This report presents a brief introduction to wind energy and technologies available for horizontal wind turbines. A detailed taxonomy for horizontal axis wind turbines is presented covering parts of the turbine, control systems, applications among others. A detailed landscape analysis of patent and non-patent literature is done with a focus on Doubly-fed Induction Generators (DFIG) used in the horizontal axis wind turbines for efficient power generation. The product information of major players in the market is also captured for Doubly-fed Induction Generators. The final section of the report covers the existing and future market predictions for wind energy-based power generation.
[[Image:Wind_Flowchart.PNG|right|580px|thumb|Process Flow]]
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=Introduction=
* Humans We have been using wind power for at least since 5000 BC to propel sailboats and sailing ships, and architects have used wind-driven natural ventilation in buildings since similarly ancient times. The use of wind to provide mechanical power came later.
* Harnessing renewable alternative energy is the ideal way to tackle the energy crisis, with due consideration given to environmental pollution, that looms large over the world.
* Renewable energy is also called "clean energy" or "green power" because it doesn’t pollute the air or the water. Wind energy is one such renewable energy source that harnesses natural wind power.<br> == Read More? ==Click on '''[[Wind Energy Background]]''' to read more about wind energy.
==Brief History of Wind Energy==Although In order to overcome the use of problems associated with fixed speed wind power started around 5000 BC, but electric power generation through turbine system and to maximize the wind energy started in 18th century and increasing drastically in 19th and 20th centuries. A brief view on developments on capture, many new wind power sector farms are listed below.[[Image:totalcapacityworld2009.JPEG|thumb|right|400px|Fig 1 [http://www.wwindea.org/home/index.php Development of employing variable speed wind power worldwide]]] * [http://www.brighthub.com/environment/renewable-energy/articles/71440.aspx 1887] : Prof. James Blyth of Scotland used windmills for generating electricity.* [http://www.brighthub.com/environment/renewableconversion systems (WECS) with doubly-energy/articles/71440.aspx 1888] : Charles Brush developed the first wind-powered turbine that generated electricity in the United States based on emulated James Blyth work.* [http://www.brighthub.com/environment/renewable-energy/articles/71440.aspx 1927] : Joe Jacobs and Marcellus Jacobs improved the wind turbine fed induction generator for use in farms.* [http://www.brighthub.com/environment/renewable-energy/articles/71440.aspx 1931] : development of Darrieus wind turbine(DFIG). It is a vertical axis turbine that rotates with wind from any direction.* 1941: Largest mega watt range wind turbine was connected to the local electrical distribution system on most popular and widely used scheme for the mountain known as Grandpa's Knob in Castleton, Vermont, USA. * 1971: Denmark installed the first offshore wind farms* 1990s: More than 2200 MW capacity of wind turbines are installed in california.* 2003: the largest offshore wind farm North Hoyle was built in the United Kingdom.* 2003-2010: Research is going is on wind turbines in blades structures, generators, operation and protection, efficiency of wind turbines.Source:[[Media:windenergy.pdf| Wind Energy]]<br>The total installed wind power capacity from 2001 due to 2010 is shown in fig. 1. All wind turbines installed by the end of year 2009 worldwide are generating 340 TWh per annum.The country wise share of wind energy by the end of year 2009 is shown in fig. 2its advantages.
[[Image:countryshareFor variable-speed systems with limited variable-speed range, e.JPEG|thumb|center|350px|Fig 2 [http://wwwg.wwindea±30% of synchronous speed, the doubly-fed induction generator(DFIG) can be an interesting solution.org/home/index.php Country share This is mainly due to the fact that the power electronic converter only has to handle a fraction (20-30%) of the total capacity]]]power as the converters are connected to the rotor and not to the stator. Therefore, the losses in the power electronic converter can be reduced, compared to a system where the converter has to handle the total power. The overall structure of wind power generation through DFIG as shown in the figure below.
Source:[http://www.wwindea.org/home/index.php?option=com_content&taskMarket Research=view&id=266&Itemid=43 World The History of Wind Energy Report 2009]==
==Working Principle To read about '''the History of Wind Turbine ==Wind is air in motion. It is a form of solar energy. Solar radiation heats every part of the Earth’s surface unevenly due to irregularities and rotation of earth. The flow of wind patterns are modified by the earthEnergy'''s terrain, bodies of water, and vegetative cover'''[http://dolcera. When air moves, causing wind, it has kinetic energy. The kinetic energy of wind can be captured by a wind turbine and converted to other forms of energy such as electricity or mechanical powercom/wiki/index.php?title=The_History_of_Wind_Energy click here]'''
==Global Wind Energy Market=====Market Overview===* In the year 2010, the wind capacity reached worldwide '''196’630 Megawatt''', after '''159’050 MW''' in 2009, '''120’903 MW''' in 2008, and '''93’930 MW''' in 2007.[[Image:windprincipleWorld_Installed2.pngPNG|center|550px600px|thumb|Fig 3 Source: [http://www.atlantissolarwwindea.comorg/wind_storyhome/images/stories/pdfs/worldwindenergyreport2010_s.html pdf World Wind turbine principleEnergy Report, 2010]]]* Wind power showed a growth rate of '''23.6 %''', the lowest growth since 2004 and the second lowest growth of the past decade.* For the first time in more than two decades, the market for new wind turbines was smaller than in the previous year and reached an overall size of '''37’642 MW''', after 38'312 MW in 2009.[[Image:New.PNG|center|600px|thumb|Source: [http://www.wwindea.org/home/images/stories/pdfs/worldwindenergyreport2010_s.pdf World Wind Energy Report, 2010]]]* All wind turbines installed by the end of 2010 worldwide can generate '''430 Tera watt hours per annum''', more than the total electricity demand of the United Kingdom, the sixth largest economy of the world, and equaling 2.5 % of the global electricity consumption.* In the year 2010, altogether '''83 countries''', one more than in 2009, used wind energy for electricity generation. 52 countries increased their total installed capacity, after 49 in the previous year.* The turnover of the wind sector worldwide reached '''40 billion Euros (55 billion US$) in 2010''', after 50 billion Euros (70 billion US$) in the year 2009. The decrease is due to lower prices for wind turbines and a shift towards China.* China became number one in total installed capacity and the center of the international wind industry, and added '''18’928 Megawatt''' within one year, accounting for more than 50 % of the world market for new wind turbines.* The wind sector in 2010 employed '''670’000 persons''' worldwide.* Nuclear disaster in Japan and oil spill in Gulf of Mexico will have long-term impact on the prospects of wind energy. Governments need to urgently reinforce their wind energy policies.* WWEA sees a global capacity of '''600’000 Megawatt''' as possible by the year 2015 and more than '''1’500’000 Megawatt''' by the year 2020.
SourcesSource:[http://windeiswww.anlwwindea.govorg/guidehome/basicsimages/indexstories/pdfs/worldwindenergyreport2010_s.cfm pdf World Wind Energy Basics]Report,[http://www1.eere.energy.gov/windandhydro/wind_how.html#inside How Wind Turbines Work2010]
==Horizontal Axis and Vertical Axis Wind Turbines =Global Market Forecast===* Global Wind turbines are mainly classified into two types based on the axis in which turbine rotatesEnergy Outlook 2010, provides forecast under [http://dolcera. They are Horizontal axis wind turbine com/wiki/index.php?title=Forecast_Scenarios three different scenarios] - Reference, Moderate and vertical axis wind turbineAdvanced.* The Global Cumulative Wind Power Capacity is estimated to reach 572,733 MW by the year 2030, under the Reference Scenario* The Global Cumulative Wind Power Capacity is estimated to reach 1,777,550 MW by the year 2030, under the Moderate Scenario* The Global Cumulative Wind Power Capacity is estimated to reach 2,341,984 MW by the year 2030, under the Advanced Scenario* The following chart shows the Global Cumulative Wind Power Capacity Forecast,under the different scenarios:
{|border="2" cellspacing="0" cellpadding="4" width="100%"| align = "center" bgcolor = "#83caff"|'''Horizontal axis wind turbines'''| align = "center" bgcolor = "#83caff"|'''Vertical axis wind turbines'''|-|* It is mounted on top of a tower ,requires huge towers leads to complex in operation, maintanace and high intial costs.* It operates only with upstream or down stream wind directions.* It can be constructed in offshores.* It produces large amount of electricity with high efficiency.[[Image:HorizontalGlobal_Forecast.jpgPNG|center|1080px|thumb|Fig 4(a) [http://www.windturbinesnow.com/horizontalaxis-windturbines.htm Horizontal axis wind turbine]]]|* These are easy to build and maintainGlobal Cumulative Wind Power Capacity Forecast, safer, easier to transport and they can be mounted close to the ground.* These can handle much turblence in wind than horizontal wind turbines.* Mostly it can be constructed with two blades* It operates with any direction of wind* Production of electricity is less due to low wind speeds near to ground[[ImageSource:vertical.jpg|center|thumb|Fig 4(b)[http://www.solarpowerwindenergygwec.orgnet/2009fileadmin/12documents/25Publications/types-of-wind-turbines/ Vertical axis wind turbineGWEO%202010%20final.pdf Global Wind Energy Outlook 2010]]]|}
Source:[http://www.windpowertv.com/forum/index.php?topic=18.0 Different types of wind turbines]
=Horizontal Axis Wind Turbines=== Onshore and Offshore Wind Turbines =={|border="2" cellspacing="0" cellpadding="4" width="100Source: [http://www.gwec.net/fileadmin/documents/Publications/GWEO%"| align = "center" bgcolor = "#83caff"| '''Onshore wind turbines'''| align = "center" bgcolor = "#83caff"| '''Offshore wind turbines'''202010%20final.pdf Global Wind Energy Outlook 2010]
|-===Market Growth Rates===| Advantages* The growth rate is the relation between the new installed wind power capacity and the installed capacity of the previous year.* With '''23.6 %''', the year 2010 showed the second lowest growth rate of the last decade.
* It requires cheaper foundations* Easily intergrated with the electrical- grid network * cheaper Installation and access during the construction phase[[Image:World_Market_Growth Rates.* It can be operated and maintained easily and cheaplyPNG|center|600px|thumb|World Market Growth Rates, Source:[http://www.house-energywwindea.comorg/Windhome/images/stories/pdfs/Offshore-Onshoreworldwindenergyreport2010_s.htm Onshore Vs Offshore pdf World Wind TurbinesEnergy Report, 2010]]]
| These are two types* Before 2010, the annual growth rate had continued to increase since the year 2004, '''peaking in 2009 at 31.7%''', the highest rate since 2001.* The highest growth rates of the year 2010 by country can be found in '''Romania''', which increased its capacity by 40 times.* The second country with a growth rate of more than 100 % was '''Bulgaria (112%)'''.* In the year 2009, four major wind markets had more than doubled their wind capacity: '''China, Mexico, Turkey, namely Near shore and Off shoreMorocco'''.* Next to China, strong growth could be found mainly in '''Eastern European and South Eastern European''' countries: Romania, Bulgaria, Turkey, Lithuania, Poland, Hungary, Croatia and Cyprus, and Belgium.* Africa (with the exception of Egypt and Morocco) and Latin America (with the exception of Brazil), are again lagging behind the rest of the world in the commercial use of wind power. * The Top 10 countries by Growth Rate are shown in the figure listed below (only markets bigger than 200 MW have been considered):
Advantages[[Image:Top_Growth_Countries.PNG|center|600px|thumb|Top Countries by Market Growth Rates, Source: [http://www.wwindea.org/home/images/stories/pdfs/worldwindenergyreport2010_s.pdf World Wind Energy Report, 2010]]]
==Geographical Market Distribution==* The roughness China became number one in total installed capacity and the center of the water surface is very low Wind international wind industry, and obstacles to added '''18'928 Megawatt''' within one year, accounting for more than 50 % of the world market for new wind are lessturbines. so, large turbines * Major decrease in new installations can be installed* Noise pollution is also not a factor because these are too far from shores* Less affected to turbulance observed in wind North America and low wind shear<br/> |-| Disadvantages* Neagtive visual impact or noisethe '''USA lost its number one position''' in total capacity to China.* Limted avaliability Many Western European countries are showing stagnation, whereas there is strong growth in a number of landsEastern European countries.* Restrictions asscociated '''Germany''' keeps its number one position in Europe with obstructions like buildings'''27'215 Megawatt''', mountains, etcfollowed by Spain with 20'676 Megawatt.* Noise pollution* Afftected to more turbulanceSourcesThe highest shares of wind power can be found in three European countries:[http://library'''Denmark (21.thinkquest.org/06aug/01335/wind0%20Power.htm Wind Power]),[http://wwwPortugal (18.ehow0 %) and Spain (16.com/list_5938067_types-wind-farms-there_0%)'''.html Types of Wind Farms]| Disadvantages:* Installing offshore windturbines is much more complex and costly* Connection to '''Asia''' accounted for the utility grid is also much more complex largest share of new installations '''(54.6%)''', followed by '''Europe (27.0%)''' and expensive'''North America (16.7 %)'''.* Operation '''Latin America (1.2%)''' and maintanances is also '''Africa (0.4%)''' still played only a complex task with off shore wind turbinesSource:[http://www.offshorewindenergy.org/ca-owee/indexpages/Offshore_technology.php?file=offtech_p2marginal role in new installations.php Offshore Technology]|-| align = "center"|[[Image* Africa:Onshore.jpeg|center|thumb|Fig 5(North Africa represents still lion share of installed capacity, wind energy plays hardly a) [http://www.ecorole yet in Sub-treesSahara Africa.org/europes-biggest-onshore* Nuclear disaster in Japan and oil spill in Gulf of Mexico will have long-term impact on the prospects of wind-farm-goes-online/ Onshore Wind turbines]]]| align = "center"|[[Image:offshoreenergy.jpeg|center|thumb|Fig5(b) [http://www.house-Governments need to urgently reinforce their wind energypolicies.com/Wind/Offshore-Onshore.htm Offshore wind turbines]]]|}
==Parts of a Horizontal Axis Source: [http://www.wwindea.org/home/images/stories/pdfs/worldwindenergyreport2010_s.pdf World Wind Turbine==Energy Report, 2010]
The regional breakdowns for the period 2009-2030 has been provided for the following three scenarios:
;# [[Regional Breakdown: Reference scenario (GWEO 2010)]]
;# [[Regional Breakdown: Moderate scenario (GWEO 2010)]]
;# [[Regional Breakdown: Advanced scenario (GWEO 2010)]]
The basic parts of a horizontal axis wind turbine(HAWT) is foundation, tower, nacelle, Generator, Rotor Blades''Note: To know more about the '''Forecast Scenarios''' [http://dolcera.com/wiki/index.php?title=Forecast_Scenarios click here]''
[[Image:partss.jpeg|center|300px|thumb|Fig 6 [http://www.solarpowerwindenergy.org/2010/04/02/parts==Country-of-a-wind-turbine/ Wind turbine parts]]]wise Market Distribution==
* In 2010, the Chinese wind market represented more than half of the world market for new wind turbines adding '''Foundation18.9 GW''': , which equals a market share of '''50.3%'''.* A very good foundation is required sharp decrease in new capacity happened in the USA whose share in new wind turbines fell down to support '''14.9% (5.6 GW)''', after 25.9% or 9.9 GW inthe tower year 2009.* '''Nine further countries''' could be seen as major markets, with turbine sales in a range '''between 0.5 and various parts 1.5 GW''': Germany, Spain, India, UnitedKingdom, France, Italy, Canada, Sweden and the Eastern European newcomer Romania.* Further, '''12 markets''' for new turbines had a medium size '''between 100 and 500 MW''': Turkey, Poland, Portugal, Belgium, Brazil, Denmark, Japan, Bulgaria, Greece, Egypt, Ireland, and Mexico.* By end of 2010, '''20 countries''' had installations of '''more than 1 000 MW''', compared with 17 countries by end of 2009 and 11 countries byend of 2005.* Worldwide, '''39 countries''' had wind farms with '''a capacity of 100 Megawatt''' or more installed, compared with 35 countries one year ago, and 24 countries five years ago.* The top five countries (USA, China, Germany, Spain and India) represented '''74.2%''' of the worldwide wind turbine capacity, significantly more than 72.9 % in the year.which weighs * The '''USA and China''' together represented '''43.2%''' of the global wind capacity (up from 38.4 % in tonnes2009).* The newcomer on the list of countries using wind power commercially is a Mediterranean country, '''Cyprus''', which for the first time installed a larger grid-connected wind farm, with 82 MW.
