Mixed-integer-linear-programming-based energy management system for hybrid PV-wind-battery microgrids: Modeling, design, and experimental verification

© 2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other worksMicrogrids are energy systems that aggregate distributed energy resources, loads, and power electronics devices in a stable and balanced way. They rely on energy management systems to schedule optimally the distributed energy resources. Conventionally, many scheduling problems have been solved by using complex algorithms that, even so, do not consider the operation of the distributed energy resources. This paper presents the modeling and design of a modular energy management system and its integration to a grid-connected battery-based microgrid. The scheduling model is a power generation-side strategy, defined as a general mixed-integer linear programming by taking into account two stages for proper charging of the storage units. This model is considered as a deterministic problem that aims to minimize operating costs and promote self-consumption based on 24-hour ahead forecast data. The operation of the microgrid is complemented with a supervisory control stage that compensates any mismatch between the offline scheduling process and the real time microgrid operation. The proposal has been tested experimentally in a hybrid microgrid at the Microgrid Research Laboratory, Aalborg University.Peer ReviewedPostprint (author's final draft

Fuzzy-based cooperative interaction between stand-alone microgrids interconnected through VSC-based multiterminal converter

© 2023 Elsevier. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/This paper proposes a cooperative strategy for the flexible integration of stand-alone AC microgrids using an intermediate multiterminal DC link based on voltage source converters. The strategy manages cooperative power exchange between microgrids through a knowledge-based fuzzy inference system that relies on the current operating conditions of the microgrids. By determining the amount of power to be exchanged between microgrids to improve global reliability, the cooperative strategy achieves an overall reduction in load loss and an increase in the use of available renewable energy. Additionally, the multiterminal DC link provides complete isolation between microgrids, allowing for independent AC bus voltage regulation and management. The effectiveness and expandability of the proposed cooperative energy exchange strategy for enhancing the overall operation of multiple integrated microgrids have been fully verified by simulation and experimental validation.Peer ReviewedPostprint (published version

Marco legal de los riesgos profesionales y la salud ocupacional en colombia, siglo xx

Objetivo Analizar la normativa emitida en Colombia desde la perspectiva del derecho del trabajo, la seguridad social y la salud pública en el siglo XX, para identificar las concepciones en torno a la salud ocupacional y los riesgos profesionales, estableciendo las convergencias y diferencias que existen entre cada una de estas líneas y si responden o no a una visión complementaria.Método Investigación documental, mediante un análisis categorial temático de las reglamentaciones y estatutos promulgados en el siglo XX en Colombia, considerando el elemento o materia principal que se encarguen de regular relacionado con los riesgos profesionales o la salud ocupacional.Resultados Se construyó una periodización del desarrollo normativo en salud laboral en el país en el siglo XX, permitiendo evidenciar el predominio histórico de la visión del derecho social, que se concentra en la protección de los riesgos profesionales de los trabajadores dependientes, como una tendencia que se extiende hasta el Sistema General de Riesgos Laborales.Conclusiones Las etapas propuestas como eje ordenador de la normativa en riesgos profesionales y salud ocupacional posibilitan reconocer elementos trascendentales del contexto social, legal e institucional en el que emergieron tales reglamentaciones preocupadas por la salud de los trabajadores, advirtiéndose una tensión histórica entre las preceptivas dirigidas a la reparación y compensación de las contingencias relacionadas con el trabajo y aquellas directrices con una orientación preventiva

Isolation and identification of fungi associated with Ilex paraguariensis St. Hil.

El cultivo de Ilex paraguariensis es importante en el norte de Argentina, principalmente en la provincia de Misiones. En los últimos años se ha observado la presencia de diferentes síntomas de enfermedades causadas por hongos de los cuales no se conoce agente causal, epidemiología y daño económico. En este estudio, se aislaron hongos de hojas de yerba mate que presentaban síntomas visibles de lesiones foliares. Cinco aislados (Alternaria, Colletotrichum, Phoma y Pilidium) fueron seleccionados por sus características micro y macromorfológicas. Estos hongos fueron identificados utilizando un microscopio óptico y claves morfológicas. Se realizaron ensayos de patogenicidad en hojas y en plantas de un año de yerba mate. Los resultados mostraron que Colletotrichum sp. LBM 183 y Phoma sp. LBM 207 son patógenos de hoja de yerba mate capaces de desarrollarse en el tejido. Mientras que Alternaria sp. LBM 186 y Pilidium sp. LBM 208 fueron capaces de enfermar la planta ingresando por la raíz de yerba mate.The cultivation of Ilex paraguariensis is important in northern Argentina, mainly in Misiones province. The presence of different symptoms of diseases caused by fungi has recently been observed. Neither the causative agents nor the epidemiological or economic damages have been identified yet. In this study, fungi were isolated from yerba mate leaves that showed visible symptoms of foliar lesions. Five isolated samples: Alternaria, Colletotrichum, Phoma and Pilidium; which were selected because of both, their micro and macro morphological characteristics. These fungi were identified by using an optical microscope together with morphological keys. Pathogenicity tests were carried out on yerba mate leaves and on one-year-old plants. The results showed that Colletotrichum sp. LBM 183 and Phoma sp. LBM 207 are pathogens typical of the yerba mate leaves capable of developing within the plant tissue, while Alternaria sp. LBM 186 and Pilidium sp. LBM 208 were able to sicken the plant by entering into the yerba mate root.Centro de Investigación y Desarrollo en Fermentaciones Industriale

