Detta examensarbete behandlar ett uppsamlingsnät för en ny vindkraftpark som planeras i norra Sverige av företaget AB.Parken skall bestå av 101 stycken vindkraftverk som skall förbindas samman med ett kabelnät och anslutas till en transformatorstation. Rapporten behandlar två förslag på hur nätet skall dimensioneras och förläggas. Uppdelningen av vindkraftverken i kluster illustreras av kartor och enlinjescheman.Valda förläggningsätt och dimensioneringar motiveras med kabelberäkningar och grundläggande teori gällande kabeldimensionering. Kabeltyp samt längder för båda förslagens samtliga radialer presenteras i tabeller tillsammans med en enklare kostnads jämförelse.Simuleringar för uppsamlingsnäten utförs i programmet Power World Simulator. För att kontrollera riktigheten i värdena från simuleringen utförs kontrollberäkningar på en radial med pi-modellen.Beräkningarna visar att dimensioneringen är utförd så förluster och spänningsökningar är väl inom gränsvärden för båda förslagen. Uppsamlingsnätets totala reaktiva tillskott är väl inom gränserna för vad vindkraftverken kan kompensera för.Förslag på fortsatt arbete för detta projekt vore att se över konstruktionen av transformatorstationen samt skydd för uppsamlingsnätet. / This report contains a suggestion for a projected wind farm in northern Sweden.The farm contains 101 wind turbines that shall be connected together with a collection grid and connected to a substation.The report contains two different suggestions of dimension and location of the cables for the grid. The turbines are divided into clusters and shown in maps and single line diagramsChosen suggestions and dimensions are reasoned with calculations and basic theory regarding cable sizing. The chosen cable types and lengths for both suggestions are shown in table form, together with a simplified cost comparison.After simulations have been run in power world simulator programme, the values was checked for authenticity with the π-circuit formula.The calculations shows that the selection of cables have accomplished low losses, and the increase of voltage is well within limits for both suggestions.The contribution of reactive power in the collection grid is also within the limits of what the wind turbines can compensate.A suggestion for future work on this project could be the design and dimension of the substation and the safety equipment.

Made available in DSpace on 2014-12-17T14:55:57Z (GMT). No. of bitstreams: 1 ClovisBMO.pdf: 4499915 bytes, checksum: b3ed589a5cb7e5f7a1b113d606f615e2 (MD5) Previous issue date: 2006-02-20 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / 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 / Este trabalho apresenta uma descri??o do desenvolvimento de modelos no programa DigSILENT PowerFactoryTM voltados ao estudo de estabilidade transit?ria em sistemas de pot?ncia com aerogerador. O objetivo ? disponibilizar meios para se utilizar um programa de simula??o din?mica em sistemas de pot?ncia, amplamente divulgado, e utiliz?-lo como uma ferramenta que auxilie na avalia??o dos resultados de programas usados para este fim. Ap?s a fase de descri??o da montagem dos modelos inicia-se o processo de simula??o e an?lise dos resultados. ? durante esta fase que s?o comparados os resultados do DigSILENT PowerFactoryTM com os resultados obtidos com o ATP, programa escolhido para avalia??o, tamb?m com reconhecimento internacional. S?o apresentadas as principais ferramentas e diretrizes do uso do programa PowerFactoryTM, direcionando tais elementos ? solu??o do problema formulado. Para simula??o, utiliza-se uma rede real, na qual ser? introduzido um parque e?lico. Dois tipos de tecnologias de gera??o e?lica foram implementadas: aerogerador de indu??o duplamente excitado com conversor de freq??ncia, conectando o rotor ao estator e ? rede, e aerogerador s?ncrono com conversor de freq??ncia, interligando o gerador ? rede. Al?m de apresentar os conceitos b?sicos de simula??o din?mica, descrevem-se as estrat?gias de controle implementadas e os modelos de turbinas e conversores. A estabilidade do aerogerador interligado ? rede ? avaliada em diversas condi??es operacionais, resultante de variados tipos de perturba??es

