Generador axial para un generador eólico de baja potencia, selección, diseño y simulación en COMSOL multiphysic

Axial flux generators are machines used in wind generation systems, and given the growing interest in small-scale renewable energy, it is required to look for new configurations to address the increase in energy needs globally. This document discusses the selection, design and simulation of three topologies of a dual-rotor permanent axial flux magnet generator for low-speed, low-power (10 watt) applications, which are modeled by applying the finite element method in COMSOL 2D software, as a contribution to the Low Power Wind Generator Topologies research project. Thanks to this method it is possible to optimize the design and observe the density of magnetic flux in the teeth of the stator, air gap and magnetic poles. The results obtained are compared taking as reference the output power generated under the loads of 10, 40,100, 150 and 260 ohms, in addition indicate that topologies 1 and 3 (purely coreless and slotted stator) exhibit better behavior both in no-load and under load, when looking to reduce the weight of the machine implemented a HALBACH type matrix on the magnetic poles of the rotors.Los generadores de flujo axial son máquinas utilizadas en sistemas de generación eólica, y dado el creciente interés por las energías renovables a pequeña escala se requiere buscar nuevas configuraciones que permitan enfrentar el aumento de las necesidades energéticas a nivel mundial.  En este documento se analiza la selección, diseño y simulación de tres topologías de un generador de imanes permanentes de flujo axial de doble rotor para aplicaciones de baja velocidad y baja potencia (10 watios), las cuales se modelan aplicando el método de elementos finitos en el software COMSOL 2D, como aporte al proyecto de investigación Topologías de Generador Eólico de Baja Potencia, gracias a este método es posible optimizar el diseño y observar la densidad de flujo magnético en los dientes del estator, entrehierro y polos magnéticos. Los resultados obtenidos se comparan tomando como referencia la potencia de salida generada bajo las cargas de 10, 40,100, 150 y 260 ohmios, además indican que las topologías 1 y 3 (puramente sin núcleo y estado ranurado) presentan un mejor comportamiento tanto en vacío como bajo carga, al buscar reducir el peso de la maquina implementado una matriz tipo HALBACH en los polos magnéticos de los rotores

A power electronic controlled dump load with negligible harmonics for accurate loading used in testing small wind turbines

Permanent magnet synchronous generators (PMSG) are at the core of small scale wind power generators manufactured by a wide range of manufacturers in different configurations: vertical or horizontal axis blades, with various geometries and aerodynamics of the blades; by installing these small scale wind turbines in very large numbers at household levels, it is expected that these will make a positive contribution to the increase of renewable energy generation, reducing the use of fossil fuels that are blamed for climate change. However, a proper evaluation of the technical specification of these small scale wind generators in various weather conditions is necessary in order to assess the full potential of benefits. This paper reports on the implementation and testing of a power electronic dump load that allows continuously adjustable loading of a PMSG with sinusoidal currents and have the capability to self synchronize to its frequency/speed whilst avoiding transient/loosing of synchronism

Development of a linear permanent magnet generator topology for low power through finite elements

Uno de los principales problemas de los generadores lineales es que debido a la baja velocidad de traslación de su parte móvil, para poder generar grandes potencias la máquina deberá soportar grandes esfuerzos lo que conlleva a dispositivos muy grandes, por ende, mediante el uso de múltiples dispositivos de mediana potencia en lugar de un bajo número de estos de gran potencia se consigue una forma de onda más adecuada de cara a su integración en red. En el presente artículo se propone dos topologías diferentes de generador lineal con características obtenidas a partir de una recopilación de la literatura científica, se presenta los parámetros tenidos en cuenta para el diseño y su respectivo modelado a través de simulaciones 2D en COMSOL, como contribución al proyecto de investigación Topologías de generador eólico de baja potencia. Los resultados obtenidos resaltan a la segunda de las topologías propuestas, siendo la de mejor comportamiento bajo carga, una señal en bornes más limpia y mayor salida de potencia frente a variaciones en la magnitud de la carga.One of the main problems of linear generators is that due to the low speed of translation of their moving part, in order to generate large powers the machine must withstand great efforts which leads to very large devices, therefore, through the use of multiple Medium-power devices instead of a low number of high-power devices, a more suitable waveform is achieved for their integration into the network. In this article, two different linear generator topologies are proposed with characteristics obtained from a compilation of scientific literature, the parameters taken into account for the design and their respective modeling are presented through 2D simulations in COMSOL, as a contribution to the research project TOPOLOGIES OF LOW POWER WIND GENERATOR. The results obtained highlight the second of the proposed topologies, being the one with the best behavior under load, a cleaner terminal signal and greater power output in the face of variations in the magnitude of the load

