Experimental device for mechanical balance of rod under wind power

Abstract

The invention discloses a pole mechanical balance experimental device under wind power, and belongs to the technical field of balance experimental devices.The pole mechanical balance experimental device under wind power comprises two SBR long guide rails and two aluminum profile long supports, the SBR long guide rails are fixed to the top ends of the aluminum profile long supports, and first synchronizing wheels are installed at the top ends of the aluminum profile long supports; a first belt is arranged between the two first synchronizing wheels, a first motor is fixedly installed on a support of one first synchronizing wheel, first sliding blocks are connected to the SBR long guide rails in a sliding mode, two aluminum profile short supports are fixed between the two first sliding blocks, and an SBR short guide rail is fixedly installed at the top end of each aluminum profile short support. The two SBR short guide rails are connected with a second sliding block in a sliding mode, and the top end of the second sliding block is provided with a three-dimensional angle offset measuring sensor device. The device is simple in structural design, experimental tests in multiple directions can be achieved, the accuracy of the device during testing and calculation is improved, and meanwhile experiments under different wind loads can be effectively completed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of balancing experimental devices, in particular to a wind down rod mechanical balance experimental device. BACKGROUND

[0002] The balance of a wind turbine unit refers to ensuring the uniform distribution of the mass of the rotor of a wind turbine to avoid vibration and wear caused by imbalance. Currently, the adjustment methods for balancing the stability of a wind turbine unit mainly include: ①Using a damper or the like to control the upper part of the wind turbine unit to achieve self-balance; ②Adjusting the water level of the ballast tank to maintain the stability of the wind turbine; ③Using an inverted rod system, and the inverted rod system is in the traditional inverted pendulum mode; However, the above methods still have defects in the actual application in the balance of the wind turbine unit. The damper performs poorly when dealing with large wind loads, the water level of the ballast tank is high, and the design is complex, making it difficult to adapt to complex environments, and the traditional inverted rod system can only achieve inverted rod in one dimension.

[0003] Therefore, in view of the above, the existing structure is studied and improved, and a wind down rod mechanical balance experimental device is provided to achieve a more practical purpose. SUMMARY

[0004] 1. Technical problem to be solved In view of the problems in the prior art, the purpose of the present application is to provide a wind down rod mechanical balance experimental device, which has a simple structure and can realize experimental testing in multiple directions, improving the accuracy of the device during testing and calculation, and effectively completing experiments under different wind loads.

[0005] 2. Technical scheme To solve the above problems, the present application adopts the following technical scheme.

[0006] A wind down rod mechanical balance experimental device, comprising two SBR long guide rails and two aluminum profile long supports, the SBR long guide rails and the aluminum profile long supports form a rectangular frame structure, the SBR long guide rails are fixed to the top end of the aluminum profile long supports, a synchronous wheel is installed at the top end of the aluminum profile long support, a belt is arranged between the two synchronous wheels, and a motor is fixedly installed on the support of one of the synchronous wheels, the output end of the motor is drivingly connected to the central shaft of the adjacent synchronous wheel through a shaft coupling, and a sliding block is slidingly connected to the SBR long guide rail; Two aluminum profile short supports are fixed between the two No. 1 sliders. The two aluminum profile short supports are connected side by side in parallel to form a whole, and both ends of each aluminum profile short support are fixed to the top of the No. 1 slider at the corresponding position. The side of the No. 1 belt is fixed to the aluminum profile short supports. Each aluminum profile short bracket is fixedly mounted with an SBR short guide rail at its top, and two sliders are slidably connected on the two SBR short guide rails. A three-dimensional angle offset measurement sensor is mounted on the top of the slider. Two synchronous pulleys are fixedly mounted at both ends of the SBR short guide rails. A belt is set between the two synchronous pulleys. A motor is fixedly mounted on the support of one of the synchronous pulleys. The stereo angle offset measurement sensor device includes an assembly box. An angle sensor dimension reduction arc is movably connected to the inner center of the assembly box via a bearing. A ball table is fixedly installed at the inner bottom of the assembly box. A centering ball is set on the ball table. The centering ball can rotate freely and does not detach from the ball table. The centering ball is located directly below the angle sensor dimension reduction arc. A test rod is fixedly installed at the top of the centering ball.

