Measuring tool and measuring method for deformation test of liquid-immersed transformer

Abstract

The invention relates to the field of transformers, and discloses a measuring tool and a measuring method for a deformation test of an immersed transformer, the measuring tool for the deformation test of the immersed transformer comprises a measuring frame body, a pull rope type displacement sensor with a magnetic attraction function and a digital display instrument, the measuring frame body comprises a base, a square tube is vertically welded on the base, and the square tube is connected with the digital display instrument. A moving assembly is arranged at the bottom of the base, a guide rail is vertically installed on the side wall of the square pipe, a bearing box is arranged on the guide rail in a sliding mode through a sliding block, a plurality of sets of containing holes are formed in the bearing box and used for containing aluminum pipes in the X-axis direction and the Y-axis direction, and a hand-cranking steel wire rope reel is arranged on the side wall of the square pipe. The top of the square tube is provided with a fixed pulley, one end of the steel wire rope is wound on the hand-cranking steel wire rope reel, the other end of the steel wire rope is wound around the fixed pulley to be connected with the bearing box, and the measuring tool can achieve more accurate measured data and higher efficiency.

Description

Technical Field

[0001] The invention relates to the field of transformers, and in particular discloses a measuring tool and a measuring method for a liquid-immersed transformer deformation test. Background Art

[0002] The vacuum deformation test and pressure deformation test of liquid-immersed transformers are special test items in the GB1094.1 standard. According to the standard, "the test should be carried out on a complete liquid-filled transformer", which is different from the mechanical strength test of a single oil tank.

[0003] At present, more and more project agreements require vacuum and pressure deformation tests. The commonly used measurement method in the past is: with the help of 4 fixed poles about 1.5m high, cotton ropes are tied between the poles, and the distance between each reference point on the tank wall and the cotton rope under different conditions is measured with a spirit level to obtain the permanent deformation of each reference point on the tank under vacuum and pressure conditions.

[0004] The disadvantages of the above-mentioned measuring tools and methods are as follows: the cotton rope is elastic and the measurement data is not accurate enough; the vacuum and pressure deformation tests require measuring the deformation of the oil tank in five states: initial state, evacuated to the required vacuum degree, released from vacuum, filled with transformer oil and pressurized, and released from pressure. The measurement cycle is too long and is easily affected by human interference, resulting in the pole and cotton rope not being able to maintain their original state and displacement; there are also unfavorable factors such as human measurement errors. Summary of the invention

[0005] The purpose of the present invention is to provide a measuring tool and a measuring method for a liquid immersed transformer deformation test with a simple structure and reasonable design in order to solve the above problems.

[0006] A first aspect of the present invention provides a measuring tool for a liquid-immersed transformer deformation test, comprising a measuring frame, a pull-rope displacement sensor with a magnetic suction function, and a digital display, wherein the measuring frame comprises a base, a square tube is vertically welded on the base, a moving component is arranged at the bottom of the base, a guide rail is vertically installed on the side wall of the square tube, a supporting box is slidably arranged on the guide rail through a slider, a plurality of groups of placement holes are provided on the supporting box, and the placement holes are used to place aluminum tubes in the X-axis and Y-axis directions, a hand-cranked wire rope reel is arranged on the side wall of the square tube, a fixed pulley is arranged on the top of the square tube, and also comprises a wire rope, one end of the wire rope is wound around the hand-cranked wire rope reel, and the other end is connected to the supporting box by bypassing the fixed pulley.

[0007] Furthermore, the moving assembly includes universal wheels, four sets of universal wheels are provided, and the universal wheels have a self-locking function.

[0008] Furthermore, the hand-cranked wire rope reel is connected to the square tube via two groups of brackets, the hand-cranked wire rope reel is rotatably connected to the brackets, the hand-cranked wire rope reel comprises a reel frame and a rotating shaft, a rocker is provided at one end of the rotating shaft, and also comprises a locking device for locking the state of the hand-cranked wire rope reel.

[0009] Furthermore, the locking device comprises a ratchet wheel arranged on the rotating shaft, and a group of the brackets are correspondingly provided with a pawl on one side close to the ratchet wheel.

[0010] Furthermore, the reel frame is in an "I" shape, and an internal cavity is set up. One end of the rotating shaft is set inside the cavity, and the other end passes through the reel frame and passes through one group of brackets to be connected to the rocker. The other side of the reel frame is rotatably connected to another group of brackets through a fixed rod.

[0011] Furthermore, a disc is arranged at one end of the rotating shaft away from the rocker, a limiting groove is provided on the disc, a limiting protrusion matching the limiting groove is arranged in the cavity, and the rotating shaft is rotated by rotating the rocker, and the reel frame is also rotated at the same time.

[0012] Furthermore, the disc is connected to the inner wall of the cavity via a spring in the moving direction.

