WO2011039777A2

WO2011039777A2 - System for controlling cone and pitch angle of a rotor blade assembly of a wind turbine

Info

Publication number: WO2011039777A2
Application number: PCT/IN2010/000633
Authority: WO
Inventors: Varadharajan Ponnudurai
Original assignee: Varadharajan Ponnudurai
Priority date: 2009-10-01
Filing date: 2010-09-20
Publication date: 2011-04-07
Also published as: WO2011039777A3

Abstract

A system for controlling cone and pitch angle of a rotor blade assembly of a wind turbine comprises a rotor mounted to a tower (1) of the wind turbine positioned on the ground surface/foundation/platform. The rotor is incorporated with a hub (2) and one or more rotor blades (3). A control mechanism (4) is associated between the hub (2) and the rotor blades (3) in such a way that the rotor blades (3) are swivel connected to the hub (2). The control mechanism (4) is configured with a drive, i.e. cone drive (6) and pitch drive (7), for coupling the hub to the rotor blades through a bearing, i.e. cone bearing (4b) and pitch bearing (5), in an inclined and swiveled manner. The control mechanism comprises an intermediate part that connects the cone bearing and the pitch bearing for coupling the hub to the rotor blades at the inclined angle for swiveling. The control mechanism is configured for operating the drive to drive the bearing, such that cone and pitch angles of the rotor blades are controlled simultaneously, independently or intermittently or synchronously to adjust rotor diameter along with changing the cone and pitch angles of the rotor blades, in accordance with variations in wind speeds. Such system improves a productivity and efficiency of the wind turbine in low, medium and high wind speeds, and effectively reduces the loads and stresses acting on the parts of the wind turbine due to the high and excessive wind speeds.

Description

SYSTEM FOR CONTROLLING CONE AND PITCH ANGLE OF A ROTOR BLADE ASSEMBLY OF A WIND TURBINE

FIELD OF THE INVENTION

The present invention relates to the fields of rotor control system of a wind turbine. The present invention specifically relates to a system for controlling cone and pitch angle of a rotor blade assembly and rotor blade of the wind turbine.

BACKGROUND OF THE INVENTION

In general, wind turbines are used to extract energy from wind, which includes both horizontal-axis and vertical-axis turbine systems, in typical horizontal-axis wind turbines, rotor systems include one or more blades attached to a rotor hub, which turns a generator through an operating connection. The nacelle, bearing the rotor systems, typically pivots about the vertical tower to take advantage of wind from any direction. Horizontal-axis turbines include upwind turbines and downwind turbines. In downwind turbines, the rotor blades are contacted by wind after the wind travels past the tower and nacelle whereas in upwind turbines, the rotor blades are contacted by wind before the wind passes the tower and nacelle. The blade cross-section is often aerodynamic and may be based upon any airfoil configuration that enhances the efficiency of the blade. As wind moves past the blades with enough speed to generate sufficient lift to overcome inertial and drag forces, the rotor system rotates and the wind turbine converts the wind energy into electrical or mechanical energy for performing useful work. Major factor affecting the operation and efficiency of the wind turbines is variable nature of wind , which causes uneven or excessive load. Existing designs have limited and inadequate ability to position the rotor system properly in relation to the low, medium and high wind speeds for maximizing energy generation and for improving survival wind speed in excessive wind speeds. Undesirable movement of the rotor blades in such excessive wind speeds result in tower collision, which leads to damage of rotor components and damage to the parts of the wind turbines. When the rotor system is not properly positioned with reference to the wind direction and the wind forces, the life, reliability and efficiency of the rotor system gets reduced. In lower wind speeds, the wind turbine is operating below its capacity. In higher wind speeds, the energy potential is higher than the rated capacity of the wind turbine. Using larger rotors improves capacity factor but aiso increases loads on the turbine and its related parts like rotor, tower and foundation. While using larger rotors with smaller generators, though wind speed is higher than the speed required, the energy generation is not reaching its rated capacity due to higher degree of pitch angles needed for operation parameters result in increase of blade's tangential force and stalling force.

