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

Wireless sensor network for forest fire detection

Some methods for fire detection include monitoring from watch towers and the use of satellite images [1] [2]. Unfortunately, these are not efficient due to several reasons, such as high infrastructure costs (sophisticated equipment), the fact that they require a large number of trained personnel and that they make real-time monitoring difficult, since when the phenomenon is detected, its speed of propagation has produced uncontrollable levels of damage. This paper proposes a method for detecting forest fires, using a network of wireless sensors and information fusion methods

Firmeza y Compromiso para Seguir Creciendo

Editoral Note V24N3 Nota Editorial V24N

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

Diseño y simulación de un balastro electrónico con corrección de factor de potencia con topología buck-boost e inversor alimentado por corriente-Design and simulation of an electronic ballast with power factor correction buck-boost topology and current-fed invertir

Las lámparas fluorescentes compactas o CFL (compact fluorescent lamp) se han convertido en uno de los tipos de iluminación más usados en la actualidad. Sin embargo, las CFL comerciales poseen en su mayoría balastros electrónicos de bajo factor de potencia. Esto genera un aumento en los niveles de distorsión del sistema de generación y distribución debido al uso masivo de estas lámparas. En el presente artículo se presenta el diseño y simulación de un balastro electrónico con corrección de factor de potencia para lámparas fluorescentes compactas. La propuesta busca evaluar la viabilidad de integrar  el correcto funcionamiento, tamaño y costo de este dispositivo.La topología propuesta es una etapa buck-boost operando enmodo de conducción discontinua integrada a un inversoralimentado por corriente. La alta factibilidad deimplementación de esta topología es mostrada mediantesimulaciones que logran un factor de potencia de 0.998 y unadistorsión total armónica menor de 5 %

Experimental Study of the Inductance of Pinned Vortices in Superconducting YBa2Cu3O7-d Films

Using a two-coil mutual inductance method, we have measured the complex resistivity, rho_v(T,Be), of pinned vortices in c-axis pulsed laser deposited YBa2Cu3O7-d films with magnetic field Be applied perpendicular to the film. At low frequencies, (<100 kHz), rho_v is inductive and is inversely proportional to the Labusch parameter, the average vortex pinning force constant, kappa_exp. The observed weakening of kappa_exp with Be is consistent with a simple model based on linear pinning defects. Adding classical thermal fluctuations to the model in a simple way describes the observed linear T dependence of rho_v, below ~15 K and provides reasonable values for the effective radius (.3 nm to >.8 nm) of the defects and the depth of the pinning potential. The success of this model implies that thermal supercurrent (phase) fluctuations have their full classical amplitude down to 5 K for frequencies below the characteristic depinning frequency. To date, no sufficient theory exists to explain the data between ~15 K and the vortex glass melting temperature.Comment: 31 pages, 8 figures. Subm. to PR

The CaT strength in Seyfert nuclei revisited: analyzing young stars and non-stellar light contributions to the spectra

In a former paper (Garcia-Rissmann et al. 2005; hereafter Paper I), we have presented spectra of 64 active, 9 normal and 5 Starburst galaxies in the region around the near-IR Calcium triplet absorption lines and the [SIII]9069 line. In the present paper we analyze the CaT strength (WCaT), and kinematical products derived in that study, namely stellar and ionized gas velocity dispersions. Our main results may be summarized as follows: (1) Seyfert 2s show no sign of dilution in WCaT with respect to the values spanned by normal galaxies, even when optical absorption lines such as the CaII K band at 3933 A are much weaker than in old, bulge-like stellar populations. (2) The location of Seyfert 2s in the WCaT-WCaK plane is consistent with evolutionary synthesis models. The implication is that the source responsible for the dilution of optical lines in these AGN is a young stellar population, rather than an AGN featureless continuum, confirming the conclusion of the pioneer study of Terlevich, Diaz & Terlevich. (3) In Seyfert 1s, both W[SIII] and WCaT tend to be diluted due to the presence of a non-stellar component, in agreement with the unification paradigm. (4) A comparison of stellar and gas velocity dispersions confirms the existence of a correlation between the typical velocities of stars and clouds of the Narrow Line Region. The strength and scatter around this correlation are similar to those previously obtained from the [OIII]5007 line width.Comment: 14 pages, 15 figures. Paper accepted for publication in MNRA

GW150914: First search for the electromagnetic counterpart of a gravitational-wave event by the TOROS collaboration

We present the results of the optical follow-up conducted by the TOROS collaboration of the first gravitational-wave event GW150914. We conducted unfiltered CCD observations (0.35-1 micron) with the 1.5-m telescope at Bosque Alegre starting ~2.5 days after the alarm. Given our limited field of view (~100 square arcmin), we targeted 14 nearby galaxies that were observable from the site and were located within the area of higher localization probability. We analyzed the observations using two independent implementations of difference-imaging algorithms, followed by a Random-Forest-based algorithm to discriminate between real and bogus transients. We did not find any bona fide transient event in the surveyed area down to a 5-sigma limiting magnitude of r=21.7 mag (AB). Our result is consistent with the LIGO detection of a binary black hole merger, for which no electromagnetic counterparts are expected, and with the expected rates of other astrophysical transients.Comment: ApJ Letters, in pres

A comparison between padding and bath exhaustion to apply microcapsules onto cotton

