Optimal Operation of an Urban Microgrid Using Model Predictive Control Considering Power Quality Improvements

Abstract Microgrids have been widely applied to improve the energy quality parameters of a distribution system locally, in addition to ensuring the operation of the system in an isolated manner. The Model Predictive Control (MPC) is a great solution to guarantee the operation of the system considering forecasting models and also physical restrictions of the system, which ensure the optimal operation of the Microgrid. However, the construction of a control scheme following the objectives established in order to meet the connected and isolated operation of a Microgrid is still a challenge. This paper proposes the development of an MPC control scheme that assures optimal system operation in connected and islanded mode, improving power quality indexes, ensuring network requirements, and extending battery life cycle. The proposed control operation in the connected mode can attend to the needs of the Microgrid, reducing the impacts of peak demand and the intermittent variations in renewable generation, where a linear objective function is developed for this purpose. In the islanded mode, grid requirements are guaranteed through load shedding, considering improvements in continuity indicators. Forecasting models are implemented considering the MPC approach and a detailed network model is developed. Simulation results highlight the effectiveness of the proposed control strategy.

Improved Active Harmonic Current Elimination Based on Voltage Detection.

With the increasing penetration of power electronic equipment in modern residential distribution systems, harmonics mitigation through the distributed generation (DG) interfacing converters has received significant attention. Among recently proposed methods, the so-called active resonance damper (ARD) and harmonic voltage compensator (HVC) based on voltage detection can effectively reduce the harmonic distortions in selected areas of distribution systems. However, it is found out that when traditional ARD algorithm is used to eliminate harmonic current injected by non-linear loads, its performance is constrained by stability problems and can at most eliminate half of the load harmonic currents. Thus, inspired by the duality between ARD and HVC, this paper presents a novel improved resistive active power filter (R-APF) algorithm based on integral-decoupling control. The design guideline for its parameters is then investigated through carefully analyzing the closed-loop poles' trajectory. Computer studies demonstrate that the proposed algorithm can effectively mitigate the load harmonic currents and its performance is much better than traditional ARD based on proportional control.

Analysis of thermal characteristics of electrical wiring for load groups in cattle barns.

The purpose of the current study is to analyze the thermal characteristics of electrical wirings depending on the number of operating load by connecting four types of electrical wirings that are selected by surveying the conditions for the electric fans, automatic waterers and halogen warm lamps that were installed in cattle barns in different years. The conditions of 64 cattle barns were surveyed and an experimental test was conducted at a cattle barn. The condition-survey covered inappropriate design, construction and misuse of electrical facility, including electrical wiring mostly used, and the mode of load current was evaluated. The survey showed that the mode of load current increased as the installation year of the fans, waterers and halogen lamps became older. Accordingly, the cattle barn manager needed to increase the capacity of the circuit breaker, which promoted the degradation of insulation of the electrical wires' sheath and increased possibility for electrical fires in the long-run. The test showed that the saturation temperature of the wire insulated sheath increased depending on the installation year of the load groups, in case of VCTFK and VFF electric wires, therefore, requiring their careful usage in the cattle barns.

