Wind Turbine Technology

Iran is one of the main non-renewable energy producers in the world due to its plentiful fossil fuel resources. Utilization of
natural gas and petroleum in transportation and industrial sectors has been developed vastly in Iran because of their low
prices. Consequently, the increasing rate of pollutant formation and depletion of non-renewable fuels have emerged as new
challenges in the energy scenario of this country. Since Iran has plenty of fossil fuel resources, alternative fuel and renewable
resources have not been taken into consideration seriously. This existing trend of fossil fuel utilization is not according to the sustainable development aims which have been adapted for the country. Recently, controlling the unbridled fossil fuel
consumption has become one of the main targets of the Iranian Government. A variety of natural resources in different
regions of Iran can be applied as the main sources of renewable and sustainable energy (RSE) and considered as the
supplementary energy in the energy mix policies. Biofuel, hydropower, wind, solar and geothermal are the main RSE that can be utilized for energy supply. Moreover, regarding the increasing rate of the population, bioenergy generation from waste materials can play a crucial role in sustainability of waste management strategies. In this regard, the present study has been conducted to evaluate wind and solar energy potentials from various resources in Iran.

—This paper discusses the currently used generator systems in wind energy conversion systems and some of the newer concepts with their technical features. The Brushless doubly fed induction generator, Brushless doubly fed reluctance generator and the Switched reluctance generator are viable alternatives for wind power applications. This paper also highlights the hybrid wind generator solutions which is an emerging trend in hybrid renewable energy solutions. Using the appropriate control techniques, these generator technologies unlike the conventional wind turbine generator can produce constant wind power irrespective of the changes in velocity of wind speed. This has tremendous application in Africa as the installed capacity increases and the need to provide remote communities with electricity remains paramount. The merits and demerits of the various technologies are uniquely grouped in a novel way to aid decision making based on available resources. Index Terms—Doubly fed induction generator (DFIG), induction generators, permanent magnet synchronous generator (PMSG), squirrel cage induction generator (SCIG), wind energy conversion systems (WECS)

The objective of this research is to study the performance of horizontal axis wind turbine has three-layer triple flat blades. The design of this turbine model is the development of a multi-blade flat-type wind turbine design which is currently used in the field. The turbine model has 9 flat blades that are grouped into three, each three layered. The turbine performance characteristic test is performed on both models was made. Test the turbine performance characteristics performed at various wind speeds. The test results are shown in graphical form of turbine performance characteristics. Based on the graph, turbine performance is compared descriptively. Based on wind turbine performance test, flat triple wind turbine is better than multiblade wind turbine at wind speed variation 8 m / s-11 m / sec. The highest power coefficient value is obtained at 8 m / sec with variation of inter-distance distance 3 cm blade with a blade15º angle of 13.6042. While the multiblade power coefficient value of 5.77518 Abstrak Tujuan penelitian adalah mengkaji kinerja model turbin angin poros horisontal bersudu tiga flat berlapis tiga. Desain model turbin ini merupakan pengembangan dari desain turbin angin multi blade tipe flat yang saat ini masih dipakai di lapangan. Model turbin memiliki 9 sudu flat yang dikelompokkan menjadi tiga, masing-masing berlapis tiga. Uji karakteristik kinerja turbin dilakukan terhadap kedua model yang sudah dibuat. Uji karakteristik kinerja turbin dilakukan pada berbagai kecepatan angin. Hasil uji ditampilkan dalam bentuk grafik karateristik kinerja turbin. Berdasarkan grafik tersebut kinerja turbin dibandingkan secara diskriptif. Berdasarkan uji kinerja turbin angin, turbin angin flat tiga lapis lebih baik dibandingkan turbin angin multiblade pada variasi kecepatan angin 8 m/detik-11 m/detik.. Nilai koefisien daya (Cp) tertinggi didapat pada kecepatan 8 m/detik dengan variasi jarak antar sudu 3 cm dengan sudut blade15º sebesar 13,6042. Sedangkan pada multiblade nilai koefisien daya (Cp) sebesar 5,77518 Kata kunci: Turbin angin, sudu flat, lapis tiga, karakteristik kinerja, koefisien daya PENDAHULUAN Krisis energi yang dikenal secara internasional sebagai "Peak Oil" yang disebabkan oleh kelangkaan bahan bakar minyak, telah mendorong pemerintah untuk mengambil kebijakan di bidang energi antara lain melalui Keppres Nomor 43 tahun 1991 tentang konservasi energi, Keppres Nomor 10 tahun 2005 tentang penghematan energi. Keppres ini mengisyaratkan perlunya segera mengembangkan dan menerapkan sumber energi terbarukan guna mengurangi ketergantungan terhadap bahan bakar fosil.

