A mho type phase comparator relay guideline using phase comparison technique for a power system

This paper presents a mho distance relay simulation based on the phase comparison technique using a typical electrical power systems analysis software for two cases: when the operation state is close to the static voltage limit and during a dynamic perturbation in the system. The paper evaluates the impedance variations caused by complex voltage values, the mho polarization, and the comparator operating region into the complex plane. In addition, the paper found the information for the dynamic perturbations from the outputs considering a mid-term stability program. The simulation of the mho-phase comparator in the static voltage proximity limit detects unit distance elements with impedance measured close to reach the threshold in the steady-state. Dynamic mho simulations in the complex plane are successfully tested by plotting time phase difference curves on the comparator input signals. Relay programmers can use these curves to analyze other phase comparators applications and the corresponding models in the complex plane

Role of age and comorbidities in mortality of patients with infective endocarditis

[Purpose]: The aim of this study was to analyse the characteristics of patients with IE in three groups of age and to assess the ability of age and the Charlson Comorbidity Index (CCI) to predict mortality. [Methods]: Prospective cohort study of all patients with IE included in the GAMES Spanish database between 2008 and 2015.Patients were stratified into three age groups:<65 years,65 to 80 years,and ≥ 80 years.The area under the receiver-operating characteristic (AUROC) curve was calculated to quantify the diagnostic accuracy of the CCI to predict mortality risk. [Results]: A total of 3120 patients with IE (1327 < 65 years;1291 65-80 years;502 ≥ 80 years) were enrolled.Fever and heart failure were the most common presentations of IE, with no differences among age groups.Patients ≥80 years who underwent surgery were significantly lower compared with other age groups (14.3%,65 years; 20.5%,65-79 years; 31.3%,≥80 years). In-hospital mortality was lower in the <65-year group (20.3%,<65 years;30.1%,65-79 years;34.7%,≥80 years;p < 0.001) as well as 1-year mortality (3.2%, <65 years; 5.5%, 65-80 years;7.6%,≥80 years; p = 0.003).Independent predictors of mortality were age ≥ 80 years (hazard ratio [HR]:2.78;95% confidence interval [CI]:2.32–3.34), CCI ≥ 3 (HR:1.62; 95% CI:1.39–1.88),and non-performed surgery (HR:1.64;95% CI:11.16–1.58).When the three age groups were compared,the AUROC curve for CCI was significantly larger for patients aged <65 years(p < 0.001) for both in-hospital and 1-year mortality. [Conclusion]: There were no differences in the clinical presentation of IE between the groups. Age ≥ 80 years, high comorbidity (measured by CCI),and non-performance of surgery were independent predictors of mortality in patients with IE.CCI could help to identify those patients with IE and surgical indication who present a lower risk of in-hospital and 1-year mortality after surgery, especially in the <65-year group

Systematic Collaborative Reanalysis of Genomic Data Improves Diagnostic Yield in Neurologic Rare Diseases

Altres ajuts: Generalitat de Catalunya, Departament de Salut; Generalitat de Catalunya, Departament d'Empresa i Coneixement i CERCA Program; Ministerio de Ciencia e Innovación; Instituto Nacional de Bioinformática; ELIXIR Implementation Studies (CNAG-CRG); Centro de Investigaciones Biomédicas en Red de Enfermedades Raras; Centro de Excelencia Severo Ochoa; European Regional Development Fund (FEDER).Many patients experiencing a rare disease remain undiagnosed even after genomic testing. Reanalysis of existing genomic data has shown to increase diagnostic yield, although there are few systematic and comprehensive reanalysis efforts that enable collaborative interpretation and future reinterpretation. The Undiagnosed Rare Disease Program of Catalonia project collated previously inconclusive good quality genomic data (panels, exomes, and genomes) and standardized phenotypic profiles from 323 families (543 individuals) with a neurologic rare disease. The data were reanalyzed systematically to identify relatedness, runs of homozygosity, consanguinity, single-nucleotide variants, insertions and deletions, and copy number variants. Data were shared and collaboratively interpreted within the consortium through a customized Genome-Phenome Analysis Platform, which also enables future data reinterpretation. Reanalysis of existing genomic data provided a diagnosis for 20.7% of the patients, including 1.8% diagnosed after the generation of additional genomic data to identify a second pathogenic heterozygous variant. Diagnostic rate was significantly higher for family-based exome/genome reanalysis compared with singleton panels. Most new diagnoses were attributable to recent gene-disease associations (50.8%), additional or improved bioinformatic analysis (19.7%), and standardized phenotyping data integrated within the Undiagnosed Rare Disease Program of Catalonia Genome-Phenome Analysis Platform functionalities (18%)