Cuatro claves para una instalación hospitalaria sana y eficiente / No disponible

Una instalación hidráulica capaz de proporcionar el confort y la eficiencia energética previstas en el proyecto merece el calificativo de "instalación sana". Tanto la salud inicial de la instalación como la evolución de este "paciente" se miden por el mantenimiento de cuatro parámetros fundamentales. Adecuada Presión Estática: instalación libre de aire, sin fugas ni rellenados innecesarios, con mínima formación de depósitos de corrosión. Se consigue mediante elementos de presurización, llenado y desgasificación, de buena calidad y adecuadamente dimensionados. Equilibrado y Medición de Caudales en la instalación: todos los terminales y climatizadores reciben en situaciones de máxima demanda los caudales de diseño, con la mínima altura manómetrica de bomba. Gracias a las válvulas de equilibrado se consigue la velocidad de giro óptima de la bomba y el mínimo gasto de energía Buena Autoridad de las válvulas de control gracias a una presión diferencial adecuada y estable. Los caudales siguen en cada instante a la carga térmica, obedeciendo a las necesidades de la instalación, que se traducen en órdenes de apertura y cierre modulantes marcadas por el control de la instalación. Temperaturas de impulsión y retorno adecuadas gracias a la compatibilidad de caudales en los circuitos hidráulicos. Ningún circuito recibe temperaturas diferentes a las de diseño, para mantener el mejor rendimiento de las unidades terminales y las condiciones de temperatura y humedad adecuadas. Un médico diría que temperatura adecuada, presión arterial controlada, buen ritmo cardiaco, en sus límites, adaptado a la actividad del paciente, y un sistema circulatorio libre de obstrucciones definen, a falta de análisis ulteriores, a un paciente saludable. Por tanto, la instalación sana tiene: • Mayor vida útil, con menores averías por depósitos de corrosión, y menor gasto de agua • Proporciona las condiciones de confort aunque las de ocupación del hospital o el clima exterior sean cambiantes. • Reduce al máximo el consumo de energía por bombeo y adapta la producción de agua fría y caliente a las necesidades de cada instante. La ponencia tratará de mostrar las medidas a adoptar y su impacto en el ahorro y el confort térmico de la instalación hospitalaria que las incorpore (AU)

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Sobre sistemas de iluminación en hospitales / No disponible

Es importante poder recoger los conceptos que aporta un arquitecto a un tema en el que la colaboración de ingeniero-arquitecto es fundamental para un correcto desarrollo del Proyecto. Tanto más cuándo el arquitecto en este caso aporta su visión del tema desde otras partes del mundo. El artículo enuncia y comenta las dos principales características de los sistemas de iluminación en los hospitales · La funcionalidad (diseño funcional). La luz y el confort ambiental. Luz natural diurna y luz artificial en los principales departamentos de un hospital · La eficiencia energética (ahorro en consumo eléctrico) Estrategias para la optimización del consumo energético en iluminación Este trabajo de análisis de los principales conceptos de diseño de los sistemas de iluminación en hospitales ha sido presentado por el autor dentro del curso de Instalaciones correspondiente al Master en Diseño y Planificación de Centros Sanitarios de la Universidad Oberta de Catalunya, en la asignatura de Instalaciones Eléctricas (AU)

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El reglamento de baja tensión y las instalaciones eléctricas sanitarias como locales de pública concurrencia / The regulation of low voltage electrical installations as local public health crowd

El objeto de esta artículo es intentar definir cuales son las exigencias para los locales de pública concurrencia en el Reglamento de Baja tensión y sus ITYC’s en lo que a instalaciones sanitarias se refiere, y establecer a la vez cuales son las prescripciones que han generado problemas de interpretación en su aplicación, aportando finalmente la opción que se considera más lógica y razonable cumplir (AU)

The purpose of this article is trying to define what are the requirements for crowded public premises in the regulation of low voltage and ITYC’s as far as sanitation is concerned, and simultaneously establish what are the requirements that have generated problems interpretation in their application, ultimately providing the option to be the most logical and reasonable to meet (AU)

Health impact assessment of an urban regeneration project: opportunities and challenges in the context of a southern European city.

BACKGROUND: Social values and the political context have an influence on the use and spread of health impact assessment (HIA). In Spain, there is little experience in HIA but some regional governments are already introducing it. The aim of this article is to describe the health impacts of a local regeneration project to improve accessibility in a neighbourhood of Bilbao (Spain), and discuss the main difficulties, opportunities and challenges of the process, considering the specificities of the social and political context. METHODS: A concurrent and prospective assessment, based on a broad model of health, was carried out following the Merseyside guidelines. A literature review, community profiling and qualitative data collection were undertaken. Profound involvement of members of the community and key informants was judged as essential in the HIA process. RESULTS: The overall expected effect of the new lifts, roads, park and the rainwater collection system was positive. Uncertain or negative impacts were identified in some of those areas, and also concerning the burying of four high-voltage power lines. Historical and current characteristics of the community were highly influential on the way local people perceived the project and its impacts. Likewise, the way in which processes of planning and implementation were developing also played an important role. CONCLUSION: The spread of HIA in southern European countries will depend on the progressive introduction of values underlying HIA, as well as on the promotion of intersectoral work, a better knowledge of the social model of health and community's participation in policy making.