This paper provided a review on wind turbine technology and control. The technologies, differences, advantages and disadvantages of horizontal and vertical axis wind turbine structures were reported. The control strategies of wind turbine such as fixed speed and variable speed were also discussed along with the wind turbine distribution profile for both vertical and horizontal axis configuration. The aim is to cover the appropriate wind turbine structures and control strategies to be used in the certain area condition. Regardless similar wind speed distribution profile except the power coefficient, horizontal axis wind turbine (HAWT) and vertical axis wind turbine (VAWT) have different structures and control strategies. As a conclusion, HAWT structure is less suitable for urban area as compared to VAWT nevertheless is more appropriate for large-scale wind farm. For the control approach, variable speed wind turbine (VSWT) is more appropriate for high wind speed area due to its abilit...

This interactive qualifying project focused on the ever advancing hybrid vehicle technology and
its integration with wind energy. The main objective of this project is to design and fabricated a self-starting
small vertical axis wind Turbine (VAWT) .This VAWT s can be mounted over the roof of the car or in front of
the cooler. Usually, a car moves through a layer of fluid and this fluid layer always is a disadvantage for
the moving car because it poses a drag force due to moving forward . In this research project, we are going
to use this force for developing electrical energy. This VAWT is build to achieve RPM at minimum wind
speed. The Twisted blade is the main function which plays the role to rotate it at minimum wind speed. Our
optimized view for this project is to set this VAWT in a car and run it by wind. From experiment 11.77watt
power can be generated when the turbine is run at 112rpm for the wind speed is 6m/s.

A series of wind tunnel tests were performed to investigate the effect of turbulent inflows on the aerodynamic characteristics of variously modified leading-edge protuberanced (LEP) wing configurations at various turbulence intensities. A self-developed passive grid made of parallel arrays of round bars was placed at different locations of the wind tunnel to generate desired turbulence intensity. The aerodynamic forces acting over the baseline straight leading-edge model and the modified small, medium and high LEP wing configurations were obtained from the surface pressure measurements made over the wing at different turbulence intensities using MPS4264 Scanivalve simultaneous pressure scanner corresponding to a sampling frequency of 700Hz. All the test models were tested for a wide range of angles of attack ranging between À45 α 45 at turbulence intensities varying between 0.51% TI 4.92%. Results reveal that the time-averaged mean coefficient of lift (C L) increases with the increase in the turbulence intensity associated with smooth stall characteristics rendering the modified LEP test models advantageous. Furthermore, based on the surface pressure coefficients the underlying dynamics behind the stall delay tendency were discussed. Additionally, attempts were made to statistically quantify the aerodynamic forces using standard deviation at both the pre-stall and the post-stall angles.

Oklahoma is the second windiest state after Texas, in the United States. Given that the Wind Turbine business is a new business activity here in the United States, and indeed the world, the way Wind Energy is regulated in Oklahoma, and the United States has had no answers to many legal questions that may arise, relying heavily on the literature in Oil & Gas Law. in Criticizing the newly amended "Oklahoma Wind Energy Development Act", this work tries to point out some of those loopholes the act does not cover, as well as potential causes of action that may arise, as well as suggest and explains defenses and remedies that plaintiffs' and defendants my have available.

