Digital balance control method for transformer hanging cover construction

Abstract

The invention relates to a digital balance control method for transformer hanging cover construction, which aims at the cover lifting and falling processes of a transformer bell cover, and realizes the detection of an unbalanced inclination angle of the bell cover by installing a three-axis angular acceleration sensor in the center of the top of a transformer. The Beidou RTU modules are installed on a crane lifting hook and four lifting points on the upper portion of the transformer to achieve detection of space coordinate values of the lifting hook and the lifting points, software data analysis is conducted according to obtained parameters to obtain a conclusion, the telescopic amount of chain hoists in the four directions is automatically controlled, and therefore intelligent leveling of the transformer bell jar in the rising and falling process is achieved. Errors and dangerousness caused by human factors are avoided, the safety of construction operation is improved, and meanwhile the efficiency and precision of whole hanging cover construction are improved.

Description

Technical Field

[0001] The invention relates to the technical field of transformer hoisting technology, and in particular to a digital balance control method for transformer hoisting cover construction. Background Art

[0002] During the transformer cover lifting operation, the following steps must be taken: construction preparation, crane and personnel in place, removal of internal transport fixtures and related connectors, removal of body bolts, removal of on-load tap changer, cover lifting, inspection personnel entering the body for inspection, removal of temporary fasteners, core testing, inspection for leftovers, personnel evacuation, cover removal, body reinstallation, on-load tap changer reinstallation, vacuuming and injection of dry air, etc. Therefore, balance control during transformer cover lifting construction is particularly important.

[0003] In the prior art, the leveling of the transformer cover is mostly done manually, that is, the construction workers stand in the middle of the top of the transformer to check the length between the hook and the hanging point to determine whether the transformer cover is balanced. This leveling method is dangerous to the construction workers and also tests their operating experience. Secondly, when the construction workers adjust the chain hoist above the transformer body, the weight of the body will be uneven and eccentric due to the workers' own weight, resulting in large errors. Finally, in the early stage of lifting, the workers have to repeatedly adjust the chain hoist on the body, which can easily cause the bell cover to collide with the internal structure of the transformer due to eccentricity, causing damage to internal components.

[0004] With the widespread use of sensors, Beidou RTU sensors are installed between the lifting point and the hook to measure the horizontal and vertical distances between the lifting point and the hook, which brings a lot of convenience to the leveling work. However, during the lifting process, the Beidou RTU sensor has a large error when measuring at high levels, which usually exceeds 5cm. During the lifting process of the transformer, the high-level error of the four lifting points is greater than 1cm, which will cause serious eccentricity, so it is not allowed. Therefore, when the error is relatively large, it cannot meet the lifting requirements. Therefore, an accurate and reliable suspension cover balance control method is urgently needed. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides a digital balance control method for transformer hanging cover construction to solve the above problems.

[0006] The present invention provides the following technical solutions:

[0007] A digital balance control method for transformer cover construction, a chain hoist control box is arranged in the middle of the transformer box, the power lines and control lines of the chain hoists at four lifting points are connected to the chain hoist control box, and the chain hoist can be electrically and wirelessly controlled; Beidou RTU sensors are respectively installed on the four lifting points A, B, C, and D of the transformer, and a Beidou RTU sensor is also installed on the crane hook P; an angular acceleration sensor is installed at the center position O of the top of the transformer; a control terminal device is placed next to the frame, and it communicates with five Beidou RTU sensors and one angular acceleration sensor by wireless communication; the specific operation steps are as follows:

[0008] (1) Construction preparation: The operator assembles the lifting belt and chain hoist for the transformer cover on the ground, manually or electrically adjusts each chain hoist to an appropriate length, and turns on the control system of the control terminal device; according to the actual situation of the on-site transformer and working space, the lifting rope inclination angle is set on the control terminal device (the setting range is between 30° and 60°);

[0009] (2) Adjust the crane. After the crane is placed in place, insert the prepared lifting equipment and slowly move the hook to the center of the top of the transformer. At this time, the horizontal distance of each lifting point, the lifting height, and the vertical and horizontal distances of the hook from the four lifting points can be seen on the screen of the control terminal device. The initial value of the lifting height is 0 cm. When the hook is adjusted to the range that meets the lifting requirements, the screen displays "Hook is centered" and the loudspeaker announces "Hook is centered". Then, each lifting equipment can be hung on each lifting point.