Rhizopus arrhizus ucp1295 como fonte econômica para produção de biopolímeros funcionais quitina e quitosana utilizando substratos renováveis / Rhizopus arrhizus ucp1295 as economic source for production of functional biopolymers chitin and chitosan using renewable substrates

Neste trabalho foi investigada a produção de quitina e quitosana por Rhizopus arrhizus UCP 1295 isolado do solo da Caatinga do Estado de Pernambuco, Brasil, utilizando o efluente industrial de doces e milhocina como substratos de baixo custo, considerando a versatilidade de aplicação das biomoléculas. O micro-organismo foi cultivado em diferentes concentrações dos substratos efluente da indústria de doces e milhocina (CSL) em diferentes valores de pH, de acordo com um planejamento fatorial completo 23. Após 96 h de fermentação, a biomassa produzida foi liofilizada e submetida ao tratamento com álcali- ácido-. Os polissacarídeos extraídos foram caracterizados por espectroscopia por transformada de Fourier (FTIR) na região do infravermelho. A maior produção de biomassa (14,11 g/L) foi obtida na condição 6 (8% de efluente industrial de doces, 5% de milhocina e pH 5), enquanto os maiores rendimentos de quitina (169,3 mg/g) e quitosana (239,1 mg/g) foram obtidos em meio contendo 4% de efluente da indústria de doces, sem milhocina, nas condições 3 (pH 7) e 1 (pH 5), respectivamente. A quitina apresentou grau de acetilação de 71,4% e a quitosana de 86,0%, de desacetilação, respectivamente. Além disso, foi demonstrado que o efluente industrial de balas e milhocina são substratos renováveis e alternativos na formulação de novos meios de produção de quitina e quitosana. A versatilidade das biomoléculas deve-se as suas propriedades bioquímicas únicas, como biocompatibilidade, biodegradabilidade, não toxicidade, capacidade de formar filmes e aplicações industriais promissoras

Regeneración de oreomunnea mexicana (Juglandaceae), una especie relicto, amenazada del bosque de niebla de sierra juárez, oaxaca, México

Oreomunnea mexicana (Stand.) J.F. Leroy is a relict species, threatened and a key species for cloud ecosystem functionof the Sierra Juárez, Oaxaca, the most extensive and best conserved in Mexico. This study includes a diagnostic on two critical stages of the process of population regeneration of O. mexicana. To this end, it analyzed the: 1) production, dispersion, viability and germination of seeds, 2) effect of predation on the growth and survival of the seedlings, and 3) effect of environmental variables (soil, canopy structure and solar radiation) on the regeneration of the species. The study was made from 2014 to 2015 in the cloud forest of Santiago Comaltepec, Oaxaca, Mexico, in two locations (San Bernardo and El Orquidiario). Differences in seed production were found between years and between locations, as well as low seed viability and a high percentage of seed parasitism. The establishment and growth of the seedlings are subject to find suitable microhabitats, since seedlings have specific illumination and soil requirements. The high edaphic specificity faced by the species could be a key factor for its fragmented and discontinuous distribution in Sierra Juárez. Further population regeneration studies are recommended to increase knowledge of the species and thereby achieve its conservation. © 2019, Instituto de Ecologia, A.C. All rights reserved

Generation-side power scheduling in a grid-connected DC microgrid

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Energy management systems and tertiary regulation in hierarchical control architectures for islanded micro-grids

Preprin

Variation in Competence for ZIKV Transmission by Aedes aegypti and Aedes albopictus in Mexico

BACKGROUND: ZIKV is a new addition to the arboviruses circulating in the New World, with more than 1 million cases since its introduction in 2015. A growing number of studies have reported vector competence (VC) of Aedes mosquitoes from several areas of the world for ZIKV transmission. Some studies have used New World mosquitoes from disparate regions and concluded that these have a variable but relatively low competence for the Asian lineage of ZIKV. METHODOLOGY/PRINCIPAL FINDINGS: Ten Aedes aegypti (L) and three Ae. albopictus (Skuse) collections made in 2016 from throughout Mexico were analyzed for ZIKV (PRVABC59-Asian lineage) VC. Mexican Ae. aegypti had high rates of midgut infection (MIR), dissemination (DIR) and salivary gland infection (SGIR) but low to moderate transmission rates (TR). It is unclear whether this low TR was due to heritable salivary gland escape barriers or to underestimating the amount of virus in saliva due to the loss of virus during filtering and random losses on surfaces when working with small volumes. VC varied among collections, geographic regions and whether the collection was made north or south of the Neovolcanic axis (NVA). The four rates were consistently lower in northeastern Mexico, highest in collections along the Pacific coast and intermediate in the Yucatan. All rates were lowest north of the NVA. It was difficult to assess VC in Ae. albopictus because rates varied depending upon the number of generations in the laboratory. CONCLUSIONS/SIGNIFICANCE: Mexican Ae. aegypti and Ae. albopictus are competent vectors of ZIKV. There is however large variance in vector competence among geographic sites and regions. At 14 days post infection, TR varied from 8-51% in Ae. aegypti and from 2-26% in Ae. albopictus