Accordingly, it would be useful to provide a wind turbine, which can effectively handle and withstand such variability to improve energy capture in low, medium and high wind speeds and to reduce the loads and fatigue failure of turbine components due to higher and excessive wind speeds with higher survival wind speed capabilities. Conventional approaches configure to control pitch, stall and aerodynamic stall in the rotor systems of the wind turbines to handle wind forces and fatigue failure due to variable wind speeds and repeated occurrence of a gust of wind. Some of the existing approaches also configure to control cone angle of the rotor systems. US4533297 describes a rotor system for horizontal axis wind turbines, which includes compound coning of blades relative to a reference plane of blade rotation, which is perpendicular to the axis of blade rotation. This system exhibits only limited coning angle and the rotor blades made of two parts, which results in decreased reliability and lot of moving parts. When the wind turbine gets bigger, wind forces acting on the rotor are much higher. US5584655 describes a rotor device and control for wind turbine adjusts the rotor cone angle, to counter-balance aerodynamic force with centrifugal force, by attaching the blades to a hub by means of hinge. The hinged blades are controlled by actuators. Further, US7530785 discloses a method and apparatus for controlling pitch and flap angles of a wind turbine adjusts the pitch and flap angles by means of hinged blades. Such hinged blades are difficult to control as the size of the wind turbine increases. Moreover, such approach exhibits only limited flapping angle. US7071578 discloses a wind turbine provided with a controller for adjusting active annular plane area and the operating method thereof uses elbows, links and hinges to adjust the cone and pitch angle, which are less reliable and results in cantilever forces on the elbow and the hub. Hence, it is necessary to have a coning turbine with parts that can handle and withstand loads experienced in the operating environment.

With respect to the conventional approaches, it is very difficult and more expensive to provide wide range of rotor diameter, cone and pitch angle variations with survival wind speed capabilities. Further, it causes less reliability and damage to the components of the wind turbines, which reduces the productivity and efficiency of the wind turbine, Moreover, increasing the rotor diameter increases forces acting in the turbine, which results in increased size of the parts used in the wind turbine. An adequate, durable, reliable and effective solution is needed to solve the problems associated with inadequate controlling of cone and pitch angle of the rotor blades. Therefore, it is desirable to provide a system for controlling cone and pitch angle of a rotor blade assembly of the wind turbine, which is capable of overcoming the above-mentioned drawbacks. OBJECT OF THE INVENTION

An object of the present invention is to provide a system for controlling cone and pitch angle of a rotor blade assembly of a wind turbine, which is capable of improving a productivity and efficiency of the wind turbine by adjusting the rotor diameter of the wind turbine.

Another object of the present invention is to provide a system for controlling cone and pitch angle of a rotor blade assembly of a wind turbine, which effectively reduces the loads and stresses acting on the parts of the wind turbine and foundation due to variations in wind speeds.

Yet another object of the present invention is to provide a system for controlling cone and pitch angle of a rotor blade assembly of a wind turbine, which is capable of improving the fatigue life of all parts of the wind turbine.

Yet another object of the present invention is to provide a system for controlling cone and pitch angle of a rotor blade assembly of a wind turbine, which is capable of increasing survival wind speed of the wind turbine

Yet another object of the present invention is to provide a system for controlling cone and pitch angle of a rotor blade assembly of a wind turbine, which improves the capacity factor and operating range of the wind turbine with range of 2 m/s up to 30 or 35 m/s.

Yet another object of the present invention is to provide a system for controlling cone and pitch angle of a rotor blade assembly of a wind turbine, which is capable of controlling rotor thrust, blade root stress centrifugal force, blade deflection, tangential force on the blade, diameter, tip speed. RPM, pitch angle, cone angle and torque of the rotor and coefficient of Sift and drag to generate energy at its maximum output level. Yet another object of the present invention is to provide a system for controlling cone and pitch angle of a rotor blade assembly of a wind turbine, which attains its rated capacity even at the lowest possible wind speed