[0010] (3) Lifting adjustment: the hook is slowly lifted, and when there is a direction of the lifting device under force, it enters the intelligent leveling state; based on the five positioning coordinates obtained by the five Beidou RTU sensors, the length from the crane hook to each lifting point (PA, PB, PC, PD) can be roughly measured. We adjust the one with the shortest length obtained by rough measurement, assuming it is one of the A and C directions; among them, according to the data measured by the angular acceleration sensor, the initially set lifting rope inclination angle, the horizontal distance between each lifting point in the ideal horizontal state, and the adjustment amount obtained by the theoretical algorithm, the length of the chain hoist in the A and C directions is adjusted until the requirements are met, and then the length of the chain hoist in the B and D directions is adjusted until the requirements are met; when the four directions A, B, C, and D are adjusted, the screen displays "the box has been leveled" and the speaker announces "it can be lifted";

[0011] (4) After the lifting is completed, print out the data of the force in each direction and the total length of the lifting equipment per minute during the lifting process as a reference for related operations.

[0012] Furthermore, the adjustment amount obtained by the theoretical algorithm is

[0013] Among them, the offset angle θ value can be calculated by the x, y, and z three-axis offsets obtained by the angular acceleration sensor. The theoretical length of the rope under the initially set rope inclination angle is PA=PC=a, and the distance between the two diagonal hanging points is AC=b.

[0014] and

[0015] Among them, the horizontal distance between each hook in the ideal horizontal state is AB=CD=g, AD=BC=h; x is the distance from the crane hook to the center of the top surface of the transformer, which is a variable. γ is the initial setting of the rope inclination angle.

[0016] Furthermore, the five Beidou RTU sensors and one angular acceleration sensor are all magnetic and come with their own power modules.

[0017] Furthermore, it is possible to switch to manual mode and control the operation by operating the terminal device, using input length or "long" or "short" button operation.

[0018] Furthermore, before lifting, it is necessary to unplug the power supply to the chain hoist control box so that the chain hoist automatically enters a self-locking state.

[0019] Furthermore, during the lifting process, the stress conditions of the lifting equipment in the four directions of A, B, C, and D can be viewed on the screen to facilitate further judgment.

[0020] The present invention has the following beneficial technical effects:

[0021] The invention provides a digital balancing control method for transformer hanging cover construction. The entire leveling work only needs to set the angle between the hook and the hanging rope, that is, the initially set hanging rope inclination angle, and the hanging cover balance can be completed digitally by the control terminal equipment. Manual leveling is no longer required, thus avoiding errors and dangers caused by human factors and improving the safety and effectiveness of construction operations.

[0022] In addition, the digital balancing control method for transformer hanging cover construction of the present invention obtains the adjustment amount based on the data measured by the Beidou RTU sensor and the angular acceleration sensor and the theoretical algorithm, thereby avoiding the error caused by the distance measurement using only the RTU sensor, making the hanging cover more accurately leveled and improving the efficiency and accuracy of the entire hanging cover construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the front mechanical assembly of the transformer hanging cover of the present invention;

[0024] Figure 2 It is a schematic diagram of the installation of the sensor on the top surface of the transformer cover of the present invention;

[0025] Figure 3 is a schematic diagram of a control terminal device of the present invention;

[0026] Figure 4 It is a schematic diagram of leveling of the present invention;

[0027] Figure 5-Figure 9 It is a schematic diagram of the planar calculation of the adjustment amount of the theoretical algorithm of the present invention. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] Example

[0030] A digital balance control system for transformer cover construction includes a power supply system, a Beidou RTU sensor, an angular acceleration sensor, a hanger mechanical part and a data acquisition and digital control terminal.

[0031] The equipment that needs to be powered by this system includes Beidou RTU sensor, angular acceleration sensor, mechanical part of the spreader and data acquisition and digital control terminal. Among them, the mechanical part of the spreader is mainly a weight-measurable electric chain hoist, which uses a controllable motor to adjust the chain, and a weight-measurable wireless tension sensor terminal is installed at the hook of the chain hoist.

[0032] A chain hoist control box is set in the middle of the transformer box, and the control chain motor power supply and motor control circuit of the four electric chain hoists are connected to the chain hoist control box. A wireless transmission module is installed in the chain hoist control box, which can communicate with the data acquisition and digital control terminal. The chain hoist control box is powered by an external power supply. The data acquisition and digital control terminal, Beidou RTU sensor, and angular acceleration sensor are directly powered by the power supply mode of the built-in lithium battery.

[0033] The Beidou RTU sensor and angular velocity sensor are equipped with magnetic suction structures respectively, and built-in wireless modules are used to communicate with the digital control terminal. The Beidou RTU sensor is used to collect the coordinates of each lifting point and hook, and the angular velocity sensor is used to collect the three-axis inclination angle of the transformer.

[0034] The data acquisition and digital control terminal is mainly modified from a microcomputer, which is equipped with a wireless communication module to enable communication with various sensors.