[0007] Furthermore, the length of the short aluminum profile bracket is slightly shorter than that of the long aluminum profile bracket, and the two have the same cross-section. The length of the SBR short guide rail is slightly shorter than that of the SBR long guide rail, and the two have the same cross-section. The structure of the second slider is the same as that of the first slider. The structure of the second synchronous pulley is the same as that of the first synchronous pulley. The second belt is slightly shorter than the first belt, and both have the same cross-section. The structure of the No. 2 motor is the same as that of the No. 1 motor.

[0008] Furthermore, the assembly box includes an open box body and a height-adjusting frame, the bottom end of which is fixed to the top end of the second slider, and the top end of which is fixed to the bottom end of the open box body.

[0009] Furthermore, the riser frame is a hollow frame structure, and the second belt is fixed to the inner top of the riser frame.

[0010] Furthermore, the dimensionality reduction arc of the corner sensor includes two horizontal dimensionality reduction arcs and two vertical dimensionality reduction arcs. The two horizontal dimensionality reduction arcs are arranged in parallel to each other, and the two vertical dimensionality reduction arcs are arranged in parallel to each other. Moreover, the horizontal dimensionality reduction arcs and the vertical dimensionality reduction arcs are spatially perpendicular. A gap structure is formed between the two horizontal and two vertical dimension-reduced arcs, and the test rod passes through the gap.

[0011] Furthermore, angle sensors are installed at the positions where the horizontal and vertical dimension-reduced arcs connect to the assembly box.

[0012] Further, the inner diameter of the gap structure is slightly larger than the rod diameter of the test rod, and the length of the test rod is not less than eight times the length of the assembled box.

[0013] 3. Beneficial effects Compared with the prior art, the application has the advantages that: The device is combined with a wind power system and a data acquisition terminal to form a two-dimensional non-inverted rod system, the structure of the device is a cross slide way, the device has a simple structure, and multiple direction test can be realized. The single-chip microcomputer and the upper computer are combined to control the double motors by using the PID algorithm, the platform can be moved in the plane, the rod can be kept from falling in any direction on the plane, the inclination angle of the rod can be easily and accurately measured in real time by using the solid angle offset measurement sensor device, and the accuracy of the device in testing and calculation is improved. The double-motor belt drive structure is designed to adjust the stress of the rod by changing the center mode in time, external interference is offset, the purpose of not falling is achieved, and the device can effectively complete experiments under different wind loads. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 It is a schematic diagram of the solid structure of the entire device in the application; Figure 2 It is a schematic diagram of the solid structure of the solid angle offset measurement sensor device in the application; Figure 3 It is a schematic diagram of the solid structure of the connection position of the angle sensor dimension reduction arc, the spherical table and the centering ball in the application; Figure 4 It is a schematic diagram of the structure of the entire device during the experiment in the application; Figure 5 It is a schematic diagram of the structure when the X-axis and the Y-axis are divided in the plane in the application; Figure 6 It is a schematic diagram of the mechanical model of the experiment in the application Figure 1 ; Figure 7 It is a schematic diagram of the mechanical model of the experiment in the application Figure 2 ; Figure 8 It is a schematic diagram of the mechanical model of the experiment in the application Figure 3 ; Figure 9 It is a schematic diagram of the overall circuit design of the application; Figure 10 It is a schematic diagram of the motor speed change curve of the application; Figure 11 It is a schematic diagram of the encoder principle of the application.

[0015] Explanation of reference numerals in the drawings: 1. Stereometric angle offset measurement sensor device 101. Assembly box; 1011. Box body without cover; 1012. Height increasing stand 102. Angular sensor dimension reduction arc; 1021. Transverse dimension reduction arc; 1022. Longitudinal dimension reduction arc; 1023. Angular sensor 103. Spherical platform; 104. Centering ball; 105. Test rod 2. SBR long guide rail; 3. Aluminum profile long support; 4. First motor; 5. First belt 6. First sliding block; 601. Aluminum profile short support; 602. SBR short guide rail; 603. Second sliding block; 604. Second synchronous wheel; 605. Second belt; 606. Second motor 7. First synchronous wheel DETAILED DESCRIPTION

