Sähköverkosta irti olevan pienhybridijärjestelmän toteutus

Lappeen siniset –partiolippukunnalla on käytössään leiripaikka Humaljärvellä, Lappeenrannassa. Leiripaikalla ei ole liityntää sähköverkkoon, joten leiripaikalle on asennettu kaksi erillistä aurinkovoimalla toimivaa sähköjärjestelmää. Leiripaikan sähköistetyt rakennukset ovat pääkämppä ja saunan sekä vanhan kämpän muodostama kokonaisuus. Aurinkopaneeleilla tuotettu sähköenergia varastoidaan akustoihin. Lippukunta on havainnot käytössä, ettei talvella tuotettu aurinkoenergia riitä kattamaan pääkämpän sähkönkulutusta, joten leiripaikalle on päätetty hankkia tuulivoimala lisäämään tuotantoa. Tässä kandidaatin työssä esitellään hybridijärjestelmään kuuluvien aurinko- ja tuulivoiman toimintaperiaatteita sekä näiden komponentteja. Aurinko- ja tuulivoimalla tuotetulle sähköenergialle lasketaan arviot, joita verrataan leiripaikan sähköjärjestelmän arvioituun kulutukseen. Leiripaikalle tulevaa tuuliturbiinia ja sen lataussäädintä testataan laboratoriossa, jotta varmistutaan niiden soveltuvuudesta sekä toimivuudesta kohteeseen. Testausten ja laitteiden datalehtien avulla suunnitellaan leiripaikalle toimiva hybridijärjestelmä, joka kattaa leiripaikan ympärivuotisen sähkönkulutuksen.

Liquid cooling solutions for rotating permanent magnet synchronous machines

In the design of electrical machines, efficiency improvements have become very important. However, there are at least two significant cases in which the compactness of electrical machines is critical and the tolerance of extremely high losses is valued: vehicle traction, where very high torque density is desired at least temporarily; and direct-drive wind turbine generators, whose mass should be acceptably low. As ever higher torque density and ever more compact electrical machines are developed for these purposes, thermal issues, i.e. avoidance of over-temperatures and damage in conditions of high heat losses, are becoming of utmost importance. The excessive temperatures of critical machine components, such as insulation and permanent magnets, easily cause failures of the whole electrical equipment. In electrical machines with excitation systems based on permanent magnets, special attention must be paid to the rotor temperature because of the temperature-sensitive properties of permanent magnets. The allowable temperature of NdFeB magnets is usually significantly less than 150 ˚C. The practical problem is that the part of the machine where the permanent magnets are located should stay cooler than the copper windings, which can easily tolerate temperatures of 155 ˚C or 180 ˚C. Therefore, new cooling solutions should be developed in order to cool permanent magnet electrical machines with high torque density and because of it with high concentrated losses in stators. In this doctoral dissertation, direct and indirect liquid cooling techniques for permanent magnet synchronous electrical machines (PMSM) with high torque density are presented and discussed. The aim of this research is to analyse thermal behaviours of the machines using the most applicable and accurate thermal analysis methods and to propose new, practical machine designs based on these analyses. The Computational Fluid Dynamics (CFD) thermal simulations of the heat transfer inside the machines and lumped parameter thermal network (LPTN) simulations both presented herein are used for the analyses. Detailed descriptions of the simulated thermal models are also presented. Most of the theoretical considerations and simulations have been verified via experimental measurements on a copper tooth-coil (motorette) and on various prototypes of electrical machines. The indirect liquid cooling systems of a 100 kW axial flux (AF) PMSM and a 110 kW radial flux (RF) PMSM are analysed here by means of simplified 3D CFD conjugate thermal models of the parts of both machines. In terms of results, a significant temperature drop of 40 ̊C in the stator winding and 28 ̊C in the rotor of the AF PMSM was achieved with the addition of highly thermally conductive materials into the machine: copper bars inserted in the teeth, and potting material around the end windings. In the RF PMSM, the potting material resulted in a temperature decrease of 6 ̊C in the stator winding, and in a decrease of 10 ̊C in the rotor embedded-permanentmagnets. Two types of unique direct liquid cooling systems for low power machines are analysed herein to demonstrate the effectiveness of the cooling systems in conditions of highly concentrated heat losses. LPTN analysis and CFD thermal analysis (the latter being particularly useful for unique design) were applied to simulate the temperature distribution within the machine models. Oil-immersion cooling provided good cooling capability for a 26.6 kW PMSM of a hybrid vehicle. A direct liquid cooling system for the copper winding with inner stainless steel tubes was designed for an 8 MW directdrive PM synchronous generator. The design principles of this cooling solution are described in detail in this thesis. The thermal analyses demonstrate that the stator winding and the rotor magnet temperatures are kept significantly below their critical temperatures with demineralized water flow. A comparison study of the coolant agents indicates that propylene glycol is more effective than ethylene glycol in arctic conditions.

