WO2016011833A1

WO2016011833A1 - Apparatus for controlling load and deformation of wind turbine blade

Info

Publication number: WO2016011833A1
Application number: PCT/CN2015/077243
Authority: WO
Inventors: 顾蕴松; 李琳恺; 孙之骏
Original assignee: 南京航空航天大学
Priority date: 2014-07-24
Filing date: 2015-04-23
Publication date: 2016-01-28
Also published as: CN104234929B; CN104234929A

Abstract

Disclosed is an apparatus for controlling the load and deformation of a wind turbine blade. A free rotation type blade (5) of an appropriate length is mounted on a blade tip of a wind turbine blade (1), and a steering engine (6) inside the free rotation type blade (5) is connected to a rear control plane (7) through a transmission rod (8); the steering engine (6) drives the control plane (7) to rotate, thereby changing the aerodynamic configuration of the free rotation type blade (5); and the free rotation type blade (5) generates rotation around the wind turbine blade (1) under the action of an aerodynamic moment and changes the angle of attack between an incoming flow and same, thereby controlling the aerodynamic load and deformation of the wind turbine blade (1). The apparatus can improve the aerodynamic performance of the wind turbine blade in different operating conditions, and stabilize the output power of a wind turbine in different incoming flow conditions, thereby expanding the operating envelope of the wind turbine, aiding in increasing the annual power output of the wind turbine, and also improving the safety of the blade and related devices.

Description

Device for controlling wind turbine blade load and deformation

Technical field

The invention belongs to the technical field of wind turbines, in particular to a wind turbine auxiliary device.

Background technique

As human society enters the 21st century, issues such as environmental pollution and the depletion of traditional petrochemical resources are receiving increasing attention, and the development and use of new energy has become a common task worldwide. Among them, wind energy is widely used as a kind of renewable clean energy. Large-scale grid-connected horizontal-axis wind turbines (hereinafter referred to as wind turbines) have become the main form of utilizing wind energy.

The blade of the wind turbine acts as a wind-trapping device and is responsible for absorbing wind energy. The design of the wind turbine directly determines the performance and reliability of the unit. In the last ten years, with the use of new materials and new technologies, the blade length has increased from more than ten meters and tens of meters to more than one hundred meters. The power of wind turbines has been increased from kilowatts to megawatts, effectively reducing wind power generation. Electricity costs. Therefore, the large-scale wind turbine has become a trend in the wind power industry. However, as the blade size increases, the aerodynamic loads experienced by the wind turbine blades increase exponentially. Especially in the harsh conditions such as strong winds or gusts, the existing variable speed pitching mechanism can not quickly remove the sudden load and huge structural deformation, and even cause collisions between the blade and the tower, thus affecting Wind turbine safety and service life.

There are currently published patents, such as the Chinese patent "A wind turbine blade movable wing device" (Publication No.: 102996367A, published day 2013.3.27), "A wind turbine blade with tip winglets" ( Publication No.: 103485973A, Public Day 2014.1.1) and "Aerodynamic Design Method for Wind Turbine Blades with Low Starting Wind Speed" (Publication No.: 102108947A, Public Day 2011.6.29), the aerodynamic performance of wind turbine blades is controlled by flow control means. Controls, such as blade tip winglets, blade tip open pneumatic brakes, trailing edge flaps, etc. However, these control methods also have certain shortcomings. For example, the fixed tip winglet can increase the output power of the wind turbine. However, if the flow state exceeds the design condition, the tip winglet will not be well controlled. The effect; the tip-opening pneumatic brake can reduce the impeller speed in time under some large wind speed conditions, but the braking process is complicated and complex mechanical control devices are needed. Once working, the impeller rotation needs to be stopped to retract it to its original position. The traditional mechanical brakes convert the kinetic energy into heat energy through the wear of the brake pads, which not only causes the brake efficiency to drop, but also increases the additional energy consumption. In addition, the dynamic response is slow and safe. Loading complexes is also a common problem with existing control methods.

From the aerodynamic point of view and the existing working principle of the wind turbine blade, the main aerodynamic load and the capturing capacity of the blade are mainly concentrated near the blade tip. Therefore, the area near the tip is a sensitive area for controlling the blade load and deformation. By installing the control device at the tip, the load distribution and structural deformation of the entire blade can be effectively changed, and the wind turbine speed and output power can be stabilized.

