Guía de aplicación de energía solar como alternativa de energía renovable en embarcaciones de recreo

En este proyecto se quiere, por un lado, estudiar y mostrar la actualidad de un tema como es la implementación de energía solar en embarcaciones de recreo y, por el otro, aportar algo nuevo al tema propuesto. Ambos objetivos se han alcanzado con éxito. El primer objetivo comienza estudiando la base del tema, es decir, la energía solar, para posteriormente realizar el análisis de la situación actual de esta energía en la náutica de recreo. El análisis se ha basado en la puesta en contacto de los dos colectivos implicados en el tema, como son los propietarios de embarcaciones de recreo y los astilleros encargados de ofertarlas. La importancia de esta parte del proyecto reside en la falta de información existente hoy día en todo lo referente a implementación de energía solar en embarcaciones. La herramienta de cálculo creada, Calculadora_solar_para barcos, ha cumplido el segundo objetivo del proyecto. Para mayor entendimiento, se ha dividido esta parte del proyecto en dos: La primera, un manual de uso que explica paso a paso todas las funciones de la hoja de cálculo y la segunda, un ejemplo práctico de uso de la herramienta con un barco en concreto, el Sun Odyssey 419 del astillero Jeanneau. Calculadora_solar_para_barcos ayudará a todo aquel que tenga una embarcación de recreo a realizar su propia previsión de implementación solar fotovoltaica de una manera sencilla e intuitiva, obteniendo resultados a nivel energético y económico y poder decidir si llevar o no a cabo finalmente el proyecto

Small signal dynamic model of a self-synchronising current regulated rectifier for a permanent magnet wind energy conversion system (WECS)

Permanent magnet synchronous generators (PMSGs) are attractive for wind energy applications since they can both self-excite and operate at high power densities. Recent work has shown how the rectifiers for these systems can self-synchronise to the stator output voltage using a phase-locked-loop (PLL), and thus control the stator current without requiring rotor position sensors/observers and/or field orientation/direct torque control concepts. This paper now presents a small signal model of this strategy that accounts for the dynamic elements of the current regulator, the PLL, converter modulation delays, and the generator electrical dynamics. The model establishes design principles for this control strategy that confirm its stability when the PLL bandwidth is set to one decade below the current regulator bandwidth. The theoretical findings have been validated using a full-switched model of a PMSG based Wind Energy Conversion System (WECS).Australian Research CouncilMinisterio de Economía, Industria y Competitividad | Ref. DPI2016-75832-

Synchronous products of rewrite systems (extended version)

We present and formalize a concept of synchronous product for rewrite systems, and also a corresponding concept for general transition systems, used as semantics for the former. A series of examples shows their practical usefulness: for the strategic control of systems, and for modular specification and verification

Assessment and exploitation of the minimum current harmonic distortion under overmodulation in five-phase induction motor drives

This paper compares the most prominent overmodulation (OVM) techniques for five-phase induction motor drives with respect to the minimum current distortion (MCD) achievable. To attain a benchmark of the latter, two MCD OVM approaches are devised. Contrarily to previous strategies aimed at voltage distortion reduction/minimization, these MCD methods are focused on minimizing the harmonic stator copper loss (HSCL), thus minimizing the current total harmonic distortion (THD). One of these MCD strategies minimizes the HSCL while injecting only x–y harmonics. The other MCD method exploits α–β harmonic injection to further decrease the HSCL and to cover the whole OVM region. Moreover, the dual-mode OVM, which is one of the three-phase methods with the lowest distortion, is extended here for five-phase drives. The findings provide insight into how close the OVM methods are to the benchmark imposed by the MCD strategies. Notably, these MCD techniques yield a significant reduction of current THD, HSCL and peak current, especially for machines with negligible thirdorder space harmonic. The average switching losses are also decreased. Indications for real-time implementation of the MCD solutions are also givenAgencia Estatal de Investigación | Ref. PID2019-105612RB-I00Xunta de Galicia | Ref. ED431F 2020/07Xunta de Galicia | Ref. GPC-ED431B 2020/03Agencia Estatal de Investigación | Ref. RYC2018-024407-

A generalized overmodulation strategy with minimum current distortion for symmetrical and asymmetrical multiphase induction motor drives

Multiphase machines are a promising alternative for high-reliability applications. In these applications, overmodulation (OVM) is important since it allows attaining higher modulation indices by injecting, besides zero-sequence voltage harmonics, current-producing ones. In general, the existing techniques are able to limit to some extent the current total harmonic distortion (THD). However, most do not ensure the minimum current THD, thereby not guaranteeing the minimum harmonic stator copper loss. Furthermore, most are intended just for particular phase numbers n , symmetrical/asymmetrical winding arrangements and neutral-point (NP) configurations. OVM with low THD remains unaddressed in most types of multiphase motors. This article overcomes these limitations by proposing a generalized OVM strategy that attains the minimum current THD in induction motors with any n , winding arrangement, and NP configurations. Two techniques are outlined. One of them injects only non-torque-related harmonics, while the other technique exploits torque-producing harmonics to further reduce the current THD and to attain modulation indices up to square waveform. The superiority of the proposal in terms of current THD is substantiated through studies for multiple kinds of multiphase machines. The experiments are performed by using two six-phase induction motors with symmetrical/asymmetrical windings when 1 and 2 NPs are set.Xunta de Galicia | Ref. ED431F2020/07Xunta de Galicia | Ref. ED431B2023/12Agencia Estatal de Investigación | Ref. RYC2018-024407-IAgencia Estatal de Investigación | Ref. PID2022-136908OB-I0

Modular specification in rewriting logic (extended version)