SUMMARY OF THE INVENTION

According to one aspect, the present invention, which achieves the objectives, relates to a system for controlling cone and pitch angle of a rotor blade assembly of a wind turbine comprising a rotor mounted to a tower of the wind turbine positioned on a platform/foundation/ground surface. The rotor is incorporated with a hub and one or more rotor blades. A control mechanism is associated between the hub and the rotor blades in such a way that the rotor blades are connected to the hub in an inclined and swiveled manner The control mechanism is configured with a drive for coupling the hub to the rotor blades through a bearing in an inclined and swiveled manner. The control mechanism is configured for operating the drive to drive the bearing, such that cone and pitch angles of the rotor blades are independently or simultaneously controlled to adjust rotor diameter along with changing the cone and pitch angles of the rotor blades, in accordance with variations in wind speeds. Such system improves a productivity and efficiency of the wind turbine, and effectively reduces the loads and stresses acting on the parts of the wind turbine due to the variations in wind speeds. Furthermore, the drive is configured as a cone drive and a pitch drive, if the intermediate parts are employed in the control mechanism The bearing is configured as a cone bearing and a pitch bearing, if the intermediate parts are employed in the control mechanism. The intermediate parts connect the cone bearing and the pitch bearing for coupling the hub to the rotor blades at an inclined angle, in a swiveled connection manner. The control mechanism is configured for operating the pitch drive alone to adjust the pitch angle or stall or aerodynamic stall for further optimization. The control mechanism is configured for combined coning and pitching adjustment of the rotor blades The rotor blades are assembled in an operating connection with the hub. The rotor blades are swivel connected with the hub at an inclined angle, such that the rotor blades rotate about axis to move in a direction defining the cone angle. The cone angle of the rotor blades is adjusted with accompanied motion of the pitch of the rotor blades, where the rotor blades can be vanes.

The cone and pitch drives exhibit a freedom of rotation ranging from 0° to 360° for adjusting the cone angle up to 90° towards and away from the tower and pitch angles of the rotor blades ranging from 0° to 360°. The cone and pitch drives are operated independently or intermittently or synchronized in accordance with the variations in wind speeds, The cone and pitch angles of the rotor blades are determined based on an angle of inclination defined by the cone and pitch drives and also by angle of the axis of the blade in relation to the intermediate part. Incase, the blades are swivel connected with the hub directly, the inclination of the axis of the blades will determine pitch and cone angle. The cone and pitch angles of the rotor blades are adjusted towards, beyond or away from the tower of the wind turbine. The cone bearing is designed in such a way that it is capable of withstanding radial, axial and bending loads

In addition, two or more cone drives can be operated independently or intermittently or synchronized in accordance with the variations in wind speeds. The cone and pitch drives are assembled externally or internally and made into a compact drive. The cone angles of the rotor blades ranging from 0" to 90° and the pitch angles of the rotor blades ranging from 0° to 360° are adjusted for each rotor blade separately depending on wind forces and expected wind forces. The pitch drive is placed as first drive whereas the cone drive is placed as second drive or vice-versa. The pitch drive is configured for both pitching and stalling. In the parking position, each rotor blade is operated individually to place the rotor blades in either sides of the tower to balance the weight. Moreover, each rotor blade exhibits a main axis on its surface, which makes swiveled connection between the rotor blades and the hub at an inclined angle. The main axis of the rotor blades is created by an operating area of the rotor blades for energy capture. The rotor is in operating connection with a generator. The cone drive is operated with full brakes or partial brakes for controlling the speed of coning. The cone drive has a higher angle of rotation than resulting coning angle of the rotor blades, so as to reduce the force/torque required for drive operation. The cone and pitch angles of said rotor blades are determined based on an angle of inclination for swiveling as defined by the intermediate parts. The cone drive is operated, which results in axial and radial movement of the rotor blades, where the cone drive is an inclined and swivel drive. BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be discussed in greater detail with reference to the accompanying Figures. FIG. 1 shows a schematic view of a horizontal-axis wind turbine with a system for controlling cone and pitch angle of a rotor blade assembly, in accordance with an exemplary embodiment of the present invention

FIG. 2 illustrates a detailed view of a control mechanism for controlling cone and pitch angle of the rotor blade assembly of the wind turbine, in accordance with an exemplary embodiment of the present invention.