[0016] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0017] Embodiment 1 Please refer to Figure 1 - Figure 4 A mechanical balance experiment device for a wind force lowering rod, comprising two SBR long guide rails 2 and two aluminum profile long supports 3, the SBR long guide rails 2 and the aluminum profile long supports 3 form a rectangular frame structure, the SBR long guide rails 2 are fixed at the top end of the aluminum profile long supports 3, the top end of the aluminum profile long supports 3 is provided with a first synchronous wheel 7, a first belt 5 is arranged between the two first synchronous wheels 7, a first motor 4 is fixedly installed on the support of one of the first synchronous wheels 7, the output end of the first motor 4 is drivingly connected to the central shaft of the adjacent first synchronous wheel 7 through a shaft coupling, and a first sliding block 6 is slidingly connected to the SBR long guide rail 2; Two aluminum profile short supports 601 are fixed between the two first sliding blocks 6, the two aluminum profile short supports 601 are connected in parallel to form an integrated body, and the two ends of each aluminum profile short support 601 are fixed to the top end of the corresponding first sliding block 6, and the side surface of the first belt 5 is fixed to the aluminum profile short support 601; The top end of each aluminum profile short support 601 is fixedly installed with an SBR short guide rail 602, and the two SBR short guide rails 602 are slidably connected with a second sliding block 603, the top end of the second sliding block 603 is installed with a cube angle offset measurement sensor device 1, the two ends of the SBR short guide rail 602 are fixedly installed with a second synchronous wheel 604, and a second belt 605 is arranged between the two second synchronous wheels 604, and a second motor 606 is fixedly installed on the support of one of the second synchronous wheels 604. The cube angle offset measurement sensor device 1 comprises an assembly box 101, the inner middle part of the assembly box 101 is movably connected with an angle sensor dimension reduction arc 102 through a bearing, the inner bottom of the assembly box 101 is fixedly installed with a spherical table 103, the spherical table 103 is provided with a centering ball 104, the centering ball 104 is freely rotatable and does not separate from the spherical table 103, and the centering ball 104 is located directly below the angle sensor dimension reduction arc 102, and the top end of the centering ball 104 is fixedly installed with a test rod 105.

[0018] Referring to Figure 1 , specifically, the length of the aluminum profile short support 601 is slightly shorter than that of the aluminum profile long support 3, and the cross sections of the two are the same; The length of the SBR short guide rail 602 is slightly shorter than that of the SBR long guide rail 2, and the cross sections of the two are the same; The structure of the second sliding block 603 is the same as that of the first sliding block 6; The structure of the second synchronous wheel 604 is the same as that of the first synchronous wheel 7; The length of the second belt 605 is slightly shorter than that of the first belt 5, and the cross sections of the two are the same; The structure of the second motor 606 is the same as that of the first motor 4.

[0019] In the production or assembly of the entire experimental device, the above structures can be used alternatively or appropriately shortened and processed, so as to reduce the complexity of the production or assembly of the experimental device.

[0020] Referring to Figure 1 , Figure 2 , specifically, the assembly box 101 comprises a coverless box body 1011 and a heightening stand 1012, the bottom end of the heightening stand 1012 is fixed with the top end of the second sliding block 603, and the top end of the heightening stand 1012 is fixed with the bottom end of the coverless box body 1011.

[0021] By using the heightening stand 1012, the height of the coverless box body 1011 and the internal structure thereof can be increased, so as to reduce the influence of wind on the structure below the coverless box body 1011 during wind test.

[0022] Specifically, the heightening stand 1012 is a hollow frame structure, and the second belt 605 is fixed with the inner top of the heightening stand 1012.

[0023] When the second synchronous wheel 604 rotates, it drives the second belt 605 to move, and in turn drives the height increasing frame 1012 and the coverless box body 1011 to move synchronously.

[0024] Referring to Figure 1 , Figure 3 , specifically, the angle sensor dimension reduction arc 102 includes two transverse dimension reduction arcs 1021 and two longitudinal dimension reduction arcs 1022, the two transverse dimension reduction arcs 1021 are arranged in parallel with each other, the two longitudinal dimension reduction arcs 1022 are arranged in parallel with each other, and the transverse dimension reduction arcs 1021 and the longitudinal dimension reduction arcs 1022 are vertically distributed in space. The two transverse dimension reduction arcs 1021 and the two longitudinal dimension reduction arcs 1022 form a gap structure, and the test rod 105 passes through the gap.