Este trabajo presenta una revisión monográfica de algunos aspectos técnicos que influyen en la integración de energía eólica en la red eléctrica y la calidad de la energía.
Se realiza una revisión del estado actual de la tecnología eólica, de las topologías de aerogeneradores convencionales, del marco legal y normativo que regula la calidad del suministro eléctrico y  finalmente se expone el impacto de la generación eólica sobre la
calidad de la energía en sistemas eléctricos de potencia.
Con el constante desarrollo y la actual madurez tecnológica de la energía eólica se ha logrado un incremento de la integración en red de generación eólica, lo cual hace que la potencia generada en los parques eólicos tenga un nivel de participación mayor en el mix energético. Adicionalmente, en los últimos años, se ha incrementado la cantidad de elementos no lineales en la red eléctrica (entre los cuales están los convertidores electrónicos) y por todo ello la calidad de la energía es un tema cada vez más importante. La continuidad del servicio, la estabilidad de la red y el  mantenimiento de los parámetros básicos de la tensión y frecuencia requieren unos niveles de calidad de la energía muy exigentes para asegurar el funcionamiento del sistema eléctrico de potencia. Los aerogeneradores, como todas las demás fuentes de generación de energía eléctrica, deben contribuir a mantener la red estable bajo cualquier condición de operación.

This Special Issue collects innovative contributions in the field of wind turbine optimization technology. The general motivation of the present Special Issue is given by the fact that there has recently been a considerable boost of the quest for wind turbine efficiency optimization in the academia and in the wind energy practitioners communities. The optimization can be focused on technology and operation of single turbine or a group of machines within a wind farm. This perspective is evidently multi-faced and the seven papers composing this Special Issue provide a representative picture of the most groundbreaking state of the art about the subject. Wind turbine power optimization means scientific research about the design of innovative aerodynamic solutions for wind turbine blades and of wind turbine single or collective control, especially for increasing rotor size and exploitation in offshore environment. It should be noticed that some recently developed aerodynamic and control solutions have become available in the industry practice and therefore an interesting line of development is the assessment of the actual impact of optimization technology for wind turbines operating in field: this calls for non-trivial data analysis and statistical methods. The optimization approach must be 360 degrees; for this reason also offshore resource should be addressed with the most up to date technologies such as floating wind turbines, in particular as regards support structures and platforms to be employed in ocean environment. Finally, wind turbine power optimization means as well improving wind farm efficiency through innovative uses of pre-existent control techniques: this is employed, for example, for active control of wake interactions in order to maximize the energy yield and minimize the fatigue loads. Wind turbines are widely recognized as one of the most efficient technologies for electrical energy production from a renewable source and the expectation is that the efficiency is going to further grow, primarily because of the increasing rotor size and secondarily because of the technology optimization. Wind turbine technology optimization has therefore become in the latest years a core topic in wind energy research. The purpose of this Special Issue is collecting innovative contributions to the multi-faced issue of wind turbine power optimization technology. The power output of a wind turbine has a complex dependence on ambient conditions and operation parameters; nevertheless it can fairly be stated that the most important aspect for power extraction optimization is the aerodynamic efficiency. For this reason, a remarkable line of research deals with optimization of wind turbine blades technology. For wind farms already operating, a typical intervention is blades retrofitting through the installation of active (like Air Jet Vortex Generators) or passive (Vortex Generators, Gurney Flaps and so on) flow control devices. For new installations, in the context of wind turbine design, it is important to optimize the blade design and the flow control

Glass fibre waste (GFW) coming from wind turbine blade production was used for the first time as a reinforcement agent in inorganic polymer (geopolymer) production. The influence of glass fibre content and length on the inorganic polymer microstructure, apparent density, and compressive and tensile strength was evaluated. Results demonstrate that the use of short, randomly distributed fibres significantly enhance the geopolymers' compressive strength (by up to ~162%) and tensile strength (by up to ~77%), while overcoming the brittle nature of the geopolymers. It was also found that the glass fibre content, rather than the fibre length, is the dominant factor affecting the geopolymers' mechanical properties. These results demonstrate the possibility of using an unexplored waste stream (glass fibre waste) as a reinforcement agent in inorganic polymers, which may reduce the amount of wastes in landfill and lower inorganic polymer production costs, while simultaneously contributing towards the circular economy.