Reef habitats built by the tubiculous polychaete Sabellaria spinulosa have been identified as a habitat with significant conservation importance, based on their historic decline across Europe and the assumption that, like many other biogenic reef systems, S. spinulosa reefs enhance biodiversity. Despite the high conservation status of this habitat very little work has been undertaken to explore the role that S. spinulosa reefs play in marine ecosystems, or their sensitivity to anthropogenic disturbance. Observations of the reproductive ecology and population dynamics of the reef building organism indicate that S. spinulosa exhibit life-history traits typically associated with r-strategists, indicating that this species is likely to have the ability to recover quickly following most anthropogenic disturbance events. A series of surveys on S. spinulosa reefs identified at the Thanet Offshore Wind Farm site, where the extent of the reef habitat was found to have increased between the pre-construction and post construction survey despite extensive cable laying and turbine installation, corroborates these findings. Detailed investigations into the macrofauna associated with S. spinulosa reefs in the eastern English Channel revealed that S. spinulosa reefs support macrofaunal communities that are comparable to those associated with adjacent muddy sandy gravel and gravelly muddy sand in terms of species composition, taxonomic breadth and beta-diversity. A consistent enhancement in species richness, abundance and biomass was identified in samples collected from S. spinulosa reefs when compared with adjacent sedimentary deposits, as well as a corresponding reduction in the equitability of species, indicating that some macrofauna are able to exist in higher densities within this habitat. The increase in macrofaunal biomass associated with S. spinulosa reefs was found to influence the diet of demersal fish species, with some species feeding on the reef organism itself while others feed on species found in high densities on the reefs. The high abundance of juvenile flatfish associated with this habitat also suggests that S. spinulosa reefs may provide an important nursery habitat.

Power quality has become one of major concerns in the power industry. It can be described as the reliability of the electric power to maintain continuity operation of end-use equipment. Power quality problems are defined as deviation of voltage or current waveforms from the ideal value. The expansion plan of wind power generation has raised concern regarding how it influences the voltage and current signals. The variability nature of wind energy and the requirements of wind power generation increase the potential problems such as frequency and harmonic distortions. In order to analyze and mitigate problems in wind power generation, it is important to monitor power quality in wind farm. Therefore, the more accurate and reliable parameter estimation methods suitable for wind power generation are needed. Three parameter estimation methods are proposed in this thesis to estimate the unknown parameters, i.e. amplitude and phase angle of fundamental and harmonic components, DC component and system frequency, during the dynamic change in wind farm. In the first method, a self-tuning procedure is introduced to least square method to increase the immunity of the algorithm to noise. In the second method, nonrecursive Newton Type Algorithm is utilised to estimate the unknown parameters by obtaining the left pseudoinverse of Jacobian matrix. In the last technique, unscented transformation is used to replace the linearization procedure to obtain mean and covariance which will be used in Kalman filter method. All of the proposed methods have been tested rigorously using computer simulated data and have shown their capability to track the unknown parameters under extreme distortions. The performances of proposed methods have also been compared using real recorded data from several wind farms in Europe and have demonstrated high correlation. This comparison has verified that UKF requires the shortest processing time and STLS requires the longest.

Nordex, a wind-turbine manufacturer and developer, has just launched the development activity over Belgium’s French-speaking Region – the Walloon Region – with the current political context favorable to wind energy deployment. Since the Walloon market is unknown, the master thesis aims to identify the appropriate approach to use for optimal wind farm development and the critical issues that may impinge on it. The scope of the master thesis is thus to find two to three sites well suited for wind farm implementation in the province of Luxembourg and to develop these sites.  An exhaustive study of the wind farm potential of the province of Luxembourg has been led, based on geographic data analysis with the GIS ArcGIS®, feasibility studies conducting, meetings with districts’ administration as well as visits onsite. In addition, a thorough comparative analysis of the Belgian specification for grid connection has been performed to identify any requirement that is not included in the French and German grid codes, which are the benchmarks of the development activity in Nordex France. Many obstacles have been encountered in wind farm development, chiefly a strong existing competition in the wind energy sector and a limited grid capacity. In addition time can be a friend but it can also sometimes be a foe at some stages that rely on public administration. Consequently from the 40 identified sites with ArcGIS®, only three have succeeded. Regarding the Belgian requirements for grid connection, all can be met thanks to an existing German specification data sheet. Eventually the Walloon policy towards wind energy development is expected to evolve so as to foster wind farm deployment in Wallonia and to reach the objectives set for 2020 (2200 MW of installed wind capacity while in January 2011 only 440 MW were in operation). Consequently to that, Nordex’ approach may have to adapt to the new regulations.