FIG. 3a illustrates a perspective view of the horizontal-axis wind turbine with a rotor diameter before combined cone and pitch angle adjustment of the rotor blade assembly, in accordance with an exemplary embodiment of the present invention; FIG. 3b illustrates a perspective view of the horizontal-axis wind turbine with a rotor diameter after combined cone and pitch angle adjustment away from a tower in an upwind turbine, in accordance with an exemplary embodiment of the present invention;

FIG. 4a illustrates a perspective view of the horizontal-axis wind turbine without blade pitch adjustment, in accordance with an exemplary embodiment of the present invention

FIG. 4b illustrates a perspective view of the horizontal-axis wind turbine with blade pitch adjustment, in accordance with an exemplary embodiment of the present invention; FIG. 5 illustrates combined cone and pitch angle adjustment away from the tower in a downwind turbine, in accordance with an exemplary embodiment of the present invention;

FIG. 6a illustrates combined cone and pitch angle adjustment towards the tower in the upwind turbine, in accordance with an exemplary embodiment of the present invention;

FIG. 6b illustrates combined cone and pitch angle adjustment towards the tower in the downwind turbine, in accordance with an exemplary embodiment of the present invention; and

FIG. 7 illustrates combined cone and pitch angle adjustment beyond the tower in the upwind turbine, in accordance with an exemplary embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG 1 . a schematic view of a horizontal-axis wind turbine with a system for controlling cone and pitch angle of a rotor blade assembly is illustrated, in accordance with an exemplary embodiment of the present invention. The system for controlling the cone and pitch angle of the rotor blade assembly can specifically be designed, but not limited to the horizontal-axis wind turbine. Hereafter, the wind turbine is being referred as horizontal-axis wind turbine only for the purpose of clarity and specificity; however, they should not be interpreted in any limiting way. The wind turbine can be upwind or downwind type and installed on shore or off shore. In such horizontal-axis wind turbine, a generator (not shown), a rotor hub (2) and blades or blade assemblies {3) are positioned at a distance above the surface of the ground by a tower ( 1 ) mounted on the ground. The rotor can be made of single or multi blades (3). where the blades (3) can be segmented blades and vanes. The rotor blades (3) are configured in an operating connection with the rotor hub (2) and the generator for converting rotor motion into mechanical or electrical energy. The blades (3) are swivel connected to the rotor hub (2) at an inclined angle. Thus, the blades (3) can rotate about inclined axis to move in a direction defining a cone angle. The system comprises a control mechanism (4) that couples the blades (3) to the rotor hub (2).

Referring to FIG. 2, a detailed view of the control mechanism (4) for controlling cone and pitch angle of the rotor blade assembly of the wind turbine is illustrated, in accordance with an exemplary embodiment of the present invention. The same reference numbers are assigned to identical components in FIGS. 1-7. The control mechanism (4) is an arrangement for combined coning and pitching adjustment of the rotor blades (3). The control mechanism (4) is mounted between the rotor hub (2) and the blades (3) in an inclined angle. A cone drive (6) drives the control mechanism (4) so as to permit, the rotor blades (3) to move to a cone angle, which decreases the amount of energy absorbed by the blades (3), and to limit peak pitching and moment loads. Since it is mounted in an inclined angle, the control mechanism (4) makes different cone and pitch angles simultaneously when the drive (6) is operated up to 180° , but exhibits the freedom up to 360°.

The control mechanism (4) includes a cone bearing (4b) , a pitch bearing (5) and an intermediate part (4a) that is connected with the hub (2) through the cone bearing (4b). Similarly, the intermediate part (4a) is connected with the blades (3) through the pitch bearing (5). The cone bearing (4b) is driven by the cone drive (6) whereas the pitch bearing is driven by a pitch drive (7), where the cone drive (6) and the pitch drive (7) through the intermediate part (4a) are connected with the control mechanism (4). Primarily, the control mechanism (4) controls cone and pitch simultaneously for each rotor blade (3). to the front or back, in order to adjust the rotor diameter along with changing cone and pitch angles of the blades (3) The control mechanism (4) adjusts the cone angle with accompanied motion of the pitch of the blades (3).