[0035] A digital balance control method for transformer bell construction is used to hoist the transformer bell. A chain hoist control box is set in the middle of the transformer box, and the power lines and control lines of the chain hoists at the four lifting points are connected to the control box for power supply and operation. Magnetic Beidou RTU sensors are installed at the four lifting points of the transformer, and a magnetic Beidou RTU sensor is also installed on the crane hook. A magnetic angular acceleration sensor is installed at the center of the top of the transformer. A control terminal device is placed next to the on-site structure, which communicates with the chain hoist control box, 5 Beidou RTU sensors and angular acceleration sensor using wireless communication (such as Figure 1 , 2 The specific steps are as follows:

[0036] (1) Construction preparation

[0037] The operator assembled the slings and chain hoists for the transformer cover on the ground. Each chain hoist was manually or electrically adjusted to an appropriate length. The power supply of each device was connected and the control system terminal system was turned on.

[0038] (2) Crane adjustment

[0039] After the crane is placed in place, the hoisting equipment is inserted and the hook is slowly moved to the center of the top of the transformer. At this time, the horizontal distance of each lifting point, the lifting height (initial value is 0cm) and the vertical and horizontal distances of the hook from the four lifting points can be seen on the terminal screen. When the hook is adjusted to the range that meets the lifting requirements, the screen displays "The hook is centered" and the speaker announces "The hook is centered". Each hoisting equipment can be hung on each lifting point.

[0040] (3) Lifting adjustment

[0041] The hook is slowly lifted, and when the hoist is stressed in one direction, it enters the intelligent leveling state. The four corners on the top of the transformer are the lifting points A, B, C, and D, and the hook is P. According to the five positioning coordinates obtained by the five Beidou RTU sensors, the lengths of PA, PB, PC, and PD can be roughly measured, and the one with the shortest length measured can be adjusted first. According to the data measured by the angular acceleration sensor and the adjustment amount obtained by the theoretical algorithm, the length of the chain hoist in directions A and C (or B and D) is adjusted until the requirements are met, and then the length of the chain hoist in directions B and D (or A and C) is adjusted until the requirements are met. When the four directions A, B, C, and D are adjusted, the screen displays "The box has been leveled" and the speaker announces "It can be lifted."

[0042] At this time, unplug the power supply to the chain hoist control box, and the chain hoist will automatically enter the self-locking state and then command the crane to lift slowly. During the lifting process, we can also see the force conditions of the hoist in the four directions of A, B, C, and D on the screen to make the next judgment.

[0043] Here is a point to explain, we can also switch to manual mode, by operating the control terminal (such as Figure 3 It can be controlled by inputting the length or pressing the “Long” or “Short” buttons.

[0044] (4) Lifting is completed

[0045] After the lifting is completed, print out the data of the forces in all directions and the total length of the sling every minute during the lifting process as a reference for related operations.

[0046] In this embodiment, according to the data measured by the angular acceleration sensor, the length of the chain hoist in the A and C directions (or the B and D directions) is adjusted until the requirements are met by the adjustment amount obtained by the theoretical algorithm. The derivation process is as follows ( Figure 5-9 ):

[0047] The transformer is approximated as a cuboid, with the four corners at the top as hanging points A, B, C, and D, and a hook P at the top. Assuming the cuboid is in an unbalanced state, it is necessary to adjust the lengths of PA, PB, PC, and PD to keep the cuboid balanced (e.g. Figure 4 As shown). Then we need to study which variables can determine the length adjustment of PA, PB, PC, and PD. Here, the lengths of the four lines are adjusted in groups. First adjust PA and PC, then adjust PB and PD, and finally achieve the leveling purpose.

[0048] First, calculate the plane adjustment formula and introduce an offset angle θ (such as Figure 5 As shown). Given: PA = PC = a, AC = b, O is the midpoint of AC, point Q moves on PA, what is the relationship between PQ and θ?

[0049] Solution: Let PQ = m, OQ = n

[0050] From the sine theorem we get

[0051]

[0052] Then, from the sine theorem, we get

[0053]

[0054] Combining equations ① and ②, we get

[0055]

[0056] Right now

[0057] Then we start from Figure 5 It can be concluded that when Q and P coincide, QA = QC, forming an isosceles triangle, a stable shape. We can apply this principle to the cuboid leveling system to achieve PA = PC (similarly PB = PD). Next, we need to explain several quantities in formula ③, a, b, θ.

[0058] During the transformer cover hanging process, the lengths between several hanging points are determined. Assuming constants g and h, AB=CD=g, AD=BC=h, then we can get

[0059] Assuming that the distance from the crane hook to the center of the top surface of the transformer is a change x, we can get the following triangle, and then we can get a.