This paper provided a review on wind turbine technology and control. The technologies, differences, advantages and disadvantages of horizontal and vertical axis wind turbine structures were reported. The control strategies of wind turbine such as fixed speed and variable speed were also discussed along with the wind turbine distribution profile for both vertical and horizontal axis configuration. The aim is to cover the appropriate wind turbine structures and control strategies to be used in the certain area condition. Regardless similar wind speed distribution profile except the power coefficient, horizontal axis wind turbine (HAWT) and vertical axis wind turbine (VAWT) have different structures and control strategies. As a conclusion, HAWT structure is less suitable for urban area as compared to VAWT nevertheless is more appropriate for large-scale wind farm. For the control approach, variable speed wind turbine (VSWT) is more appropriate for high wind speed area due to its ability to achieve maximum efficiency as compared to a fixed speed wind turbine (VSWT).

Increase of energy consumption in the world and importance of CO2 reduction
stimulate development of alternative sources of energy. Kazakhstan territory has high
potential for wind energy industry development. As a result, Republic of Kazakhstan
increases energy production from wind, solar and other renewable resources.
This purpose of the Project is Feasibility Report for construction of 50 MW wind farm
station near Ereymentau, Akomla region. Initially, current wind industry situation is
investigated in Chapter 1. After that, Ereymentau’ wind potential assessment is done in order
to calculate possible energy production. Then, turbine type is chosen and technical details of
wind park is analyzed. Afterward, detailed economy analysis of the project is given in
Chapter 6. Safety and Risk assessment are covered in Chapters 7 and 8. Next, environmental
impact is discussed in Chapter 9. Project Management is given in the last Chapter.
Summary of Final Feasibility of the wind park Project near Ereymentau and
recommendations are given in Chapter 11.

The European Strategic Energy Technology Plan, adopted by the European Union in 2008, is a first step to establish an energy technology policy for Europe and to support the 2020 energy and climate change
targets from the technology development point of view. One of its initiatives is to assess the characteristics of the materials that will be needed in order to achieve the 2020 targets, in terms both of amounts of materials and their technical specifications, along with the way to get there for the latter. The Materials Initiative was created to foster a roadmap which is based on a scientific assessment of the current situation. This paper presents the work of the author in the (wind turbine) electricity generator part of that assessment, it includes the aspects of technology and system state-of-the-art; material supply status; on-going research and players; materials specification targets for 2020/2030 and beyond.
The assessment found that the performance of permanent magnets is the single item potentially to provide the most significant improvement in component specification, but that in order to achieve this perhaps new chemical components -based on rare earths, as currently, or not-will be necessary in order to achieve these high-performance magnets. The search for these new materials is stimulated by the current dependency of the world in a nearly-monopolistic supplier of rare earth elements. The assessment also concluded that the improvement of materials specifications is challenging but achievable in most areas, and a crucial aspect for the necessary cost reductions in wind energy production.

This qualitative research deals with moderation of vertical-axis wind turbine (VAWT) of Darrieus type. We performed a research in which three twisted bladed vertical axis wind turbines (VAWT) were designed and tested for optimal performance at various wind speeds. A blade with twist will have a variation in angle of attack from hub to tip because of the variation of distance from the hub. The lift and drag have optimum values for a single angle of attack so a blade without twist is less efficient than a blade with the proper twist to maintain a nearly constant angle of attack from hub to tip. Even the blades were twisted and the pitch angle will change from hub to tip to improve the efficiency. Wind energy has to compete with many other energy sources in future. To compete with others it had to cope with the least affirmative conditions to maximum positive conditions. Usual challenge for the turbines is performing at low wind speed. So far we have achieved 22rpm at 1.8m/s wind speed when the blades are wider and twisted by 120 degree. While twisted by 70 degree we got no rpm at 1.8m/s wind speed. It implies that the former condition produces better performance.