Проектирование ветрогенераторов для малоэтажного строительства в Томской области

В дипломной работе рассмотрены вопросы использование ветроэнергетических установок в Томской области. В ходе работы был рассчитан и спроектирован ветрогенератор. Проведён финансовый и социальный анализ.In the thesis, the issues of using wind power plants in the Tomsk region are considered. In the course of the work, the wind generator was designed and designed. Financial and social analysis was carried out

Energy harvesting from railway vibrations - A numerical study based on beam-on-elastic-foundation under quasi-static loading

The objective of this paper is to investigate energy harvesting of train-induced rail vibrations and to provide a comparison between various feasible harvesting locations based on the expected electrical power output. The vibrations of the railway track are modelled using the beam-on-elastic-foundation model under quasi-static loading. The loading applied is from a passenger train moving at a constant velocity. The vibrations of the railway track are then used to determine the energy harvested at each location using one-degree-of-freedom models. The numerical study concludes that the optimal configuration of the harvester is on the rail for the vibration harvester and as a harvesting rail pad between the sleeper and the rail for the compression harvester. The harvested energy with each configurations is O(∼ 10−6) and O(1) J/kg of harvester, respectively.This paper has been carried out under a research project entitled “Framework for Research on Railway Engineering” which is supported by a grant sponsored by Qatar Rail and managed by Qatar University under reference number: QUEX-CENG-Rail 17/18

Partial Solution of Hybrid System with Low-Temperature Fuel Cells and Renewable Sources