Moreover, the cone angles are formed relative to a reference plane of blade rotation, which is perpendicular to the axis of blade rotation. The inclination angle with the hub is preferably fixed, but the blades (3) can be swivel connected to the rotor hub (2) in a manner that permits free coning. With free coning, the cone angles change during operation in response to fluctuations in wind speeds, rotor thrust and centrifugal forces. Additionally, the control mechanism (4) adjusts the pitch angle or stall or aerodynamic stall alone for further optimization to reduce the loads and fatigue. The rotor diameter, cone angle and pitch angle can be adjusted depending upon the wind speed and forces, in response to changes in wind speeds and gust. The pitch angle can be adjusted by means of the pitch drive (7), which exhibits a freedom of 360° of rotation. In the present invention, the cone angles range from 0° to 90° and pitch angles range from 0° to 360°. It should be understood that blades are typically somewhat flexible and the term "fixed coning angle" must be read to account for the flexing of blades during operation in response to centrifugal and wind forces. In addition the term "horizontal-axis wind turbines" includes wind turbines whose axis of rotation forms a slight angle of tilt relative to the horizontal. Such control mechanism (4) adjusts the cone angle to more effectively to reduce thrust forces of the wind In a downwind turbine, it counterbalances aerodynamic force with centrifugal force on the rotor blades (3) while reducing flapping results in reduced flap moment loads on the rotor blades (3), This is achieved by changing the cone angle and pitch angle of the blades 13) and rotor diameter. The control mechanism (4) is arranged in such a way that the hub (2) is connected to the blades (3) directly or indirectly through an inclined angle, swivel connection. When the cone drive (6) from the hub (2) rotates the connection, the cone angle of the rotor blades (3) can be changed along with pitch angle due to the inclined angle, which achieves up to 90° coning of the rotor blades (3). The combined cone and pitch angle ratios can be determined based on the inclination of the swiveling angle defined in the wind turbine design.

Referring to FIG. 3a, a perspective view of the horizontal-axis wind turbine with a rotor diameter before combined cone and pitch angle adjustment of the rotor blade assembly is illustrated, in accordance with an exemplary embodiment of the present invention. When there is no combined cone and pitch angle adjustment in the rotor blades (3), then the rotor diameter is at / closer to maximum level of its range. In this position, the wind turbine can generate more energy in low and medium wind speeds, as shown in FIG 3a. which improves the efficiency of the wind turbine in the low and medium wind speeds. Similarly, in higher wind speeds, the cone angle can be increased to reduce the rotor diameter by means of combined cone and pitch angle adjustment away from the tower (1 ) in an upwind turbine, as shown in FIG. 3b, which illustrates a perspective view of the horizontal-axis wind turbine with a rotor diameter after combined cone and pitch angle adjustment away from a tower in an upwind turbine. In the upwind turbine, the wind is directed towards the front side of the blades (3), which is away from the tower (1 ). In down wind turbine, the wind is directed towards the side of the blades (3) closer to the tower (1 ). Thus, the loads are reduced in the higher wind speeds through the combined coning and pitching adjustment alone or along with other adjustment like pitch, stall and aerodynamic stall. As the loads in the blades (3) are reduced, thus the stress is reduced in the rotor hub (2), the tower (1 ), foundation, yaw and the blades (3), which improves the fatigue life of all parts of the wind turbine. Further, the diameter reduction can also be done in the excessive wind speeds. FIGS. 4a and 4b respectively illustrate perspective views of the horizontal- axis wind turbine without and with blade pitch adjustment, in accordance with an exemplary embodiment of the present invention. In higher wind speeds, the cone angle can be adjusted to reduce the wind forces. In lower wind speeds, the pitch angle can be changed for maximum energy generation. At that point, the blade pitch is changed to enhance the wind forces directed to the blades (3), as shown in FIG. 4a. In higher wind speeds, the blade pitch is changed to suppress the forces directed to the blades (3), as shown in FiG. 4b. The cone and pitch drives (6, 7) are arranged in such a way that it is flexible to use each drive independently or intermittently or synchronized depending on wind forces and expected wind forces

Referring to FIG. 5, combined cone and pitch angle adjustment away from the tower in a downwind turbine is illustrated, in accordance with an exemplary embodiment of the present invention. When the rotor diameter of the downwind turbine is increased, which increases generation of energy, but it also increases loads acting on the parts of the wind turbine like rotor, gearbox, generator, tower, foundation, yaw bearing, yaw drive and machine frame. In downwind turbine, the blades (3) are swiveied at the inclined angle to cone the blades (3) with accompanied motion of the blade pitch. Such combined cone and pitch angle adjustment makes the blades (3) away from the tower (1 ), as shown in FIG. 5, to limit the aerodynamic forces in the higher and excessive wind speeds to maintain generation of energy is equal or close to its capacity. In low and medium wind speeds, the rotor is close to or at its maximum diameter for energy capture.