Yliopiston sähköverkon mallintaminen

Lappeenrannan teknillinen yliopisto tutkii älykkäiden sähköverkkojen kehittämistä. Yliopisto on hankkinut sähköverkkoonsa tuuliturbiinin ja aurinkopaneeleita, joilla pystytään tuottamaan sähköenergiaa sähköverkkoon. Näitä tuotantoja voidaan käyttää myös tutkimuksessa. Tässä työssä luodaan simulaatiomalli yliopiston sähköverkosta Matlab® Simulink® -ohjelmalla. Simulaatiomalliin mallinnetaan yliopiston sisäinen keskijänniteverkko ja osa pienjänniteverkosta. Simulaatiomalli toteutetaan ohjelman valmiilla komponenteilla, joihin lasketaan tarvittavat parametrit. Tuuliturbiinin ja aurinkopaneelien sähköntuotantotehot määritetään säätiladatojen avulla. Verkon komponenteille lasketaan arvot komponenttien tyyppitietojen perusteella ja asetetaan simulaatiomallin parametreiksi. Simulaatiomalli luodaan yliopiston sisäisen verkon tehonjaon tarkastelemiseksi. Työssä selvitetään myös mahdollisuuksia luodun simulaatiomallin käyttämiseen vikatilanteiden tarkastelussa.

3D-tulostettu tuuliturbiinin vaihteen pienoismalli

Työn aiheena on vaihteen pienoismallin suunnittelu ja toteutus 3d-tulostusta hyväksi käyttäen. Pienoismalli tehdään Moventas Gears Oy:n suunnittelemasta tuuliturbiinin vaihteesta. Vaihteen pienentämisestä johtuen malliin on suunniteltava uudet laakeripesät ja hammaspyörät. 3D-tulostuksen ja pienoismallin pienen koon ansiosta vaihdetta voidaan yksinkertaistaa suuresti ja näin vähentää tulostettavien osien määrää. Lisäksi työssä selvitetään, mitä ongelmia 3D-tulostus tuo valmistukseen ja suunnitteluun. Työn kirjallisessa osassa selvennetään planeettavaihteen toimintaa yleisesti sekä esitellään Exceed Series 3+ vaihdetta. Lisäksi kerrotaan 3D-tulostuksesta, sen periaatteesta, erilaisista tulostusmenetelmistä, tulostinlaitteesta ja mahdollisista ongelmista tulostuksessa. Kokeellinen osa koostuu pienoismallin suunnittelusta ja valmistuksesta. Valmistuksessa olleiden virheiden takia muutama osa jouduttiin tulostamaan uudelleen. Muutamia osia jouduttiin myös hieman jälkikäsittelemään tulostuksen jälkeen, jotta malli saatiin kasattua. Ongelmakohdaksi muodostui tulostimen ohjelmisto ja tulostustiedostot. Tulostusprosessi sujui kuitenkin hyvin. Lopputuloksena saatiin toimiva pienoismalli. 3D-tulostus toimii hyvin monimutkaisten kappaleiden tulostuksessa. Tulostuksen hinta nousi kuitenkin varsin korkeaksi. Tulostuslaitteistosta riippuen tulostuksen voisi mahdollisesti suorittaa myös halvemmallakin.