===Tower===Source: [http://www.wwindea.org/home/images/stories/pdfs/worldwindenergyreport2010_s.pdf World Wind Energy Report, 2010]
A tower that supports the nacelle and rotor hub at its The top. These are made from tubular steel, concrete, or steel lattice. Height of 10 countries by Total Installed Capacity for the tower is an important in design of HWAT. Because wind speed increases with heightyear 2010, taller towers enable turbines to capture more energy and generate more electricity. Generally output power of the wind system increase with increase in height and also reduces the turbulance in wind. The theoritical view of tower height versus power out is shown illustrated in figure 7 .click on the link to get more about towers [[Wind Turbine Towers]]chart below:[[Image:heightTop_Installed_Countries.jpegPNG|center|300px600px|thumb| Fig 7 Top Countries by Market Growth Rates, Source: [http://www.windsolarenergywwindea.org/map-of-best-locations-for-wind-power.htm Tower height Vs Power output]]]Source:[http:home/images/stories/pdfs/windsineworldwindenergyreport2010_s.org/?act=spage&f=wind The Fundamentals of pdf World Wind EnergyReport, 2010]]]
{|border="2" cellspacing="0" cellpadding="4" width="100%"| align = "center" bgcolor = "#83caff"|'''Different types of wind turbine towers'''| align = "center" bgcolor = "#83caff"|'''Structure'''|-|'''Tubular Tower: '''They are constructed from rolled steel plates welded together with flanges top and bottom, being sprayed with several coats of gray weatherproof paint at To view the construction yard. They have doors top and bottom allowing entrance to Top 10 countries by different other parameters for the vertical ladders inside used to access the power cables and the yaw mechanism. There are also a set of vertical ladders year 2010, click on the outside of the tower accessing the nacelle for maintenance and other checks.links below:|;# [[Image:turbular.jpeg|200px|center|thumb|Fig 8(a) [http://americanrenewableenergycorp.com/towers Tubular tower]Top 10 countries by Total New Installed Capacity]]|-| '''Lattice tower''': A Lattice tower can be constructed with perfectly shapped steel rods that are put together to form a lattice. These towers are very strong and inexpensive to manufacture and easy to transport and erect. |;# [[Image:lattices.jpeg|center|200px|thumb|Fig 8Top 10 countries by Capacity per Capita (bkW/cap) [http://www.mywindpowersystem.com/2010/03/wind-power-stats-quiet-critics/ Lattice tower]]]|-| '''Guyed wind tower''': These are very strong and most economical when properly installed. But it requires more space around the tower for guy wires|;# [[Image:guyed.jpeg|center|200px|thumb|Fig 8Top 10 countries by Capacity per Land Area (c) [http:kW//itgiproductssq.com/energy/windTowers.asp Guy tower]km)]]|-| '''Tilt up wind towers:'''These type of towers are used for consumer wind energy. These turbines have locking system, while working the turbine is locked. It can easily ulocked and lowered to ground to perform repairs.| ;# [[Image:tiltup.jpeg|center|200px|thumb|Fig 8Top 10 countries by Capacity per GDP (d) [http:kW//itgiproducts.com/energy/windTowers.asp Tiltup tower]]]|-| '''Free standing tower:'''These can be used for small wind turbines with cautions.| [[Image:free.jpeg |center|thumb|Fig 8(emillion USD) [http://itgiproducts.com/energy/windTowers.asp Free stand tower]]]|}Sources:[http://windertower.com/ Winder Tower],[http://www.thesolarguide.com/wind-power/wind-towers.aspx Wind Towers]
=== Blades===Wind turbine blades are used to extract To view the kinetic energy of wind and convert to mechanical energy. These blades are made up of fiber glass'''[[Country-reinforced polyester or woodwise Installed Wind Power Capacity]]''' (MW) 2002-epoxy. 2010 (Source: World Wind turbines have one or two or three or multiple blades based up on the constructionEnergy Association), '''[http://dolcera. Most of the HAWT have three blades. These are connected to rotor hub. Multiple blade concept is used in earlier days for pumping water and grinding etccom/wiki/index.php?title=Country-wise_Installed_Wind_Power_Capacity click here]'''
{|border="2" cellspacing="0" cellpaddingCountry Profiles="4" width="100%"| align = "center" bgcolor = "#99ccff"|'''Single blade HAWT'''| align = "center" bgcolor China= "#99ccff"|'''Two blade HAWT'''| align = "center" bgcolor = "#99ccff"|<br>'''Three blade HAWTWind Energy Outlook for China - 2011 & Beyond'''|-<br>Despite its rapid and seemingly unhampered expansion, the| It reduces the cost Chinese wind power sector continues to face significantchallenges, including issues surrounding grid access and weight integration, reliability of the turbineturbines and a coherent strategy fordeveloping China’s offshore wind resource. These are rarely used due to tower shadow effects, needs counter weights on issues willbe prominent during discussions around the other side of the bladetwelfth Five-YearPlan, less stabilitywhich will be passed in March 2011.According to thedraft plan, this is expected to reflect the Chinesegovernment’s continuous and reinforced commitment to[[Image:single.jpeg|center|200px|thumb|Fig 9(a) [http://www.wind-power development, with national wind energy-the-facts.org/en/part-i-technology/chapter-3-wind-turbine-technology/evolution-targetsof-commercial-wind-turbine-technology/design-styles90 GW for 2015 and 200 GW for 2020.html Single blade turbine]]]
| It requires more complex design due to sustain of wind shocks. It is also less stable. It saves the cost and weight of one rotor blade.[[Image:two.jpeg|center|300px|thumb|Fig 9(b) [http://www.trendir.com/green/?start=15 Two blade turbine]]]|Modern wind trubines uses three blade concept. Because this structure have hight strength to withstand heavy wind stroms. Less effect due to towe shadow. Produces high output[[Image:three.jpeg|center| 200px|thumb|Fig 9(c) [http://www.china-windturbine.com/wind-turbines-blades.htm Three blade turbine]]]|}Sources:[http://guidedtour.windpower.org/en/tour/design/concepts.htm Wind Turbine Blades],[http://www.wind-energy-the-facts.org/en/part-i-technology/chapter-3-wind-turbine-technology/evolution-of-commercial-wind-turbine-technology/design-styles.html Wind Turbine Design Styles] ===Nacelle===A housing which contains all the components which is essential to operate the turbine efficiently is called For a nacelle. It is fitted at the top detailed country profile of a tower and includes the gear box, low- and high-speed shafts, generator, controller, and brakes. A wind speed anemometer and a wind vane are mounted on the nacelle. [[Image:nacell.png |center|400px|thumb|Fig 10 [http://windturbinesforthehome.com/ Internal nacelle structure]]] '''Hub'''A rotor hub is provided for coupling a wind turbine rotor blade and a shaft. The hub assembly consists of hub, bolts, blade bearings, pitch system and internals. Rotor hubs are made with welded sheet steel, cast iron, fored steel. The types of rotor hubs are * Hingeless hub* Teetering hub [[Image:rotorhub.jpg |center|thumb|Fig 11 [http://syigroup.en.made-in-china.com/product/dbTQyzJOHYRi/China-Iron-Casting-Wind-Mill-Tower-Rotor-Hub.html Rotor hub]]] '''Drive shaft'''Drive shafts are a hollow or solid steel hardened shaft under very high stresses and considerable torque. Drive shafts are used to transfer rotational mechanical energy from blade hub to the generator to produce electricity. A wind turbine normally consists two shafts . '''''Main shaft''''': It is connected between blade hub and input to the gear box. It rotates at low speeds. So It is also called as 'low speed shaft'. '''''Generator shaft''''': It connects the gear box output to the generator input. It rotates at very high speed equals to the rating of the generator. It is also called 'high speed shaft'. please visit this [[Image:mainshaft.jpg|center|200px||thumb|Fig 12 [http://jiangyinzkforging.en.made-in-china.com/product/hewxIQjbgTpr/China-Wind-Turbine-Shaft-For-Wind-Power-Generator-ALIM2143-.html Shaft systemEnergy Profile Link]]] '''Gear box'''Gear box used in wind energy systems to change low speed high toque power coming from a rotor blade to high speed low torque power which is used for generator. It is connected in between main shaft and generator shaft to increase rotational speeds from about 30 to 60 rotations per minute (rpm) to about 1000 to 1800 rpm.Gearboxes used for wind turbine are made from superior quality aluminum alloys, stainless steel, cast iron etc. The various gear boxes used in wind turbines are # Planetary Gearbox# Helical Gearbox# Worm Gearbox [[Image:Gearra.jpg |center|250px|thumb|Fig13 [http://machinedesign.com/article/green-technology-inside-an-advanced-wind-turbine-0605 Gear box]]] '''Generator''' The output rotational mechanical energy of the gear box is connected to the generator through generator shaft. It works on the principle of 'Faraday's law of electromagnetic induction". It converts mechanical energy into electrical energy. Sources:[http://windturbinesforthehome.com/ Wind Power Turbines], [http://www.awewind.com/Products/TurbineConstruction/MainAssembly/RotorHub/tabid/81/Default.aspx Rotor Hub Assembly],[http://www.gears-gearbox.com/wind-turbines.html Gearbox for Wind Turbines], [http://www.top-alternative-energy-sources.com/inside-a-wind-turbine.html A Wind Turbine],[http://guidedtour.windpower.org/en/tour/wtrb/yaw.htm The Wind Turbine Yaw Mechanism] ===Anemometers===Wind speed is the most important factor for determing the power content in the wind. The power content in the wind is directly proportional to cube of the wind velocity. Measuring wind speed is important for site selection. The device which is used for measuring wind speed is called anemometer. These are usally located on top of the nacelle.
[[Image:windvane===India===<br>'''Wind Energy Main market developments in 2010'''<br>Today the Indian market is emerging as one of the majormanufacturing hubs for wind turbines in Asia.png|center|300px|thumb|Fig 14 [http://www1Currently,seventeen manufacturers have an annual production capacityof 7,500 MW.eereAccording to the WISE, the annual wind turbinemanufacturing capacity in India is likely to exceed17,000 MW by 2013.energy<br>The Indian market is expanding with the leading windcompanies like Suzlon, Vestas, Enercon, RRB Energy and GEnow being joined by new entrants like Gamesa, Siemens, andWinWinD, all vying for a greater market share.gov/windandhydro/wind_howSuzlon, however,is still the market leader with a market share of over 50%.html Anemometer & Wind vane]]]Source:[http://blog<br>The Indian wind industry has not been significantly affectedby the financial and economic crises.mapawattEven in the face of aglobal slowdown, the Indian annual wind power market hasgrown by almost 68%.com/2009/07/06/make-sure-you-However, it needs to be pointed outthat the strong growth in 2010 might have-wind-speed/ Anemometer]been stimulatedby developers taking advantage of the accelerateddepreciation before this option is phased out.