FIGS. 6a and 6b illustrate combined cone and pitch angle adjustment towards the tower in the upwind turbine and in the downwind turbine, in accordance with an exemplary embodiment of the present invention in lower wind speeds, both the upwind and downwind turbines are normally working below its capacity due to lesser forces available in the lower wind speeds. In such conditions, the combined cone and pitch angle adjustment makes the blades (3) to maximize the rotor diameter to allow the wind turbine to attain its rated capacity in the lower wind speeds. Further adjustment reduces the diameter to reduce forces and control output Thus, generation of energy is controlled to achieve more efficient machine with higher capacity factor. Such capacity factor improvement leads to better utilization of the grid.

Referring to FIG. 7, combined cone and pitch angle adjustment beyond the tower in the upwind turbine is illustrated, in accordance with an exemplary embodiment of the present invention. This is a parking position in the upwind turbine. In such conditions, the combined cone and pitch angle adjustment makes the blades (3) to angle beyond the tower (1), which improves the fatigue life of all parts of the wind turbine. Such design allows the use of larger rotor to capture more energy, but it reduces stress of higher and excessive wind forces by the combined coning and pitching adjustment in parked position. In this position, rotor lock is suitably provided, to safeguard the turbine

Moreover, survival wind speeds are also increased by optimizing the pitching or stall or aerodynamic stall along with the combined coning and pitching adjustment. So, the loads acting on the rotor and the turbine are greatly reduced, which reduces the loads, fatigue and stresses on the turbine parts to achieve optimization of the turbine parts. Such system can cone up to 90 degrees, which makes the blades (3) horizontal to the ground to improve survival wind speeds. The further optimization on the blade pitch can make the major surface area of the blades (3) to become parallel to the ground, which increases the survival wind speed even further Two or more control mechanisms for combined coning and pitching adjustment can be mounted and work together with identical or different angles for each mechanisms. These control mechanisms can be work independently or synchronized as the situation demands.

In the present invention , the expansion and contraction of the rotor blades (3) to increase or decrease rotor diameter, respectively, is based on wind conditions and blade cone and pitch angles. For example, in low wind speeds, the rotor can be fully expanded. As the winds increase in speed , the blades start to pitch and if required the rotor blades can be contracted. Thus, the diameter of the rotor can be increased to increase energy capture in frequently occurring moderate wind speeds (e.g. , wind speed operating turbine below rated capacity) where most of the wind resources is available. At the same time, the rotor diameter can be reduced in the higher wind speeds. Further diameter reduction can be done in excessive wind speeds. The cone drive can also be fitted with brakes (not shown) to control coning. The wind force can be utilized for supporting the cone drive to improve the coning speed by applying partial brake. The cone drive can be utilized to increase rpm of the rotor for adapting it to the generator requirements.

A number of variations and modifications of the present invention can also be used. Although a three-blade turbine has been illustrated , at least the cone angle adjustment and pitch adjustment aspects of the invention , and can be used in connection with turbines having one or more blades. The present invention can be used in connection with a variety of sizes and output capacities of wind turbines. Although the present invention has been described principally in connection with drive controls and other devices, additional types of controls and devices can be used including mechanical, electro-mechanical, pneumatic, computer controlled devices, and the like. However, it is currently believed that increased benefit is derived by using several or all aspects of the invention since many or all aspects of the invention work in coordination with one another. For example, pitch angle or stall or aerodynamic stall can be controlled as a function of cone angle at the same time that cone angle is controlled as a function of pitch angle or stall or aerodynamic stall.

Claims

WE CLAIM:

1. A system for controlling cone and pitch angle of a rotor blade assembly of a wind turbine, comprising.

a rotor mounted to a tower of the wind turbine positioned on the ground surface/foundation/platform, said rotor is incorporated with a hub and one or more rotor blades; and

a control mechanism associated between said hub and said rotor blades in such a way that said rotor blades are swivel connected to said hub, said control mechanism is configured with at least one drive for coupling said hub to said rotor blades through a bearing in an inclined and swiveled manner,

wherein said control mechanism is configured for operating said drive to drive said bearing, such that cone and pitch angles of said rotor blades are simultaneously controlled to adjust rotor diameter along with changing the cone and pitch angles of said rotor blades, in accordance with variations in wind speeds.