Aerosorgailu palen aplikazioetarako pvc espumaren degradazio termiko eta propietate mekanikoen karakterizazioa

[EU]Energia berriztagarria iturri naturaletatik sortzen den energia mota da. Energia lortzeko erabiltzen diren baliabide naturalak asko dira, eguzki-energia, haizea, ura… Energia berriztagarrien artean, eolikoa da zabalkunde handien lortu duena; batez ere ingurumen-inpaktu urriagatik eta bere kostuak gero eta txikiagoak izateagatik. Honen ondorioz, energia garbi, lehiakor eta ekonomikoki bideragarria da gaur egun. Hala ere, aerosorgailu hauen ekoizpen prozesuak desabantaila nabaria aurkezten du palen ontze prozesuan. Tenperatura igoeraren ondorioz material konkretu baten degradazioa dela eta. Ikerketa lan honetan, aerosorgailu palen karakterizazioa egingo da eta ontze prozesuan, “polikloruro de binilo” (PVC)-ak jasaten duen degradazioaren azterketa.

Discrete demand side control performance under dynamic building simulation: a heat pump application

This study presents the findings of applying a Discrete Demand Side Control (DDSC) approach to the space heating of two case study buildings. High and low tolerance scenarios are implemented on the space heating controller to assess the impact of DDSC upon buildings with different thermal capacitances, light-weight and heavy-weight construction. Space heating is provided by an electric heat pump powered from a wind turbine, with a back-up electrical network connection in the event of insufficient wind being available when a demand occurs. Findings highlight that thermal comfort is maintained within an acceptable range while the DDSC controller maintains the demand/supply balance. Whilst it is noted that energy demand increases slightly, as this is mostly supplied from the wind turbine, this is of little significance and hence a reduction in operating costs and carbon emissions is still attained.

Relação entre stakeholders, recursos estratégicos e sustentabilidade em uma organização atuante na cadeia de valor da indústria brasileira de energia eólica

This paper approaches the strategy in business management and aimed at identifying and outlining the interests and commitment of stakeholders in strategic resources management concerning production and implementation of wind turbine equipment of a Brazilian wind power company and also verifying if internal and external results deriving from such activities were sustainable, taking as main reference seminal publications and periodicals relevant to the research point that discuss the Resource Theory, Stakeholders and Sustainability. An analysis was carried out to assess how stakeholders, beyond the temporal context, intermediated the composition, development and management of the organization´s resources, as well as the social, environmental and economic results obtained from resources management in the production and supply of wind turbines to a Wind Power Plant located in the State of Ceara, in order to portray that Brazil sustainability can be an important competitive advantage source that creates value for shareholders and the community (Hart & Milstein, 2003). The strategy herein applied was the qualitative investigation using a single study case, which allowed for the thorough examination of an active organization operating in the Brazilian industry of wind power and also the resources used in the production and implementation of wind turbines supplied to the a Wind Power Plant in Ceara. Considering the content analysis and the triangulation principle, three qualitative data collection methods were applied to identify and characterize stakeholders’ interest and commitment in resource management of the organization operating in the Brazilian wind power industry, as follows, semistructured deep interview with managers of tactic-strategic level and analysts of organization´s value chain nine activities, analysis of public internal and external documents; and analysis of audio-visual material. Nonetheless, to identify the internal and external economic, social and environmental results of implementation and supply of wind turbines to the Wind Power Plant in Ceara, semistructured interviews were also carried out with the residents of the region. Results showed the BNDES (Brazilian Development Bank) and the organization head office were the stakeholders who exerted the strongest influence on resources related to production and implementation of the aerogenerator product at Trairi Wind Plant in Ceara. Concerning the organization resources, at the current stage of the Brazilian Wind Industry ,although the brand, reliability and reputation of the organization under study were valuable esources, rare, hard to imitate and exploited by the organization, it was noticed that opposed to RBV, they did not actually represent a source of competitive advantage . For the local community the social, economic and environmental results related to the wind turbines implementation were more positive than negative, despite the fact that the productive process caused negative environmental impacts such as the high emission of CO2 to transport wind turbines components to Trairi Wind Power Plant.