'''Types For a detailed country profile of anemometers'''The various types of anemometers are used in measuring wind speed is shown in flow chart below.India please visit this [[India Wind Energy Profile Link]]
[[Image:anemometers==Market Share Analysis=====Global Market Share===* Vestas leads the Global Market in the 2010 with a 12% market share according to Make Consulting, while BTM Consulting reports it to have a 14.png|center|600px]]8% market share.* According to Make Consulting, the global market share of Vestas has decreased from 19% in 2008, to 14.5% in 2009, to 12% in 2010.* According to BTM Consulting, the global market share of Vestas has changed from 19% in 2008, to 12% in 2009, to 14.8% in 2010.* According to Make Consulting, the global market share of GE Energy has decreased from 18% in 2008, to 12.5% in 2009, to 10% in 2010.* The market share of world no. 2 Sinovel, has been constantly increasing, from 5% in 2008 , to 9.3% in 2009, to 11% in 2010* The top 5 companies have been occupying more than half of the Global Market Share from 2008 to 2010
Source:[[Mediahttp:wind_power_energy//www.pdf| Wind Power Energymake-consulting.com Make Consulting], [http://www.btmgcs.com/ BTM Global Consulting]
'''Wind vane'''Wind vanes are used to measure The chart given below illustrates the wind directions and communicates with the yaw system to orient the turbine properly with respective to wind directions, to extract maximum amount Global Market Share Comparison of power from wind. Major Wind turbines are oriented to upstream wind or down stream wind. Source:[http://www.topEnergy Companies for the period 2008-alternative-energy-sources.com/inside-a-wind-turbine.html A Wind Turbine] ===Yaw Mechanism===yaw mechanism turns the rotor into the upwind direction 2010, as the wind direction changes. Electric motors provided by two different agencies, Make Consulting and gear boxes are used to keep the turbine yawed against wind. This can be also used as controlling mechanism during high wind speeds.BTM Consulting:[[Image:yawsystemMarket_Share_Comparison.pngJPG|center|350px1080px|thumb|Fig 15 Yaw structure]]Global Market Share Comparison of Major Companies for the period 2008-2010, Source: [http://guidedtourwww.windpowermake-consulting.org/en/tour/wtrb/yaw.htm sourcecom Make Consulting] , [[Mediahttp:Windturbines//www.pdf| source]] =Electrical Generating Systems= The various types of electrical generators are used in wind energy systems are shown in figurebtmgcs.[[Image:generator.png|center|600pxcom/ BTM Global Consulting]] [[Media:windturbinegenerators.pdf|source]] The most commonly used generator systems applied in wind turbines are are explained below. {|border="2" cellspacing="0" cellpadding="4" width="100%"| align = "center" bgcolor = "#83caff"| | align = "center" bgcolor = "#83caff"|'''Fixed speed generating systems'''| align = "center" bgcolor = "#83caff"|'''Variable speed generating systems'''| align = "center" bgcolor = "#83caff"|'''Doubly fed induction generator'''
===Market Share - Top 10 Markets===
* While Vestas is the Global Leader, it is the leader in only one of Top 10 markets, which is 10<sup>th</sup> placed Sweden
* But, Vestas is ranked 2<sup>nd</sup> in 5 of Top 10 markets
* Sinovel, ranked 2<sup>nd</sup> globally, features only once in the Top 3 Companies list in the Top 10 markets, but scores globally because it leads the largest market China
* The table given below illustrates the Top 3 players in Top 10 Wind Energy Markets of the world:
{|border="2" cellspacing="0" cellpadding="4" width="50%" align="center"
|bgcolor = "#4F81BD"|<font color="#FFFFFF">'''Market'''</font>
|align = "center" bgcolor = "#4F81BD"|<font color="#FFFFFF">'''MW'''</font>
|align = "center" bgcolor = "#4F81BD"|<font color="#FFFFFF">'''No. 1'''</font>
|align = "center" bgcolor = "#4F81BD"|<font color="#FFFFFF">'''No. 2'''</font>
|align = "center" bgcolor = "#4F81BD"|<font color="#FFFFFF">'''No. 3'''</font>
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| Structurebgcolor = "#DBE5F1"|'''China'''| [[Image:fixed.png|align = "center" bgcolor = "#DBE5F1"|250px]]18928| [[Image:variable.png|align = "center" bgcolor = "#DBE5F1"|250px]]Sinovel| [[Image:dfigg.png|align = "center" bgcolor = "#DBE5F1"|250px]]Goldwind|align = "center" bgcolor = "#DBE5F1"|Dongfang
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| Machinesbgcolor = "#DBE5F1"|'''USA'''| SQIGalign = "center" bgcolor = "#DBE5F1"|5115| PMSG/WRSG/WRIGalign = "center" bgcolor = "#DBE5F1"|GE Energy| DFIGalign = "center" bgcolor = "#DBE5F1"|Vestas|align = "center" bgcolor = "#DBE5F1"|Siemens
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| Advantagesbgcolor = "#DBE5F1"|'''India'''| <nowiki>* Simple and low cost </nowiki>align = "center" bgcolor = "#DBE5F1"|2139<nowiki>* Low maintanace </nowiki>|align = "center" bgcolor = "#DBE5F1"|Suzlon| <nowiki>* Complete control of real and reactive powers</nowiki>align = "center" bgcolor = "#DBE5F1"|Enercon|align = "center" bgcolor = "#DBE5F1"|Vestas<nowiki>* High energy efficiency </nowiki>|-| <nowiki>* Reduced capacity converter</nowiki>bgcolor = "#DBE5F1"|'''Germany'''|align = "center" bgcolor = "#DBE5F1"|1551<nowiki>* Decoupled control of active and reactive power flow</nowiki>|align = "center" bgcolor = "#DBE5F1"|Enercon|align = "center" bgcolor = "#DBE5F1"|Vestas<nowiki>* Smooth grid connection</nowiki>|align = "center" bgcolor = "#DBE5F1"|Suzlon
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| Drawbacksbgcolor = "#DBE5F1"|'''UK'''| <nowiki>* </nowiki>No control on real and reactive poweralign = "center" bgcolor = "#DBE5F1"|1522|align = "center" bgcolor = "#DBE5F1"|Siemens<nowiki>* Less optimum power extraction capability</nowiki>|align = "center" bgcolor = "#DBE5F1"|Vestas|align = "center" bgcolor = "#DBE5F1"|Gamesa|-|bgcolor = "#DBE5F1"|'''Spain'''|align = "center" bgcolor = "#DBE5F1"|1516|align = "center" bgcolor = "#DBE5F1"|Gamesa|align = "center" bgcolor = "#DBE5F1"|Vestas|align = "center" bgcolor = "#DBE5F1"|GE Energy|-|bgcolor = "#DBE5F1"|'''France'''|align = "center" bgcolor = "#DBE5F1"|1186|align = "center" bgcolor = "#DBE5F1"|Enercon|align = "center" bgcolor = "#DBE5F1"|Suzlon|align = "center" bgcolor = "#DBE5F1"|Vestas|-|bgcolor = "#DBE5F1"|'''Italy'''|align = "center" bgcolor = "#DBE5F1"|948|align = "center" bgcolor = "#DBE5F1"|Gamesa|align = "center" bgcolor = "#DBE5F1"|Vestas|align = "center" bgcolor = "#DBE5F1"|Suzlon|-|bgcolor = "#DBE5F1"|'''Canada'''|align = "center" bgcolor = "#DBE5F1"|690|align = "center" bgcolor = "#DBE5F1"|Siemens|align = "center" bgcolor = "#DBE5F1"|GE Energy|align = "center" bgcolor = "#DBE5F1"|Enercon|-|bgcolor = "#DBE5F1"|'''Sweeden'''|align = "center" bgcolor = "#DBE5F1"|604|align = "center" bgcolor = "#DBE5F1"|Vestas|align = "center" bgcolor = "#DBE5F1"|Enercon|align = "center" bgcolor = "#DBE5F1"|Siemens|-|align = "center" bgcolor = "#DBE5F1" colspan = "5"|''Source: BTM Consult - part of Navigant Consulting - March 2011''|-|}<nowiki>* Poor power factor</nowikibr clear="all">
<nowiki>* High mechanical stress on turbine mechanical components<Source: [http:/nowiki>| <nowiki>* Additional cost of power electronics</nowiki>www.btm.dk/reports/world+market+update+2010 BTM Consult]
<nowiki>* Limited fault ride through capability</nowiki>| <nowiki>* Regular maintenance of slip ring and gearbox</nowiki>==Company Profiles==
<nowiki>* Limited fault ride-through capability<# '''[[Vestas Wind Systems A/nowiki>S]]'''# '''[[Suzlon Energy]]'''
|}[http://www.uni-hildesheim.de/~irwin/inside_wind_turbines.html source] ==Major Wind Turbine Control SystemsSuppliers==As the wind turbines increases in size and power, control systems plays a major role to operate wind turbines in safe region and also to improve efficiency and quality of power conversion. The main objectives of wind turbine control systems is *''Energy capture'' : Operating the wind turbine to extract maximum amount of energy considering safe restrictions like rated power, rated speed, cut-out wind speed etc.,* ''Mechanical loads'': protecting the systems from transient loads.* ''Power quality'': Conditioning the generated power with grid interconnection standards.The various control techniques used in wind turbines are shown in table below {|border="2" cellspacing="0" cellpadding="4" width="10050%" align="center"|align = "center" bgcolor = "#83caff4F81BD"|<font color="#FFFFFF">'''Control SystemTurbine maker'''</font>|align = "center" bgcolor = "#83caff4F81BD"|<font color="#FFFFFF">'''Pitch contolRotor blades'''</font>|align = "center" bgcolor = "#83caff4F81BD"|<font color="#FFFFFF">'''Yaw controlGear boxes'''</font>|align = "center" bgcolor = "#83caff4F81BD"|<font color="#FFFFFF">'''Stall controlGenerators'''</font>|align = "center" bgcolor = "#83caff4F81BD"|<font color="#FFFFFF">'''Generator torque controlTowers'''</font>|align = "center" bgcolor = "#4F81BD"|<font color="#FFFFFF">'''Controllers'''</font>
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|align bgcolor = "center#DBE5F1" |Vestas|bgcolor = "#83caffDBE5F1"|'''Description'''Vestas, LM| A method of controlling the speed of a wind turbine by varying the orientationbgcolor = "#DBE5F1"|Bosch Rexroth, or pitchHansen, of the bladesWingery, and thereby altering its aerodynamics and efficiency.Moventas[[Image:pitch.jpg|thumbbgcolor = "#DBE5F1"|centerWeier, Elin, ABB, LeroySomer|175pxbgcolor = "#DBE5F1"|Fig 16(a) [http://zone.ni.com/devzone/cda/tut/p/id/8189 Pitch control]]][http://www.moog.com/markets/energy/wind-turbines/blade-pitch-control/ source]Vestas, NEG, DMI| The rotation of horizontal axis wind turbine around its tower to orient the turbine in upwind or down wind direction.[[Image:Yaw.jpg|thumb|center|175pxbgcolor = "#DBE5F1"||Fig 16Cotas (bVestas) [http://zone.ni.com/devzone/cda/tut/p/id/8189 Yaw control]]][http://zone.ni.com/devzone/cda/tut/p/id/8189 source]|Stall control works by increasing the angle at which the relative wind strikes the blades ,<br>NEG (angle of attackDancontrol). As the wind speed increases drag force on the blade increase and lift force gets reduces, thus finally reduces the speed of turbine.A fully stalled turbine blade, when stopped, has the flat side of the blade facing directly into the wind. Compare with furling. [http://www.windmeup.org/2008/03/stall-control-basics.html source]|As the aerodynamic torque control changes, rotor speed changes. it changes the output power frequency. A frequency converter is connected in between generator and the network to maintain generator power constant.[[Media:windenergycontrol.pdf|source]]
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|} bgcolor =Taxonomy for Wind Turbines=[[Image:windTurbines.jpeg"#DBE5F1"|thumb|center|999px]] ==Major IPC classes==A majority of patents describing wind turbines or wind GE energy are classified in the following IPC classifications. {|borderbgcolor ="2#DBE5F1" cellspacing|LM, Tecsis|bgcolor ="0" cellpadding="4" width="100%#DBE5F1"|Wingery, Bosch, Rexroth, Eickhoff, GE| align = "center" bgcolor = "#99ccffDBE5F1"|'''S.NO'''Loher, GE| align = "center" bgcolor = "#99ccffDBE5F1"|'''IPC Classification'''DMI, Omnical, SIAG| align = "center" bgcolor = "#99ccffDBE5F1"|'''Description'''GE
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| align bgcolor = "center#DBE5F1" |Gamesa|bgcolor = "#99ccffDBE5F1"|1Gamesa, LM| align bgcolor = "center#DBE5F1"|F03DEchesa (Gamesa), Winergy, Hansen| WIND MOTORSbgcolor = "#DBE5F1"|Indar (Gamesa), Cantarey|bgcolor = "#DBE5F1"|Gamesa|bgcolor = "#DBE5F1"| Ingelectric (Gamesa)
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| align bgcolor = "center#DBE5F1" |Enercon|bgcolor = "#99ccffDBE5F1"|2Enercon| align bgcolor = "center#DBE5F1"|F16CDirect drive| SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OF CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGSbgcolor = "#DBE5F1"|Enercon|bgcolor = "#DBE5F1"|KGW, SAM|bgcolor = "#DBE5F1"|Enercon
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| align bgcolor = "center#DBE5F1" | Siemens<br>wind|bgcolor = "#99ccffDBE5F1"|3Siemens, LM| align bgcolor = "center#DBE5F1"|F16HWinergy| GEARINGbgcolor = "#DBE5F1"|ABB|bgcolor = "#DBE5F1"|Roug, KGW|bgcolor = "#DBE5F1"| Siemens, KK Electronic
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| align bgcolor = "center#DBE5F1" |Suzlon|bgcolor = "#99ccffDBE5F1"|4Suzlon| align bgcolor = "center#DBE5F1"|F03BHansen, Winergy| MACHINES OR ENGINES FOR LIQUIDS bgcolor = "#DBE5F1"| Suzlon,<br>Siemens|bgcolor = "#DBE5F1"|Suzlon|bgcolor = "#DBE5F1"| Suzlon, Mita Teknik
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|align bgcolor = "center#DBE5F1" |Repower|bgcolor = "#99ccffDBE5F1"|5LM|align bgcolor = "center#DBE5F1"|H02KWinergy, Renk, Eickhoff|DYNAMO-ELECTRIC MACHINESbgcolor = "#DBE5F1"|N/A|bgcolor = "#DBE5F1"|N/A|bgcolor = "#DBE5F1"| Mita Teknik, ReGuard
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| align bgcolor = "center#DBE5F1" |Nordex|bgcolor = "#99ccffDBE5F1"|6Nordex| align bgcolor = "center#DBE5F1"|H02PWinergy, Eickhoff, Maag| CONTROL OR REGULATION OF ELECTRIC MOTORSbgcolor = "#DBE5F1"|Loher|bgcolor = "#DBE5F1"| Nordex, GENERATORS, OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERSOmnical|bgcolor = "#DBE5F1"| Nordex, REACTORS OR CHOKE COILSMita Teknik
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| align = "center" bgcolor = "#99ccffDBE5F1"|7| align colspan = "center6"|H02M| APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION''Source: BTM Consult''