In the recent year, the significance of wind generation is found to be multifold due to huge demand and supply gap in electrical energy system. In this respect the current project work would like to address certain design issues and proposes to design, fabricate and test a prototype of magnetically levitated vertical axis wind turbine providing stated advantages, the prototype will be fabricated and tested for the outcome. This paper presents the design an experimental investigation on magnetically levitated vertical axis wind mill system helps to ability to operate in both low and high 1.5m/s to 40m/s wind speed conditions. Magnetically levitated to reduce the internal friction of the rotor which is considered as a revolution in the magnetic field of technology. This provides a more efficient, versatile and elegant method of producing power from with nearly zero pollution. Power is generated with magnetic flux, which incorporates the utilization of neodymium magnet and its set of coils.

This paper examines the failure of shear pins that connect gearbox and generator in a wind turbine generator. Chemical and micro-structural together with hardness measurements have been performed to check any deviation in the material specification. The failure mechanism is analyzed by both visual and Scanning Electron Microscope (SEM) inspection on the fractured surface. Finite Element Analysis (FEA) of shear pin is carried out to determine the root cause for its failure. The neck diameter of shear pin is optimized for the safe operation of the wind turbine. It is inferred from the observations based on fractography study on the fractured surface of the shear pins that the misalignment between the driving and the driven elements in the wind turbine leads to low cyclic fatigue growth.

Wind energy has the potential to be a strong contributor to a more sustainable future.
Globally it is a major player in the market and is expected to become more in
uential in
the future. In South Africa the potential exists and major development is under way. A
modern wind turbine has a horizontal axis orientation, three rotor blades, active pitch
and face into the wind using yaw control. It has a steel monopole tower between 60m and
80m high with a reinforced concrete foundation. However, this design presents various
problems for structural integrity, manufacturing and viability at heights above 80m.
These constraints has led to a movement towards steel-concrete hybrid and full concrete
towers. Such designs present an alternative and possibly more optimal solution for tower
heights over 100 m.
This hypothesis was tested for South African conditions. Steel and prestressed concrete
tower designs were acquired for a 3MW reference wind turbine with 100m hub height.
Towers were loaded according to local conditions and the structural soundness thereof
was tested and proved. Structural parameters were optimized and material mass and
volume were determined for each. A cost estimation and sensitivity analysis was performed
for the following life-cycle phases: manufacture, construction and installation;
transport; and disposal and recycling.
Margins of cost between the tower designs were low enough for all three to be considered
competitive alternatives at 100m in height. The cast-in-place prestressed concrete
design was estimated to be the most aordable solution. However, its high sensitivity to
variation in erection cost causes uncertainty and a higher nancial risk. Furthermore,
the steel tower was the most viable for low steel prices and high erection costs. For a
larger foundation size it still remained a competitive alternative to the concrete towers.
Overall the prestressed precast design was the most expensive. However, for high erection
costs it was more aordable than the cast-in-place tower. For disposal and recycling
the steel solution was a much more favourable nancial alternative to the concrete design.
However, salvage income does not contribute a signicant gain compared to overall
cost.

Research shows energy crisis has almost reached a critical stage. However, some people still do not pay enough attention and it can lead to adverse consequences such as rise of prices for energy supply and the public starting to criticize local government. The causes of energy crisis can be various, however the most probable ones are growing population and extensive industrialization.