Summary of the invention

The problem to be solved by the present invention is to provide a device for controlling the load and deformation of a wind turbine blade with simple structure, which is suitable for various working conditions, and can quickly remove the wind turbine blade caused by the environment by simple adjustment. The sudden load and large structural deformation ensure that the wind turbine has stable speed and output power as well as safety.

The invention discloses a device for controlling load and deformation of a wind turbine blade, which comprises a freely rotating blade, a rudder surface and a rudder surface driving device. The wind turbine blade is a carrier for mounting the device for controlling the load and deformation of the wind turbine blade, the freely rotating blade being mounted to the top end of the wind turbine blade by the first rotary pair, the first rotational secondary axis being perpendicular to the cross section of the wind turbine blade; the control surface The second rotating pair is mounted on the trailing edge of the freely rotatable blade, and the axes of the first rotating pair and the second rotating pair are parallel.

As a further improvement of the above technical solution, the rudder surface driving device is a steering gear installed inside the freely rotatable blade, and the rudder surface is connected to the steering gear through a transmission rod. The steering gear is embedded in the freely rotatable blade instead of the freely rotatable blade surface to ensure a smooth, non-embossed surface of the freely rotatable blade. The steering gear can change the angle of the rudder surface through the transmission rod to change rapidly, changing the aerodynamic shape of the freely rotating blade, thereby changing the surface pressure distribution and aerodynamic characteristics of the freely rotating blade. At high wind speeds, it has a high pneumatic brake function, which can reduce the load of the wind turbine and stabilize the output power. At low wind speeds, it has the function of increasing the speed of the wind turbine, reducing the starting wind speed and smoothing the output power. The angle of rotation of the rudder surface relative to the freely rotating blade string ranges from -30° to +30°.

As another improvement of the above solution, the first rotating pair includes a rotating shaft and a rotating shaft fixing device, and one end of the rotating shaft is installed in the rotating shaft fixing device, and the rotating shaft is rotatable relative to the rotating shaft fixing device, that is, the freely rotating blade is freely rotatable around the rotating shaft Rotation, the angle of rotation ranges from -180° to +180°. The rotating shaft is fixedly connected with the freely rotating blade, and the rotating shaft fixing device is fixedly mounted inside the wind turbine blade, or the rotating shaft is fixedly connected with the wind turbine blade, and the rotating shaft fixing device is fixedly mounted and freely rotated. The interior of the moving blade.

As a further improvement of the above technical solution, the second rotating pair is a hinge.

As a further improvement of the above technical solution, the device for controlling wind turbine blade load and deformation further includes a damping adjuster that applies damping to the rotating shaft.

As a further improvement of the above technical solution, the damping adjuster is provided with a locking device for locking the rotating shaft.

As a further improvement of the above technical solution, the freely rotating blade 5 has a radial length of 5% to 50% of the radial length of the wind turbine blade, and the planar shape is a straight form or a sharpened form, and the freely rotating blade is close to The cross-sectional shape of the end of the wind turbine blade matches the cross-sectional shape of the top end of the wind turbine blade.

As a further improvement of the above technical solution, the position of the rotating shaft is close to the leading edge of the wind turbine blade.

As a further improvement of the above technical solution, the rudder surface chordwise dimension is 10% to 30% of the chordwise dimension of the freely rotating blade.

As a further improvement of the above technical solution, the device for controlling the load and deformation of the wind turbine blade further comprises a closed loop control system composed of the incoming flow detector, the onboard processor, the control system and the wind turbine operating state detector. The closed-loop feedback control system is used to monitor the flow velocity, wind direction and wind turbine operating state, and can automatically send control signals to the steering gear in the free-rotating blade according to the incoming flow condition and the wind turbine state, realizing closed-loop feedback control without human intervention. And operation.