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|}<br clear="all"> ==Products of Top Companies=={|border="2" cellspacing="0" cellpadding="4" width="100%"| align = "center" bgcolor = "#99ccff4F81BD"width=”42”|<font color="#FFFFFF">'''S.No.'''</font>|align = "center" bgcolor = "#4F81BD"|<font color="#FFFFFF">'''Company'''</font>|align = "center" bgcolor = "#4F81BD"|<font color="#FFFFFF">'''Product'''</font>|align = "center" bgcolor = "#4F81BD"|<font color="#FFFFFF">'''Specifications'''</font>|-valign="top"|align = "center" bgcolor = "#DCE6F1"|1|bgcolor = "#DCE6F1"|<font color="#0000FF"><u>[http://www.vestas.com/en/wind-power-plants/procurement/turbine-overview/v80-2.0-mw.aspx#/vestas-univers Vestas]</u></font>|bgcolor = "#DCE6F1"|V80|bgcolor = "#DCE6F1"|'''Rated Power: '''2.0 MW, '''Frequency:''' 50 Hz/60 Hz, '''Number of Poles:''' 4-pole, '''Operating Temperature: -'''30°C to 40°|- valign="top"|align = "center"|2|<font color="#0000FF"><u>[http://www.vestas.com/en/wind-power-plants/procurement/turbine-overview/v80-2.0-mw.aspx#/vestas-univers Vestas]</u></font>|V90|'''Rated Power:''' 1.8/2.0 MW, '''Frequency :''' 50 Hz/60 Hz, '''Number of Poles :''' 4-pole(50 Hz)/6-pole(60 Hz), '''Operating Temperature: -'''30°C to 40°|- valign="top"| align = "center" bgcolor = "#DCE6F1"|H02J3| CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWERbgcolor = "#DCE6F1"|<font color="#0000FF"><u>[http://www.vestas.com/en/wind-power-plants/procurement/turbine-overview/v80-2.0-mw.aspx#/vestas-univers Vestas]</u></font>|bgcolor = "#DCE6F1"|V90 Offshore|bgcolor = "#DCE6F1"|'''Rated Power:''' 3.0 MW, '''Frequency:''' 50 Hz/60 Hz, '''Number of Poles:''' 4-pole, '''Operating Temperature: '''-30°C to 40°|- valign="top"|align = "center"|4|<font color="#0000FF"><u>[http://www.china-windturbine.com/news/doubly_wind_turbines.htm North Heavy Company]</u></font>|2 MW DFIG|'''Rated Power:''' 2.0 MW, '''Rated Voltage:''' 690V, '''Rated Current:''' 1670A, '''Frequency:''' 50Hz, '''Number of Poles :''' 4-pole, '''Rotor Rated Voltage:''' 1840V, '''Rotor Rated Current''' 670A, '''Rated Speed:''' 1660rpm; SYSTEMS FOR STORING ELECTRIC ENERGY''' Power Speed Range: '''520-1950 rpm, '''Insulation Class:''' H, '''Protection Class:''' IP54, '''Motor Temperature Rise''' =<nowiki><</nowiki>95K|-valign="top"| align = "center" bgcolor = "#99ccffDCE6F1"|95|bgcolor = "#DCE6F1"|<font color="#0000FF"><u>[http://docs.google.com/viewer?a=v&q=cache:X9KReq0YEigJ:www.iberdrolarenewables.us/bluecreek/docs/primary/03-Appendices/_Q-Brochure-of-G-90-Turbine/Brochure-G-90-Turbine.pdf+gamesa+g90&hl=en&pid=bl&srcid=ADGEESgldaLogi1i5Pg71zE-FO_AMqbeKL5wJiA8LVklgq5ev2in Gamesa]</u></font>|bgcolor = "#DCE6F1"|G90|bgcolor = "#DCE6F1"|'''Rated Voltage:''' 690 V, '''Frequency:''' 50 Hz, '''Number of Poles:''' 4, '''Rotational Speed:''' 900:1,900 rpm (rated 1,680 rpm) (50Hz); '''Rated Stator Current: '''1,500 A @ 690 V, '''Protection Class:''' IP 54, '''Power Factor(standard):''' 0.98 CAP - 0.96 IND at partial loads and 1 at nominal power, '''Power Factor(Optional):''' 0.95 CAP - 0.95 IND throughout the power range|- valign="top"| align = "center"|G06F6| ELECTRIC DIGITAL DATA PROCESSING<font color="#0000FF"><u>[http://www.nordex-online.com/en/products-services/wind-turbines/n100-25-mw Nordex]</u></font>| N80|'''Rated Power:''' 2.5 MW, '''Rated Voltage:''' 690V, '''Frequency:''' 50/60Hz, '''Cooling Systems:''' liquid/air|-valign="top"| align = "center" bgcolor = "#99ccffDCE6F1"|7|bgcolor = "#DCE6F1"|<font color="#0000FF"><u>[http://www.nordex-online.com/en/products-services/wind-turbines/n100-25-mw Nordex]</u></font>|bgcolor = "#DCE6F1"| N90|bgcolor = "#DCE6F1"|'''Rated Power:''' 2.5 MW, '''Rated Voltage: '''690V,''' Frequency: '''50/60Hz,''' Cooling Systems: '''liquid/air|- valign="top"|align = "center"|8|<font color="#0000FF"><u>[http://www.nordex-online.com/en/products-services/wind-turbines/n100-25-mw Nordex]</u></font>|N100|'''Rated Power:''' 2.4 MW, '''Rated Voltage: '''690V, '''Frequency: '''50/60Hz, '''Cooling Systems: '''liquid/air|- valign="top"|align = "center" bgcolor = "#DCE6F1"|9|bgcolor = "#DCE6F1"|<font color="#0000FF"><u>[http://www.nordex-online.com/en/products-services/wind-turbines/n100-25-mw Nordex]</u></font>|bgcolor = "#DCE6F1"| N117|bgcolor = "#DCE6F1"|'''Rated Power:''' 2.5 MW, '''Rated Voltage: '''690V, '''Frequency: '''50/60Hz, '''Cooling Systems: '''liquid/air|- valign="top"|align = "center"|10|<font color="#0000FF"><u>[http://www.converteam.com/majic/pageServer/1704040148/en/index.html Converteam]</u></font>|DFIG|NA|- valign="top"| align = "center" bgcolor = "#DCE6F1"|G05F11| SYSTEMS FOR REGULATING ELECTRIC OR MAGNETIC VARIABLESbgcolor = "#DCE6F1"|<font color="#0000FF"><u>[http://geoho.en.alibaba.com/product/252321923-0/1_5MW_doubly_fed_asynchronous_generator.html Xian Geoho Energy Technology]</u></font>|bgcolor = "#DCE6F1"|1.5MW DFIG|bgcolor = "#DCE6F1"|'''Rated Power:''' 1550KW, '''Rated Voltage: '''690V, '''Rated Speed: '''1755 r/min, '''Speed Range: '''975<nowiki>~</nowiki>1970 r/min, '''Number of Poles: '''4-pole, '''Stator Rated Voltage: '''690V±10%, '''Stator Rated Current: '''1115A; '''Rotor Rated Voltage: '''320V, '''Rotor Rated Current: '''430A, '''Winding Connection: '''Y / Y, '''Power Factor: '''0.95(Lead) <nowiki>~</nowiki> 0.95Lag,''' Protection Class: '''IP54, '''Insulation Class: '''H, '''Work Mode: '''S1, '''Installation ModeI: '''M B3, '''Cooling Mode: '''Air cooling, '''Weight: '''6950kg|- valign="top"|align = "center"|12|<font color="#0000FF"><u>[http://www.tecowestinghouse.com/products/custom_engineered/DF_WR_ind_generator.html Tecowestinghouse]</u></font>|TW450XX (0.5-1 KW)|'''Rated Power:''' 0.5 -1 KW, '''Rated Voltage: '''460/ 575/ 690 V, '''Frequency: '''50/ 60 Hz, '''Number of Poles: '''4/6,''' Ambient Temp.(°C): -'''40 to 50, '''Speed Range (% of Synch. Speed): '''68% to 134%, '''Power Factor (Leading): -'''0.90 to <nowiki>+</nowiki>0.90 , '''Insulation Class: '''H/F, '''Efficiency: '''<nowiki>></nowiki>= 96%|- valign="top"|align = "center" bgcolor = "#DCE6F1"|13|bgcolor = "#DCE6F1"|<font color="#0000FF"><u>[http://www.tecowestinghouse.com/products/custom_engineered/DF_WR_ind_generator.html Tecowestinghouse]</u></font>|bgcolor = "#DCE6F1"|TW500XX (1-2 KW)|bgcolor = "#DCE6F1"|'''Rated Power:''' 1-2 kW,''' Rated Voltage:''' 460/ 575/ 690 V, '''Frequency:''' 50/ 60 Hz, '''Number of Poles:''' 4/6, Ambient Temp.(°C): -40 to 50; '''Speed Range (% of Synch. Speed):''' 68 to 134%, '''Power Factor(Leading): -'''0.90 to <nowiki>+</nowiki>0.90, '''Insulation Class: '''H/F, '''Efficiency:''' <nowiki>></nowiki>= 96%|- valign="top"|align = "center"|14|<font color="#0000FF"><u>[http://www.tecowestinghouse.com/products/custom_engineered/DF_WR_ind_generator.html Tecowestinghouse]</u></font>|TW560XX (2-3 KW)|'''Rated Power: '''2-3kW, '''Rated Voltage: '''460/ 575/ 690 V, '''Frequency: '''50/ 60 Hz, '''Number of Poles: '''4/6, '''Ambient Temp(°C): ''' -40 to 50, '''Speed Range(% of Synch. Speed)''':''' '''68 to 134%, '''Power Factor(Leading):''' -0.90 to <nowiki>+</nowiki>0.90, '''Insulation Class: '''H/F, '''Efficiency:''' <nowiki>></nowiki>= 96%.|- valign="top"|align = "center" bgcolor = "#DCE6F1"|15|bgcolor = "#DCE6F1"|<font color="#0000FF"><u>[http://www.acciona-na.com/About-Us/Our-Projects/U-S-/West-Branch-Wind-Turbine-Generator-Assembly-Plant.aspx Acciona]</u></font>|bgcolor = "#DCE6F1"|AW1500|bgcolor = "#DCE6F1"|'''Rated Power:''' 1.5MW, '''Rated Voltage: '''690 V, '''Frequency: '''50 Hz, '''Number of Poles: '''4, '''Rotational Speed: '''900:1,900 rpm(rated 1,680 rpm) (50Hz), '''Rated Stator Current: '''1,500 A @ 690 V, '''Protection Class: '''IP54, '''Power Factor(standard): '''0.98 CAP - 0.96 IND at partial loads and 1 at nominal power, '''Power factor(optional):''' 0.95 CAP - 0.95 IND throughout the power range|- valign="top"|align = "center"|16|<font color="#0000FF"><u>[http://www.acciona-na.com/About-Us/Our-Projects/U-S-/West-Branch-Wind-Turbine-Generator-Assembly-Plant.aspx Acciona]</u></font>|AW3000|'''Rated Power:''' 3.0MW, '''Rated Voltage: ''' 690 V, '''Frequency: '''50 Hz, '''Number of Poles: '''4, '''Rotational Speed: '''900:1,900 rpm(rated 1,680 rpm) (50Hz), '''Rated Stator Current: '''1,500 A @ 690 V, '''Protection Class: '''IP54, '''Power Factor(standard): '''0.98 CAP - 0.96 IND at partial loads and 1 at nominal power, '''Power Factor (optional):''' 0.95 CAP - 0.95 IND throughout the power range|- valign="top"|align = "center" bgcolor = "#DCE6F1"|17|bgcolor = "#DCE6F1"|<font color="#0000FF"><u>[http://gepower.com/businesses/ge_wind_energy/en/index.htm General Electric]</u></font>|bgcolor = "#DCE6F1"|GE 1.5/2.5MW|bgcolor = "#DCE6F1"|'''Rated Power:''' 1.5/2.5 MW, '''Frequency(Hz): '''50/60
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== Major Players=IP Search & Analysis =Major players in the Wind Energy sector include: General Electric, Vestas Wind Systems, Siemens AG, Mitsubishi Ltd, REPower Systems AG, Gamesa Innovation & Technology, Enercon, Nordex, Suzlon and Sinovel Wind Group Co. Ltd. == Doubly-fed Induction Generator: Search Strategy ==
The present study on the IP activity in the area of horizontal axis wind turbines with focus on '''''Doubly-fed Induction Generator (DFIG)''''' is based on a search conducted on Thomson Innovation.
===Thomson Innovation SearchControl Patents===A search is carried out using a combination of keywords and classifications in Thomson Innovation.The Classifications identified relevant to the scope of the search are:
IPC{|border="2" cellspacing="0" cellpadding="4" width="100%"|align = "center" bgcolor = "#4F81BD" width="38"|<font color="#FFFFFF">'''S. No.'''</ ECLA font>|align = "center" bgcolor = "#4F81BD"|<font color="#FFFFFF">'''Patent/Publication No.'''</font>|align = "center" bgcolor = "#4F81BD" width="15%"|<font color="#FFFFFF">'''Publication Date<br>'''(mm/dd/yyyy)</font>|align = "center" bgcolor = "#4F81BD"|<font color="#FFFFFF">'''Assignee/Applicant'''</font>|align = "center" bgcolor = "#4F81BD"|<font color="#FFFFFF">'''Title'''</font>|- valign="top"|align = "center" bgcolor = "#DCE6F1"|1|align = "center" bgcolor = "#DCE6F1"|<font color="#0000FF"><u>[http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=6278211.PN.&OS=PN/6278211&RS=PN/6278211 US6278211]</u></font>|align = "center" bgcolor = "#DCE6F1"|08/02/01|bgcolor = "#DCE6F1"|Sweo Edwin|bgcolor = "#DCE6F1"|Brush-less doubly-fed induction machines employing dual cage rotors|- valign="top"|align = "center"|2|align = "center"|<font color="#0000FF"><u>[http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=6954004.PN.&OS=PN/6954004&RS=PN/6954004 US6954004]</u></font>|align = "center"|10/11/05|Spellman High Voltage Electron|Doubly fed induction machine|- valign="top"|align = "center" bgcolor = "#DCE6F1"|3|align = "center" bgcolor = "#DCE6F1"|<font color="#0000FF"><u>[http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=7411309.PN.&OS=PN/7411309&RS=PN/7411309 US7411309]</u></font>|align = "center" bgcolor = "#DCE6F1"|08/12/08|bgcolor = "#DCE6F1"|Xantrex Technology|bgcolor = "#DCE6F1"|Control system for doubly fed induction generator|- valign="top"|align = "center"|4|align = "center"|<font color="#0000FF"><u>[http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=7485980.PN.&OS=PN/7485980&RS=PN/7485980 US7485980]</u></font>|align = "center"|02/03/09|Hitachi|Power converter for doubly-fed power generator system|- valign="top"|align = "center" bgcolor = "#DCE6F1"|5|align = "center" bgcolor = "#DCE6F1"|<font color="#0000FF"><u>[http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=7800243.PN.&OS=PN/7800243&RS=PN/7800243 US7800243]</u></font>|align = "center" bgcolor = "#DCE6F1"|09/21/10|bgcolor = "#DCE6F1"|Vestas Wind Systems|bgcolor = "#DCE6F1"|Variable speed wind turbine with doubly-fed induction generator compensated for varying rotor speed|- valign="top"|align = "center"|6|align = "center"|<font color="#0000FF"><u>[http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=7830127.PN.&OS=PN/7830127&RS=PN/7830127 US7830127]</u></font>|align = "center"|11/09/10|Wind to Power System|Doubly-controlled asynchronous generator|-|} ===Patent Classes===
{|border="2" cellspacing="0" cellpadding="4" width="100%"
|align = "center" bgcolor = "#99ccff4F81BD" width="38"|<font color="#FFFFFF">'''IPCS. No.'''</ ECLA font>|align = "center" bgcolor = "#4F81BD"|<font color="#FFFFFF">'''ClassNo.'''</font>|align = "center" bgcolor = "#99ccff4F81BD"|<font color="#FFFFFF">'''Class Type'''</font>|align = "center" bgcolor = "#4F81BD"|<font color="#FFFFFF">'''Definition'''</font>|-valign="top"|align = "center" bgcolor = "#DCE6F1"|1|bgcolor = "#DCE6F1"|<font color="#0000FF"><u>[http://www.wipo.int/ipcpub/#refresh=page¬ion=scheme&version=20110101&symbol=F03D0009000000 F03D9/00 ]</u></font>|bgcolor = "#DCE6F1"|IPC|bgcolor = "#DCE6F1"|Machines or engines for liquids; wind, spring, or weight motors; producing mechanical power or a reactive propulsive thrust, not otherwise provided for / Wind motors / '''Adaptations of wind motors for special use; Combination of wind motors with apparatus driven thereby (aspects predominantly concerning driven apparatus) '''|-valign="top"|align = "center"|2|<font color="#0000FF"><u>[http://v3.espacenet.com/eclasrch?classification=ecla&locale=en_EP&ECLA=f03d9/00c F03D9/00C ]</u></font>|ECLA|Machines or engines for liquids; wind, spring, or weight motors; producing mechanical power or a reactive propulsive thrust, not otherwise provided for / Wind motors / Adaptations of wind motors for special use; Combination of wind motors with apparatus driven thereby (aspects predominantly concerning driven apparatus) /''' The apparatus being an electrical generator '''|-valign="top"|align = "center" bgcolor = "#DCE6F1"|3|bgcolor = "#DCE6F1"|<font color="#0000FF"><u>[http://www.wipo.int/ipcpub/#&refresh=page¬ion=scheme&version=20110101&symbol=H02J0003380000 H02J3/38 ]</u></font>|bgcolor = "#DCE6F1"|IPC|bgcolor = "#DCE6F1"|Generation, conversion, or distribution of electric power / Circuit arrangements or systems for supplying or distributing electric power; systems for storing electric energy / Circuit arrangements for ac mains or ac distribution networks / '''Arrangements for parallely feeding a single network by two or more generators, converters or transformers '''|-valign="top"|align = "center"|4|<font color="#0000FF"><u>[http://www.wipo.int/ipcpub/#refresh=page¬ion=scheme&version=20110101&symbol=H02K0017420000 H02K17/42 ]</u></font>|IPC|Generation, conversion, or distribution of electric power / Dynamo-electric machines / Asynchronous induction motors; Asynchronous induction generators / '''Asynchronous induction generators '''|-valign="top"|align = "center" bgcolor = "#DCE6F1"|5|bgcolor = "#DCE6F1"|<font color="#0000FF"><u>[http://www.wipo.int/ipcpub/#refresh=page¬ion=scheme&version=20110101&symbol=H02P0009000000 H02P9/00 ]</u></font>|bgcolor = "#DCE6F1"|IPC|bgcolor = "#DCE6F1"|Generation, conversion, or distribution of electric power / Control or regulation of electric motors, generators, or dynamo-electric converters; controlling transformers, reactors or choke coils /''' Arrangements for controlling electric generators for the purpose of obtaining a desired output '''|-valign="top"|align = "center"|6|<font color="#0000FF"><u>[http://www.uspto.gov/web/patents/classification/uspc290/sched290.htm#C290S044000 290/044]</u></font>|USPC|Prime-mover dynamo plants / electric control / Fluid-current motors / '''Wind '''|-valign="top"|align = "center" bgcolor = "#DCE6F1"|7|bgcolor = "#DCE6F1"|<font color="#0000FF"><u>[http://www.uspto.gov/web/patents/classification/uspc290/sched290.htm#C290S055000 290/055]</u></font>|bgcolor = "#DCE6F1"|USPC|bgcolor = "#DCE6F1"|Prime-mover dynamo plants / Fluid-current motors / '''Wind''' |-valign="top"|align = "center"|8|<font color="#0000FF"><u>[http://www.uspto.gov/web/patents/classification/uspc318/sched318.htm#C318S727000 318/727]</u></font>|USPC|Electricity: motive power systems / '''Induction motor systems '''|-valign="top"|align = "center" bgcolor = "#DCE6F1"|9|bgcolor = "#DCE6F1"|<font color="#0000FF"><u>[http://www.uspto.gov/web/patents/classification/uspc322/sched322.htm#C322S047000 322/047]</u></font>|bgcolor = "#DCE6F1"|USPC|bgcolor = "#DCE6F1"|Electricity: single generator systems / Generator control / '''Induction generator '''
