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Power from wind in india


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Wind Energy conversion systems for India are discussed here.

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Power from wind in india

  1. 1. WIND ENERGY ENGINEERING Wind Electric Conversion Systems * Wind Energy Availability • Energy in wind, speed • Wind Turbine, Design • Variables – wind power density • Generator and power output • PV-Wind, Diesel-set-Wind Hybrid System • Tower design • Wind Electric Conversion System economics
  2. 2. 2 Wind Energy Engineering Syllabus-1  Wind energy Assessment by Measurement and instrumentation – Beaufort number -Gust parameters – Wind type – power law index -Betz constant -Terrain value.  Energy in wind– study of wind data and applicable Indian standards – Steel Tables, Structural Engineering for tower design- Wind farms–– fatigue stress – Tower design.
  3. 3. 3 Wind Energy Engineering Syllabus-2  Wind Energy Conversion Systems: Variables – wind power density – power in a wind stream – Wind turbine efficiency – Forces on the blades of a propeller –Solidity and selection curves.  Horizontal Axis –WT and Vertical Axis -WT- Power duration curves- wind rose diagrams - study of characteristics - actuator theory- Controls and instrumentations.  Grid-Connected WECS and Independent WECS- Combination of WECS and diesel generator, Battery storage – Wind Turbine Circuits.
  4. 4. 4 CL 716 WIND ENERGY ENGINEERING: Text & Reference Books  1. S. Rao & B. B. Parulekar, “Energy Technology”, 3rd Edition, Khanna publishers, 1995.  2. Wind and Solar Power Systems, Mukund. R. Patel, 2nd Edition, Taylor & Francis, 2001  3. Wind Energy Handbook, Edited by T. Burton, D. Sharpe N. Jenkins and E . Bossanyi, John Wiley & Sons, N.Y. 2001  4. . L .L. Freris, Wind Energy Conversion Systems, Prentice Hall, 1990.  5. D. A. Spera, Wind Turbine Technology: Fundamental concepts of Wind Turbine Engineering, ASME Press
  5. 5. 5 From wind to electricity. The first wind powered electricity was produced in 1888. It had a rated power of 12 kW (direct current - dc). In the 1930's the first large scale AC turbine was constructed in the USA. In the 1970's the fuel crises sparked a revival in R & D work in America (USA and Canada) and Europe (Denmark, Germany, the Netherlands,Sweden and the UK) and modern wind turbine-generators were developed. This was achieved due to improvements in aerodynamic and structural design, materials technology and mechanical, electrical and control engineering and led to capablilty to produce several megawatts of electricity.
  6. 6. 6 Wind power is economically viable.  Over the last two decades, there has been a tremendous amount of technical improvement in wind turbines. Their costs have increased by about a factor of 9, due to more advanced controls, materials, and engineering, but at the same time their energy production has increased by a factor of 56, leading to a net decline in the cost per watt of a factor of more than six. Wind power is thus rapidly becoming economically viable.
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  9. 9. 9 Kinetic energy > Mechanical [Rotational] > Electrical energy Wind turbines convert the kinetic energy in wind into mechanical power that runs a generator to produce electricity.
  10. 10. 10 horizontal-axis vs vertical-axis  There are two basic designs of wind electric turbines: vertical-axis, or "egg-beater" style, and horizontal-axis (propeller-style) machines.  Horizontal-axis wind turbines are most common today, constituting nearly all of the "utility-scale" (100 kilowatts, kW, capacity and larger) turbines in the global market.
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  13. 13. 13 Wind power for developing countries  Large-scale grid connected wind turbines are common with wind farm; This can be the main national network, in which case electricity can be sold to the electricity utility.  Micro-grids distribute electricity to smaller areas, typically a village or town. When wind is used for supplying electricity to such a grid, a diesel generator set is often used as a backup for the periods when windspeeds are low.