[0013] A second aspect of the present invention provides a measurement method based on the above-mentioned liquid immersed transformer deformation test measurement tool, comprising the following steps:

[0014] S1. Move the six measuring frames to the four corners of the transformer and the ends of both sides of the long axis, find the correct position, lock the universal wheels, and achieve fixed position;

[0015] S2. Adjust the height of the support box 6 in the X-axis, Y-axis and Z-axis directions by manually cranking the wire rope reel to facilitate the placement of the aluminum tube between the measuring frames;

[0016] S3. Place the aluminum tube clamp on the opening of the support box between the two measuring frames;

[0017] S4. Select appropriate measurement reference points on the wall and top of the transformer oil tank, apply adhesive tape, and use a marker to make an "×" mark on the adhesive tape;

[0018] S5. Fix the magnetic base of the displacement sensor at the position marked with ×, pull out the lead wire, hook the S-shaped hook at the end of the lead wire to the appropriate position of the aluminum tube, and fix it with a cable tie;

[0019] S6, connecting each channel line between each displacement sensor arranged on the box wall and the box top and the display instrument;

[0020] S7, turn on the display power, read and record the data of each channel, and turn off the display power;

[0021] S8. Record the displacement data in the five states of initial, vacuum, vacuum release, positive pressure, and positive pressure release respectively. Calculate the difference and calculate the permanent deformation of the vacuum deformation and pressure deformation of the oil tank.

[0022] Beneficial effects: The measuring tool can achieve more accurate measurement data; and the measurement work is more efficient. Once the measuring tool is installed in place, only one person is needed to complete multiple data reading and recording work in subsequent measurement work in various states; thirdly, the tool can easily achieve accurate measurement of different oil tank deformation by adjusting the height of the bracket iron box and the length of the plug-in aluminum tube according to the different lengths, widths and heights of the transformer oil tank. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the structure of the measuring frame of the present invention;

[0024] Figure 2 It is a schematic diagram of the structure of the hand-cranked wire rope reel of the present invention;

[0025] Figure 3 It is a schematic diagram of the internal structure of the hand-cranked wire rope reel of the present invention.

[0026] In the figure: 1. base; 2. square tube; 3. universal wheel; 4. guide rail; 5. slider; 6. support box; 7. hand-cranked wire rope reel; 701. reel frame; 702. rotating shaft; 703. rocker; 704. disc; 705. limiting groove; 706. limiting protrusion; 707. ratchet; 708. fixing rod; 709. spring; 8. fixed pulley; 9. bracket; 10. wire rope. DETAILED DESCRIPTION

[0027] The subject matter described herein will now be discussed with reference to example implementations. It should be understood that the discussion of these implementations is only to enable those skilled in the art to better understand and implement the subject matter described herein, and the functions and arrangements of the elements discussed may be changed without departing from the scope of protection of the present specification. Various examples may omit, replace, or add various processes or components as needed. In addition, the features described in some examples may also be combined in other examples.

[0028] Example 1

[0029] like Figure 1-Figure 3As shown, a measuring tool for a liquid-immersed transformer deformation test comprises a measuring frame, a pull-rope displacement sensor with a magnetic suction function (not shown in the figure) and a digital display instrument (not shown in the figure), wherein the measuring frame comprises a base 1, a square tube 2 is vertically welded on the base 1, a moving assembly is arranged at the bottom of the base 1, a guide rail 4 is vertically installed on the side wall of the square tube 2, a supporting box 6 is slidably arranged on the guide rail 4 through a slider 5, a plurality of groups of placement holes with a diameter of 40 mm are provided on the supporting box 6, the placement holes are used to place aluminum tubes in the X-axis and Y-axis directions, and the diameter of the aluminum tube is 40 mm, a hand-cranked wire rope reel 7 is arranged on the side wall of the square tube 2, a fixed pulley 8 is arranged on the top of the square tube 2, and a wire rope 10 is also included, one end of the wire rope 10 is wound around the hand-cranked wire rope reel 7, and the other end is connected to the supporting box 6 by bypassing the fixed pulley 8.

[0030] The base 1 is made of 20 mm thick steel plate, the height of the square tube 2 is 4500 mm, the guide rail 4 is 4000 mm, and an aluminum rod pipe joint can also be provided for plugging in the aluminum tube.

[0031] In actual use, the wire rope 10 is wound up by rotating the hand-cranked wire rope reel 7 so as to adjust the height of the supporting box 6, and the deformation test of transformers at different heights can be measured.

[0032] Among them, the drawstring displacement sensor uses a drawstring (usually a high-strength wire) to connect to the object to be measured. When the object is displaced, the drawstring is pulled, and the measuring mechanism (such as an encoder) inside the sensor can detect the pulling length, thereby calculating the displacement of the object;

[0033] The magnetic feature allows it to be attached to metal surfaces without the need for additional mounting brackets or fixtures. This makes the installation process easier and allows for flexibility in adjusting the position or removing the sensor.