Treatment with tocilizumab or corticosteroids for COVID-19 patients with hyperinflammatory state: a multicentre cohort study (SAM-COVID-19)

Objectives: The objective of this study was to estimate the association between tocilizumab or corticosteroids and the risk of intubation or death in patients with coronavirus disease 19 (COVID-19) with a hyperinflammatory state according to clinical and laboratory parameters. Methods: A cohort study was performed in 60 Spanish hospitals including 778 patients with COVID-19 and clinical and laboratory data indicative of a hyperinflammatory state. Treatment was mainly with tocilizumab, an intermediate-high dose of corticosteroids (IHDC), a pulse dose of corticosteroids (PDC), combination therapy, or no treatment. Primary outcome was intubation or death; follow-up was 21 days. Propensity score-adjusted estimations using Cox regression (logistic regression if needed) were calculated. Propensity scores were used as confounders, matching variables and for the inverse probability of treatment weights (IPTWs). Results: In all, 88, 117, 78 and 151 patients treated with tocilizumab, IHDC, PDC, and combination therapy, respectively, were compared with 344 untreated patients. The primary endpoint occurred in 10 (11.4%), 27 (23.1%), 12 (15.4%), 40 (25.6%) and 69 (21.1%), respectively. The IPTW-based hazard ratios (odds ratio for combination therapy) for the primary endpoint were 0.32 (95%CI 0.22-0.47; p < 0.001) for tocilizumab, 0.82 (0.71-1.30; p 0.82) for IHDC, 0.61 (0.43-0.86; p 0.006) for PDC, and 1.17 (0.86-1.58; p 0.30) for combination therapy. Other applications of the propensity score provided similar results, but were not significant for PDC. Tocilizumab was also associated with lower hazard of death alone in IPTW analysis (0.07; 0.02-0.17; p < 0.001). Conclusions: Tocilizumab might be useful in COVID-19 patients with a hyperinflammatory state and should be prioritized for randomized trials in this situatio

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Aplicación de flujos de cargas sucesivos con jacobiana constante para la determinación del punto de colapso de tensión. Validación con patrón IEEE-14

Este trabajo presenta un metodo de solucion para el analisis estatico de las inestabilidades de tension. El principal aporte del trabajo es la obtencion de la region inestable de la curva P-V utilizando flujos sucesivos basados en un metodo Newton con jacobiana constante que mantiene los lazos de acoplamiento P-V y Q-�Â. El algoritmo se implemento en el paquete de programas PSX, se modela la carga dependiente del voltaje, los limites de potencia activa y reactiva de las maquinas y la variacion de la generacion de potencia activa de los nodos P-V teniendo en cuenta la reserva de cada maquina que participa en la variacion de generacion. Se comparan los resultados con un flujo continuado implementado en el software PSAT para el patron de 14 nodos de la IEEE. Para ambos casos se obtienen resultados muy similares, comprobandose asi la exactitud obtenida con la tecnica implementada.This paper presents a solution method for tension instability static analyses. The main contribution of this research is the determinations of the unstable part of P-V curve using a multiple power flow based on the Newton method with constant Jacobian that keeps the links between P-V y Q-ä. This algorithm was implemented within PSX program, the load is modeled as voltage dependent and the limits of active and reactive power of the machines, plus the variation of P-V node generation, taking into account the reserve in each node. The result are compared with a continuation power flow implemented in PSAT software for a grid of 14 nodes patron. In both cases the result are very similar verifying the exactitude of the program developed

Implementación de modelos de control de los SVC en el programa PSX; Implementation of SVC models in programs PSX

Los dispositivos de compensación estática de reactivo (SVC) han adquirido auge en las aplicaciones a los Sistemas Eléctricos de Potencia (SEP). El SVC, también conocido como compensador estático de reactivo, es un equipamiento eléctrico usado para brindar una compensación de energía reactiva de rápida acción en redes de transmisión de electricidad de alto voltaje. Estos dispositivos brindan soluciones a problemas de estabilidad y control de la tensión de forma rápida y eficiente además son una alternativa para superar situaciones de transporte de energía eléctrica y calidad de suministro. Muchos de los software desarrollados a nivel mundial para el análisis de la operación de los SEP´s incluyen en sus estudios la modelación de los compensadores estáticos para evaluar su comportamiento ante averías o para realizar estudios de diseño y ubicación. En este artículo se describen los modelos implementados en el Paquete de programas PSX, usado por el Despacho Nacional de Cargas (DNC). The devices of static compensation of reactive (SVC) have acquired prosperity in the applications to Electric Power Systems (SEP). The SVC, also known as reactive power static compensator, is used for offering a compensation of reactive power of fast action in high-voltage transmission grids. These devices offer solutions to problems of stability and control of the tension of fast and efficient form, and they are an alternative to surpass transmission situations of electric power and supplying quality between another one. Many of them software developed worldwide for the analysis of the operation of the SEPs include in his studies the modelation of the static compensators to evaluate your behavior in front of contingences or to accomplish designing studies and position. In this work the models implemented in the programs PSX themselves, used for Loads National Center (DNC).</p