Distribution system operators face the challenge to connect users rapidly to the grid and the opportunity to reduce costs for new connections. A method to enhance network operation and planning is dynamic transformer rating (DTR), which considers load and temperature variations to increase the rating of the transformer while maintaining in safe operation. This project investigates DTR application to an existing population of transformers connected to a wind park and proposes a method for adding new turbines to the grid using installed transformers. Five transformer locations and nine units belonging to E.ON AB are used to find the potential of DTR for network expansion. A weather analysis reveals that simultaneous high wind speeds and high temperatures seldom occur. An aging estimation based on the IEC 60076-7 standard shows that the transformers for wind power applications are underused. Considering the transformer thermal model, a sensitivity analysis shows that the parameters that mostly affect the aging rate are the moisture content, the hot spot factor, and the top-oil temperature rise. The maximum load to assure aging below 50 years is calculated for each transformer for different maximum hot-spot temperature levels showing that increasing the maximum allowed temperature reduces curtailment and increases aging. A single node analysis depicts the optimal expansion of wind power from a generator perspective, and a network analysis introduces further restrictions to the network. As a result, the optimal increase factor is around 30 to 50 % and is larger for higher hot-spot temperature limits. Accurate weather measurements and transformer parameters are necessary to make a proper estimation of transformer aging to unlock transformer potential. To use fiber optic temperature sensors in new transformers and on-site temperature measurements can increase the rating of the transformer. A maximum allowed temperature of 110◦C is conservative and limits the potential of the transformer for wind power applications. Finally, society benefits from DTR in wind power applications because there is a more efficient use of resources and additional renewable energy can be introduced to the network. / Eldistributionsnätet står inför en utmaning att snabbt ansluta användare till nätet och en möjlighet att miska kostnaderna i nya ansultnigar. En metod för att förbättra nätverksdrift och planering är dynamisk lastbarhet hos transformatorer, eller dynamic transformer rating (DTR). Metoden beaktar belastings- och temperaturvariationer för att öka transformatorns lastbarhet samtidigt som den upprätthåller säker drift. Detta projekt undersöker tillämpningen av dynamisk lastbarhet till en befintling population av transformatorer kopplade till en vindkraftpark och föreslår en metod för att ansluta ytterligare turbiner till nätet med hjälp av befintliga transformatorer. Fem transformatorplatser och nio enheter som tillhör E.ON AB används för att undersöka potentialen för DTR inom tillämpningar för nätverksexpansion. En vänderanalysis avslöhar att både höga vindhastigheter och temperaturer sällan uppstår samtidigt. En uppskattning av åldrandet baserad på IEC 60076-7-standarden visar att transformatorer för vindkraftstillämpningar är underanvända. Med avseende på den termisk transformatormodellen visar en känslighetsanalys att parametrarna som påverkar minskning av livslängden mest är fuktinnehållet, hot spot-faktorn och ökning av top-olja-temperaturen. Den maximala belastningen för att säkerställa en åldring under 50 år beräknas för varje transformator, för olika värden på den maximala hotspottemperaturen. Detta visar att med ökning av den maximala tillåtna temperaturen minskar produktionsbortfall och ökar åldrandet. En-nods-analys visar den optimala expansionen av vindkraft från en producents perspektiv, och en nätverksanalys introducerar ytterligare begränsningar för nätverket. Detta resulterar i en optimal ökningsfaktor på cirka 30-50% och är större för högre värden på den maximala hotspottemperaturen. Noggranna vädermätningar och transformatorparametrar är nödvändiga för att göra en korrekt uppskattning av transformatorns åldrande. Att använda fiberoptiska temperatursensorer i nya transformatorer och platsspecifika temperaturmätningar kan öka transformatorns lastbarhet. En maximal tillåten temperatur på 110 ◦C är för konservativ och begränsar transformatorns potential för vindkraftstillämpningar. Samhället drar fördel av DTR i vindkraftstillämpningar eftersom det leder till en effektivare resursanvändning och att ytterligare förnybar energi kan introduceras i nätverket.

For the grid to be stable, the supply of power must equal the demands of the consumer at every moment during the day. The unpredictable intermittent nature of wind results in inconsistent power generation. Energy storage technologies coupled with a wind farm can not only provide power during fluctuations but also maintain a stable and reliable grid. The objective of the thesis is to perform a comprehensive analysis of different types of energy storage technologies that can be coupled with a wind farm. The analysis is performed on the basis of multiple characteristics which affect their viability. We identified key characteristics for a range of storage technologies, including lead-acid, sodium-sulphur, nickel cadmium, lithium-ion, superconducting magnetic energy storage, electrochemical capacitors, flywheels, flow batteries, pumped hydro and compressed air energy storage systems. We performed a comparison study to analyze trade-offs and assessed potential improvement areas that will make them more competitive in the electric power industry. We suggested viable energy storage systems that could be better and suitable for different applications for an electric grid integrated with a wind farm.

