A method for measuring deformation of power transformer oil tank

Abstract

The present invention provides a method for measuring the deformation of a power transformer tank, comprising: marking a corresponding number of measuring points on the wall of the transformer tank to be tested; placing a number of fixed, movable, and fixed poles along the outer periphery of the transformer tank to be tested and securing them; bringing the dial indicator probes on the horizontal poles into full contact with the corresponding measuring points on the wall of the transformer tank to be tested; performing a zero check on the dial indicator and adjusting it to an initial value for the estimated deformation; applying a preset pressure value or evacuating the transformer tank to a preset vacuum level; and after the pressure stabilizes for a period of time, recording the readings of each dial indicator to calculate the elastic and permanent deformation of the tank. This method can eliminate the influence of factors such as personnel, tooling, and measuring equipment on measurement accuracy, significantly improving detection accuracy.

Description

Technical Field

[0001] The present invention relates to the technical field of power systems, and in particular to a method for measuring the deformation of an oil tank of a power transformer. Background Art

[0002] The oil tank of an oil-immersed transformer must have sufficient mechanical strength to ensure the safe operation of the transformer. During factory testing of power transformers, the oil tank mechanical strength test and pressure vacuum deformation test must be carried out. It is required that the transformer oil tank should not have a permanent deformation value exceeding the standard requirements when subjected to the pressure specified in the standard.

[0003] GB / T 1094.1-2013 stipulates the required values for permanent deformation of the oil tank after the vacuum or pressure is released: medium-sized power transformers should not exceed 1mm, and large power transformers above 100MVA should not exceed 5mm. According to the above millimeter-level deformation assessment requirements, the industry currently generally uses the oil tank deformation measurement method specified in the JB / T 501-2021 standard, that is, by pulling a thin rope around each tested surface around the oil tank as a test reference line, the thin rope is fixed at both ends of the test point, and the reference line should not move with the deformation of the transformer. When performing vacuum deformation test and pressure deformation test on the power transformer oil tank, a steel tape measure (box ruler) or a steel plate ruler is used to measure the distance change between each test point and the thin rope reference line to detect the oil tank deformation. This method has the following shortcomings: (1) For large power transformers, the oil tank size is large, and it is difficult to establish a reliable measurement reference by pulling the thin rope, and the measurement results are easily affected by the inaccuracy of the thin rope reference; (2) The minimum resolution of the steel tape measure (ruler) is 1mm, which cannot meet the precise measurement requirements below the millimeter level; (3) The span of the thin rope between the vertical poles is large, and the elastic thin rope will cause displacement deviation, affecting the accuracy of the measurement results. In addition, the current measurement method requires testers to perform manual measurements next to the fuel tank, which is prone to human errors and also poses the risk of personal injury due to fuel tank explosion. Summary of the Invention

[0004] In view of this, the present invention proposes a method for measuring the deformation of a power transformer oil tank, aiming to solve the problems of low measurement accuracy and inconvenient operation of the existing power transformer oil tank deformation.

[0005] The present invention proposes a method for measuring the deformation of a power transformer oil tank, comprising the following steps:

[0006] Step 1: Mark a corresponding number of measuring points on a designated area on the wall of the transformer tank to be tested;

[0007] Step 2: According to the position of each measuring point, a plurality of fixed-point movable fixed pole devices are placed along the outer side of the transformer tank to be measured, corresponding to each measuring point, and each fixed-point movable fixed pole device is fixed. A dial indicator is set on the horizontal benchmark of each fixed-point movable fixed pole device:

[0008] Step 3: Keep the measuring probe of each dial indicator perpendicular to the area where each measuring point on the wall of the transformer tank to be tested is located, and fully contact the measuring probe of each dial indicator with the corresponding measuring point;

[0009] Follow steps 4 to 6 below, or follow steps 4, 7, and 8 below.

[0010] Step 4: performing a zero check operation on each of the dial indicators and adjusting each of the dial indicators to an initial value D1 of the estimated deformation;

[0011] Step 5: applying a preset pressure value to the oil tank of the transformer to be tested, and after the pressure stabilizes for a period of time, recording the reading D2 in each of the dial indicators, and the difference between D2 and D1 is the elastic deformation of the oil tank corresponding to the preset pressure value;

[0012] Step 6, releasing the pressure in the oil tank of the transformer to be tested, leaving it to stand for a period of time, and then recording the reading D4 in each dial indicator again. The difference between D4 and D1 is the permanent deformation of the oil tank corresponding to the preset pressure value;

[0013] Step 7: evacuate the pressure in the transformer tank to be tested to a preset vacuum degree, wait for the vacuum pressure to stabilize for a period of time, and then record the reading D3 on the dial indicator. The difference between D3 and D1 is the elastic deformation of the tank corresponding to the preset vacuum degree.