[0025] When the test rod 105 is deflected, it drives the two transverse dimension reduction arcs 1021 and the two longitudinal dimension reduction arcs 1022 to produce synchronous deflection.

[0026] Specifically, the transverse dimension reduction arc 1021 and the longitudinal dimension reduction arc 1022 are connected with the assembly box 101, and the positions are provided with angle sensors 1023.

[0027] The model of the angle sensor 1023 is WDD35D4, which can monitor the deflection angle of the transverse dimension reduction arc 1021 and the longitudinal dimension reduction arc 1022 in real time and feed back to the computer end.

[0028] Specifically, the inner diameter of the gap structure is slightly larger than the rod diameter of the test rod 105, and the length of the test rod 105 is not less than eight times the length of the assembly box 101.

[0029] When the wind force test is performed, the wind force can be applied to different heights of the test rod 105, so as to obtain the mechanical balance test effect of the test rod 105 under different height wind forces, and improve the practicability of the device.

[0030] Embodiment 2: Based on the above embodiment 1, further description is made.

[0031] Referring to Figure 1 , Figure 2 , Figure 3 , specifically, the solid angle offset measurement sensor device 1 in the device can be struck by a 3D printer.

[0032] The parts of the experimental device are sequentially combined and installed, and the stability and sensitivity of each part are detected.

[0033] Referring to Figure 4In the experiment, an electric fan is arranged beside the whole experimental device to simulate the wind power system, and then the electrical elements in the experimental device are connected to the data acquisition terminal through wires.

[0034] Before the experiment, the device is adjusted and calibrated, and then the operation is performed.

[0035] Referring to Figure 5 , the device forms X and Y axes, and the three-dimensional angular offset measurement sensor device 1 can move in the two-directional planes formed by the X and Y axes, and the motion state of the test rod 105 is transmitted to the data acquisition terminal through the STM32 controller.

[0036] Example 3: Based on the above examples 1 and 2, further description is made.

[0037] Referring to Figure 6 , specifically, when performing mechanical model analysis, the movement of the platform can be decomposed into X and Y directions, and the two directions are the same, so only one direction of the rod needs to be analyzed, and the motion state in the two-dimensional plane can be obtained by superposition.

[0038] Referring to Figure 7 , specifically, m1, m4, and m3 are considered as a part of the rod, and m2 and m5 are considered as a part of the platform, and the model is simplified.

[0039] Referring to Figure 8 , specifically, the whole device can be considered as a system composed of a trolley and a pendulum rod.

[0040] Specifically, the pendulum rod can be obtained by the rigid body fixed-axis rotation law According to Newton's second law, the horizontal component of the force on the slider is H, and the vertical component of the force on the slider is G. , According to Newton's third law, the slider will be subjected to a reaction force of the pendulum rod, and the size of the horizontal component of the force is also H. Then, according to Newton's second law, the displacement of the slider m .

[0041] : displacement of the slider m : mass of the pendulum kg : inclination angle of the pendulum rad : distance from the centroid of the pendulum to the rotation axis m : size of the force on the slider N : the vertical component of the force on the swing bar N : the horizontal component of the force on the swing bar N : the moment of inertia of the swing bar kg m2 The above is the inverted pendulum model, since the device needs to withstand wind force, so the angle is not a constant value, the angle is solved by the equation: , and the wind force on the rod when it is vertical is : The wind force to the left makes the rod tilt to the left, at this time the motor needs to drive the platform to give the rod a right acceleration, so that the rod tilts to the wind direction Because the angle sensor used by the instrument has high resolution, under the low delay of the whole device, the acceleration will be very small Kp is the proportional term in the PID algorithm in the tilt ring, and because , so Due to inertia, the rod will cross the balance point , and oscillate back and forth at , and form a stable period. In order to stabilize the rod, a damping force , is introduced, which is the derivative term in the PID algorithm of the tilt ring , at this time the total force on the rod is Under ideal conditions , the wind force is analyzed, and the actual wind , in the balanced state , , is a constant value, and the product of r and L is the force area, so the final tilt angle of the rod with different density and different wind force area is different. : air density, : the radius of the rod, the length of the rod.