The device for controlling the load and deformation of the wind turbine blade of the present invention controls the flow field state of the blade tip portion of the wind turbine blade, thereby achieving the following beneficial effects:

1. By using the angle change of the rudder surface, the angle of attack between the freely rotating blade and the incoming flow direction can be changed, thereby adjusting the aerodynamic load of the blade: at a low wind speed, the actual angle of attack of the freely rotating blade can be increased, and the main The lift and torque of the blade stabilize the power generation of the wind turbine; at high wind speeds, the actual angle of attack of the freely rotating blades can be reduced, the lift and torque of the main blades can be reduced, and the load of the impeller can be reduced. Since the deformation of the blade is positively correlated with the blade tip load, reducing the aerodynamic load of the blade tip can effectively suppress the deformation of the main blade.

2. Through the independent control of the control device on each blade, the problem of inconsistent load on the upper and lower blades of the wind turbine blade caused by the atmospheric boundary layer can be overcome, which is beneficial to the stability of the wind turbine impeller and the reduction of dynamic imbalance.

3. No complicated mechanical actuating mechanism is required. Only one steering gear and transmission rod are required to drive the deflection of the rudder surface, and the power consumption is very small.

4. Free-rotating blades have a high dynamic response rate, enabling load reduction and deformation control in a very short time.

5. The dynamic response rate of the free-rotating blades can be adjusted by the damping regulator to meet the control requirements under different working conditions. When no control is required, it can be locked to form an integral wind turbine blade.

6. The closed-loop feedback control system is used to realize the intelligent regulation of the whole work envelope, without human intervention and control.

7. The control device can be used for a pitch wind turbine, and can also be used for a fixed wind turbine, and has good versatility.

The invention has a wide application range and can be modified on the existing mature commercial wind turbine blades. It not only saves valuable time and re-research and development expenses, but also improves the aerodynamic performance of wind turbine blades under different working conditions, stabilizes the output power of wind turbines under different wind speeds, and expands the working envelope of wind turbines. It is beneficial to increase the annual power generation of wind turbines and also increase the safety of blades and related equipment.

DRAWINGS

1 is a schematic view showing the overall structure of a device for controlling load and deformation of a wind turbine blade mounted on a wind turbine blade according to the present invention;

2 is an enlarged view of the apparatus for controlling load and deformation of a wind turbine blade according to the present invention;

Figure 3 is a cross-sectional view of the apparatus for controlling load and deformation of a wind turbine blade of the present invention;

4 is a schematic view showing the operation of the device for controlling the load and deformation of a wind turbine blade according to the present invention;

Figure 5 is a flow chart of the control of the closed loop control system.

detailed description

A device for controlling load and deformation of a wind turbine blade according to the present invention will be described in detail below with reference to the accompanying drawings.

As shown in Figures 1, 2 and 3, a device for controlling the load and deformation of a wind turbine blade includes a damping adjuster 2, a rotating shaft fixing device 3, a rotating shaft 4, a freely rotating blade 5, a steering surface 7, a steering gear 6, Transmission rod 8, hinge 9. The radial length of the freely rotating blade 5 is the radial length of the wind turbine blade 1 5% to 50%, the radial length of the freely rotatable blade 5 is determined according to factors such as the use environment, the length of the wind turbine blade 1, and the like. The planar shape is a straight form or a sharpened form, and the sectional shape of the freely rotatable blade 5 matches the sectional shape of the tip end of the wind turbine blade 1, and the freely rotating blade 5 is close to the section chord length of the wind turbine blade 1 and the wind turbine blade 1 The cross section of the top section is consistent.

The freely rotating blade 5 is mounted to the top end of the wind turbine blade 1 via a rotating shaft 4 and a rotating shaft fixing device 3, and one end of the rotating shaft 4 is mounted in the rotating shaft fixing device 3, and the rotating shaft 4 is rotatable relative to the rotating shaft fixing device 3, and the rotating shaft 4 and the freely rotating blade 5 are rotated. The fixed connection can be regarded as a whole, the shaft fixing device 3 is installed inside the wind turbine blade 1, and the freely rotating blade 5 and the rotating shaft 4 are freely rotatable about an axis perpendicular to the cross section of the wind turbine blade 1, and the rotation angle range thereof is -180° to 180°. Alternatively, the rotating shaft 4 is fixedly coupled to the wind turbine blade 1, and the rotating shaft fixing device 3 is mounted inside the freely rotatable blade 5. The axis of the rotating shaft 4 is perpendicular to the cross section of the wind turbine blade 1. The position of the rotating shaft 4 is close to the leading edge of the wind turbine blade 1. The central position of the rotating shaft 4 is located on the chord of the freely rotating blade section, preferably 15% of the chord length from the leading edge. position. The shaft fixing device 3 can select a bearing or other rotating auxiliary device.