A state indicator on regional scale for high-voltage power lines: defining a priority for in situ inspections.

An integrated system to evaluate the magnetic field generated by power lines exposure has been developed using a specific simulation model (PLEIA-EMF). This is part of a software toolset, subjected to internal suitability verifications and in-field validations. A state indicator related to each span has been determined using the data extracted from digital cartography, the magnetic field calculated by PLEIA and the number of people living in the nearest buildings. In this way, it is possible to determine eventual criticalities in the considered area, focusing attention on those cases with more considerable exposure levels and involving a higher number of people. A campaign of inspections has been planned using PLEIA simulations. The reliability of stored technical data and the real population exposure levels have been evaluated in critical cases, individuated through the following described methodology. The procedures leading to the indicator determination and the modalities of in situ inspections are here presented.

Seguridad eléctrica en quirófano / No disponible

En nuestra actividad profesional diaria es básica la anticipación y conocimiento del entorno donde se ejerce. Los hipotéticos problemas anestésicos que puedan surgir en quirófano deben ser conocidos, detectados y corregidos cuanto antes para una satisfactoria resolución. Dentro del hospital, es el quirófano uno de los lugares donde es mayor la implicación de los sistemas eléctricos; tanto por su suministro, como por la gran cantidad de aparataje que depende de él con las consiguientes implicaciones de su mal funcionamiento. Dichas implicaciones son extrapolables a unidades de recuperación postoperatorias, salas de cuidados críticos,... Dichas complicaciones son muy temidas por los anestesiólogos, tanto por su desconocimiento como por su potencial lesivo. Se pretende realizar una revisión de conceptos básicos de electricidad, qué conocimientos y precauciones debemos manejar en nuestro entorno de trabajo para optimizar el uso de los aparatos eléctricos en quirófano: comprender su funcionamiento y prevenir los posibles daños derivados de un mal uso o un mal funcionamiento

In our daily practice is important to be ready for the unforeseen situations and to have an excellent knowledge of our environment. The problems that could arise in the operating theatre have to be known, detected and corrected as soon as possible in order to have a satisfactory resolution. In the hospital is the operating theatre where are the main electrical systems involved, being this importance based in the correct supply and in the fact that there is important equipment which work is based in such correct supply. All the items involved can be applied to all the postanesthesia and critical care units. All these inconveniences and complications are feared by the anesthesia due to the ignorance and to the injures that can be caused. The main objective is to review all the elementary electrical concepts, the knowledge and the preventive measures and steps we should take in order to optimize the electrical device used; to ensure the understanding and the correct way of working and to take the necessary steps in order to avoid the problems derived of an incorrect use

Problemas de segurança e desempenho em equipamentos eletromédicos relacionados aos diferentes padrões de alimentação elétrica / Medical electrical equipment safety and performance problems related to different standards or mains supply

Alguns problemas encontrados na certificação de equipamentos eletromédicos relacionados aos diferentes padrões de alimentação elétrica existentes no Brasil e em outros países são apresentados. Para analisá-los foi executado um conjunto de ensaios (medeições da potência de entrada, corrente de fuga para o terra, temperaturas excessivas e parâmetros de saída) em um grupo de equipamentos eletromédicos operando em diferentes padões de alimentação elétrica. Adicionalmente, foi proposto e executado um ensaio complementar de conexão à tensão errada para verificar a segurança de equipamentos com comutação manual de tensão de alimentação. Resultados com diferenças bastante significativas entre as cinco condições de alimentação utilizadas foram obtidos, demonstrando as deficiências que podem ocorrer na utilização de Memorandos de Entendimento (MoU) realizados para aproveitar certificações pré-existentes, assim como a necessidade de regulamentação complementar para o processo. Conclui-se que há necessidade de uma adaptação normativa para corrigir algumas imperfeições das normas nacionais e internacionais. Essa adaptações deveriam incluir, pelo menos: prescrições claras relativas às condições de alimentação elétrica nas quais os equipamentos devem ser ensaiados e certificados no Brasil; um ensaio adicional, como o proposto nesta pesquisa, para avaliar a segurança de equipamentos com comutação de tensão de alimentação através de chave manual; e prescrições sobre quais plugues de rede são aceitáveis para o uso no Brasil.