Modelación de la carga para estudios estáticos de estabilidad de tensión: Modelling of the load for stable state studies of voltage stability

En este trabajo se presenta un análisis de la influencia de la naturaleza de la carga en la estabilidad de tensión. El margen de carga es un índice considerado exacto para el análisis de la estabilidad de la tensión, sin embargo tradicionalmente se ha asumido la carga para obtener este índice como carga de potencia constante, esto no refleja fielmente el comportamiento de la misma cuando se deterioran las condiciones de tensión en el sistema eléctrico. Se demuestra la influencia del factor de potencia de la carga en la obtención del punto de máxima carga del sistema, así como la influencia de la misma en la obtención del punto de estabilidad por tensión y el punto de máxima carga. Se implementó un programa para la determinación en tiempo real del margen de carga. La metodología fue probada con sistemas de prueba de la IEEE y con un sistema real.In this paper an analysis of the influence of the nature of the load is presented in the stability tension. The load margin is an exact indices to analyses voltage stability, however traditionally it has been considered the load for obtain these indices as a constant power load, this does not show faithfully the behavior of the load when the condition of tension in the electric system are deteriorate. It is demonstrated the influence of the load power factor in the obtaining of the maximum power load of the system, such as the influence of this one in the obtaining of the stability point and maximum load point. This paper presents software to obtain the load margin for on-line studies. The methodology was tested with IEEE test systems and a real system

Modelación de la carga para estudios estáticos de estabilidad de tensión

En este trabajo se presenta un análisis de la influencia de la naturaleza de la carga en la estabilidad de tensión. El margen de carga es un índice considerado exacto para el análisis de la estabilidad de la tensión, sin embargo tradicionalmente se ha asumido la carga para obtener este índice como carga de potencia constante, esto no refleja fielmente el comportamiento de la misma cuando se deterioran las condiciones de tensión en el sistema eléctrico. Se demuestra la influencia del factor de potencia de la carga en la obtención del punto de máxima carga del sistema, así como la influencia de la misma en la obtención del punto de estabilidad por tensión y el punto de máxima carga. Se implementó un programa para la determinación en tiempo real del margen de carga. La metodología fue probada con sistemas de prueba de la IEEE y con un sistema real.In this paper an analysis of the influence of the nature of the load is presented in the stability tension. The load margin is an exact indices to analyses voltage stability, however traditionally it has been considered the load for obtain these indices as a constant power load, this does not show faithfully the behavior of the load when the condition of tension in the electric system are deteriorate. It is demonstrated the influence of the load power factor in the obtaining of the maximum power load of the system, such as the influence of this one in the obtaining of the stability point and maximum load point. This paper presents software to obtain the load margin for on-line studies. The methodology was tested with IEEE test systems and a real system

Modelación de la carga para estudios estáticos de estabilidad de tensión; Modelling of the load for stable state studies of voltage stability

<p>En este trabajo se presenta un análisis de la influencia de la naturaleza de la carga en la estabilidad de tensión. El margen de carga es un índice considerado exacto para el análisis de la estabilidad de la tensión, sin embargo tradicionalmente se ha asumido la carga para obtener este índice como carga de potencia constante, esto no refleja fielmente el comportamiento de la misma cuando se deterioran las condiciones de tensión en el sistema eléctrico. Se demuestra la influencia del factor de potencia de la carga en la obtención del punto de máxima carga del sistema, así como la influencia de la misma en la obtención del punto de estabilidad por tensión y el punto de máxima carga. Se implementó un programa para la determinación en tiempo real del margen de carga. La metodología fue probada con sistemas de prueba de la IEEE y con un sistema real.</p><p> </p><p> </p><p>In this paper an analysis of the influence of the nature of the load is presented in the stability tension. The load margin is an exact indices to analyses voltage stability, however traditionally it has been considered the load for obtain these indices as a constant power load, this does not show faithfully the behavior of the load when the condition of tension in the electric system are deteriorate. It is demonstrated the influence of the load power factor in the obtaining of the maximum power load of the system, such as the influence of this one in the obtaining of the stability point and maximum load point. This paper presents software to obtain the load margin for on-line studies. The methodology was tested with IEEE test systems and a real system.</p