The rudder surface 7 is mounted on the side of the freely rotatable blade 5 by a hinge 9, and the rudder surface 7 has a chordwise dimension of 10% to 30%, preferably 20%, of the chordwise dimension of the freely rotatable blade 5. The axis of the shaft 4 and the hinge 9 are parallel, i.e., the axis about which the freely rotatable blade 5 rotates relative to the wind turbine blade 1 is parallel to the axis about which the rudder surface 7 rotates relative to the freely rotatable blade 5. As shown in Fig. 2, the steering gear 6 is mounted inside the freely rotatable blade 5, and the steering surface 7 is connected to the steering gear 6 via a transmission rod 8. The steering gear 6 drives the transmission rod 8 to produce a displacement change, thereby causing a continuous angular change of the steering surface 7 about the hinge 9. The angle of rotation of the rudder surface 7 relative to the chord of the freely rotatable blade 5 ranges from -30° to 30°. The steering gear 6 can also be replaced by a motor or a hydraulic drive for driving the rudder surface 7.

The damping adjuster 2 is fitted on the rotating shaft 4 at the end close to the rotating shaft fixing device 3. The damper adjuster 2 can also be mounted on the side of the rotating shaft 4 as long as damping can be applied to the rotating shaft 4. Damping can be produced by mechanical damping, electromagnetic damping or other damping.

The damping adjuster 2 is provided with a locking device, and when necessary, a sufficient frictional force (or damping) can be applied to the rotating shaft 4, so that the rotating shaft 4 cannot generate a rotational motion with respect to the wind turbine blade 1 or the freely rotating blade 5. The locking device is embedded in the damping regulator 2, and the opening and releasing of the locking device and the length of locking can be controlled by the control system 12. Locking device The implementation forms include hydraulic lock cylinders, mechanical pins, self-locking motors, and the like.

The apparatus for controlling wind turbine blade load and deformation further includes a closed loop control system consisting of the incoming flow detector 10, the onboard processor 11, the control system 12, and the wind turbine operating state detector 13. As shown in Figure 5, the incoming flow detector 10 acts as a wind speed flow monitoring device and is mounted at a suitable location on the wind turbine. The real-time monitoring data of the incoming flow detector 10 and the wind turbine operating state detector 13 is transmitted to the onboard processor 11 on the wind turbine, processed and analyzed, transmitted to the control system 12, and then wired and wireless by the control system 12. , Bluetooth or other signal transmission mode, the control signal is transmitted to the steering gear 6 on the freely rotating blade 5, and the load and deformation control of the wind turbine blade 1 is performed. The wind turbine operating state detector 13 also continuously feeds back the working state of the wind turbine to the onboard processor 11.

The working process of the device for controlling the load and deformation of a wind turbine blade of the present invention is as follows:

As shown in FIG. 4, taking the severe wind speed as an example, when the incoming flow detector 10 finds that the wind speed and wind direction has exceeded the safe range, the onboard processor 11 will be notified in time, after the onboard processor 11 undergoes the comparison analysis. After confirming the execution action, the control system 12 issues a corresponding control command, and after receiving the control command, the steering gear 6 drives the steering surface 7 to deflect around the hinge 9 through the transmission rod 8, so that the steering surface 7 and the freely rotatable blade 5 are between Produces an angle δ. At this time, since the outer shape of the freely rotatable blade 5 is changed, the pressure distribution on the blade surface changes. The blades of the freely rotating blade 5 are rotated about the rotating shaft by the aerodynamic moment and finally stabilized at an equilibrium position, at which point the angle between the freely rotating blade 5 and the wind turbine blade 1 is enlarged to Θ.