2. The system as claimed in claim 1 , wherein said drive is configured as a cone drive and a pitch drive, if one or more intermediate parts are employed in said control mechanism, such that cone and pitch angles of said rotor blades are independently or simultaneously controlled to adjust rotor diameter along with changing the cone and pitch angles of said rotor blades, in accordance with variations in wind speeds.

3. The system as claimed in claim 1 , wherein said bearing is configured as a cone bearing and a pitch bearing, if said one or more intermediate parts are employed in said control mechanism.

4. The system as claimed in claim 2 and 3, wherein said intermediate parts connect said cone bearing and said pitch bearing for coupling said hub to said rotor blades at an inclined angle, in a swiveled connection manner.

5. The system as claimed in claim 1 and 2, wherein said control mechanism is configured for operating said pitch drive alone to adjust the pitch angle or stall or aerodynamic stall for further optimization.

6. The system as claimed in claim 1 , wherein said control mechanism is configured for combined coning and pitching adjustment of said rotor blades.

7. The system as claimed in claim 1 , wherein said rotor blades are assembled in an operating connection with said hub.

8. The system as claimed in claim 1 , wherein said rotor blades are swivel connected to said hub at an inclined angle, such that said rotor blades rotate about axis to move in a direction defining the cone angle.

9. The system as claimed in claim 1 , wherein the cone angle of said rotor blades is adjusted with accompanied motion of the pitch of said rotor blades.

10. The system as claimed in claim 2, wherein said cone and pitch drives exhibit a freedom of rotation ranging from 0° to 360° for adjusting the cone and pitch angles of said rotor blades ranging from 0° to 360°.

11. The system as claimed in claim 2, wherein said cone and pitch drives are operated independently or intermittently or synchronized in accordance with the variations in wind speeds.

12. The system as claimed in claim 1 or 2, wherein the cone and pitch angles of said rotor blades are determined based on an angle of inclination defined by said cone and pitch drives.

13. The system as claimed in claim 1 , wherein the cone and pitch angles of said rotor blades are adjusted towards, beyond or away from said tower of the wind turbine.

14. The system as claimed in claim 1 , wherein the wind turbine includes an upwind turbine and a downwind turbine.

15. The system as claimed in claim 2, wherein two or more cone drives are operated independently or intermittently or synchronized in accordance with the variations in wind speeds

16. The system as claimed in claim 2, wherein said pitch drive is placed as first drive whereas said cone drive is placed as second drive or vice- versa.

17. The system as claimed in claim 2, wherein said pitch dnve is configured for pitching and stalling.

18. The system as claimed in claim 2, wherein in the parking position, each rotor blade is operated individually to place said rotor blades in either sides of said tower to balance the weight.

19. The system as claimed in claim 1 , wherein each rotor blade exhibits a main axis on its surface, which makes swiveling connection between said rotor blades and said hub at an inclined angle.

20. The system as claimed in claim 19. wherein the main axis of said rotor blades is created by an operating area of said rotor blades for energy capture.

21. The system as claimed in claim 2, wherein said cone and pitch drives are assembled externally or internally and made into a compact drive.

22. The system as claimed in claim 2, wherein the cone angles of said rotor blades ranging from 0^a to 90" and the pitch angles of said rotor blades ranging from 0° to 360° are adjusted for each rotor blade separately depending on wind forces and expected wind forces

23. The system as claimed in claim 1 , wherein said rotor is in operating connection with a generator.

24. The system as claimed in claim 1 , wherein said rotor blades comprise vanes.

25. The system as claimed in claim 2, wherein said cone drive is operated with full brakes or partial brakes for controlling the speed of coning.

26. The system as claimed in claim 1 and 2, wherein said cone drive imparts higher degree of rotational angle of said rotor blades than resulting coning angle of said rotor blades, so as to reduce the force/torque required for drive operation.

27. The system as claimed in claim 2, wherein the cone and pitch angles of said rotor blades are determined based on an angle of inclination tor swiveling as defined by said intermediate parts.

28. The system as claimed in claim 2, wherein said cone drive is operated, which results in axial and radial movement of said rotor blades.

29. The system as claimed in claim 2, wherein said cone drive is an inclined and swivel drive.