Estudo comparativo de pás para aerogeradores de grande porte fabricadas em materiais compósitos reforçadas com fibra de carbono ou fibra de vidro

The research and development of wind turbine blades are essential to keep pace with worldwide growth in the renewable energy sector. Although currently blades are typically produced using glass fiber reinforced composite materials, the tendency for larger size blades, particularly for offshore applications, has increased the interest on carbon fiber reinforced composites because of the potential for increased stiffness and weight reduction. In this study a model of blade designed for large generators (5 MW) was studied on a small scale. A numerical simulation was performed to determine the aerodynamic loading using a Computational Fluid Dynamics (CFD) software. Two blades were then designed and manufactured using epoxy matrix composites: one reinforced with glass fibers and the other with carbon fibers. For the structural calculations, maximum stress failure criterion was adopted. The blades were manufactured by Vacuum Assisted Resin Transfer Molding (VARTM), typical for this type of component. A weight comparison of the two blades was performed and the weight of the carbon fiber blade was approximately 45% of the weight of the fiberglass reinforced blade. Static bending tests were carried out on the blades for various percentages of the design load and deflections measurements were compared with the values obtained from finite element simulations. A good agreement was observed between the measured and calculated deflections. In summary, the results of this study confirm that the low density combined with high mechanical properties of carbon fibers are particularly attractive for the production of large size wind turbine blades

Modelagem de usinas eólicas através de um processo de Markov e técnicas de confiabilidade para a estimativa anual da energia produzida

This study aims to use a computational model that considers the statistical characteristics of the wind and the reliability characteristics of a wind turbine, such as failure rates and repair, representing the wind farm by a Markov process to determine the estimated annual energy generated, and compare it with a real case. This model can also be used in reliability studies, and provides some performance indicators that will help in analyzing the feasibility of setting up a wind farm, once the power curve is known and the availability of wind speed measurements. To validate this model, simulations were done using the database of the wind farm of Macau PETROBRAS. The results were very close to the real, thereby confirming that the model successfully reproduced the behavior of all components involved. Finally, a comparison was made of the results presented by this model, with the result of estimated annual energy considering the modeling of the distribution wind by a statistical distribution of Weibull

Desenvolvimento de Modelos no Programa DigSILENT PowerFactoryTM para o Estudo de Estabilidade Transitória em Sistemas Elétricos de Potência com Aerogerador

This work presents a description of models development at DigSILENT PowerFactoryT M program for the transient stability study in power systems with wind turbine. The main goal is to make available means to use a dynamic simulation program in power systems, widely published, and utilize it as a tool that helps in programs results evaluations used for this intent. The process of simulations and analyses results starts after the models setting description phase. The results obtained by the DigSILENT PowerFactoryT M and ATP, program chosen to the validation also international recognized, are compared during this phase. The main tools and guide lines of PowerFactoryT M program use are presented here, directing these elements to the solution of the approached problem. For the simulation it is used a real system which it will be connected a wind farm. Two different technologies of wind turbines were implemented: doublyfed induction generator with frequency converter, connecting the rotor to the stator and to the grid, and synchronous wind generator with frequency converter, interconnecting the generator to the grid. Besides presenting the basic conceptions of dynamic simulation, it is described the implemented control strategies and models of turbine and converters. The stability of the wind turbine interconnected to grid is analyzed in many operational conditions, resultant of diverse kinds of disturbances

Desenvolvimento de modelos no programa digSILENT powerfactoryTM para o estudo de estabilidade transitória em sistemas elétricos de potência com aerogerador

This work presents a description of models development at DigSILENT PowerFactoryTM program for the transient stability study in power systems with wind turbine. The main goal is to make available means to use a dynamic simulation program in power systems, widely published, and utilize it as a tool that helps in programs results evaluations used for this intent. The process of simulations and analyses results starts after the models setting description phase. The results obtained by the DigSILENT PowerFactoryTM and ATP, program chosen to the validation also international recognized, are compared during this phase. The main tools and guide lines of PowerFactoryTM program use are presented here, directing these elements to the solution of the approached problem. For the simulation it is used a real system which it will be connected a wind farm. Two different technologies of wind turbines were implemented: doubly-fed induction generator with frequency converter, connecting the rotor to the stator and to the grid, and synchronous wind generator with frequency converter, interconnecting the generator to the grid. Besides presenting the basic conceptions of dynamic simulation, it is described the implemented control strategies and models of turbine and converters. The stability of the wind turbine interconnected to grid is analyzed in many operational conditions, resultant of diverse kinds of disturbances

Otimização de sistema de bombeamento com energia eólica: sistema de bombeamento de São Gabriel/BA