Práce se zabývá principy funkce nízkoteplotního palivového článku s polymerním elektrolytem (PEMFC), fotovoltaického zdroje (FVE) a větrného zdroje energie (VTE) a řeší jejich podrobná matematická vyjádření. V rámci práce jsou jednotlivé zdroje simulovány a jejich modely jsou podrobeny důkladné analýze. Samotnému simulování předchází seznámení se s významnými historickými milníky ve vývoji palivových článků. Dále je provedena základní klasifikace palivových článků a jsou uvedeny charakteristické vlastnosti článků používaných v energetice. V práci jsou také uvedeny informace o projektech, které řeší implementaci PEMFC jako primárního nebo doplňkového zdroje energie. Ve spojitosti s nastíněnou možností uplatnění nízkoteplotních palivových článků, jako vodíkové technologie v blízké budoucnosti, jsou pro komplexnost představeny i základní metody výroby vodíku a možnosti jeho skladování. Práce je výhradně zaměřena na zdokonalení matematických modelů PEMFC, které v rámci hybridního systému kooperují s obnovitelnými zdroji energie (OZE). Součástí práce je proto krátké review jednotlivých provozovaných nebo modelovaných konceptů hybridních systémů v energetice, na kterých jsou specifikovány hlavní nedostatky modelů PEMFC nebo systému jako celku. Specifikace nedostatků vede k vytvoření nového zdokonaleného dynamického modelu palivového článku, který umožňuje analýzu vývoje elektrických a neelektrických veličin v rámci scénáře s dlouhodobou zátěží. Dále jsou zde představeny výsledky tepelných experimentů a dynamického chování palivového článku, které byly získány pomocí modelu rozšířeného ještě o reformér a DC/DC konvertor. V práci je dále vytvořen model fotovoltaického modulu, který je založen na parametrizaci výhradně ze štítkových hodnot a který je podroben základním experimentům s využitím reálně změřených hydrometeorologických dat. V případě, že hybridní systém využívá OZE, je dobré znát vývoj atmosférických podmínek v místě instalace těchto zdrojů. Konkrétně pro FVE je možné využít veřejně dostupných databází obsahující informace o hodnotách dopadajícího slunečního záření pro zvolenou lokalitu. Veřejné databáze často slouží pro prvotní návrh a výrobní možnosti FVE. V reakci na to je v práci provedeno zhodnocení relevance těchto databází, a to na základě konfrontace s dlouhodobě reálně měřenými daty, jež jsou využita pro zmíněné experimenty fotovoltaického modulu. Částečně je zde také řešena problematika větrného zdroje energie. V této souvislosti je zde popsán a simulován pouze zjednodušený model VTE. V navazující práci pak lze vytvořené modely subsystémů všeobecně implementovat jako parciální vstupy hybridního systémů. Práce byla zpracována v Centru výzkumu a využití obnovitelných zdrojů energie (CVVOZE) za finanční podpory Ministerstva školství, mládeže a tělovýchovy České republiky v rámci projektu č. LO1210 - Energie v podmínkách udržitelného rozvoje (EN-PUR) a v rámci projektu specifického výzkumu č. FEKT-S-14-2520 - Nové technologie pro udržitelnou elektroenergetiku a dále za finanční podpory Technologické agentury České republiky v rámci projektu č. TA03020523 - Dynamický model distribuční sítě.The thesis deals with the principle functions of low-temperature fuel cells with proton exchange membrane (PEMFC), photovoltaic sources (PVPP) and wind energy sources (WPP), along with solving their detailed mathematical expressions. In this work, the individual sources and their simulated models are analyzed in depth. The actual simulation is preceded by familiarization with important historical milestones in the development of fuel cells. Furthermore there is a basic classification of fuel cells and the characteristics of the cells used in the energy sectors. The text also provides information on projects that address the implementation of PEMFC as a primary or supplementary source of energy. Along with outlining the options for PEMFC as a perspective hydrogen technologies in the near future, the basic methods of hydrogen production and storage options are presented for the complexity. The work is exclusively focused on improving PEMFC mathematical models that under the hybrid system cooperate with renewable energy sources (RES). Part of the theses contains a short review of run or modeled concepts of hybrid systems in the energy sector. Using these models the main deficiencies of the models or of the whole PEMFC system can be identify. Specifications of the deficiencies lead to the creation of a new advanced dynamic PEMFC model that allows an analysis of the development of electrical and non-electrical quantities using long term tests. Furthermore, the thesis presents results of the experiments of thermal and dynamic behavior PEMFC, which were obtained from the additionally extended model with a reformer and the DC/DC converter. In this text there is a model of a photovoltaic module created, which is based on the nominal values parameterization. The model is subjected to basic experiments in which measured hydrometeorological data are used. If the hybrid system utilizes renewable energy sources, it is good to know the evolution of atmospheric conditions in the installation of these resources. Specifically for PVPP, publicly available databases containing information about solar radiation levels can be used for the selected location. Public databases are often used for initial design and manufacturing options for PVPP. An evaluation of the relevancy of public databases is performed based on a long-term observation of real measured data. Furthermore, these data are used for experiments on the photovoltaic module. Partially the text addresses the issue of the wind energy sources, however, it is simulated only on a simplified model of WPP. Created models of subsystems can be generally implemented as partial inputs hybrid systems in the future work. The thesis was developed at Centre for Research and Utilization of Renewable Energy (CVVOZE) with the financial support of the National Programme for Sustainability and the Ministry of Education, Youth and Sports of the Czech Republic under the project no. LO1210 - Energy for Sustainable Development and the project no. FEKT-S-14-2520 - New Technologies for Sustainable Development of Electrical Power Systems. The thesis was also generated under the project no. TA03020523 - Dynamic model of distribution network with the financial support of Technology Agency of the Czech Republic.

Eco-energy Smart Card”: A human-interactive all paper based, mechanical energy harvester

Nowadays, it is imperative that modern society finds sustainable ways to harvest energy. This means society is forced to look to new ways to generate and store energy, while reducing, simultaneously, the stress on raw materials demand and the amount of waste generated. Our research tackles these two points by making close to zero e-waste clean energy harvesting devices. The core idea behind it is based on the mechano-responsive charge-transfer mechanism and energy-transfer process in π-conjugated polymer at the organic-metal interface layer. A localized forced deformation of the interface has been applied against the polymer surface, allowing charge transfer between material interfaces. The experimental results demonstrated that during contacting force, the conjugated polymer film shows electrical output through the charge transfer mechanism within metal/polymer interfaces. Flexible and low-cost energy harvesting devices built have an active layer constituted by a PANi/cellulose composite which was tapped together to a charge collector layer, that was made from a paper based metallic electrode. These devices have a total maximum power density and maximum current density of 1.75 Wm-2 and 33.5 mA m-2 , respectively. Towards the practical applicability, these devices are able to light up to 40 blue LEDs as well as a commercial humidity sensor