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|} ===Concept Table==={|border="2" cellspacing="0" cellpadding="4" width="100%"|align = "center" bgcolor = "#4F81BD" rowspan = "2" width="38"| F03D9<font color="#FFFFFF">'''S. No.'''</00font>|Adaptations of wind motors for special use; Combinations of wind motors with apparatus driven thereby (aspects predominantly concerning driven apparatus)align = "center" bgcolor = "#4F81BD"|<font color="#FFFFFF">'''Concept 1'''</font>|align = "center" bgcolor = "#4F81BD"|<font color="#FFFFFF">'''Concept 2'''</font>|align = "center" bgcolor = "#4F81BD"|<font color="#FFFFFF">'''Concept 3'''</font>
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|align = "center" bgcolor = "#95B3D7"| F03D9/00C'''Doubly Fed'''|Adaptations of wind motors for special use; Combinations of wind motors with apparatus driven thereby (aspects predominantly concerning driven apparatus)/ the apparatus being an electrical generatoralign = "center" bgcolor = "#95B3D7"|'''Induction'''|align = "center" bgcolor = "#95B3D7"|'''Generator'''
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|align = "center" bgcolor = "#DCE6F1"| H02J3/381|Circuit arrangements for ac mains or ac distribution networks/ Arrangements for parallely feeding a single network by two or more generators, converters or transformersbgcolor = "#DCE6F1"|doubly fed|bgcolor = "#DCE6F1"|induction|bgcolor = "#DCE6F1"|generator
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|align = "center"| H02K17/422|double output|asynchronous|machines|DYNAMO-ELECTRIC MACHINES/ Asynchronous induction motors; Asynchronous induction generators/ Asynchronous induction generators|align = "center" bgcolor = "#DCE6F1"|3|bgcolor = "#DCE6F1"|dual fed|bgcolor = "#DCE6F1"| |bgcolor = "#DCE6F1"|systems|-|align = "center"|4|dual feed| |
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|align = "center" bgcolor = "#DCE6F1"| H02P9/005|CONTROL OR REGULATION OF ELECTRIC MOTORS, GENERATORS, OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS / Arrangements for controlling electric generators for the purpose of obtaining a desired bgcolor = "#DCE6F1"|dual output|bgcolor = "#DCE6F1"| |bgcolor = "#DCE6F1"|
|-
|}
===Thomson Innovation Search==='''Database:''' Thomson Innovation<br>'''Patent coverage:''' US ClassesEP WO JP DE GB FR CN KR DWPI<br> '''Time line:''' 01/01/1836 to 07/03/2011
{|border="2" cellspacing="0" cellpadding="4" width="100%"
|align = "center" bgcolor = "#99ccff4F81BD" width="38"|<font color="#FFFFFF">'''US ClassS. No.'''</font>|align = "center" bgcolor = "#99ccff4F81BD"|<font color="#FFFFFF">'''DefinitionConcept'''</font>|align = "center" bgcolor = "#4F81BD"|<font color="#FFFFFF">'''Scope'''</font>|align = "center" bgcolor = "#4F81BD"|<font color="#FFFFFF">'''Search String'''</font>|align = "center" bgcolor = "#4F81BD"|<font color="#FFFFFF">'''No. of Hits'''</font>|-valign="top"|align = "center" bgcolor = "#DCE6F1"|2901|bgcolor = "#DCE6F1"|Doubly-fed Induction Generator: Keywords(broad)|bgcolor = "#DCE6F1"|Claims, Title, and Abstract|bgcolor = "#DCE6F1"|(((((doubl<nowiki>*</044nowiki>3 OR dual<nowiki>*</nowiki>3 OR two) ADJ3 (power<nowiki>*</nowiki>2 OR output<nowiki>*</nowiki>4 OR control<nowiki>*</nowiki>4 OR fed OR feed<nowiki>*</nowiki>3)) NEAR5 (induction OR asynchronous)) NEAR5 (generat<nowiki>*</nowiki>3 OR machine<nowiki>*</nowiki>1 OR dynamo<nowiki>*</nowiki>1)) OR dfig or doig)|align = "right" bgcolor = "#DCE6F1"|873|PRIME-MOVER DYNAMO PLANTSvalign="top"|align = "center"|2|Doubly-fed Induction Generator: Keywords(broad)|Full Spec.|(((((doubl<nowiki>*</ ELECTRIC CONTROLnowiki>3 OR dual<nowiki>*</ Fluidnowiki>3 OR two) ADJ3 (power<nowiki>*</nowiki>2 OR output<nowiki>*</nowiki>1 OR control<nowiki>*</nowiki>4 OR fed OR feed<nowiki>*</nowiki>3)) NEAR5 (generat<nowiki>*</nowiki>3 OR machine<nowiki>*</nowiki>1 OR dynamo<nowiki>*</nowiki>1))) OR dfig or doig)|align = "center"|<nowiki>-current motors </ Windnowiki>|-valign="top"|align = "center" bgcolor = "#DCE6F1"|3|bgcolor = "#DCE6F1"|Induction Machine: Classes|bgcolor = "#DCE6F1"|US, IPC, and ECLA Classes|bgcolor = "#DCE6F1"|((318/727 OR 322/047) OR (H02K001742))|align = "center" bgcolor = "#DCE6F1"|<nowiki>-</nowiki>|-valign="top"|align = "center"|4|Generators: Classes|US, IPC, and ECLA Classes|((290/044 OR 290/055) OR (F03D000900C OR H02J000338 OR F03D0009<nowiki>*</nowiki> OR H02P0009<nowiki>*</nowiki>))|PRIMEalign = "center"|<nowiki>-MOVER DYNAMO PLANTS</ FLUIDnowiki>|-CURRENT MOTORSvalign="top"|align = "center" bgcolor = "#DCE6F1"|5|bgcolor = "#DCE6F1"|Combined Query|align = "center" bgcolor = "#DCE6F1"|<nowiki>-</ Windnowiki>|align = "left" bgcolor = "#DCE6F1"|2 AND 3|align = "right" bgcolor = "#DCE6F1"|109|-valign="top"|align = "center"|3186|Combined Query|align = "center"|<nowiki>-</727nowiki>|ELECTRICITY: MOTIVE POWER SYSTEMSalign = "left"|2 AND 4|align = "right"|768|-valign="top"|align = "center" bgcolor = "#DCE6F1"|7|bgcolor = "#DCE6F1"|French Keywords|bgcolor = "#DCE6F1"|Claims, Title, and Abstract|bgcolor = "#DCE6F1"|((((doubl<nowiki>*</ INDUCTION MOTOR SYSTEMSnowiki>3 OR dual<nowiki>*</nowiki>3 OR two OR deux) NEAR4 (nourris OR feed<nowiki>*</nowiki>3 OR puissance OR sortie<nowiki>*</nowiki>1 OR contrôle<nowiki>*</nowiki>1)) NEAR4 (induction OR asynchron<nowiki>*</nowiki>1) NEAR4 (générateur<nowiki>*</nowiki>1 OR generator<nowiki>*</nowiki>1 OR machine<nowiki>*</nowiki>1 OR dynamo<nowiki>*</nowiki>1)) OR dfig or doig)|align = "right" bgcolor = "#DCE6F1"|262|-valign="top"|align = "center"|3228|German Keywords|Claims, Title, and Abstract|(((((doppel<nowiki>*</047nowiki>1 OR dual OR two OR zwei) ADJ3 (ausgang OR ausgänge OR kontroll<nowiki>*</nowiki> OR control<nowiki>*</nowiki>4 OR gesteuert OR macht OR feed<nowiki>*</nowiki>1 OR gefüttert OR gespeiste<nowiki>*</nowiki>1)) OR (doppeltgefüttert OR doppeltgespeiste<nowiki>*</nowiki>1)) NEAR4 (((induktion OR asynchronen) NEAR4 (generator<nowiki>*</nowiki>2 OR maschine<nowiki>*</nowiki>1 OR dynamo<nowiki>*</nowiki>1)) OR (induktion?maschinen OR induktion?generatoren OR asynchronmaschine OR asynchrongenerator))) OR dfig)|ELECTRICITYalign = "right"|306|-valign="top"|align = "center" bgcolor = "#DCE6F1"|9|bgcolor = "#DCE6F1"|Doubly-fed Induction Generator: SINGLE GENERATOR SYSTEMSKeywords(narrow)|bgcolor = "#DCE6F1"|Full Spec.|bgcolor = "#DCE6F1"|(((((((doubl<nowiki>*</ GENERATOR CONTROLnowiki>3 OR dual<nowiki>*</ Induction generatornowiki>3) ADJ3 (power<nowiki>*</nowiki>2 OR output<nowiki>*</nowiki>4 OR control<nowiki>*</nowiki>4 OR fed OR feed<nowiki>*</nowiki>3))) NEAR5 (generat<nowiki>*</nowiki>3 OR machine<nowiki>*</nowiki>1 OR dynamo<nowiki>*</nowiki>1))) SAME wind) OR (dfig SAME wind))|align = "right" bgcolor = "#DCE6F1"|1375|-valign="top"|align = "center"|10| Top Assignees|align = "center"|<nowiki>-</nowiki>|(vestas* OR (gen* ADJ2 electric*) OR ge OR hitachi OR woodward OR repower OR areva OR gamesa OR ingeteam OR nordex OR siemens OR (abb ADJ2 research) OR (american ADJ2 superconductor*) OR (korea ADJ2 electro*) OR (univ* NEAR3 navarra) OR (wind OR technolog*) OR (wind ADJ2 to ADJ2 power))|align = "center"|-|-valign="top"|align = "center" bgcolor = "#DCE6F1"|11|bgcolor = "#DCE6F1"|Combined Query|align = "center" bgcolor = "#DCE6F1"|<nowiki>-</nowiki>|bgcolor = "#DCE6F1"|2 AND 10|align = "right" bgcolor = "#DCE6F1"|690|-valign="top"|align = "center"|12|Top Inventors|align = "center"|<nowiki>-</nowiki>|((Andersen NEAR2 Brian) OR (Engelhardt NEAR2 Stephan) OR (Ichinose NEAR2 Masaya) OR (Jorgensen NEAR2 Allan NEAR2 Holm) OR ((Scholte ADJ2 Wassink) NEAR2 Hartmut) OR (OOHARA NEAR2 Shinya) OR (Rivas NEAR2 Gregorio) OR (Erdman NEAR2 William) OR (Feddersen NEAR2 Lorenz) OR (Fortmann NEAR2 Jens) OR (Garcia NEAR2 Jorge NEAR2 Martinez) OR (Gertmar NEAR2 Lars) OR (KROGH NEAR2 Lars) OR (LETAS NEAR2 Heinz NEAR2 Hermann) OR (Lopez NEAR2 Taberna NEAR2 Jesus) OR (Nielsen NEAR2 John) OR (STOEV NEAR2 Alexander) OR (W?ng NEAR2 Haiqing) OR (Yuan NEAR2 Xiaoming))|align = "center"|-|-valign="top"|align = "center" bgcolor = "#DCE6F1"|13|bgcolor = "#DCE6F1" |Combined Query|align = "center" bgcolor = "#DCE6F1"|<nowiki>-</nowiki>|bgcolor = "#DCE6F1"|((3 OR 4) AND 10)|align = "right" bgcolor = "#DCE6F1"|899|-valign="top"|align = "center"|14|Final Query|align = "center"|<nowiki>-</nowiki>|1 OR 5 OR 6 OR 7 OR 8 OR 9 OR 11 OR 13|'''2466(1060 INPADOC Families)'''
|-
|}
==Taxonomy==
*''Use the mouse(click and drag/scroll up or down/click on nodes) to explore nodes in the detailed taxonomy''
*''Click on the red arrow adjacent to the node name to view the content for that particular node in the dashboard''
{|border="2" cellspacing="0" cellpadding="4" width="100%"
|<mm>[[Doubly_fed_Induction_Generator.mm|Interactive Mind-map|center|flash|Doubly-fed Induction Generator|600pt]]</mm>
|}
The databases covered in ==Sample Analysis==A sample of 139 patents from the search include: US Grant, GB App, US App, FR App, WO App, DE Util, EP Grant, DE Grant, EP App, DE App, JP Util, JP Grant, JP App, CN Util, CN App, KR Util , KR Grant, KR App, Other, DWPI is analyzed based on the taxonomy.Provided a link below for sample spread sheet analysis for doubly-fed induction generators.<br>===Patent Analysis===
{|border="2" cellspacing="0" cellpadding="4" width="100%"
|align = "center" bgcolor = "#99ccff4F81BD" rowspan = "2" width="38"|<font color="#FFFFFF">'''S.No.'''</font>|align = "center" bgcolor = "#99ccff4F81BD" rowspan = "2"|<font color="#FFFFFF">'''Patent/Publication No. of Hits'''</font>|align = "center" bgcolor = "#99ccff4F81BD" rowspan = "2" width="105"|<font color="#FFFFFF">'''RemarksPublication Date<br>'''(mm/dd/yyyy)</font>|align = "center" bgcolor = "#99ccff4F81BD" rowspan = "2"|<font color="#FFFFFF">'''Assignee/Applicant'''</font>|align = "center" bgcolor = "#4F81BD" rowspan = "2"|<font color="#FFFFFF">'''Title'''</font>|align = "center" bgcolor = "#4F81BD" colspan = "2"|<font color="#FFFFFF">'''Search StringDolcera Analysis'''</font>
|-
|align = "center" bgcolor = "#95B3D7"|'''Problem'''|align = "center" bgcolor = "#95B3D7"|'''Solution'''|-valign="top"|align = "center" bgcolor = "#DCE6F1"|1|bgcolor = "#DCE6F1"|<font color="#0000FF"><u>[http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220100117605%22.PGNR.&OS=DN/20100117605&RS=DN/20100117605 US20100117605]</u></font>|align = "center"bgcolor = "#DCE6F1"|05/13/10|bgcolor = "#DCE6F1"|Woodward|bgcolor = "#DCE6F1"|Method of and apparatus for operating a double-fed asynchronous machine in the event of transient mains voltage changes|bgcolor = "#DCE6F1"|The short-circuit-like currents in the case of transient mains voltage changes lead to a corresponding air gap torque which loads the drive train and transmission lines can damages or reduces the drive train and power system equipments.|bgcolor = "#DCE6F1"|The method presents that the stator connecting with the network and the rotor with a converter. The converter is formed to set a reference value of electrical amplitude in the rotor, by which a reference value of the electrical amplitude is set in the rotor after attaining a transient mains voltage change, such that the rotor flux approaches the stator flux.|-valign="top"|align = "center"|2|<font color="#0000FF"><u>[http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220100045040%22.PGNR.&OS=DN/20100045040&RS=DN/20100045040 US20100045040]</u></font>|align = "center"|02/25/10|795 hitsVestas Wind Systems|Doubly Variable speed wind turbine with doubly-fed induction generator keywordscompensated for varying rotor speed|CTBThe DFIG system has poor damping of oscillations within the flux dynamics due to cross coupling between active and reactive currents, which makes the system potentially unstable under certain circumstances and complicates the work of the rotor current controller. These oscillations can damage the drive train mechanisms.|A compensation block is arranged, which feeds a compensation control output to the rotor of the generator. The computation unit computes the control output during operation of the turbine to compensate partly for dependencies on a rotor angular speed of locations of poles of a generator transfer function, so that the transfer function is made independent of variations in the speed during operation of the turbine which eliminates the oscillations and increases the efficiency of the wind turbine.|-valign=(((((Doubl*"top"|align = "center" bgcolor = "#DCE6F1"|3 or dual*3 or two) adj3 (|bgcolor = "#DCE6F1"|<font color="#0000FF"><u>[http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220090267572%22.PGNR.&OS=DN/20090267572&RS=DN/20090267572 US20090267572]</u></font>|align = "center" bgcolor = "#DCE6F1"|10/29/09|bgcolor = "#DCE6F1"|Woodward|bgcolor = "#DCE6F1"|Current limitation for a double-fed asynchronous machine|bgcolor = "#DCE6F1"|Abnormal currents can damage the windings in the doubly- fed induction generator. Controlling these currents with the subordinate current controllers cannot be an efficient way to extract the maximum amount of active power*2 .