Det föreligger idag bristfällig kunskap om energislagens ekonomier och utan tillräcklig kännedom om lönsamheten förknippad med sol- och vindkraft kan det vara svårbedömt för investerare att beräkna en potentiell avkastning. Det kan resultera i en ovillighet att satsa kapital i förnybar energi och därmed hämma utvecklingen av energiomställningen. Syftet med studien har därför varit att jämföra sol- och vindkraftsparker för att avgöra vilket investeringsalternativ som är mest ekonomiskt lönsamt. Genom att analysera de förfarande som etablerare har att förhålla sig till, syftar studien även till att belysa och kartlägga processen för etableringen av en storskalig energipark. Arbetet grundar sig på en flermetods-undersökning bestående av en kvantitativ och en kvalitativ metod. Den kvantitativa studien består av data som erhållits från Energimyndigheten tillsammans med inhämtad statistik från tidigare rapporter. Den kvalitativa studien består av semistrukturerade intervjuer med branschföretag och organisationer. Fokus i studien har legat på att framställa två scenarion för att producera LCOE-värden samt nettonuvärden för sol- och vindkraftsparker där parametrar som CAPEX, OPEX, etableringstid, kalkylränta, pris på el, degraderingsgrad och produktionsförmåga utgjort en väsentlig roll i beräkningsunderlaget. Resultaten som framställts i det första scenariot tyder på att solparkens nettonuvärde och LCOE-värde är bättre i jämförelse med vindkraftsparken när kalkylräntan återspeglar den risk som associeras med energislagen. Däremot påvisar resultaten i det andra scenariot att vindkraft är det energislag som är mer ekonomiskt lönsamt när kalkylräntan för bägge energislagen fastställs till samma räntesats. Baserat på resultaten har kalkylräntan en väsentlig påverkan på nuvärdet och LCOE-värdet. Vikten av att välja en korrekt kalkylränta är därför avgörande för att kunna jämföra energislagen mot varandra. Även etableringstiden har visat sig ha en avgörande påverkan på nuvärdesberäkningarna. Avslutningsvis kan studien fastställa att vindkraft är det energislag som är mer fördelaktigt utifrån dess prestationsförmåga och lönsamhet när båda energislagen betraktas med en likartad risk. Däremot, när en investerare står inför ett investeringsbeslut, bör hänsyn tas till riskerna förknippade med investeringen varför solparken således bör anses vara det investeringsalternativ som är mest ekonomiskt lönsamt. / There is currently inadequate knowledge regarding the economics of the energy sources and without sufficient understanding of the profitability associated with solar and wind power, it can be difficult for investors to calculate a potential return. This can result in a reluctance to invest capital in renewable energy and thereby inhibit the development of the energy transition. Therefore, the aim of this study has been to compare solar and wind farms to determine which investment alternative is the most economically profitable. By analyzing the procedures that establishers have to adhere to, the study also aims to illuminate and map out the process of establishing a large-scale energy park. The study is based on a mixed-method survey consisting of a quantitative and a qualitative method. The quantitative study consists of data obtained from the Energy Agency along with gathered statistics from previous reports. The qualitative study consists of semi-structured interviews with industry companies and organizations. The focus of the study has been to present two scenarios to produce LCOE values and net present values for solar and wind farms where parameters such as CAPEX, OPEX, establishment time, discount rate, price of electricity, degradation rate and production capacity have played a significant role in the calculation basis. The results produced in the first scenario indicate that the net present value and LCOE value of the solar park are better compared to the wind farm when the discount rate reflects the risk associated with the energy sources. However, the results in the second scenario shows that wind power is the energy source that is more economically profitable when the discount rate for both energy sources is set at the same interest rate. Based on the result, the discount rate has a significant impact on the present value and the LCOE value. The importance of selecting a correct discount rate is therefore crucial to be able to compare the energy sources against each other. Additionally, the establishment time has proven to be a determining factor that greatly influences the net present value calculations. In conclusion, the study can establish that wind power is the more advantageous energy source based on its performance and profitability when both energy sources are considered with similar risk. However, when an investor faces an investment decision, consideration should be given to the risks associated with the investment, which is why the solar park should be considered the most economically profitable investment option.

No description available.

No description available.