Our aim is to bring modularity to system specification in rewriting logic. Modularity here is in the sense of decomposing a system into its functional components, coding the specification for each component as a separate system, and then assembling them back. Rewriting logic is well suited for the specification of concurrent and non-deterministic systems but, up to now, modularity could hardly be addressed within it. The base of our proposal is the operation that we call synchronous composition. We discuss the reasons and implications of our proposal, and formalize it for rewriting logic and also for transition structures, to be used as semantics. To show the power of our approach, we include a few small but realistic examples and a larger example on cached computer architecture

La arquitectura geográfica manchega : recurso y compromiso educativo

En La Mancha, donde la llanura entra en contacto con los Montes de Toledo y el vulcanismo del Campo de Calatrava, allí, donde no ha mucho tiempo, el Guadiana nacía en los enigmáticos Ojos, y junto con el Gigüela se desbordaban ambos formando un amplio humedal de tablas, aparece una expresión cultural, formal, espacial y temporal que es síntesis de un paisaje, de un tiempo y de una forma de vida: la arquitectura geográfica manchega. Esta arquitectura popular, en gran parte deteriorada, olvidada y abandonada, presenta una gran diversidad de formas, como resultado de la interacción de diversos factores, bióticos y abióticos, como: el clima, el sustrato, los materiales disponibles, la herencia histórica, las actividades rurales, las creencias populares, etc. La confluencia de estos factores, originó diversos modelos arquitectónicos, resultado del cual es un amplio muestrario tipológico, que incluye manifestaciones como la quintería, el molino de agua y de viento, el bombo, el silo, la bodega, el caserío, etc. En este artículo, presentamos una aproximación al estudio geográfico de la arquitectura popular de La Mancha, un objeto que responde a un espacio, a un tiempo y a una forma, de manera que a partir del conocimiento de las influencias del medio sobre estas construcciones (espacio), de la huella histórica y la actividad humana (tiempo, técnica y función) y de las ideas, creencias y valores estéticos (forma), presentamos una tipología que, aun habiendo perdido actualmente en gran parte su significado funcional primigenio, creemos que cuenta con una serie de valores patrimoniales y didácticos cuya transmisión pretende contribuir a la sensibilización ciudadana, a su conocimiento, valoración y conservación.In La Mancha, where the plain enters contact with the Montes de Toledo and the volcanism of the Campo de Calatrava, there, where there is not a lot of time, the Guadiana was born in the enigmatic Ojos, and along with the Gigüela both overflowed forming an extensive one overflow, a temporary, spatial, formal, and cultural expression appears that is synthesis of a landscape, of a time and of a form life: the geographical architecture of La Mancha. This popular architecture, to a large extent deteriorated, forgot and abandoned, presente a great diversity morphological, as a consequence of the interaction of diverse factors, biotic and abiotic, as: the climate, the substrate, the available materials, the historie inheritance, the rural activities, the popular beliefs, etc. The confluence of these, originated diverse architectural models, result of which is an extensivo one typoligy that includes demonstrations as the farmhouse, the mili of water and of wind, the bass drum, the silo, the wine cellar, the settiement, etc. In this article, we present an approximation to geographical study of the popular architecture of La Mancha, an object that responds to a space, at the same time and to a form, so that from the knowledge of the influences of the middie on these constructions (space), of the historie track and the human activity (time, technical and function) and of the ideas, beliefs and esthetic values (form), we present a typology that, even having lost to a large extent its original functional meaning, we believe that counts on a series of didactic and hereditary values whose broadcast intends to contribute to the contributing to the civic sensibility, to its knowledge, appraisal and conservation

Analysis of the shoes in a population over 60

El calzado representa una de las partes indispensables en la indumentaria de las personas en la cultura occidental. Utilizado de manera adecuada sirve como un elemento de protección al pie y de ayuda a la deambulación. Sin embargo cuando se utiliza de manera no adecuada se relaciona directamente con caídas, alteraciones en la marcha y aparición o agravamiento de patologías en el pie. En el presente trabajo realizamos un estudio del tipo de calzado más utilizado en una población mayor de 60 años, si éste era adecuado o no y si la población geriátrica poseía información acerca de cuál es el calzado mas adecuado para ellos e intentamos relacionar la visita al Podólogo con la utilización de calzado adecuado o no.Footwear represents an essential part of garment of people in occidental culture. If utilized in a correct way, it provides protection and aid in human gait. Nevertheless, if utilized incorrectly, it’s related to falls, alterations in gait and appearance or worsening in foot pathology. In the present issue, we studied what style of footwear is the most commonly used in a community older of 60, if it was appropriate or inappropriate and if geriatric community had information enough to know what is the most appropriat

DC-current injection with minimum torque ripple in interior permanent-magnet synchronous motors

Several proposals based on dc-current injection have been reported for estimating the stator winding resistance in induction machines, and recently extended for synchronous machines. Tracking this resistance can be very useful, e.g., for thermal monitoring or preserving control dynamics. In surface-mounted permanent-magnet synchronous machines (PMSMs), it is possible to inject a dc component in the d -axis, without perturbing the torque. However, it has been claimed that, for synchronous machines with saliency, it is not possible to avoid the torque ripple due to such injection. This letter proposes optimum reference currents to impose dc current in three-phase interior PMSMs while minimizing to practically zero its associated torque ripple. Namely, the dc signal is injected in combination with a suitable second-order harmonic so that the stator current space vector follows the constant-torque locus, while the fundamental is set according to the maximum-torque-per-ampere strategy. Experimental results validate the theory.Agencia Estatal de Investigación | Ref. DPI2016-75832-