[0042] Referring to Figure 9 ​Specifically, the device first acquires the angle by the angular displacement sensor and the position by the encoder, transmits the data to the STM32 main control board for processing data, and transmits the calculated data to the motor drive, so as to finally keep the rod in a balanced state. The upper computer monitors the entire experimental device, acquires the motion state of the rod in real time, processes data, calculates the most suitable PID value, and transmits it to the STM32 main control board.

[0043] Referring to Figure 10 Specifically, the acceleration of the swing rod is controlled by controlling the rotating speed of the motor, so as to keep the swing rod balanced. The rotating speed of the motor is realized by changing the driving voltage thereon.

[0044] The voltage change output to the motor can be realized by PWM (pulse width modulation). The average voltage formula of PWM output is: In the formula, T is the pulse clock period, Us is the instantaneous voltage, Um is the maximum value of voltage amplitude, and D is the PWM voltage duty cycle (0<D<1).

[0045] Referring to Figure 11 Specifically, when the rising edge of TI1 comes, if TI2 is low, count up; when the rising edge of TI2 comes, if TI1 is high, continue to count up. That is, at each transition edge of the two channels, the count is generated according to the level of the other. The number of pulses calculated when the motor rotates one circle = the number of encoder lines × the motor reduction ratio × the frequency multiplication number, so the number of pulses calculated when the motor rotates one circle is 13×20×4=1040. Thus, the four times frequency multiplication greatly improves the accuracy of the encoder.

[0046] Example 4 Based on the above example 1, example 2, example 3, further description is made.

[0047] Specifically, the calculation of the inclination ring is as follows: PID control mainly includes proportional, integral, and differential control, which is a process of comparing the target value with the current value to obtain the control deviation, and then controlling the proportion, differential, and integral of the deviation to make the deviation tend to zero. The PID formula is as follows: In the formula, e(t) is the deviation of the target value at the current time and the current value, and u(t) is the output control amount. For the convenience of computer processing, the discretization processing is as follows: .

[0048] For our specific system, the inclination ring control uses PD control, i.e. proportional-differential control. Controlling the PWM size is equivalent to controlling the acceleration applied to the swing rod. Our acceleration algorithm The PWM is suitable for controlling the motor. Thus, the formula of the PD control is obtained: through the angle and the angular velocity feedback, the inverted pendulum reaches the balance state. The feedback formula is: , wherein Tav is the target angle of the tilt angle loop.

[0049] Specifically, the calculation of the position loop is performed: The most basic balance not only requires that the pendulum rod can keep from falling, but also requires that the pendulum rod can stop at the original position as much as possible, i.e. the position change is 0. At this time, the position loop needs to be added. Therefore, the most basic balance requires two loops: the tilt angle loop and the position loop. The position loop also uses the PD controller. The experiment requires that the position change is slow and smooth, and the position change is reduced to reduce the influence on the tilt angle loop. Therefore, in the position loop, a first-order low-pass filter is applied to make the speed change slowly. The time domain expression of the first-order low-pass filter is: .

[0050] wherein K is a filter coefficient. The smaller the coefficient is, the more stable the filter is, and the smoother the curve is, but the sensitivity is low; the larger the coefficient is, the higher the sensitivity is, but the result is unstable. In the program, the filter coefficient K=0.2 is taken. The feedback formula of the position loop is: , e(k) is the deviation of the target position and the current position, is the integral of the position deviation.

[0051] The above merely describes the preferred specific embodiments of the present application; however, the protection scope of the present application is not limited thereto. Any skilled person in the art, according to the technical solution and the improved concept of the present application, makes equivalent replacement or change within the technical range disclosed by the present application, which should be covered in the protection scope of the present application.