  14. 14. 14 Figure: The Practical Action small wind turbine ©Practical Action
  15. 15. 15 Performance of WECS  The availability of wind resources are governed by the climatic conditions of the region concerned- for which wind survey is extremely important to exploit wind energy. Performance of W E C S depends upon: Subsystems like  wind turbine (aerodynamic),  gears (mechanical),  generator (electrical) and Control (electronic)
  16. 16. 16 Wind Electric Potential in India  Gross Potential: 45,000 MW Technical Potential:13,000 MW Sites with Annual Average Wind Power Density > 200 watts/m2 generally viable, 208 such sites in 13 states identified States with high potential :  Gujarat, Andhra Pradesh, Tamil Nadu, Karnataka, Kerala, Madhya Pradesh, and Maharashtra.
  17. 17. 17 India’s Installed Wind Power Gen Capacity at end of 2001 State Installed capacity, MW Tamil Nadu 828 Maharashtra 236 Gujarat 167 Andhra 92 Karnataka 50 M.P. 23 All Others 111
  18. 18. 18 Wind resources  Apart from having a good wind turbine, the most critical aspects for the success of investment in the wind energy sector are  having a good site and  an accurate assessment of the wind resource at the site.
  19. 19. 19 Wind Resource Monitoring  Site selection  Wind Monitoring  Wind Resource Mapping
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  21. 21. 21 Choosing an exact location for the monitoring tower:  Place the tower as far away as possible from local obstructions to the wind  Select a location that is representative of the majority of the site.
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  23. 23. 23 anemometer  An instrument for measuring the force or velocity of wind. There are various types:  A cup anemometer, is used to measure the wind speed from the speed of rotation of a windmill which consist of 3 or 4 hemispherical or conical cups, each fixed to the ends of horizontal arms attached to a vertical axis.  A Byram anemometer is a variety of cup anemometer.
  24. 24. 24  A counting anemometer has cups or a fan whose rotation is transmitted to a counter which integrates directly the air movement speed.  A hand anemometer is small portable anemometer held at arm's length by an observer making a wind speed measurement.  A pressure tube anemometer (Dines anemometer) is an instrument that derives wind speed from measurements of the dynamic wind pressures. Wind blowing into a tube develops a pressure greater than the static pressure, while wind blowing across a tube develops a pressure less than the static. This pressure difference is proportional to the square of the wind speed.
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  26. 26. 26 WIND Wind Speed at 10 m height SPEED Beaufort scale SCALE Wind 0.0-0.4 m/s (0.0-0.9 knots) 0 Calm 0.4-1.8 m/s (0.9-3.5 knots) 1 Light 1.8-3.6 m/s (3.5-7.0 knots) 2 Light 3.6-5.8 m/s (7-11 knots) 3 Light 5.8-8.5 m/s (11-17 knots) 4 Moderate 8.5-11 m/s (17-22 knots) 5 Fresh 11-14 m/s (22-28 knots) 6 Strong 14-17 m/s (28-34 knots) 7 Strong 17-21 m/s (34-41 knots) 8 Gale 21-25 m/s (41-48 knots) 9 Gale 25-29 m/s (48-56 knots) 10 Strong Gale 29-34 m/s (56-65 knots) 11 >34 m/s (>65 knots) 12 Hurricane
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  29. 29. 29 For wind data from selected stations, essential attributes are:  Station location  Local topography  Anemometer height and exposure  Type of observation (instantaneous or average)  Duration of record.
  30. 30. 30 Topographic maps  provide the analyst with a preliminary look at other site attributes, including:  Available land area  Positions of existing roads and dwellings  Land cover (e.g., forests)  Political boundaries  Parks  Proximity to transmission lines.
  31. 31. 31 For verifying site conditions items of importance include:  Available land area  Land use  Location of obstructions  Trees deformed by persistent strong winds (flagged trees)  Accessibility into the site  Potential impact on local aesthetics  Cellular phone service reliability for data transfers  Possible wind monitoring locations.
  32. 32. 32 Cost – economics-1  The cost of producing electricity form the wind is heavily dependent on the local wind regime.  The power output from the wind machine is proportional to cube of the windspeed and so a slight increase in windspeed will mean a significant increase in power and a subsequent reduction in unit costs.  Capital costs for windpower are high, but running costs are low and so access to initial funds, subsidies or low interest loans are an obvious advantage when considering a wind-electric system.
  33. 33. 33 Cost – economics-2  If a hybrid system is used a careful cost- benefit analysis needs to be carried out.  A careful matching of the load and energy supply options should be made to maximise the use of the power from the wind - a load which accepts a variable input is ideally matched to the intermittent nature of windpower.
