she exhibited great difficulties when reading. Both neurological tests and exploration of the anterior and posterior ocular segments showed results within normal limits. The patient was diagnosed with fusional vergence dysfunction, associated with accommodative infacility and oculomotor dysfunction. To eliminate her symptoms, a visual rehabilitation program was implemented; it consisted of accommodative, anti-suppressive, vergential, motility, hand–eye coordination, and peripheral vision exercises. Results: The symptoms manifested by the patient gradually dissipated throughout the course of therapy. However, not all optometric parameters reached normal values after visual therapy, which could indicate a traumatic injury that limited the achievement of normal optometric ranges. Conclusions: After a mild traumatic brain injury (mTBI), it is necessary to carry out a complete examination of the patient’s visual function. This visual examination must include an analysis of vergences, ocular motility, and the accommodative system to obtain an accurate diagnosis. The outcomes of the present clinical case imply that visual therapy should be considered as a treatment in cases of mTBIs

Disfunción de las Vergencias Fusionales e Inflexibilidad Acomodativa

Se expone el caso clínico de una mujer de 14 años que tras haber sufrido un traumatismo en la zona superior de la ceja es sometida a una batería de pruebas. El diagnóstico obtenido fue una disfunción de las vergencias fusionales acompañada de una inflexibilidad acomodativa y disfunción oculomotora. La paciente en primera instancia presentaba dolor ocular, disminución del campo visual y visión borrosa. Mostraba grandes dificultades al leer y refería ver una luz con los ojos cerrados. Con el objetivo de eliminar sus síntomas y de mejorar sus habilidades visuales se decidió realizar un programa de terapia visual, el cual se encuentra recogido en esta memoria.<br /

Mapeo de la situación y atención social de la infancia y el Programa CaixaProinfancia en once territorios del estado español. 2012-13

Esta publicación es el resultado de un estudio sobre pobreza y exclusión social infantil, los servicios de atención social y la incidencia del programa CaixaProinfancia (programa CPI) en en once ciudades del estado español. La investigación se realizó en el curso 2011-12 y fue actualizada en el curso 2013-14, bajo la dirección de Jordi Riera y Jordi Longás, del grupo de investigación Pedagogía, Sociedad e Innovación con el apoyo de las Tecnologías de la Información y la Comunicación (PSITIC) de la Universidad Ramon Llull, en el marco del convenio de colaboración establecido entre la Fundación “la Caixa” y la FPCEE Blanquerna para asesorar el programa CaixaProinfancia. En esta investigación colaboraron investigadores de diversas universidades españolas: Universidad de Deusto, Universidad de La Laguna (ULL), Universidad de Las Palmas de Gran Canaria (ULPGC), Universidad de Málaga (UMA), Universidad de Murcia (UM), Universidad de Zaragoza, Universitat de les Illes Balears (UIB), Universidad Pablo de Olavide de Sevilla (UPO), Universidad Pontificia Comillas de Madrid y Universitat Rovira i Virgili (URV). Las ciudades analizadas son Barcelona, Bilbao, Las Palmas de Gran Canaria, Madrid, Málaga, Murcia, Palma de Mallorca, Sevilla, Tenerife, Valencia y Zaragoza. El trabajo ha dado como resultado un mapa de la situación de la infancia y la atención social en dichas ciudades y áreas metropolitanas, y en el caso de las islas el análisis se ha extendido en otras poblaciones próximas a las capitales donde el programa CPI también se desarrolla

Visual Rehabilitation in Post Mild Traumatic Brain Injury. Case-Based Review

Background: Traumatic brain injury (TBI) can cause visual dysfunction affecting binocularity, spatial orientation, posture, and balance. Currently, there are several options for treating manifested visual disturbances; vision therapy is one of the possible treatment options. Methods: A 14-year-old female fainted and sustained trauma to the upper-temporal part of her right eyebrow. The patient presented with eye pain, a decreased visual field, and blurred vision and she exhibited great difficulties when reading. Both neurological tests and exploration of the anterior and posterior ocular segments showed results within normal limits. The patient was diagnosed with fusional vergence dysfunction, associated with accommodative infacility and oculomotor dysfunction. To eliminate her symptoms, a visual rehabilitation program was implemented; it consisted of accommodative, anti-suppressive, vergential, motility, hand–eye coordination, and peripheral vision exercises. Results: The symptoms manifested by the patient gradually dissipated throughout the course of therapy. However, not all optometric parameters reached normal values after visual therapy, which could indicate a traumatic injury that limited the achievement of normal optometric ranges. Conclusions: After a mild traumatic brain injury (mTBI), it is necessary to carry out a complete examination of the patient’s visual function. This visual examination must include an analysis of vergences, ocular motility, and the accommodative system to obtain an accurate diagnosis. The outcomes of the present clinical case imply that visual therapy should be considered as a treatment in cases of mTBIs.</jats:p

Visual Rehabilitation in Post Mild Traumatic Brain Injury. Case-Based Review

Background: Traumatic brain injury (TBI) can cause visual dysfunction affecting binocularity, spatial orientation, posture, and balance. Currently, there are several options for treating manifested visual disturbances; vision therapy is one of the possible treatment options. Methods: A 14-year-old female fainted and sustained trauma to the upper-temporal part of her right eyebrow. The patient presented with eye pain, a decreased visual field, and blurred vision and she exhibited great difficulties when reading. Both neurological tests and exploration of the anterior and posterior ocular segments showed results within normal limits. The patient was diagnosed with fusional vergence dysfunction, associated with accommodative infacility and oculomotor dysfunction. To eliminate her symptoms, a visual rehabilitation program was implemented; it consisted of accommodative, anti-suppressive, vergential, motility, hand&ndash;eye coordination, and peripheral vision exercises. Results: The symptoms manifested by the patient gradually dissipated throughout the course of therapy. However, not all optometric parameters reached normal values after visual therapy, which could indicate a traumatic injury that limited the achievement of normal optometric ranges. Conclusions: After a mild traumatic brain injury (mTBI), it is necessary to carry out a complete examination of the patient&rsquo;s visual function. This visual examination must include an analysis of vergences, ocular motility, and the accommodative system to obtain an accurate diagnosis. The outcomes of the present clinical case imply that visual therapy should be considered as a treatment in cases of mTBIs