|bgcolor = "#DCE6F1"|The method involves delivering or output*receiving of a maximum permissible reference value of an active power during an operation of a double-fed asynchronous machine, where predetermined active power and reactive power reference values are limited to a calculated maximum permissible active and reactive power reference values, and hence ensures reliable regulated effect and reactive power without affecting the power adjustment, the rotor is electrically connected to a pulse-controlled inverter by slip rings with a static frequency changer, and thus a tension with variable amplitude and frequency is imposed in the rotor.|-valign="top"|align = "center"|4 or |<font color="#0000FF"><u>[http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220090008944%22.PGNR.&OS=DN/20090008944&RS=DN/20090008944 US20090008944]</u></font>|align = "center"|01/08/09|Universidad Publica De Navarra|Method and system of control*4 or of the converter of an electricity generation facility connected to an electricity network in the presence of voltage sags in said network|Double-fed or feed*3asynchronous generators are very sensitive to the faults that may arise in the electricity network, such as voltage sags. During the sag conditions the current which appears in said converter may reach very high values, and may even destroy it.|During the event of a voltage sag occurring, the converter imposes a new set point current which is the result of adding to the previous set point current a new term, called demagnetizing current, It is proportional to a value of free flow of a generator stator. A difference between a value of a magnetic flow in the stator of the generator and a value of a stator flow associated to a direct component of a stator voltage is estimated. A value of a preset calculated difference is multiplied by a factor for producing the demagnetizing current.|-valign="top"|align = "center" bgcolor = "#DCE6F1"|5|bgcolor = "#DCE6F1"|<font color="#0000FF"><u>[http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=7355295.PN.&OS=PN/7355295&RS=PN/7355295 US7355295]</u></font>|align = "center" bgcolor = "#DCE6F1"|04/08/08|bgcolor = "#DCE6F1"|Ingeteam Energy|bgcolor = "#DCE6F1"|Variable speed wind turbine having an exciter machine and a power converter not connected to the grid|bgcolor = "#DCE6F1"|a)The active switching of the semiconductors of the grid side converter injects undesirable high frequency harmonics to the grid.<br>b) near5 The use of power electronic converters (induction or asynchronous4)connected to the grid (9) near5 causes harmonic distortion of the network voltage.|bgcolor = "#DCE6F1"|Providing the way that power is only delivered to the grid through the stator of the doubly fed induction generator, avoiding undesired harmonic distortion. <br>Grid Flux Orientation (generat*3 or GFO) is used to accurately control the power injected to the grid. An advantage of this control system is that it does not depend on machine*parameters, which may vary significantly, and theoretical machine models, avoiding the use of additional adjusting loops and achieving a better power quality fed into the utility grid.|-valign="top"|align = "center"|6|<font color="#0000FF"><u>[http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1 &u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220080203978%22.PGNR.&OS=DN/20080203978&RS=DN/20080203978 US20080203978]</u></font>|align = "center"|08/28/08|Semikron|Frequency converter for a double-fed asynchronous generator with variable power output and method for its operation|Optislip circuit with a resistor is used when speed is above synchronous speed, results in heating the resistor and thus the generator leads to limitation of operation in super synchronous range which results in tower fluctuations.|Providing a back-to-back converter which contains the inverter circuit has direct current (DC) inputs, DC outputs, and a rotor-rectifier connected to a rotor of a dual feed asynchronous generator. A mains inverter is connected to a power grid, and an intermediate circuit connects one of the DC inputs with the DC outputs. The intermediate circuit has a semiconductor switch between the DC outputs, an intermediate circuit condenser between the DC inputs, and a diode provided between the semiconductor switch and the condenser. Thus the system is allowed for any speed of wind and reduces the tower fluctuations.|-valign="top"|align = "center" bgcolor = "#DCE6F1"|7|bgcolor = "#DCE6F1"|<font color="#0000FF"><u>[http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220070210651%22.PGNR.&OS=DN/20070210651&RS=DN/20070210651 US20070210651]</u></font>|align = "center" bgcolor = "#DCE6F1"|09/13/07|bgcolor = "#DCE6F1"|Hitachi|bgcolor = "#DCE6F1"|Power converter for doubly-fed power generator system|bgcolor = "#DCE6F1"|During the ground faults, excess currents is induced in the secondary windings and flows into power converter connected to secondary side and may damage the power converter. Conventional methods of increasing the capacity of the power converter increases system cost, degrade the system and takes time to activate the system to supply power again.|bgcolor = "#DCE6F1"|The generator provided with a excitation power converter connected to secondary windings of a doubly-fed generator via impedance e.g. reactor, and a diode rectifier connected in parallel to the second windings of the doubly-fed generator via another impedance. A direct current link of the rectifier is connected in parallel to a DC link of the converter. A controller outputs an on-command to a power semiconductor switching element of the converter if a value of current flowing in the power semiconductor switching element is a predetermined value or dynamo*larger.|-valign="top"|align = "center"|8|<font color="#0000FF"><u>[http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220070132248%22.PGNR.&OS=DN/20070132248&RS=DN/20070132248 US20070132248]</u></font>|align = "center"|06/14/07|General Electric|System and method of operating double fed induction generators|Wind turbines with double fed induction generators are sensitive to grid faults. Conventional methods are not effective to reduce the shaft stress during grid faults and slow response and using dynamic voltage restorer (DVR)) OR DFIG);is cost expensive.|The protection system has a controlled impedance device. Impedance device has bidirectional semiconductors such triac, assembly of thyristors or anti-parallel thyristors. Each of the controlled impedance devices is coupled between a respective phase of a stator winding of a double fed induction generator and a respective phase of a grid side converter. The protection system also includes a controller configured for coupling and decoupling impedance in one or more of the controlled impedance devices in response to changes in utility grid voltage and a utility grid current. High impedance is offered to the grid during network faults to isolate the dual fed wind turbine generator.|-valign="top"|align = "center" bgcolor = "#DCE6F1"|9|bgcolor = "#DCE6F1"|<font color="#0000FF"><u>[http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220060192390%22.PGNR.&OS=DN/20060192390&RS=DN/20060192390 US20060192390]</u></font>|align = "center" bgcolor = "#DCE6F1"|08/31/06|bgcolor = "#DCE6F1"|Gamesa Innovation|bgcolor = "#DCE6F1"|Control and protection of a doubly-fed induction generator system|bgcolor = "#DCE6F1"|A short-circuit in the grid causes the generator to feed high stator-currents into the short-circuit and the rotor-currents increase very rapidly which cause damage to the power-electronic components of the converter connecting the rotor windings with the rotor-inverter.|bgcolor = "#DCE6F1"|The converter is provided with a clamping unit which is triggered from a non-operation state to an operation state, during detection of over-current in the rotor windings. The clamping unit comprises passive voltage-dependent resistor element for providing a clamping voltage over the rotor windings when the clamping unit is triggered.|-valign="top"|align = "center"|10|<font color="#0000FF"><u>[http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220050189896%22.PGNR.&OS=DN/20050189896&RS=DN/20050189896 US20050189896]</u></font>|align = "center"|09/01/05|ABB Research|Method for controlling doubly-fed machine|Controlling the double fed machines on the basis of inverter control to implement the targets set for the machine, this model is extremely complicated and includes numerous parameters that are often to be determined.|A method is provided to use a standard scalar-controlled frequency converter for machine control. A frequency reference for the inverter with a control circuit, and reactive power reference are set for the machine. A rotor current compensation reference is set based on reactive power reference and reactive power. A scalar-controlled inverter is controlled for producing voltage for the rotor of the machine, based on the set frequency reference and rotor current compensation reference.
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Click '''[[Media:Doublyfed_induction_generator1.xls| here]]''' to view the detailed analysis sheet for doubly-fed induction generators patent analysis.
===Article Analysis===
{|border="2" cellspacing="0" cellpadding="4" width="100%"
|align = "center" bgcolor = "#4F81BD" width="38"|<font color="#FFFFFF">'''S.No.'''</font>
|align = "center" bgcolor = "#4F81BD"|<font color="#FFFFFF">'''Title'''</font>
|align = "center" bgcolor = "#4F81BD" width="105"|<font color="#FFFFFF">'''Publication Date<br>'''(mm/dd/yyyy)</font>
|align = "center" bgcolor = "#4F81BD"|<font color="#FFFFFF">'''Journal/Conference'''</font>
|align = "center" bgcolor = "#4F81BD"|<font color="#FFFFFF">'''Dolcera Summary'''</font>
|-valign="top"
|align = "center" bgcolor = "#DCE6F1"|1
|bgcolor = "#DCE6F1"|<font color="#0000FF"><u>[http://ieeexplore.ieee.org/search/freesrchabstract.jsp?tp=&arnumber=1709031&queryText=Study+on+the+Control+of+DFIG+and+Its+Responses+to+Grid+Disturbances&openedRefinements=*&searchField=Search+All Study on the Control of DFIG and its Responses to Grid Disturbances ]</u></font>
|align = "center" bgcolor = "#DCE6F1"|01/01/06
|bgcolor = "#DCE6F1"|Power Engineering Society General Meeting, 2006. IEEE
|bgcolor = "#DCE6F1"|Presented dynamic model of the DFIG, including mechanical model, generator model, and PWM voltage source converters. Vector control strategies adapted for both the RSC and GSC to control speed and reactive power independently. Control designing methods, such as pole-placement method and the internal model control are used. MATLAB/Simulink is used for simulation.
|-valign="top"
|align = "center"|2
|<font color="#0000FF"><u>[http://ieeexplore.ieee.org/search/freesrchabstract.jsp?tp=&arnumber=1649950&queryText=Application+of+Matrix+Converter+for+Variable+Speed+Wind+Turbine+Driving+an+Doubly+Fed+Induction+Generator&openedRefinements=*&searchField=Search+All Application of Matrix Converter for Variable Speed Wind Turbine Driving an Doubly Fed Induction Generator ]</u></font>|align = "center"|93 hits05/23/06|Induction motor classes AND Doubly Power Electronics, Electrical Drives, Automation and Motion, 2006. SPEEDAM 2006. |A matrix converter is replaced with back to back converter in a variable speed wind turbine using doubly fed induction generator keywords. Stable operation is achieved by stator flux oriented control technique and the system operated in both sub and super synchronous modes, achieved good results. |(UC-valign=(318"top"|align = "center" bgcolor = "#DCE6F1"|3|bgcolor = "#DCE6F1"|<font color="#0000FF"><u>[http://ieeexplore.ieee.org/727 OR 322search/047) OR AIOEfreesrchabstract.jsp?tp=(H02K001742)) AND ALL&arnumber=4778305&queryText=Optimal+Power+Control+Strategy+of+Maximizing+Wind+Energy+Tracking+and+Conversion+for+VSCF+Doubly+Fed+Induction+Generator+System&openedRefinements=(((((Doubl*3 or dual*3 or two) adj3 (&searchField=Search+Al Optimal Power Control Strategy of Maximizing Wind Energy Tracking and Conversion for VSCF Doubly Fed Induction Generator System ]</u></font>|align = "center" bgcolor = "#DCE6F1"|08/14/06|bgcolor = "#DCE6F1"|Power Electronics and Motion Control Conference, 2006. IPEMC 2006. CES/IEEE 5th International |bgcolor = "#DCE6F1"|Proposed a new optimal control strategy of maximum wind power*2 or output*1 or extraction strategies and testified by simulation. The control*algorithm also used to minimize the losses in the generator. The dual passage excitation control strategy is applied to decouple the active and reactive powers. With this control system, the simulation results show the good robustness and high generator efficiency is achieved. |-valign="top"|align = "center"|4 or |<font color="#0000FF"><u>[http://docs.google.com/viewer?a=v&q=cache:HqaFsMBhchcJ:iris.elf.stuba.sk/JEEEC/data/pdf/3_108-8.pdf+A+TORQUE+TRACKING+CONTROL+ALGORITHM+FOR+DOUBLY–FED+INDUCTION+GENERATOR&hl=enπd=bl&srcid=ADGEESgbHXoAbKe4O7b5DnykDc7h_LaHwCMIhkVrGX_whx4iUuE4Mc-3Rfq1DyW_h A Torque Tracking Control algorithm for Doubly–fed Induction Generator ]</u></font>|align = "center"|01/01/08|Journal of Electrical Engineering|Proposed a torque tracking control algorithm for Doubly fed or feedinduction generator using PI controllers. It is achieved by controlling the rotor currents and using a stator voltage vector reference frame. |-valign="top"|align = "center" bgcolor = "#DCE6F1"|5|bgcolor = "#DCE6F1"|<font color="#0000FF"><u>[http://ieeexplore.ieee.org/search/freesrchabstract.jsp?tp=&arnumber=4651578&queryText=Fault+Ride+Through+Capability+Improvement+Of+Wind+Farms+Usind+Doubly+Fed+Induciton+Generator&openedRefinements=*3)) near5 (generat*3 or machine*1 or dynamo*1))) OR DFIG);&searchField=Search+All Fault Ride Through Capability Improvement Of Wind Farms Using Doubly Fed Induction Generator ]</u></font>|align = "center" bgcolor = "#DCE6F1"|09/04/08|bgcolor = "#DCE6F1"|Universities Power Engineering Conference, 2008. UPEC 2008. 43rd International |bgcolor = "#DCE6F1"|An active diode bridge crowbar switch presented to improve fault ride through capability of DIFG. Showed different parameters related to crowbar such a crowbar resistance, power loss, temperature and time delay for deactivation during fault.