  34. 34. 34 WIND RESOURCE ASSESSMENT- India- Implemented through : (i) State Nodal Agencies (ii) Centre for Wind Energy Technology (C- WET) Financial Assistance : (i) Full establishment costs of Wind Resource Assessment Project (WRAP) of C-WET by the Central Government.
  35. 35. 35 WIND RESOURCE ASSESSMENT Implemented through…. : (ii) The cost of setting up the wind monitoring stations would be shared between MNRE and State Nodal agencies in 80:20 ratio, except for North-eastern and hilly States, where it would be in 90:10 ratio.
  36. 36. 36 Resource Survey in India Centre for Wind Energy Technology (C-WET) Chennai.  6 Volumes of “Wind Energy –Resource Survey in India” , containing wind data have been published  Master Plans for 87 sites prepared and available from C-WET at nominal cost.  Wind data available from C-WET on CD ROM.
  37. 37. 37 Government of India Ministry of New and Renewable Energy (Wind Power Division) Block No.14, CGO Complex, Lodhi Road, New Delhi – 110003 •C-WET would evaluate the eligibility of manufacturer, who approaches for Type. Certification, as per the evaluation criteria in vogue, which is being followed by C- WET. •Validity of Self-Certification facility for models specified in the List of Models and Manufacturers thereof issued by C- WET is extended up to 30th September, 2007. •Self-Certification facility would be available for a maximum period of 18 months from the date of signing of the agreement with C-WET for the models hereinafter including in the category "Model under Testing and Certification at C-WET" in the List to be issued by C-WET.
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  41. 41. 41 Wind Turbine, tail, support tower  The amount of power a turbine will produce depends primarily on the diameter of its rotor.  The diameter of the rotor defines its “swept area,” or the quantity of wind intercepted by the turbine.  The turbine‟s frame is the structure onto which the rotor, generator, and tail are attached. The tail keeps the turbine facing into the wind.
  42. 42. 42 Wind Turbine, tail, support tower
  43. 43. 43 Horizontal Axis upwind Wind Turbine Most turbines today are Horizontal Axis upwind machines with two or three blades, made of a composite material like fiberglass.
  44. 44. 44 Some definitions:  Solidity: In reference to a wind energy conversion device, the ratio of rotor blade surface area to the frontal, swept area that the rotor passes through.  wind rose: A diagram that indicates the average percentage of time that the wind blows from different directions, on a monthly or annual basis.  power curve: A plot of a wind energy conversion device's power output versus wind speed.  power coefficient: The ratio of power produced by a wind energy conversion device to the power in a reference area of the free wind stream.
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  46. 46. CEESAT NITT NOTES 46 The formula for calculating the power from a wind turbine is:
  47. 47. CEESAT NITT NOTES 47
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  49. 49. 49 Some definitions….  1 m/s = 3.6 km/h = 2.237 mph = 1.944 knots 1 knot = 1 nautical mile per hour = 0.5144 m/s = 1.852 km/h = 1.125 mph  average wind speed: The mean wind speed over a specified period of time.  PITCH CONROL: A method of controlling the speed of a wind turbine by varying the orientation, or pitch, of the blades, and thereby altering its aerodynamics and efficiency.
  50. 50. 50 Tip Speed Ratio The tip-speed is the ratio of the rotational speed of the blade to the wind speed. The larger this ratio, the faster the rotation of the wind turbine rotor at a given wind speed. Generation requires high rotational speeds. Lift-type wind turbines have maximum tip-speed ratios of around 10.The tip speed ratio (λ = ΩR/v), R Wind turbine blade radius (m), Ω Wind turbine rotor angular speed (rpm), v Wind speed [m/s].
  51. 51. 51 Operating Characteristics All wind machines share certain operating characteristics, such as cut-in, rated and cut- out wind speeds.  Cut-in Speed Cut-in speed is the minimum wind speed at which the wind turbine will generate usable power. This wind speed is typically between 7 and 10 mph.  Rated Speed The rated speed is the minimum wind speed at which the wind turbine will generate its designated rated power. For example, a "10 kilowatt" wind turbine may not generate 10 kilowatts until wind speeds reach 25 mph. Rated speed for most machines is in the range of 25 to 35 mph.