[0060]

[0061] Here we explain the change x (i.e. the height of PO). The ideal angle between the lifting rope and the horizontal plane of the object is 30° to 60°, and the angle between the two lifting ropes cannot be greater than 120°. Before lifting, we can set the appropriate lifting rope inclination angle γ (i.e. ∠PCO) according to the on-site working conditions.

[0062]

[0063] Assume that the crane hook is currently in Figure 8 The Q point position can be obtained by the x, y, and z three-axis offsets obtained by the angular acceleration sensor, and the θ value (i.e. ∠POQ) in the plane triangle PAC can be calculated.

[0064] In summary, we can calculate the PQ value through the values ​​of a, b, and θ. According to the PQ value, adjust the length of AQ until the Q point coincides with the P point. Fig. 9 , we adjust the length of PM until point M coincides with point P. Finally, MA=MB=MC=MD is achieved, thus achieving leveling.

[0065] Aiming at the raising and lowering processes of the transformer bell jar, the present invention installs a three-axis angular acceleration sensor at the center of the transformer top to detect the unbalanced tilt angle of the bell jar, and installs Beidou RTU modules at the four corners of the top to detect the horizontal and vertical position deviation sizes of the four corners. Then, software data analysis is performed according to the acquired parameters to draw conclusions, and the extension and contraction amounts of chain hoists in four directions are automatically controlled, thereby realizing intelligent leveling of the transformer bell jar in the raising and lowering processes.

[0066] The above-mentioned embodiments only express the specific implementation of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A digital balance control method for transformer cover construction, characterized in that: Beidou RTU sensors are installed on the four lifting points A, B, C, D of the transformer and the crane hook P, and an angular acceleration sensor is installed at the center position O on the top of the transformer; the control terminal equipment communicates with the five Beidou RTU sensors and one angular acceleration sensor using wireless communication; the specific operation steps are as follows: (1) Construction preparation: manually or electrically adjust each chain hoist to an appropriate length and turn on the control terminal device; (2) Adjust the crane and slowly move the hook to the center of the top of the transformer. When the hook is adjusted to the range required for lifting, hang each lifting device on each lifting point. Set the inclination angle of the lifting rope on the control terminal device according to the actual situation of the on-site transformer and working space. (3) Lifting adjustment: The hook is slowly lifted. When the sling is subjected to force in one direction, it enters the intelligent leveling state: according to the data measured by the angular acceleration sensor, the initially set inclination angle of the lifting rope and the horizontal distance between the hooks in the ideal horizontal state, the adjustment amount in each direction is obtained through the theoretical algorithm, and the length of each chain hoist is adjusted until the requirements are met; (4) After the lifting is completed, print the data of the force in each direction and the total length of the lifting equipment per minute during the lifting process.

2. A digital balance control method for transformer cover construction according to claim 1, characterized in that: According to the positioning coordinates obtained by the Beidou RTU sensor, the length from the crane hook to each lifting point can be roughly measured, and the one with the shortest length measured can be adjusted first.

3. A digital balance control method for transformer cover construction according to claim 2, characterized in that: The adjustment amount in each direction is obtained through the theoretical algorithm: Among them, the offset angle θ value can be calculated by the x, y, and z three-axis offsets obtained by the angular acceleration sensor. The theoretical length of the rope under the initially set rope inclination angle is PA=PC=a, and the distance between the two diagonal hanging points is AC=b.

4. A digital balance control method for transformer cover construction according to claim 3, characterized in that: Among them, the horizontal distance between each hanging point in the ideal horizontal state is AB=CD=g, AD=BC=h; x is the distance from the crane hook to the center of the top surface of the transformer, which is a variable. γ is the initial setting of the rope inclination angle.

5. A digital balance control method for transformer cover construction according to claim 1, characterized in that: The five Beidou RTU sensors and one angular acceleration sensor are all magnetic and come with their own power modules.

6. A digital balance control method for transformer cover construction according to claim 1, characterized in that: The operation control terminal device also includes a manual mode.

7. A digital balance control method for transformer cover construction according to claim 1, characterized in that: A chain hoist control box is set in the middle of the transformer box, and the power lines and control lines of the chain hoists at the four hanging points are connected to the chain hoist control box.

8. A digital balance control method for transformer cover construction according to claim 7, characterized in that: Before lifting, you need to unplug the power supply to the chain hoist control box to make the chain hoist automatically enter the self-locking state.

9. A digital balance control method for transformer cover construction according to claim 1, characterized in that: During the lifting process, the stress conditions of the lifting equipment in the four directions of A, B, C and D can be seen on the screen.

10. A digital balance control method for transformer cover construction according to claim 1, characterized in that: The initial setting of the rope inclination angle ranges from 30° to 60°.

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