The existence of environmental concerns and constraints has led to a much greater necessity for the development of renewable energy resources. Wind energy resources are one of the most promising avenues for renewable energy generation, and the field has experienced significant technological innovation and growth over the past few years. This paper reviews various issues related to wind-power generation resources. Current trends, over the last two decades, of increasing wind turbine sizes, rated power-generation capacity, efficiencies, and the actual size of wind farm facilities are projected to continue. It is theorized that the current global installed capacity of wind power generation may increase from the current generation of 540 (2017) to 5800 GW by 2050. Wind energy potential, in terms of vertical wind speed profile, mean wind-speed distribution, turbulence effects and gust, are discussed in detail in this paper. A decreasing trend in the cost of initial capital investment and the levelized cost of energy (LCOE), for both onshore and offshore wind-power generation developments, are projected to continue, although this is regionally and economy-size dependent. Key challenges have been identified for the development of wind power generation in developed and underdeveloped countries going forward. New approaches/developments in the field and avenues for further research or actions that can be undertaken are also outlined in this paper. Materialization of such lines of actions may lead to an increase in global wind energy from its current level of around 4% of the electricity generation mix to roughly 40%.

Optimal alignment of wind turbines to the wind direction is a crucial condition for the quality of power output and for the health of the turbines. Actually, bad alignment can cause degraded performances and dangerous loads that can affect, on the long run, the mechanical safety of the wind turbine. Supervisory Control And Data Acquisition (SCADA) systems are becoming widespread in modern wind energy technology because of the appreciable costs – benefits ratio. The common time scale of SCADA, yet, usually is not effective for misalignment diagnosis because the wind varies too rapidly. For this reason, misalignment is often diagnosed using ad hoc techniques as LIDAR-based or spinner anemometers. In the present work, it is shown that very useful indications for the diagnosis of misalignment can be obtained also from the SCADA data, without invoking expensive supplementary control techniques. The method is validated on the data set of a wind farm sited in Italy.

SUMMARY In this study, the effect of air holes over the tip vortices of S809 wind turbine blade were experimentally investigated at low Reynolds number ranging from 50000 to 85000 and different angles of attack. The force measurement, smoke-wire and tuft experiments were conducted at reference and new design turbine blade. The experiments indicated that the effects of tip vortices and the vortices diameter increased at reference blade as Reynolds number and angle of attack were increased, thus the lift coefficient decreased. In the experiments of the blade with air holes, it was showed that the tip vortices were swept towards the wake region of the blade, and the effect of tip vortices was minimized by the air holes. Moreover, according to reference blade, the lift coefficient increased and the drag coefficient decreased for new concept blade.

This report summarizes extensive research by the staff of the Solar Energy Research Institute into characteristics of acoustic noise emissions of the DOE/NASA MOD-2 wind turbine. The results of this study have shown that the MOD-2 noise levels are well below annoyance thresholds within residential structures a kilometer or more from the turbine rotor. It was also found that the inflow turbulent structure has a major influence on the level and characteristics of the low-frequency (2-160 Hz) range acoustic emissions which, in turn, have implications for the associated structural response of the rotor assembly. The high-frequency range (A-weighted) levels were found to vary primarily with the mean hub-height wind speed. In addition, the rotor inflow
turbulence characteristics at the Goodnoe Hills Site were found to be controlled almost entirely by the diurnal variation in the vertical stability of the first 100 m of the atmospheric boundary layer.

(This article is Open Access. Please check the links below.
http://iopscience.iop.org/1748-9326/6/4/044017/ ,  http://dx.doi.org/10.1088/1748-9326/6/4/044017 )
The cost of energy produced by offshore wind turbines is considered to be higher than land based ones because of the difficulties in construction, operation and maintenance on offshore sites. To solve the problem, we propose a concept of a wind turbine that is specially designed for an offshore environment. In the proposed concept, a floater of revolutionary shape supports the load of the wind turbine axis. The floater rotates with the turbine and the turbine axis tilts to balance the turbine thrust, buoyancy and gravity. The tilt angle is passively adjustable to wind force. The angle is 30° at rated power. The simplicity of the system leads to further cost reduction of offshore power generation.