[0034] A digital display is a device that can convert analog signals (such as displacement) measured by a sensor into digital signals and display them. Its functions usually include:

[0035] Display numbers: The digital display displays the displacement value (such as centimeters, millimeters, etc.) measured by the displacement sensor in a digital way, which is convenient for users to read.

[0036] Connection with sensor: The digital display is usually connected to the pull-wire displacement sensor through a cable, receives the electrical signal provided by the sensor and processes and displays it.

[0037] Preferably, the moving assembly includes universal wheels 3, four sets of universal wheels 3 are provided, and the universal wheels 3 have a self-locking function.

[0038] By locking the universal wheels to achieve fixed position, the measuring frame can be fixed in a certain position and will not be displaced by external force or operation, making the measurement results more accurate.

[0039] A measurement method based on the above-mentioned liquid immersed transformer deformation test measurement tooling comprises the following steps:

[0040] S1. Move the six measuring frames to the four corners of the transformer and the ends of both sides of the long axis to ensure that they can fully cover all measuring areas of the transformer, find the correct position, lock the universal wheels, and achieve fixed position;

[0041] S2. Adjust the height of the bracket iron box in the X-axis, Y-axis and Z-axis directions by manually cranking the wire rope reel 7, so as to facilitate the placement of the aluminum tube between the measuring frames, ensure that the displacement sensor can remain stable in different spatial positions, and facilitate subsequent measurements;

[0042] S3, place the aluminum tube clamp on the opening of the support box 6 between the two measuring frames;

[0043] S4. Select appropriate measurement reference points on the wall and top of the transformer oil tank, apply adhesive tape, and use a marker to make an "×" mark on the adhesive tape;

[0044] S5. Fix the magnetic base of the displacement sensor at the position marked with ×, pull out the lead wire, hook the S-shaped hook at the end of the lead wire to the appropriate position of the aluminum tube, and fix it with a cable tie to ensure that the lead wire will not get loose or affect the measurement due to external interference;

[0045] S6, connecting the channels between the displacement sensors arranged on the box wall and the box top and the display instrument, each sensor usually has an independent channel, and the displacement signal of the sensor is transmitted to the display instrument through these channels;

[0046] S7, turn on the display power, read and record the data of each channel, and turn off the display power;

[0047] S8. Record the displacement data under the five states of initial, vacuum, vacuum release, positive pressure, and positive pressure release respectively, calculate the difference, and calculate the permanent deformation of the vacuum deformation and pressure deformation of the oil tank.

[0048] Example 2

[0049] Further improvements are made based on Example 1:

[0050] The hand-cranked wire rope reel 7 is connected to the square tube 2 via two groups of brackets 9, and the hand-cranked wire rope reel 7 is rotatably connected to the brackets 9. The hand-cranked wire rope reel 7 includes a reel frame 701 and a rotating shaft 702, a rocker 703 is provided at one end of the rotating shaft 702, and also includes a locking device for locking the state of the hand-cranked wire rope reel 7.

[0051] Preferably, the locking device comprises a ratchet 707 arranged on the rotating shaft 702 , and a group of the brackets 9 are correspondingly provided with a pawl on one side close to the ratchet 707 .

[0052] Preferably, the reel frame 701 is in the shape of an "I" character, and an internal cavity is set up. One end of the rotating shaft 702 is set inside the cavity, and the other end passes through the reel frame 701 and passes through a group of the brackets 9 connected to the rocker 703. The other side of the reel frame 701 is rotatably connected to another group of the brackets 9 through a fixed rod 708.

[0053] Preferably, a disc 704 is provided at one end of the rotating shaft 702 away from the rocking arm 703, a limiting groove 705 is provided on the disc 704, and a limiting protrusion 706 matching the limiting groove 705 is provided in the cavity, and the rotating shaft 702 is driven to rotate by rotating the rocking arm 703, and the reel frame 701 is driven to rotate at the same time.

[0054] Preferably, the disk 704 is connected to the inner wall of the cavity via a spring 709 in the moving direction.

[0055] When the spring 709 is in a normal state, the side of the ratchet 707 is close to the bracket 9, so that the pawl limits the rotation direction of the ratchet 707, so that the shaft 702 can only rotate in the same direction. When the shaft 702 needs to be rotated in the opposite direction, it is only necessary to apply axial pressure to the shaft 702 to make it slide into the cavity, so that the ratchet 707 and the pawl are not on the same plane, so that the pawl cannot limit the ratchet 707, and then the shaft 702 is rotated in the opposite direction. When the support box 6 is adjusted to a suitable position, the axial pressure on the shaft 702 is cancelled, and the elastic force of the spring 709 is released, so that the ratchet 707 engages with the pawl here to achieve a fixed state.