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|}Click '''[[Media:Doublyfed_induction_generators1.xls| here]]''' to view the detailed analysis sheet for doubly-fed induction generators article analysis.<br> ===Top Cited Patents==={|border="2" cellspacing="0" cellpadding="4" width="100%"|align = "center" bgcolor = "#4F81BD" width="38"|3<font color="#FFFFFF">'''S. No.'''</font>|align = "center" bgcolor = "#4F81BD"|675 hits<font color="#FFFFFF">'''Patent/Publication No.'''</font>|Broad classes of generators AND Doubly fed induction generator keywordsalign = "center" bgcolor = "#4F81BD" width="105"|(UC<font color="#FFFFFF">'''Publication Date'''<br>(290mm/044 OR 290dd/055yyyy) OR AIOE</font>|align =(F03D000900C OR H02J000338 OR F03D0009* OR H02P0009*)) AND ALL"center" bgcolor =(((((Doubl*"#4F81BD"|<font color="#FFFFFF">'''Assignee/Applicant'''</font>|align = "center" bgcolor = "#4F81BD"|<font color="#FFFFFF">'''Title'''</font>|align = "center" bgcolor = "#4F81BD"|<font color="#FFFFFF">'''Citation Count'''</font>|-valign="top"|align = "center" bgcolor = "#DCE6F1"|1|bgcolor = "#DCE6F1"|<font color="#0000FF"><u>[http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=5289041.PN.&OS=PN/5289041&RS=PN/5289041 US5289041]</u></font>|align = "center" bgcolor = "#DCE6F1"|02/22/94|bgcolor = "#DCE6F1"|US Windpower|bgcolor = "#DCE6F1"|Speed control system for a variable speed wind turbine|align = "center" bgcolor = "#DCE6F1"|80|-valign="top"|align = "center"|2 or dual*3 or two) adj3 (power*2 or output*|<font color="#0000FF"><u>[http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1 or &u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=4982147.PN.&OS=PN/4982147&RS=PN/4982147 US4982147]</u></font>|align = "center"|01/01/91|Oregon State|Power factor motor control*system|align = "center"|62|-valign="top"|align = "center" bgcolor = "#DCE6F1"|3 or |bgcolor = "#DCE6F1"|<font color="#0000FF"><u>[http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=5028804.PN.&OS=PN/5028804&RS=PN/5028804 US5028804]</u></font>|align = "center" bgcolor = "#DCE6F1"|07/02/91|bgcolor = "#DCE6F1"|Oregon State|bgcolor = "#DCE6F1"|Brushless doubly-fed or feed*3)) near5 (induction or asynchronous)) near5 (generat*3 or generator control system|align = "center" bgcolor = "#DCE6F1"|51|-valign="top"|align = "center"|4|<font color="#0000FF"><u>[http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=5239251.PN.&OS=PN/5239251&RS=PN/5239251 US5239251]</u></font>|align = "center"|08/24/93|Oregon State|Brushless doubly-fed motor control system|align = "center"|49|-valign="top"|align = "center" bgcolor = "#DCE6F1"|5|bgcolor = "#DCE6F1"|<font color="#0000FF"><u>[http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=6856038.PN.&OS=PN/6856038&RS=PN/6856038 US6856038]</u></font>|align = "center" bgcolor = "#DCE6F1"|02/15/05|bgcolor = "#DCE6F1"|Vestas Wind Systems|bgcolor = "#DCE6F1"|Variable speed wind turbine having a matrix converter|align = "center" bgcolor = "#DCE6F1"|43|-valign="top"|align = "center"|6|<font color="#0000FF"><u>[http://www.wipo.int/pctdb/en/wo.jsp?WO=1999029034 WO1999029034]</u></font>|align = "center"|06/10/99|Asea Brown|A method and a system for speed control of a rotating electrical machine*with flux composed of two quantities|align = "center"|36|-valign="top"|align = "center" bgcolor = "#DCE6F1"|7|bgcolor = "#DCE6F1"|<font color="#0000FF"><u>[http://www.wipo.int/pctdb/en/wo.jsp?WO=1999019963 WO1999019963]</u></font>|align = "center" bgcolor = "#DCE6F1"|04/22/99|bgcolor = "#DCE6F1"|Asea Brown|bgcolor = "#DCE6F1"|Rotating electric machine|align = "center" bgcolor = "#DCE6F1"|36|-valign="top"|align = "center"|8|<font color="#0000FF"><u>[http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1 or dynamo*&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1)) &f=G&l=50&s1=7015595.PN.&OS=PN/7015595&RS=PN/7015595 US7015595]</u></font>|align = "center"|03/21/06|Vestas Wind Systems|Variable speed wind turbine having a passive grid side rectifier with scalar power control and dependent pitch control|align = "center"|34|-valign="top"|align = "center" bgcolor = "#DCE6F1"|9|bgcolor = "#DCE6F1"|<font color="#0000FF"><u>[http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=4763058.PN.&OS=PN/4763058&RS=PN/4763058 US4763058]</u></font>|align = "center" bgcolor = "#DCE6F1"|08/09/88|bgcolor = "#DCE6F1"|Siemens|bgcolor = "#DCE6F1"|Method and apparatus for determining the flux angle of rotating field machine or DFIG);for position-oriented operation of the machine|align = "center" bgcolor = "#DCE6F1"|32|-valign="top"|align = "center"|10|<font color="#0000FF"><u>[http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=7095131.PN.&OS=PN/7095131&RS=PN/7095131 US7095131]</u></font>|align = "center"|08/22/06|General Electric|Variable speed wind turbine generator|align = "center"|25
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===Top Cited Articles===
{|border="2" cellspacing="0" cellpadding="4" width="100%"
|align = "center" bgcolor = "#4F81BD" width="38"|<font color="#FFFFFF">'''S. No.'''</font>
|align = "center" bgcolor = "#4F81BD"|<font color="#FFFFFF">'''Title'''</font>
|align = "center" bgcolor = "#4F81BD"|<font color="#FFFFFF">'''Publication Date'''</font>
|align = "center" bgcolor = "#4F81BD"|<font color="#FFFFFF">'''Journal/Conference'''</font>
|align = "center" bgcolor = "#4F81BD"|<font color="#FFFFFF">'''Citations Count'''</font>
|-valign="top"
|align = "center" bgcolor = "#DCE6F1"|1
|bgcolor = "#DCE6F1"|<font color="#0000FF"><u>[http://ieeexplore.ieee.org/xpls/abs_all.jsp?&arnumber=502360 Doubly fed induction generator using back-to-back PWM converters and its application to variable-speed wind-energy generation]</u></font>
|align = "center" bgcolor = "#DCE6F1"|May. 1996
|bgcolor = "#DCE6F1"|IEEE Proceedings Electric Power Applications
|align = "center" bgcolor = "#DCE6F1"|906
|-valign="top"
|align = "center"|2
|<font color="#0000FF"><u>[http://ieeexplore.ieee.org/xpls/abs_all.jsp?&arnumber=999610 Doubly fed induction generator systems for wind turbines]</u></font>
|align = "center"|May. 2002
|IEEE Industry Applications Magazine
|align = "center"|508
|-valign="top"
|align = "center" bgcolor = "#DCE6F1"|3
|bgcolor = "#DCE6F1"|<font color="#0000FF"><u>[http://ieeexplore.ieee.org/xpls/abs_all.jsp?&arnumber=1198317 Dynamic modeling of doubly fed induction generator wind turbines]</u></font>
|align = "center" bgcolor = "#DCE6F1"|May. 2003
|bgcolor = "#DCE6F1"|IEEE Transactions on Power Systems
|align = "center" bgcolor = "#DCE6F1"|274
|-valign="top"
|align = "center"|4
|<font color="#0000FF"><u>[http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=1201089 Modeling and control of a wind turbine driven doubly fed induction generator]</u></font>|align = "center"|240 hitsJun. 2003|French keywordsIEEE Transactions on Energy Conversion| CTBalign = "center"|271|-valign="top"|align = "center" bgcolor = "#DCE6F1"|5|bgcolor = "#DCE6F1"|<font color="#0000FF"><u>[http://ieeexplore.ieee.org/iel5/60/30892/01432858.pdf?arnumber=((((Doubl*3 or dual*3or ADJ two or deux) near4 (nourris or feed*3 or puissance or sortie*1 or contrôle*1)) near4 (1432858 Ride through of wind turbines with doubly-fed induction or asynchrone*1) near4 (générateur*1 or generator*1 or machine*1 or dynamo*1)) or DFIG);during a voltage dip]</u></font>|align = "center" bgcolor = "#DCE6F1"|Jun. 2005|bgcolor = "#DCE6F1"|IEEE Transactions on Energy Conversion|align = "center" bgcolor = "#DCE6F1"|246|-valign="top"|align = "center"|6|<font color="#0000FF"><u>[http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=970114 Dynamic modeling of a wind turbine with doubly fed induction generator]</u></font>|align = "center"|July. 2001|IEEE Power Engineering Society Summer Meeting, 2001|align = "center"|196|-valign="top"|align = "center" bgcolor = "#DCE6F1"|7|bgcolor = "#DCE6F1"|<font color="#0000FF"><u>[http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=1597345 Modeling of the wind turbine with a doubly fed induction generator for grid integration studies]</u></font>|align = "center" bgcolor = "#DCE6F1"|Mar. 2006|bgcolor = "#DCE6F1"|IEEE Transactions on Energy Conversion|align = "center" bgcolor = "#DCE6F1"|174|-valign="top"|align = "center"|8|<font color="#0000FF"><u>[http://ieeexplore.ieee.org/xpls/abs_all.jsp?&arnumber=543631 A doubly fed induction generator using back-to-back PWM converters supplying an isolated load from a variable speed wind turbine]</u></font>|align = "center"|Sept. 1996|IEEE Proceedings Electric Power Applications|align = "center"|150|-valign="top"|align = "center" bgcolor = "#DCE6F1"|9|bgcolor = "#DCE6F1"|<font color="#0000FF"><u>[http://ieeexplore.ieee.org/xpls/abs_all.jsp?&arnumber=1432853 Doubly fed induction generator model for transient stability analysis]</u></font>|align = "center" bgcolor = "#DCE6F1"|Jun. 2005|bgcolor = "#DCE6F1"|IEEE Transactions on Energy Conversion|align = "center" bgcolor = "#DCE6F1"|106|-valign="top"|align = "center"|10|<font color="#0000FF"><u>[http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=1677655 Control of a doubly fed induction generator in a wind turbine during grid fault ride-through]</u></font>|align = "center"|Sept. 2006|IEEE Transactions on Energy Conversion|align = "center"|112
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|align } ===White Space Analysis===* White-space analysis provides the technology growth and gaps in the technology where further R&D can be done to gain competitive edge and to carry out incremental innovation.* Dolcera provides White Space Analysis in different dimensions. Based on Product, Market, Method of Use, Capabilities or Application or Business Area and defines the exact categories within the dimension.* Below table shows a sample representation of white space analysis for controlling DFIG parameters with converters, based on the sample analysis.{|border= "2" cellspacing="0" cellpadding="14" width="20%"| style="background-color:#4F81BD;"| <center><font color="#FFFFFF">'''White Space of converters used to control'''</font></center>|5style="background-color:#4F81BD;"| <center><font color="#FFFFFF">'''Active power'''</font></center>|align style= "background-color:#4F81BD;"| <center><font color="#FFFFFF">'''Reactive Power'''</font></center>|282 hitsstyle="background-color:#4F81BD;"| <center><font color="#FFFFFF">'''Decoupled P-Q control'''</font></center>|German keywordsstyle="background-color:#4F81BD;"| <center><font color="#FFFFFF">'''Field oriented control'''</font></center>|CTBstyle=(((((doppel*1 or dual or two or zwei) adj3 (Ausgang or Ausgänge or Kontroll* or "background-color:#4F81BD;"| <center><font color="#FFFFFF">'''Direct torque control*4 or gesteuert or Macht or feed*1 or gefüttert or gespeiste*1)) or (doppeltgefüttert or DOPPELTGESPEISTE*1)) near4 (((Induktion or asynchronen) near4 (generator*2 or Maschine*1 or dynamo*1)) or (INDUKTION?MASCHINEN or INDUKTION?generatoren or Asynchronmaschine or Asynchrongenerator))) or DFIG)'''</font></center>| style="background-color:#4F81BD;"| <center><font color="#FFFFFF">'''Speed control'''</font></center>| style="background-color:#4F81BD;"| <center><font color="#FFFFFF">'''Frequency Control'''</font></center>| style="background-color:#4F81BD;"| <center><font color="#FFFFFF">'''Pitch control'''</font></center>| style="background-color:#4F81BD;"| <center><font color="#FFFFFF">'''PWM Technique'''</font></center>| style="background-color:#4F81BD;"| <center><font color="#FFFFFF">'''Low voltage ride through'''</font></center>| style="background-color:#4F81BD;"| <center><font color="#FFFFFF">'''Network fault/Grid fault'''</font></center>| style="background-color:#4F81BD;"| <center><font color="#FFFFFF">'''Symmetrical and Asymmetrical Faults'''</font></center>| style="background-color:#4F81BD;"| <center><font color="#FFFFFF">'''Temp control'''</font></center>
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|align style= "background-color:#4F81BD;"| <center><font color="#FFFFFF">'''Grid Side active converters'''</font></center>|6[http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220070052394%22.PGNR.&OS=DN/20070052394&RS=DN/20070052394 US20070052394A1][http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220060028025%22.PGNR.&OS=DN/20060028025&RS=DN/20060028025 US20060028025A1]|align [http://appft1.uspto.gov/netacgi/nph-Parser?Sect1= "center"PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220100148508%22.PGNR.&OS=DN/20100148508&RS=DN/20100148508 US20100148508A1][http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220100133816%22.PGNR.&OS=DN/20100133816&RS=DN/20100133816 US20100133816A1][http://v3.espacenet.com/searchResults?NUM=EP2166226A1&DB=EPODOC&submitted=true&locale=en_V3&ST=number&compact=false EP2166226A1][http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220070132248%22.PGNR.&OS=DN/20070132248&RS=DN/20070132248 US20070132248A1][http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220070052394%22.PGNR.&OS=DN/20070052394&RS=DN/20070052394 US20070052394A1][http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220100096853%22.PGNR.&OS=DN/20100096853&RS=DN/20100096853 US20100096853A1]|920 hits[http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220100114388%22.PGNR.&OS=DN/20100114388&RS=DN/20100114388 US20100114388A1]
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|align style= "centerbackground-color:#4F81BD;"|7|align <center><font color= "center#FFFFFF"|>'''1434 hits (702 INPADOC Families)Grid side passive converters'''</font></center>|Combined Query[http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220030151259%22.PGNR.&OS=DN/20030151259&RS=DN/20030151259 US20030151259A1]|[http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1 OR 2 OR 3 OR 4 OR 5 OR 6&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220030151259%22.PGNR.&OS=DN/20030151259&RS=DN/20030151259 US20030151259A1]||||||[http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220030151259%22.PGNR.&OS=DN/20030151259&RS=DN/20030151259 US20030151259A1]|||||
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| style="background-color:#4F81BD;"| <center><font color="#FFFFFF">'''Rotor side converter'''</font></center>
|[http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220100142237%22.PGNR.&OS=DN/20100142237&RS=DN/20100142237 US20100142237A1]
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|[http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220100096853%22.PGNR.&OS=DN/20100096853&RS=DN/20100096853 US20100096853A1]
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| style="background-color:#ffffff;"|[http://www.wipo.int/pctdb/en/wo.jsp?WO=2010079234 WO2010079234A1]
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| style="background-color:#ffffff;"|[http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220080157533%22.PGNR.&OS=DN/20080157533&RS=DN/20080157533 US20080157533A1]
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===Taxonomy=Dolcera Dashboard ==<mm>[[Mmap825(1Image:dashboard_features.1).mmpng|Interactive Mindmapcenter|center750px|title Doubly-fed Induction Generator]]</mm>
'''Dashboard Link'''<br>{|border="2" cellspacing="0" cellpadding=Sample Analysis="4" width="100%"|'''[https://www.dolcera.com/auth/dashboard/dashboard.php?workfile_id=825 Doubly Fed Induction Generator - Dashboard] '''A sample of 139 patents from the search are analysed based on the taxonomy|width="100"|[[Image:dashboard_thumb.png|center|100px|]]Provided a link below for sample spread sheet analysis for doubly|-fed induction generators.<br>|}*Flash Player is essential to view the Dolcera dashboard
==Key Findings===== Major Players ===* [http://www.vestas.com/ Vestas Wind Energy Systems] and [Mediahttp:Doublyfed_induction_generator1//www.xls| Sample analysis on Doubly-Fed Induction Generator-Patent Literaturege.com/ General Electric]]<br>are the major players in wind energy generation technology.* [[MediaImage:Doublyfed_induction_generators1Wind_Major_Players.xlspng|center|thumb|700px| Sample analysis on Doubly-Fed Induction Generator-Non Patent Literature'''Major Players''']]
===IP Trend AnalysisKey Patents ===Patenting activity has seen high growth rate * The key patents in the last two years.[field are held by [Imagehttp:ipublication trends//www.png|center|750pxwindpoweringamerica.gov/wind_installed_capacity.asp US Windpower]]Vestas , [http://www.oregon.gov/ENERGY/RENEW/Wind Systems and General Electric are the major players in this technology field/windhome.[shtml Oregon State] and [Imagehttp:Major Players//www.png|center|750px]vestas.com/ Vestas Wind Energy Systems].