Improving production of electric power from renewable sources is fundamental in order to decrease the use of fossil fuels. A crucial aspect for future development of renewable sources is to guarantee competitive prices to end users and profitably economic returns to those who invest in these technologies. This can be reached by constantly surveying plants performances, optimizing the operative conditions and evaluating the possibility to implement upgrades. For what concerns wind turbines, there are many possibilities to increase power production. This study is focused on analyzing the HWRT (High Wind Ride Throughout) cutout strategy: it is a method that allows extending the power curve of a wind turbine above the cutout wind speed (25 m/s, typically) at which the wind turbine is abruptly shut down for structural integrity issues. The HWRT instead is a particular generator and pitch control strategy that maintains the turbine productive for higher wind speeds (up to at least 30 m/s) through a soft cutout strategy. Starting with a reverse engineering approach, this study aims at creating a mathematical model of a real wind turbine operating with the HWRT control, and then evaluating the effects of this control strategy on stresses and structural vibrations. The point of view of this study fills a lack in the way this kind of issues is commonly approached in the wind energy practitioners community: actually, wind turbine power capture optimization strategies are typically assessed mainly by the point of view of the energy balance and insufficient attention is devoted to the mechanical aspects and the possible consequences on the wind turbine remaining useful lifetime. The research is structured in the following steps. At first, the wind turbine model is constructed and the characteristic dimensions, blade shapes and natural frequencies are found. Subsequently, with this information, aeroelastic simulations through the FAST (Fatigue, Aerodynamics, Structures and Turbulence) software are implemented and validated against operation data. Finally, conclusions are drawn about the impact of the soft cutout strategy on structural health and fatigue. Abstract Improving production of electric power from renewable sources is fundamental in order to decrease the use of fossil fuels. A crucial aspect for future development of renewable sources is to guarantee competitive prices to end users and profitably economic returns to those who invest in these technologies. This can be reached by constantly surveying plants performances, optimizing the operative conditions and evaluating the possibility to implement upgrades. For what concerns wind turbines, there are many possibilities to increase power production. This study is focused on analyzing the HWRT (High Wind Ride Throughout) cutout strategy: it is a method that allows extending the power curve of a wind turbine above the cutout wind speed (25 m/s, typically) at which the wind turbine is abruptly shut down for structural integrity issues. The HWRT instead is a particular generator and pitch control strategy that maintains the turbine productive for higher wind speeds (up to at least 30 m/s) through a soft cutout strategy. Starting with a reverse engineering approach, this study aims at creating a mathematical model of a real wind turbine operating with the HWRT control, and then evaluating the effects of this control strategy on stresses and structural vibrations. The point of view of this study fills a lack in the way this kind of issues is commonly approached in the wind energy practitioners community: actually, wind turbine power capture optimization strategies are typically assessed mainly by the point of view of the energy balance and insufficient attention is devoted to the mechanical aspects and the possible consequences on the wind turbine remaining useful lifetime. The research is structured in the following steps. At first, the wind turbine model is constructed and the characteristic dimensions, blade shapes and natural frequencies are found. Subsequently, with this information, aeroelastic simulations through the FAST (Fatigue, Aerodynamics, Structures and Turbulence) software are implemented and validated against operation data. Finally, conclusions are drawn about the impact of the soft cutout strategy on structural health and fatigue.

This essay examines the innovative patterns within the role photovoltaic cells and wind turbines play in distributed generation electricity in the UK. It presents evidence that while there is some compliance with the patterns identified in Pavitt's taxonomy, there are also weaknesses within the taxonomy in explaining the complex patterns of innovation identified. The essay argues that the combination of factors influencing innovation within the specific of distributed generation from these two technologies, in practice lies outside the sector patterns within the taxonomy.