The final publication is available at Springer via http://dx.doi.org/10.1007/s10570-015-0600-8[EN] The use of Microcapsules has increased in the textile sector. They have been applied as a possible means of introducing new products to textiles, such as insect repellents, antibiotics, skin moisturizers, etc. Microencapsulation technology has improved the fragrance durability on fabrics. Historically, the durability of the fragrance was poor, especially once the fabric had been washed. Microcapsules have been used in textiles for many years, however their previous characterization, adhesion behaviour and permanence on the fabrics are not well known. Nowadays the majority of textile industries are not able to characterize commercial products, or to study the process of adhering the microcapsule to the fibre's surface nor their functionality. Thus, the characterization of microencapsulated fabrics with different active core and the knowledge of the various application processes becomes a major challenge in the field of microcapsules use. There are various industrial processes to apply microcapsules, but determining optimal amounts of products, temperature, conditions and other process variables are an important challenge for the textile sector in order to achieve the highest depositions and retention of microcapsules. This work is focused on determining and quantifying presence fragrance microcapsules when applied onto fabrics by padding and by bath exhaustion and determining which method is the most effective. Consequently, diverse analysis techniques such as microscopy (SEM), spectroscopy FTIR and XPS have been used. We concluded that proposed techniques seem to be useful to compare fabrics treated with microcapsules. Results demonstrate that padding application gives better yields than bath exhaustion.Bonet Aracil, MA.; Monllor Pérez, P.; Capablanca Francés, L.; Gisbert Paya, J.; Díaz-García, P.; Montava Seguí, IJ. (2015). A comparison between padding and bath exhaustion to apply microcapsules onto cotton. Cellulose. 22(3):2117-2127. doi:10.1007/s10570-015-0600-8S21172127223Bonet M, Quijada C, Muñoz S, Cases F (2004) Characterization of ethylcellulose with different degrees of substitution (DS): a diffuse-reflectance infrared study. Can J Anal Sci Spectrosc 49(4):234–239Bonet M, Capablanca L, Monllor P, Díaz P, Montava I (2012) Studying bath exhaust as a method to apply microcapsules on fabrics. J Text Inst 103(6):629–635Buchert J, Pere LS, Johanson JM, Campbell J (2001) Analysis of surface chemistry of linen and cotton fabrics. Text Res J 71:626–629Fras L, Johanson LS, Stenius P, Laine P, Stana-Kleinscheck K, Ribitsch V (2005) Analysis of theoxidation of cellulosefibresbytitration and XPS. Colloids Surf A 260:101–108Gisbert G, Ibañez F, Bonet M, Monllor P, Díaz P, Montava I (2009) Increasing hydration of the epidermis by microcapsules in sterilized products. J Appl Polym Sci 113(4):2282–2286Hong K, Park S (1999) Melamine resin microcapsules containing fragant oil: synthesis and characterization. J Appl Polym Sci 58:128–131Jing HU, Zuobing X, Rujun Z, Shuangshuang M, Mingxi W, Zhen L (2011) Properties of aroma sustained-release cotton fabric with rose fragrance nanocapsule. Chin J Chem Eng 19(3):523–528Kokot S, Czarnik-Matusewicz C, Ozaki Y (2002) Two- dimensional correlation spectroscopy and principal component analysis studies of temperature-dependent IR spectra of cotton-cellulose. Biopolymers 67:456–469Kondo T, Sawatari C, Manley RJ, Gray DG (1994) Characterization of hydrogen bonding in cellulose synthetic polymer blend systems with regioselectively substituted methylcellulose. Macromolecules 27(1):210–215Miró Specos MM, Escobar G, Marino P, Puggia C, Defain Tesoriero MV, Hermida L (2010) Aroma finishing of cotton fabrics by means of microencapsulation techniques. J Ind Text 40(1):13–32Monllor P, Bonet M, Cases F (2007) Characterization of the behaviour of flavour microcapsules in cotton fabrics. Eur Polym J 43:2481–2490Monllor P, Bonet M, Sánchez L, Cases F (2009) Thermal behaviour of microencapsulated flavours when applied to cellulose fabrics. Text Res J 79(4):365–380Monllor P, Capablanca L, Gisbert J, Díaz P, Bonet M (2010) Improvement of microcapsule adhesion to fabrics. Text Res J 80(7):631–635Nelson G (1991) Microencapsulates in textile coloration and finishing. Rev Prog Color Relat Top 21:72–85Nelson G (2001) Microencapsulation in textile finishing. Rev Prog Color Relat Top 321:57–64Nelson G (2002) Application of microencapsulation in textiles. Int J Pharm 242:55–62Rodrigues SN, Fernandes I, Martins IM, Mata VG, Barreiro F, Rodrigues AE (2008) Microencapsulation of limonene for textiles application. Ind Eng Chem Res 47:4142–4147Rodrigues SN, Martins, IM, Fernades IP, Gomes PB, Mata VG, Barreiro MF, Rodrigues AE (2009) Scentfashion®: microencapsulated perfumes for textile application. Chem Eng J 149(1–3):463–472. ISSN:1385-8947Sócrates G (1997) In: Infrared characteristic group frequencies. Tables and charts, 2nd ednTopalovic T, Nierstrasz VA, Bautista L, Jocic D, Navarro A, Warmoeskerken MMCG (2007) XPS and contact angle study of cotton surface oxidation by catalytic bleaching. Colloids Surf A 296:76–85Wilson RC, Pfhol WF (2000) Study of crosslinking reactions of melamine/formaldehyde resin with hydroxyl functional polyester by generalized 2-D infrared spectroscopy. Vib Spectrosc 23:13–22Zhang H, Wang X (2009) Fabrication and performances of microencapsulated phase change materials based on n-octadecane core and resorcinol-modified melamine-formaldehyde shell. Colloids Surf A 332:129–13