Claims

1. A wind force down rod mechanical balance experiment device, comprising two SBR long guide rails (2) and two aluminum profile long supports (3), characterized in that: The SBR long guide rail (2) and the aluminum profile long support (3) form a rectangular frame structure, the SBR long guide rail (2) is fixed at the top end of the aluminum profile long support (3), a synchronous wheel (7) is installed at the top end of the aluminum profile long support (3), a first belt (5) is arranged between two synchronous wheels (7), a first motor (4) is fixedly installed on the support of one of the synchronous wheels (7), the output end of the first motor (4) is drivingly connected with the central shaft of the adjacent synchronous wheel (7) through a shaft coupling, and a first sliding block (6) is slidingly connected to the SBR long guide rail (2); Two aluminum profile short supports (601) are fixed between two first sliding blocks (6), the two aluminum profile short supports (601) are connected in parallel side by side into an integrated body, and the two ends of each aluminum profile short support (601) are fixed with the top end of the corresponding first sliding block (6), and the side surface of the first belt (5) is fixed with the aluminum profile short support (601). A SBR short guide rail (602) is fixedly installed at the top end of each aluminum profile short support (601), and a second sliding block (603) is slidingly connected to the two SBR short guide rails (602), a three-dimensional angle offset measurement sensor device (1) is installed at the top end of the second sliding block (603), and a second synchronous wheel (604) is fixedly installed at the two ends of the SBR short guide rail (602), a second belt (605) is arranged between the two second synchronous wheels (604), and a second motor (606) is fixedly installed on the support of one of the second synchronous wheels (604). The three-dimensional angle offset measurement sensor device (1) comprises an assembled box (101), a corner sensor dimension reduction arc (102) is movably connected to the inner middle part of the assembled box (101) through a bearing, a ball table (103) is fixedly installed at the inner bottom of the assembled box (101), a centering ball (104) is arranged on the ball table (103), the centering ball (104) is freely rotatable and does not separate from the ball table (103), the centering ball (104) is located directly below the corner sensor dimension reduction arc (102), and a test rod (105) is fixedly installed at the top end of the centering ball (104).

2. The mechanical balance experimental device for the wind force lowering rod according to claim 1, characterized in that: The length of the aluminum profile short support (601) is slightly shorter than that of the aluminum profile long support (3), and the cross sections of the two are the same; The length of the SBR short guide rail (602) is slightly shorter than that of the SBR long guide rail (2), and the cross sections of the two are the same; The structure of the second sliding block (603) is the same as that of the first sliding block (6); The structure of the second synchronous wheel (604) is the same as that of the first synchronous wheel (7); The length of the second belt (605) is slightly shorter than that of the first belt (5), and the cross sections of the two are the same; The structure of the second motor (606) is the same as that of the first motor (4).

3. The mechanical balance experimental device for the wind force lowering rod according to claim 1, characterized in that: The assembled box (101) comprises a coverless box body (1011) and a height increasing stand (1012), the bottom end of the height increasing stand (1012) is fixed with the top end of the second sliding block (603), and the top end of the height increasing stand (1012) is fixed with the bottom end of the coverless box body (1011).

4. The mechanical balance experimental device for the wind force lowering rod according to claim 3, characterized in that: The height increasing frame (1012) is a hollow frame structure, and the second belt (605) is fixed to the inner top of the height increasing frame (1012).

5. The mechanical balance experimental device for the wind force lowering rod according to claim 1, characterized in that: The angle sensor dimension reduction arc (102) comprises two transverse dimension reduction arcs (1021) and two longitudinal dimension reduction arcs (1022), the two transverse dimension reduction arcs (1021) are arranged in parallel with each other, the two longitudinal dimension reduction arcs (1022) are arranged in parallel with each other, and the transverse dimension reduction arc (1021) and the longitudinal dimension reduction arc (1022) are vertically distributed in space. The two transverse dimension reduction arcs (1021) and the two longitudinal dimension reduction arcs (1022) form a gap structure, and the test rod (105) passes through the gap.

6. The mechanical balance experimental device for the wind force lowering rod according to claim 5, characterized in that: The transverse dimension reduction arc (1021) and the longitudinal dimension reduction arc (1022) are connected to the position of the assembly box (101), and the angle sensor (1023) is installed.

7. The mechanical balance experimental device for the wind force lowering rod according to claim 5, characterized in that: The inner diameter of the gap structure is slightly larger than the rod diameter of the test rod (105), and the length value of the test rod (105) is not less than eight times the length of the assembly box (101).

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