This paper presents the results of an experimental study that focuses on the tip leakage/vortex control of a model horizontal axis wind turbine rotor. The effects of Mie vanes and tip injection on the performance and wake characteristics of a model horizontal axis wind turbine rotor are investigated through experiments that are conducted by placing a specially designed three-bladed horizontal axis wind turbine rotor at the exit of an open-jet wind tunnel facility. The rotor blades are non-linearly twisted and tapered with NREL S826 airfoil profile all along the span. The measurements include power and thrust coefficient variations with Tip Speed Ratio (TSR) as well as wake flow field measurements at different axial locations downstream of the turbine rotor. Results show that both techniques significantly influence the power and thrust coefficient variations especially near the TSR ranges where C P is maximum. Mie-vanes reduce the strength of the tip vortex and hence reduce the associated turbulence intensity levels within the tip vortex dominated region inside the wake. Tip injection on the other hand introduce higher turbulence levels because of the strong turbulent jet injected from the blade tips. It's expected that this higher turbulence levels could contribute to the faster diffusion of the tip vortices within the wake downstream of the turbine rotor. Nomenclature C p = power coefficient C T = thrust coefficient TSR = tip speed ratio R M = Injection momentum ratio U ∞ = freestream velocity D = rotor diameter R = rotor radius x/R = axial direction y/R = radial direction z/R = vertical direction

Este trabajo presenta una revisión monográfica de algunos aspectos técnicos y económicos que influyen en el desarrollo de la tecnología de aerogeneradores de gran potencia y media tensión. Se realiza una revisión del estado actual de la tecnología eólica, de las topologías de aerogeneradores convencionales, así como una revisión comparativa de las ventajas y desventajas de incrementar las magnitudes de intensidad de corriente o de tensión al incrementar la potencia del aerogenerador.
Es indudable el destacado papel que actualmente tiene la energía eólica como fuente de energía renovable para la producción de energía eléctrica en muchos países del mundo y, a pesar de ser una tecnología que ha logrado un importante grado de madurez, aún se exploran nuevas fronteras que impulsan la búsqueda de un aprovechamiento óptimo del recurso eólico y de máquinas cada vez de mayor potencia, para lograr una mayor penetración en los sistemas eléctricos y obtener más energía de los nuevos parques eólicos.
El desarrollo de aerogeneradores de potencias cada vez mayores, del orden de 5 MW y superiores, ha impulsado la necesidad de contar con tecnología de generación en media tensión, de manera de reducir las magnitudes de las corrientes y las pérdidas por efecto Joule asociadas. Sin embargo, la aplicación de generadores eléctricos en media tensión no se ha generalizado, por el contrario, son pocos los fabricantes que ofrecen este tipo de aerogenerador y el mercado se ha mantenido cauto ante este nuevo esquema. Ciertamente no existen estudios definitivos que inclinen la balanza hacia la baja tensión o la media tensión, por lo que al momento de escoger uno u otro  esquema se debe considerar en el contexto del diseño conjunto del parque eólico y dependerá de aspectos tales como el coste, la disponibilidad de componentes, necesidad de utilizar convertidores adecuados al nivel de tensión, requisitos de seguridad, requisitos de operación y mantenimiento.

Due to high cost of wind turbines and the
need of research and development in lab scale
systems, this paper introduces the design and control
steps of one kilowatt wind emulator using a variable
speed DC-motor system controlled by a full wave
controlled Rectifier Bridge. The dynamics of wind
turbine system is considered in the proposed
emulation system. The dynamics of the designed
system is presented under deterministic and
stochastic wind speed profiles. The paper also
illustrates the design steps of current control loops
PI-controllers to control the DC motor torque.

Renewable Energy Sources are one of the greatest challenges for the future of Electrical Production and Distribution. There are two main renewable sources that are subjected to the development of Electrical Production; Wind and Sun. Wind Energy as the most targeted source for Europe from the year 2018, offers countless challenges of studying, developing and projecting of Wind Farms. Reports and studies quote that the European Wind Energy will exceed 250 GW capacity by 2022.
One of the most important aspects of wind power plant (WPP) is to determine safety and reliability of production and distribution. Evaluating different type of faults and fault contribution of wind turbines are a determinant factor when talking about safety.