===Dashboard===[[Image:Dashboard12wind_top_cited.jpgpng|center|750pxthumb|700px|'''Key Patents''']]
=== IP Activity ===* Patenting activity has seen a very high growth rate in the last two years.[[Image:ind_pat_act_3.png|center|thumb|700px|'''Dashboard LinkYear wise IP Activity'''<br>[https://www.dolcera.com/auth/dashboard/dashboard.php?workfile_id=825# Dashboard for doubly fed induction generator]]
=== Geographical Activity ===*Flash Player is essential to view the DashboardUSA, China, Germany, Spain, and India are very active in wind energy research.[[Image:wind_geographical_act.png|center|thumb|700px|'''Geographical Activity''']] ===Market ResearchTrend ===* Around 86% patents are on controlling the doubly-fed induction generation(DFIG) which indicates high research activity going on in rating and controlling of the DFIG systems. ==Major Players= Issues in the Technology ===Vestas Wind Systems* 86% of the patent on DFIG operation are focusing on grid connected mode of operation, General Electric suggesting continuous operation of the DFIG system during weak and Gamesa Innovation & Technology storm winds, grid voltage sags, and grid faults are major issues in the top players current scenario. [[Image:Windenergyanalysis.jpg|center|1200px|thumb|'''Problem Solution Mapping''']] === Emerging Player ===* [http://www.woodward.com/ Woodward] is a new and fast developing player in terms the field of installed power capacity DFIG technology. The company filed 10 patent applications in the field in year 20072010, while it has no prior IP activity.{| border "1" style="border-spacing:0;"| <span style="background-color:#99ccff;padding:0.079cm;C41E3A"| >Like this report?</span>=<p align="center">'''S.NoThis is only a sample report with brief analysis'''</centerbr>| style="background-color:#99ccff;padding:0.079cm;"| <center>'''CompanyDolcera can provide a comprehensive report customized to your needs'''</centerp>{| colspanborder="2" cellspacing="0" cellpadding="4" align="center" "|style="background-color:#99ccff;padding:0.079cm;lightgrey" align = "| <center>'''Installed Capacity" colspan = "3"|'''[mailto:info@dolcera.com <span style="color:#0047AB">Buy the customized report from Dolcera</centerspan>]'''
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| stylealign ="padding:0.079cm;center"| <center>1<[http:/center>/www.dolcera.com/website_prod/services/ip-patent-analytics-services Patent Analytics Services]| stylealign ="padding:0.079cm;center"| <center>Vestas (Denmark)<[http:/center>/www.dolcera.com/website_prod/services/business-research-services Market Research Services]| colspanalign ="2center" style="padding| [http:0//www.079cm;"| <center>4,500 MW<dolcera.com/center>website_prod/tools/patent-dashboard Purchase Patent Dashboard]
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| stylealign ="padding:0.079cm;center"| <center>2<[http:/center>/www.dolcera.com/website_prod/services/ip-patent-analytics-services/patent-search/patent-landscapes Patent Landscape Services]| stylealign ="padding:0.079cm;center"| <center>GE Energy (United States)<[http:/center>/www.dolcera.com/website_prod/research-processes Dolcera Processes]| colspanalign ="2center" style="padding| [http:0//www.079cm;"| <center>3,300 MW<dolcera.com/center>website_prod/industries Industry Focus]
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| stylealign ="padding:0.079cm;center"| <center>3<[http:/center>/www.dolcera.com/website_prod/services/ip-patent-analytics-services/patent-search/patent-landscapes Patent Search Services]| stylealign ="padding:0.079cm;center"| <center>Gamesa (Spain)<[http:/center>/www.dolcera.com/website_prod/services/ip-patent-analytics-services/alerts-and-updates Patent Alerting Services]| colspanalign ="2center" style="padding| [http:0//www.079cm;"| <center>3,050 MW<dolcera.com/center>website_prod/tools Dolcera Tools]
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| style}<br>=References ={|border="padding:0.079cm;"| <center>cellspacing="0" cellpadding="4</center>" width="100%"| style-valign="paddingtop"|'''Background References'''# [http://www.brighthub.com/environment/renewable-energy/articles/71440.aspx Wind Energy History]# [[Media:windenergy.pdf| Wind Energy]]# [http://windeis.anl.gov/guide/basics/index.cfm Wind Energy Basics]# [http://www1.eere.energy.gov/windandhydro/wind_how.html#inside How Wind Turbines Work]# [http://www.windpowertv.com/forum/index.php?topic=18.0Different types of wind turbines]# [http://www.079cm;"house-energy.com/Wind/Offshore-Onshore.htm Onshore Vs Offshore Wind Turbines]# [http://library.thinkquest.org/06aug/01335/wind%20Power.htm Wind Power]# [http://www.ehow.com/list_5938067_types-wind-farms-there_.html Types of Wind Farms]# [http://www.offshorewindenergy.org/ca-owee/indexpages/Offshore_technology.php?file=offtech_p2.php Offshore Technology]# [http://windsine.org/?act=spage&f=wind The Fundamentals of Wind Energy]# [http://windertower.com/ Winder Tower]# [http://www.thesolarguide.com/wind-power/wind-towers.aspx Wind Towers]# [http://guidedtour.windpower.org/en/tour/design/concepts.htm Wind Turbine Blades]# [http://www.wind-energy-the-facts.org/en/part-i-technology/chapter-3-wind-turbine-technology/evolution-of-commercial-wind-turbine-technology/design-styles.html Wind Turbine Design Styles]# [http://www.awewind.com/Products/TurbineConstruction/MainAssembly/RotorHub/tabid/81/Default.aspx Rotor Hub Assembly]# [http://www.gears-gearbox.com/wind-turbines.html Gearbox for Wind Turbines]# [http://guidedtour.windpower.org/en/tour/wtrb/yaw.htm The Wind Turbine Yaw Mechanism]# [http://guidedtour.windpower.org/en/tour/wtrb/yaw.htm The Wind Turbine Yaw Mechanism]# [[Media:windturbinegenerators.pdf| <center>Enercon (Germany)<Wind Turbine Generators]]# [http:/center>/www.uni-hildesheim.de/~irwin/inside_wind_turbines.html Inside wind turbines]| colspan="2" '''Image References'''# [http://www.windsimulators.co.uk/DFIG.htm DFIG Working Principle]# [http://www.wwindea.org/home/index.php styleCountry share of total capacity]# [http://www.atlantissolar.com/wind_story.html Wind turbine principle]# [http://www.windturbinesnow.com/horizontalaxis-windturbines.htm Horizontal axis wind turbine]# [http://www.solarpowerwindenergy.org/2009/12/25/types-of-wind-turbines/ Vertical axis wind turbine]# [http://zone.ni.com/devzone/cda/tut/p/id/8189 Pitch control]# [http://zone.ni.com/devzone/cda/tut/p/id/8189 Yaw control]# [http://www.eco-trees.org/europes-biggest-onshore-wind-farm-goes-online/ Onshore Wind turbines]# [http://www.house-energy.com/Wind/Offshore-Onshore.htm Offshore wind turbines]# [http://www.solarpowerwindenergy.org/2010/04/02/parts-of-a-wind-turbine/ Wind turbine parts]# [http://www.windsolarenergy.org/map-of-best-locations-for-wind-power.htm Tower height Vs Power output]# [http://americanrenewableenergycorp.com/towers Tubular tower]# [http://www.mywindpowersystem.com/2010/03/wind-power-stats-quiet-critics/ Lattice tower]# [http://itgiproducts.com/energy/windTowers.asp Guy tower]# [http://itgiproducts.com/energy/windTowers.asp Tiltup tower]# [http://itgiproducts.com/energy/windTowers.asp Free stand tower]# [http://www.wind-energy-the-facts.org/en/part-i-technology/chapter-3-wind-turbine-technology/evolution-of-commercial-wind-turbine-technology/design-styles.html Single blade turbine]# [http://www.trendir.com/green/?start="padding15 Two blade turbine]# [http:0//www.079cm;"| <center>2,700 MW<china-windturbine.com/center>wind-turbines-blades.htm Three blade turbine]# [http://windturbinesforthehome.com/ Internal nacelle structure]# [http://syigroup.en.made-in-china.com/product/dbTQyzJOHYRi/China-Iron-Casting-Wind-Mill-Tower-Rotor-Hub.html Rotor hub]# [http://jiangyinzkforging.en.made-in-china.com/product/hewxIQjbgTpr/China-Wind-Turbine-Shaft-For-Wind-Power-Generator-ALIM2143-.html Shaft system]# [http://machinedesign.com/article/green-technology-inside-an-advanced-wind-turbine-0605 Gear box]# [http://www1.eere.energy.gov/windandhydro/wind_how.html Anemometer & Wind vane]
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| style} =Contact Dolcera="padding:0.079cm;"| <center>5</center> {| style="paddingborder:0.079cm1px solid #AAA;background:#E9E9E9"| <center>Suzlon (India)</center>| colspanalign="2center" style="padding:0.079cm;"| <center>2,000 MW</center>
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| style="padding:0.079cm;"| <center>6</center>| style="padding:0.079cm;"| <center>Siemens (Denmark / Germany)</center>| colspan="2" ! style="paddingbackground:0.079cm;lightgrey"| <center>1,400 MW</center>Samir Raiyani
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| style="padding'''Email''':0.079cm;"| <center>7</center>| style="padding[mailto:0info@dolcera.079cm;"| <center>Acciona (Spain)</center>| style="padding:0com info@dolcera.079cm;"| <center>870 MW</center>com]
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| style="padding'''Phone''':0.079cm;"| <center>8</center>| style="padding:0.079cm;"| <center>Goldwind (China +1- PRC)</center>| style="padding:0.079cm;"| <center>830 MW</center>|650-| style="padding:0.079cm;"| <center>9</center>| style="padding:0.079cm;"| <center>Nordex (Germany)</center>| style="padding:0.079cm;"| <center>670 MW</center>|269-| style="padding:0.079cm;"| <center>10</center>| style="padding:0.079cm;"| <center>Sinovel (China - PRC)</center>| style="padding:0.079cm;"| <center>670 MW</center>7952
|}
Source:[http://www.mywindpowersystem.com/2009/04/the-10-major-wind-power-companies-in-the-world/ Wind power companies]
==Market Overview==
* The world's wind industry defied the economic downturn in 2008 and by he end of the year 2009, the sector saw its annual market grow by 41.5% over 2008, and total global wind power capacity increased by 31.7% to 158GW in 2009
* US, China and Germany together hold more than 50% of the global wind power capacity
* Asia and North America have seen tremendous growth in the installed wind power capacity over the last 6 years
* Asia was the world's largest regional market for wind energy with capacity additions amounting to 15.4GW. China was the world's largest market in 2009, more than doubling its capacity from 12.1GW in 2008 to 25.8GW, adding a staggering 13.8GW of capacity
* China and the US account for more than 60% of the new installed capacity of 38.3GW in 2009. India's total installed capacity increased to 10.9GW with 1.3GW of new installed capacity in 2009
* The 2009 market for turbine installations was worth about 45 bn € or 63 bn US$ and about half a million people are now employed by the wind industry around the world
[[Image:Installed capacity 2009.png|600px|center|thumb|Top 10 Cumulative Installed Capacity 2009]]
[[Image:New capacity.png|600px|center|thumb|Top 10 New Installed Capacity 2009]]
[[Image:Region Capacities.png|600px|center|thumb|Annual Installed Capacity by Region 2003-2009]]
==Market Forecast==
* Global wind power capacity could reach 2,300 GW by 2030, providing up to 22% of the world's electricity needs, from the existing 2.2% in 2010.
* Global wind capacity will stand at 409GW up from 158GW at the end of 2008. During 2014, 62.5 GW of new capacity will be added to the global total, compared to 38.3 GW in 2009
* The annual growth rates during this period will average 20.9% in terms of total installed capacity, and 10.3% for annual market growth
* Three regions will continue to drive the expansion of wind energy capacity: Asia, North America and Europe
* Asia will remain the fastest growing market in the world, driven primarily by China, which is set to continue the rapid upscaling of its wind capacity and hold its position as the world’s largest annual market. Annual additions are expected to be well over 20 GW in China by 2014
* Sustained growth is also expected in India, which will increase its capacity steadily by 2 GW every year, and be
complemented by growth in other Asian markets, including Japan, Taiwan, South Korea and the Philippines, and potentially some others
* By 2014, the annual market will reach 14.5 GW, and a total of 60 GW will be installed in Europe over this five year period
[[Image:Market forecast.png|800px|center|thumb|ANNUAL MARKET FORECAST BY REGION 2009-2013]]
<br>
Source:[http://www.gwec.net/index.php?id=167 GWEC's Global Wind Report 2009]