Construcción de un prototipo de generador eólico de baja potencia con eje vertical en el edificio de la carrera de electricidad de la Universidad Técnica del Norte

Construir un prototipo de generador eólico de baja potencia con eje vertical, para la realización de estudios de caracterización de funcionamiento eléctrico, mediante el análisis de un aerogenerador existente en la Carrera de Electricidad de la Universidad Técnica del NorteEl aprovechamiento de las energías renovables altamente abundantes, inagotables y no contaminantes, surge en respuesta para disminuir el uso excesivo de combustibles fósiles altamente contaminantes. En un aerogenerador de eje vertical de baja potencia, el generador eléctrico que en su mayoría emplea es de imanes permanentes de flujo axial, por varias razones: simplicidad de diseño, construcción y generación suficiente que ofrece a bajas velocidades, sin embargo, su funcionamiento se ve limitado por la disponibilidad del recurso eólico que no siempre es constante, siendo necesario estudiar permanentemente sus características eléctricas de funcionamiento para el mejoramiento de su rendimiento. En este proyecto de investigación se diseñó y construyó un prototipo de generador eólico de baja potencia, específicamente un generador de flujo axial, con la finalidad de realizar pruebas de caracterización y evaluar su funcionamiento. El diseño parte de considerar la disponibilidad de recurso eólico que relaciona la cantidad de revoluciones, el análisis de las características magnéticas de los imanes, útiles para determinar la geometría del generador, cantidad de polos, bobinas, conductor para el bobinado, voltaje de salida y pérdidas eléctricas. En la etapa de pruebas de caracterización se realizaron pruebas sin carga y con carga resistiva, con la finalidad de observar el comportamiento de voltaje, corriente y potencia generada en función de la velocidad de rotación medida en revoluciones por minuto, obteniendo con carga elevada mayor voltaje, menor corriente y potencia reducida; en cambio, a poca carga, se obtiene mayor corriente, menor voltaje y potencia más elevada. En cuanto a la eficiencia, el generador presenta menos pérdidas con carga resistiva elevada, las cuales las logra superar. Finalmente, se demuestra que, con los datos obtenidos, el prototipo construido si entrega corrientes y voltajes aceptables para la generación a pequeña escala, con el recurso eólico disponible y las características eléctricas de diseño establecidas.Ingenierí

Generatori eolici domestici. Studio e sviluppo del sistema di controllo

Lo scopo di questa tesi è lo studio e lo sviluppo di un azionamento atto a massimizzare l'efficienza di un sistema di microgenerazione eolic

Axial Flux Permanent Magnet coreless machine

Axial Flux Permanent Magnet (AFPM) machines are becoming increasingly popular due to introduction of the second generation of rare-earth permanent magnets. Owing their unique construction and many advantages, AFPM machines have extensive topology and applications. Among them the coreless AFPM (without ferromagnetic material in the stator) offer reduced cogging torque which proved to be particular useful for special applications, e.g. low power wind energy generation, hub motors of electrical vehicles and electrical bicycles. A Double Stator Internal Rotor prototype was designed and constructed to investigate the performance of the coreless construction. This geometry (not very popular due to poor winding utilisation) has an advantage of using less PMs. Polyester resin was used to hold eight cylindrical shape magnets of the eight pole machine. The large effective air gap of the coreless machine was minimised by keeping a physical air gap and the axial thickness of the trapezoidal stator coils to the minimum, after measuring the magnetic flux distribution around the rotor circular poles. Three types of stators were manufactured to enable a performance comparison: a blank without any conductors for mechanical losses estimation, a ribbon wire coreless and a ribbon wire with magnetic powder composite backing. Test Results confirmed the limitations of the prototype’s geometry and the validity of the AFPM design parameters. The magnetic powder composite backing countered the unfavourable magnetic flux distribution of the internal rotor allowing for increase in power output compared to the stator without backing. Both types of conductor stators do not have a cogging torque with EMF outputs being very close to pure sinusoidal. Ribbon shape of the coil conductor was very beneficial in producing thin rigid coils of large diameter. This might prove to be invaluable in a multi-disc configuration