After the Protocol of Kyoto and of the ECHO 92 - Rio de Janeiro, the attentions of the world focus to the preservation of the environment and of the maintainable use of the natural resources. People were looking for preserving environment for the future generations. Ever since, solutions are looked for the supply of energy in its more acquaintances forms and the substitution of the use of fossil fuels for the such alternative forms as: Photovoltaics, solar heat systems for water, wind , bio-diesel, etc. and in this context the Company of Engineering of the State of Bahia - Cerb changed a diesel pumping system by an wind one, It´s the first community system of this nature in Bahia. Facing problems with the model, a Cerb involved the academic segment of the Federal Center of Technological Education of Bahia Cefetba looking for a solution. This work intends to demonstrate the possibilities of optimization of the pumping communit system that supply water to approximately 50 people in the place of Romão, municipal district of São Gabriel-Ba. Technical reports were published in AGRENERGD2004-Unicamp SP and Scientific Magazine ETC,Cefetba, 2005. A simulation of the increase of energy is presented for heights of 15 and 20m, considering the eletromecanical balance from the pumping energy to the wind turbine. From the accomplished bibliographical revision, we emphasized the mechanical aspects of the engineering once in UFRN, those studies concentrate on the Department of Mechanical Engineering while, in others eletroelectronic are more emphasized. Finally, documents that we judged important were enclosed for the perfect understanding of this work

The benefits of ethanol use for hydrogen production in urban transportation

The purpose of this paper is to describe the benefits of sugar cane ethanol in Brazil, appointing the productivity of this type of fuel based on hectares of plantation, its carbon dioxide cycle and the contribution to reduce the greenhouse effect. In the following step the uses of ethanol for hydrogen production by steam reforming is analyzed and some comparison with natural gas steam reforming is performed. The sugar cane industry in Brazil, in a near future, in the hydrogen era, could be modified according to our purpose, since besides the production of sugar, and ethylic and anhydric alcohol, Brazilian sugar cane industry will also be able to produce biohydrogen.Fuel cells appear like a promising technology for energy generation. Among several technologies in the present, the PEMFC (proton exchange membrane fuel cell) is the most appropriate for vehicles application, because it combines durability, high power density, high efficiency, good response and it works at relatively low temperatures. Besides that it is easy to turn it on and off and it is able to support present vibration in vehicles. A PEMFC's problem is the need of noble catalysts like platinum. Another problem is that CO needs to be in low concentration, requiring a more clean hydrogen to avoid fuel cell deterioration.One part of this paper was developed in Stockholm, where there are some buses within the CUTE (clean urban transport for Europe) project that has been in operation with FC since January 2004. Another part was developed in Guaratingueta, Brazil. Brazil intends to start up a program of FC buses. As conclusion, this paper shows the economical analysis comparing buses moved by fuel cells using hydrogen by different kinds of production. Electrolyze with wind turbine, natural gas steam reforming and ethanol steam reforming. (C) 2009 Elsevier Ltd. All rights reserved.

Pricing of reactive power support provided by distributed generators in transmission systems

Distributed Generation, microgrid technologies, two-way communication systems, and demand response programs are issues that are being studied in recent years within the concept of smart grids. At some level of enough penetration, the Distributed Generators (DGs) can provide benefits for sub-transmission and transmission systems through the so-called ancillary services. This work is focused on the ancillary service of reactive power support provided by DGs, specifically Wind Turbine Generators (WTGs), with high level of impact on transmission systems. The main objective of this work is to propose an optimization methodology to price this service by determining the costs in which a DG incurs when it loses sales opportunity of active power, i.e, by determining the Loss of Opportunity Costs (LOC). LOC occur when more reactive power is required than available, and the active power generation has to be reduced in order to increase the reactive power capacity. In the optimization process, three objectives are considered: active power generation costs of DGs, voltage stability margin of the system, and losses in the lines of the network. Uncertainties of WTGs are reduced solving multi-objective optimal power flows in multiple probabilistic scenarios constructed by Monte Carlo simulations, and modeling the time series associated with the active power generation of each WTG via Fuzzy Logic and Markov Chains. The proposed methodology was tested using the IEEE 14 bus test system with two WTGs installed. © 2011 IEEE.

Avaliação do desempenho de um aeromotor de eixo vertical

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)