  52. 52. 52 Rated Speed…  At wind speeds between cut-in and rated, the power output from a wind turbine increases as the wind increases. The output of most machines levels off above the rated speed. Most manufacturers provide graphs, called "power curves," showing how their wind turbine output varies with wind speed.
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  54. 54. 54 Cut-out Speed  At very high wind speeds, typically between 45 and 80 mph, most wind turbines cease power generation and shut down. The wind speed at which shut down occurs is called the cut-out speed. Having a cut-out speed is a safety feature which protects the wind turbine from damage. Shut down may occur in one of several ways. In some machines an automatic brake is activated by a wind speed sensor.
  55. 55. 55 Cut out speed & yaw  Some machines twist or "pitch" the blades to spill the wind. Still others use "spoilers," drag flaps mounted on the blades or the hub which are automatically activated by high rotor rpm's, or mechanically activated by a spring loaded device which turns the machine sideways to the wind stream. Normal wind turbine operation usually resumes when the wind drops back to a safe level.
  56. 56. 56 number of blades  The number of rotor blades and the total area they cover affect wind turbine performance. For a lift- type rotor to function effectively, the wind must flow smoothly over the blades.  To avoid turbulence, spacing between blades should be great enough so that one blade will not encounter the disturbed, weaker air flow caused by the blade which passed before it.  It is because of this requirement that most wind turbines have only two or three blades on their rotors
  57. 57. 57 Transmission- Gear box  The number of revolutions per minute (rpm) of a wind turbine rotor can range between 40 rpm and 400 rpm, depending on the model and the wind speed.  Generators typically require rpm's of 1,200 to 1,800. As a result, most wind turbines require a gear-box transmission to increase the rotation of the generator to the speeds necessary for efficient electricity production.
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  59. 59. 59 Electrical Generators  It converts the turning motion of a wind turbine's blades into electricity. Inside this component, coils of wire are rotated in a magnetic field to produce electricity. Different generator designs produce either alternating current (AC) or direct current (DC),
  60. 60. 60 generators for wind turbines At the present time and for the near future, generators for wind turbines will be  synchronous generators,  permanent magnet synchronous generators, and  induction generators, including the squirrel- cage type and wound rotor type.
  61. 61. 61 Squirrel cage induction generator
  62. 62. 62 Doubly Fed Wounded Rotor Asynchronous Generator.
  63. 63. 63 Grid Connected Permanent Magnets Synchronous Generator in full converter topology
  64. 64. 64 generators for SMALL wind turbines  For small to medium power wind turbines, permanent magnet generators and squirrel-cage induction generators are often used because of their reliability and cost advantages. Induction generators, permanent magnet synchronous generators, and wound field synchronous generators are currently used in various high power wind turbines.
  65. 65. 65 Induction generator  Induction generator offers many advantages over a conventional synchronous generator as a source of isolated power supply.  Reduced unit cost, ruggedness, brush less (in squirrel cage construction), reduced size, absence of separate DC source and ease of maintenance, self-protection against severe overloads and short circuits, are the main advantages
  66. 66. 66 induction generator…  Further induction generators are loosely coupled devices, i.e. they are heavily damped and therefore have the ability to absorb slight change in rotor speed and drive train transient to some extent can therefore be absorbed.
  67. 67. 67 drawback of the induction generator Reactive power consumption and poor voltage regulation under varying speed are the major drawback of the induction generators, but the development of static power converters has facilitated the control of induction generator, regarding output voltage and frequency.
  68. 68. 68 Synchronous generator  Synchronous generators are closely coupled devices and when they are used in wind turbines which is subjected to turbulence and requires additional damping devices such as flexible couplings in the drive train or to mount gearbox assembly on springs and dampers.
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  70. 70. 70 range of output power ratings.  Generators are available in a large range of output power ratings.  The generator's rating, or size, is dependent on the length of the wind turbine's blades because more energy is captured by longer blades.
  71. 71. 71 Range of power  <100 kW  101 kW - 250 kW  251 kW - 500 kW  501 kW - 750 kW  750 kW - 1000 kW  1001 kW - 2000 kW  >2000 kW
  72. 72. 72 Applications adapted to run on DC. • Storage systems using batteries store DC and usually are configured at voltages of between 12 volts and 120 volts in USA. • A typical 100 W battery-charging machine has a shipping weight of only 15 kg.
