Control de un inversor de potencia para el soporte de tensión durante fallos de red

El siguiente trabajo muestra el funcionamiento del control de un inversor trifásico fotovoltaico conectado a la red eléctrica, con la capacidad de poder solventar fallos en la red eléctrica mediante la variación de inyección tanto de potencia activa como reactiva. Para poder caracterizar los diferentes tipos de huecos de tensión, hemos realizado un estudio teórico para poder observar el efecto de las tensiones mediante un control en lazo abierto. Para llevar a cabo este estudio tenemos que tener en cuenta cuatro parámetros (Potencia activa, Potencia reactiva y dos variables de control). Basándonos en el estudio anterior proponemos un algoritmo de control en lazo cerrado que sea capaz de detectar, caracterizar y solventar los diferentes tipos de huecos de tensión, utilizando para ello diversos ajustes de inyección tanto de potencia activa como reactiva. La capacidad de solventar los huecos está limitada por la potencia de la huerta fotovoltaica. Una vez detallado el funcionamiento del algoritmo de control comprobaremos su funcionalidad con los resultados obtenidos mediante diferentes pruebas realizadas en el entorno Matlab Simulink

Control de un inversor de potencia para el soporte de tensión durante fallos de red

El siguiente trabajo muestra el funcionamiento del control de un inversor trifásico fotovoltaico conectado a la red eléctrica, con la capacidad de poder solventar fallos en la red eléctrica mediante la variación de inyección tanto de potencia activa como reactiva. Para poder caracterizar los diferentes tipos de huecos de tensión, hemos realizado un estudio teórico para poder observar el efecto de las tensiones mediante un control en lazo abierto. Para llevar a cabo este estudio tenemos que tener en cuenta cuatro parámetros (Potencia activa, Potencia reactiva y dos variables de control). Basándonos en el estudio anterior proponemos un algoritmo de control en lazo cerrado que sea capaz de detectar, caracterizar y solventar los diferentes tipos de huecos de tensión, utilizando para ello diversos ajustes de inyección tanto de potencia activa como reactiva. La capacidad de solventar los huecos está limitada por la potencia de la huerta fotovoltaica. Una vez detallado el funcionamiento del algoritmo de control comprobaremos su funcionalidad con los resultados obtenidos mediante diferentes pruebas realizadas en el entorno Matlab Simulink

Control de un inversor de potencia para el soporte de tensión durante fallos de red

El siguiente trabajo muestra el funcionamiento del control de un inversor trifásico fotovoltaico conectado a la red eléctrica, con la capacidad de poder solventar fallos en la red eléctrica mediante la variación de inyección tanto de potencia activa como reactiva. Para poder caracterizar los diferentes tipos de huecos de tensión, hemos realizado un estudio teórico para poder observar el efecto de las tensiones mediante un control en lazo abierto. Para llevar a cabo este estudio tenemos que tener en cuenta cuatro parámetros (Potencia activa, Potencia reactiva y dos variables de control). Basándonos en el estudio anterior proponemos un algoritmo de control en lazo cerrado que sea capaz de detectar, caracterizar y solventar los diferentes tipos de huecos de tensión, utilizando para ello diversos ajustes de inyección tanto de potencia activa como reactiva. La capacidad de solventar los huecos está limitada por la potencia de la huerta fotovoltaica. Una vez detallado el funcionamiento del algoritmo de control comprobaremos su funcionalidad con los resultados obtenidos mediante diferentes pruebas realizadas en el entorno Matlab Simulink

Effects of pre-operative isolation on postoperative pulmonary complications after elective surgery: an international prospective cohort study an international prospective cohort study

We aimed to determine the impact of pre-operative isolation on postoperative pulmonary complications after elective surgery during the global SARS-CoV-2 pandemic. We performed an international prospective cohort study including patients undergoing elective surgery in October 2020. Isolation was defined as the period before surgery during which patients did not leave their house or receive visitors from outside their household. The primary outcome was postoperative pulmonary complications, adjusted in multivariable models for measured confounders. Pre-defined sub-group analyses were performed for the primary outcome. A total of 96,454 patients from 114 countries were included and overall, 26,948 (27.9%) patients isolated before surgery. Postoperative pulmonary complications were recorded in 1947 (2.0%) patients of which 227 (11.7%) were associated with SARS-CoV-2 infection. Patients who isolated pre-operatively were older, had more respiratory comorbidities and were more commonly from areas of high SARS-CoV-2 incidence and high-income countries. Although the overall rates of postoperative pulmonary complications were similar in those that isolated and those that did not (2.1% vs 2.0%, respectively), isolation was associated with higher rates of postoperative pulmonary complications after adjustment (adjusted OR 1.20, 95%CI 1.05–1.36, p = 0.005). Sensitivity analyses revealed no further differences when patients were categorised by: pre-operative testing; use of COVID-19-free pathways; or community SARS-CoV-2 prevalence. The rate of postoperative pulmonary complications increased with periods of isolation longer than 3 days, with an OR (95%CI) at 4–7 days or ≥ 8 days of 1.25 (1.04–1.48), p = 0.015 and 1.31 (1.11–1.55), p = 0.001, respectively. Isolation before elective surgery might be associated with a small but clinically important increased risk of postoperative pulmonary complications. Longer periods of isolation showed no reduction in the risk of postoperative pulmonary complications. These findings have significant implications for global provision of elective surgical care. We aimed to determine the impact of pre-operative isolation on postoperative pulmonary complications after elective surgery during the global SARS-CoV-2 pandemic. We performed an international prospective cohort study including patients undergoing elective surgery in October 2020. Isolation was defined as the period before surgery during which patients did not leave their house or receive visitors from outside their household. The primary outcome was postoperative pulmonary complications, adjusted in multivariable models for measured confounders. Pre-defined sub-group analyses were performed for the primary outcome. A total of 96,454 patients from 114 countries were included and overall, 26,948 (27.9%) patients isolated before surgery. Postoperative pulmonary complications were recorded in 1947 (2.0%) patients of which 227 (11.7%) were associated with SARS-CoV-2 infection. Patients who isolated pre-operatively were older, had more respiratory comorbidities and were more commonly from areas of high SARS-CoV-2 incidence and high-income countries. Although the overall rates of postoperative pulmonary complications were similar in those that isolated and those that did not (2.1% vs 2.0%, respectively), isolation was associated with higher rates of postoperative pulmonary complications after adjustment (adjusted OR 1.20, 95%CI 1.05–1.36, p = 0.005). Sensitivity analyses revealed no further differences when patients were categorised by: pre-operative testing; use of COVID-19-free pathways; or community SARS-CoV-2 prevalence. The rate of postoperative pulmonary complications increased with periods of isolation longer than 3 days, with an OR (95%CI) at 4–7 days or ≥ 8 days of 1.25 (1.04–1.48), p = 0.015 and 1.31 (1.11–1.55), p = 0.001, respectively. Isolation before elective surgery might be associated with a small but clinically important increased risk of postoperative pulmonary complications. Longer periods of isolation showed no reduction in the risk of postoperative pulmonary complications. These findings have significant implications for global provision of elective surgical care