[0056] The above describes an embodiment of the present invention, but this embodiment is not limited to the above-mentioned specific implementation mode. The above-mentioned specific implementation mode is merely illustrative and not restrictive. Under the guidance of this embodiment, ordinary technicians in this field can also make more forms of equivalent embodiments, all of which are within the protection of this embodiment.

Claims

1. A measuring tool for a liquid immersed transformer deformation test, characterized in that: The invention comprises a measuring frame, a pull-rope type displacement sensor with a magnetic suction function and a digital display instrument. The measuring frame comprises a base (1), a square tube (2) is vertically welded on the base (1), a moving component is arranged at the bottom of the base (1), a guide rail (4) is vertically installed on the side wall of the square tube (2), a supporting box (6) is slidably arranged on the guide rail (4) through a slider (5), a plurality of groups of placement holes are provided on the supporting box (6), and the placement holes are used to place aluminum tubes in the X-axis and Y-axis directions, a hand-cranked wire rope reel (7) is arranged on the side wall of the square tube (2), a fixed pulley (8) is arranged on the top of the square tube (2), and also comprises a wire rope (10), one end of the wire rope (10) is wound around the hand-cranked wire rope reel (7), and the other end is connected to the supporting box (6) by passing around the fixed pulley (8).

2. The measuring tool for liquid immersed transformer deformation test according to claim 1, characterized in that: The moving assembly comprises universal wheels (3), four sets of universal wheels (3) are provided, and the universal wheels (3) have a self-locking function.

3. The measuring tool for liquid immersed transformer deformation test according to claim 2, characterized in that: The hand-cranked wire rope reel (7) is connected to the square tube (2) via two groups of brackets (9), the hand-cranked wire rope reel (7) is rotatably connected to the brackets (9), the hand-cranked wire rope reel (7) comprises a reel frame (701) and a rotating shaft (702), one end of the rotating shaft (702) is provided with a rocker (703), and also comprises a locking device for locking the state of the hand-cranked wire rope reel (7).

4. The measuring tool for liquid immersed transformer deformation test according to claim 3 is characterized in that: The locking device comprises a ratchet (707) arranged on the rotating shaft (702), and a group of the brackets (9) are correspondingly provided with a ratchet pawl on one side close to the ratchet (707).

5. The measuring tool for liquid immersed transformer deformation test according to claim 4, characterized in that: The reel frame (701) is in the shape of an "I" character and has an internal cavity. One end of the rotating shaft (702) is arranged inside the cavity, and the other end passes through the reel frame (701) and penetrates a group of the brackets (9) to be connected to the rocker (703). The other side of the reel frame (701) is rotatably connected to another group of the brackets (9) via a fixing rod (708).

6. The measuring tool for liquid immersed transformer deformation test according to claim 5, characterized in that: A disc (704) is arranged at one end of the rotating shaft (702) away from the rocking arm (703), and a limiting groove (705) is provided on the disc (704). A limiting protrusion (706) matching the limiting groove (705) is arranged in the cavity. The rotating shaft (702) is driven to rotate by rotating the rocking arm (703), and the reel frame (701) is driven to rotate at the same time.

7. The measuring tool for liquid immersed transformer deformation test according to claim 6, characterized in that: The disk (704) is connected to the inner wall of the cavity via a spring (709) in the moving direction.

8. A measurement method based on the liquid immersed transformer deformation test measuring tool according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1. Move the six measuring frames to the four corners of the transformer and the ends of both sides of the long axis, find the correct positions, lock the universal wheels (3), and achieve fixed positions; S2. By manually cranking the wire rope reel (7), the height of the support box in the X-axis, Y-axis and Z-axis directions is adjusted to facilitate the placement of the aluminum tube between the measurement frames; S3, placing the aluminum tube clamp on the opening of the support box (6) between the two measuring frames; S4. Select appropriate measurement reference points on the wall and top of the transformer oil tank, apply adhesive tape, and use a marker to make an "×" mark on the adhesive tape; S5. Fix the magnetic base of the displacement sensor at the position marked with ×, pull out the lead wire, hook the S-shaped hook at the end of the lead wire to the appropriate position of the aluminum tube, and fix it with a cable tie; S6, connecting each channel line between each displacement sensor arranged on the box wall and the box top and the display instrument; S7, turn on the display power, read and record the data of each channel, and turn off the display power; S8. Record the displacement data under the five states of initial, vacuum, vacuum release, positive pressure, and positive pressure release respectively, calculate the difference, and calculate the permanent deformation of the vacuum deformation and pressure deformation of the oil tank.

9. The measuring method of the liquid immersed transformer deformation test measuring tool according to claim 8, characterized in that: In step S2, the state of the hand-cranked wire rope reel (7) is fixed by a locking device.

Images