  73. 73. 73 A .C. Generators….. • Generators that produce AC are generally equipped with features to produce the correct voltage (120 or 240 V) and • constant frequency (60 / 50 cycles) of electricity, even when the wind speed is fluctuating.
  74. 74. 74 Advantages of Induction generator over synchronous  Induction generator offers many advantages over a conventional synchronous generator as a source of isolated [A .C] power supply.  Reduced unit cost, ruggedness, brush less (in squirrel cage construction), reduced size, absence of separate DC source and ease of maintenance, self-protection against severe overloads and short circuits, are the main advantages
  75. 75. 75 Environmental Aspects of Power Generation Using WECs  Wind turbines are most environment friendly method of producing electricity.  They do not pose any adverse effect on the global environment, unlike the conventional coal or oil-fired power plants. The pollution that can be saved per year from a typical 200 kW wind turbine, involving of substitution of 120 - 200 tonnes of coal which contain pollution contents as, Sulphur dioxide (SO2): 2 –3 tonnes, Nitrogen oxide (NOX): 1.2 to 2.4 tonnes, and other particulates of 150-300 kg. .
  76. 76. 76 Audible noise  The wind turbine is generally quiet. The wind turbine manufacturers generally supply the noise level data in dB versus the distance from the tower.  A typical 600 kW wind turbine may produce 55 dB noise at 50 meter distance from the turbine and 40 dB at a 250 meter distance [4, 22] comparable with the noise level in motor car which may be approximately 75 dB.  This noise is, however, is a steady state noise. The wind turbine makes loud noise while yawing under the changing wind direction. Local noise ordinance must be compiled with.
  77. 77. 77 Towers  Tower on which a wind turbine is mounted is not just a support structure. It also raises the wind turbine so that its blades safely clear the ground and so it can reach the stronger winds at higher elevations.  Maximum tower height is optional in most cases, except where zoning restrictions apply. The decision of what height tower to use will be based on the cost of taller towers versus the value of the increase in energy production resulting from their use.
  78. 78. 78 Towers….  Studies have shown that the added cost of increasing tower height is often justified by the added power generated from the stronger winds.  Larger wind turbines are usually mounted on towers ranging from 40 to 70 meters tall.
  79. 79. 79 The tower must be strong enough to support the wind turbine and to sustain vibration, wind loading and the overall weather elements for the lifetime of the wind turbine. Tower costs will vary widely as a function of design and height.
  80. 80. 80 Research and development Research and development is going on to make wind power competitive with fossil fuel and nuclear power in strict sense, without taking into account of wind power‟s social factors such as environment benefits. Efforts are being made to reduce the cost of wind power by: design improvement, better manufacturing technology, finding new sites for wind systems, development of better control strategies (for output and power quality control), development of policy and instruments, human resource development, etc
  81. 81. 81 About Enercon - E-30-230 kW- Gearless type--1  Variable speed drive, Continuous pitch regulation,  Starts gen. at low speed of 2.5 m/s,  Gearless construction, no transmission loss,  Synchronous gen., draws < one % reactive power from grid,  By using AC_DC_AC conversion, pumps the power at „grid frequency‟, 
  82. 82. 82 About Enercon - E-30-230 kW- Gearless type--2  Produces power at all loads at near unity power factor without using capacitors  Supply reactive power to the grid to improve grid power factor  Slow speed generator of maximum 50 rpm  Three independent air breaks, no mechanical breaks  Lightning protection
  83. 83. 83 Wind Turbine Design  Design efforts benefit from  knowledge of the wind speed distribution and  wind energy content corresponding to the different speeds and  the comparative costs of different systems to arrive at the optimal rotor/generator combination.  Optimizing for the lowest overall cost considers design factors such as relative sizes of rotor, generator, and tower height.
  84. 84. 84 Thanks to extensive R&D efforts during the past 30 years, wind energy conversion has become a reliable and competitive means for electric power generation. The life span of modern wind turbines is now 20-25 years, which is comparable to many other conventional power generation technologies. The average availability of commercial wind power plants is now around 98%. Thank You