At this time, although the angle of attack between the wind turbine blade 1 and the incoming flow is maintained at α, the angle of attack between the freely rotating blade 5 and the incoming flow has been reduced to α', and the freely rotating blade 5 is from the original The positive lift state changes to a zero lift or even a negative lift state, thereby weakening the positive lift force of the entire wind turbine blade 1 and the moment acting on the blade root, thereby reducing the load and reducing the rotational speed of the wind turbine, thereby making it Stable in a safe working range, reducing the requirements for structural strength and stiffness. Moreover, due to the reduction of the aerodynamic force and torque of the wind turbine blade 1, the deformation amount of the blade is correspondingly reduced, and the collision problem of the blade-tower is avoided.

At low wind speeds, the control system 12 issues commands to the steering gear 6 to adjust the rudder surface 7 so that the freely rotating blades 5 rotate under the action of aerodynamic torque, increasing the angle of attack α with the direction of the incoming flow, thereby increasing the free rotation type. The available lift of the blade 5 increases the moment that drives the rotation of the impeller. Not only It is ensured that the aerodynamic efficiency of the wind turbine blade 1 is not reduced at a small wind speed, and the wind turbine can be smoothly started at a lower wind speed.

The invention has many specific application paths, and the above is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make some improvements without departing from the principle of the present invention. These improvements are also considered to be the scope of protection of the present invention.

Claims

A device for controlling load and deformation of a wind turbine blade, comprising: a freely rotating blade (5), a rudder surface (7), a rudder surface driving device; and a freely rotating blade (5) mounted to the first rotating pair At the top end of the wind turbine blade (1), the first rotational secondary axis is perpendicular to the cross section of the wind turbine blade (1); the steering surface (7) is mounted on the trailing edge of the freely rotating blade (5) by the second rotary pair, the first rotation The axes of the secondary and second rotating pairs are parallel.
The apparatus for controlling load and deformation of a wind turbine blade according to claim 1, wherein the rudder surface driving device is a steering gear (6) installed inside the freely rotatable blade (5), and the rudder surface (7) Connect to the steering gear (6) via the transmission lever (8).
The apparatus for controlling load and deformation of a wind turbine blade according to claim 1, wherein the first rotating pair comprises a rotating shaft (4) and a rotating shaft fixing device (3), and one end of the rotating shaft (4) is mounted on the rotating shaft fixing device. (3) Inside, the rotating shaft (4) is rotatable relative to the rotating shaft fixing device (3); the rotating shaft (4) is fixedly connected with the freely rotating blade (5), and the rotating shaft fixing device (3) is fixedly mounted inside the wind turbine blade (1) Or, the rotating shaft (4) is fixedly connected to the wind turbine blade (1), and the rotating shaft fixing device (3) is fixedly mounted inside the freely rotating blade (5).
The apparatus for controlling load and deformation of a wind turbine blade according to claim 1, wherein the second rotating pair is a hinge (9).
The apparatus for controlling load and deformation of a wind turbine blade according to claim 3, wherein said means for controlling load and deformation of the wind turbine blade further comprises a damping adjuster (2), and the damping adjuster (2) is opposite to the rotating shaft ( 4) Apply damping.
The device for controlling the load and deformation of a wind turbine blade according to claim 5, characterized in that the damping adjuster (2) is provided with a locking device for locking the rotating shaft (4).
The apparatus for controlling load and deformation of a wind turbine blade according to claim 1, wherein said freely rotating blade (5) has a radial length of 5% to 50% of a radial length of the wind turbine blade (1), The planar shape is a straight form or a sharpened form, and the cross-sectional shape of the free-rotating blade (5) near the end of the wind turbine blade (1) matches the cross-sectional shape of the tip end of the wind turbine blade (1).
A device for controlling the load and deformation of a wind turbine blade according to claim 3, characterized in that the position of the rotating shaft (4) is close to the leading edge of the wind turbine blade (1).
Apparatus for controlling load and deformation of a wind turbine blade according to claim 1 It is that the rudder surface (7) has a chordwise dimension of 20% of the chordwise dimension of the freely rotatable blade (5).
Apparatus for controlling load and deformation of a wind turbine blade according to any of claims 1, 2, 3, 4, 5, 6, 7, 8 or 9 wherein: means for controlling load and deformation of the wind turbine blade It includes a closed loop control system consisting of a flow detector (10), an onboard processor (11), a control system (12) and a wind turbine operating state detector (13).