[0014] Step 8: Release the preset vacuum degree in the oil tank of the transformer to be tested, let it stand for a period of time, and then read the reading D5 in each dial indicator again. The difference between D5 and D1 is the permanent deformation of the oil tank corresponding to the preset vacuum degree.

[0015] Furthermore, in the above-mentioned method for measuring the deformation of the power transformer oil tank, in step 1, a number of measuring points are arranged at half the height of each side of the wall surface of the power transformer oil tank to be measured, along the middle position of the length direction of the major axis and the minor axis and on both sides thereof, or the measuring points are arranged according to the position where the surface strength of the power transformer oil tank to be measured is relatively weak.

[0016] Furthermore, in the above-mentioned method for measuring the deformation of the power transformer oil tank, the fixed-point movable fixed pole device includes: a vertical pole, a horizontal pole, a first bracket, a second bracket and a movable base; wherein,

[0017] The bottom of the vertical pole is connected to the movable base;

[0018] The horizontal pole is rotatably connected to the vertical pole via a first bracket. A first sleeve is provided on the first bracket in the horizontal direction. The vertical pole is passed through the first sleeve to adjust the height of the horizontal pole in the vertical direction.

[0019] The second bracket is installed at one end of the horizontal pole, and the second bracket is rotatably connected to the horizontal pole to make the measuring probe of the dial indicator vertical to the wall surface of the transformer oil tank to be tested.

[0020] Furthermore, in the above-mentioned method for measuring the deformation of the oil tank of the power transformer, the first bracket includes: a first shaft sleeve, a second shaft sleeve and a first locking member; wherein,

[0021] The first shaft sleeve and the second shaft sleeve are arranged at an angle;

[0022] The first sleeve is provided with a first axial hole for passing the vertical rod; the first sleeve is provided with a plurality of first connecting holes at one end away from the first axial hole for passing the first locking member; the second sleeve is provided with a second axial hole for passing the horizontal rod; the second sleeve is further provided with a first threaded hole for passing the first locking member;

[0023] The first locking member passes through the first connecting hole and the first threaded hole in sequence to lock the first shaft sleeve and the second shaft sleeve.

[0024] Furthermore, in the above-mentioned method for measuring the deformation of the power transformer oil tank, the first sleeve includes: a main body portion and two connecting portions connected to each other; wherein,

[0025] A first axial hole is formed at one end of the main body, and an adjustment channel is formed in the horizontal direction on a side of the main body away from the first axial hole and passes through the first axial hole;

[0026] The two connecting parts are arranged oppositely at two ends of the adjusting channel, and the two connecting parts are correspondingly provided with first connecting holes along the horizontal direction for passing the first locking member.

[0027] Furthermore, in the above-mentioned method for measuring the deformation of the power transformer oil tank, the second sleeve is cylindrical, and a second axial hole is opened in the middle thereof along the horizontal direction, and the second axial hole is arranged perpendicular to the first connecting hole.

[0028] Furthermore, in the above-mentioned method for measuring the deformation of the power transformer oil tank, the second bracket includes: a third shaft sleeve, a fourth shaft sleeve and a second locking member; wherein,

[0029] The third shaft sleeve and the fourth shaft sleeve are arranged at an angle;

[0030] The third shaft sleeve is provided with a third axial hole for passing the horizontal mark rod; the third shaft sleeve is provided with a plurality of second connecting holes at one end away from the third axial hole for passing the second locking member; the fourth shaft sleeve is provided with a fourth axial hole for passing the fixing rod of the dial indicator; the fourth shaft sleeve is also provided with a second threaded hole for cooperating with the second locking member;

[0031] The second locking member passes through the second connecting hole and the second threaded hole in sequence to lock the third sleeve and the fourth sleeve.

[0032] Furthermore, in the above-mentioned method for measuring the deformation of the power transformer oil tank, the dial indicator in step 3 is a digital dial indicator with an accuracy of 0.01 mm based on wireless communication function.

[0033] Furthermore, in the above-mentioned method for measuring the deformation of the power transformer oil tank, the process of using each of the dial indicators includes the following steps:

[0034] Turning on each of the dial indicators and turning on the wireless communication module in each of the dial indicators to perform wireless communication with the terminal;

[0035] Turn on the terminal, connect it wirelessly to the corresponding dial indicators arranged at each measuring point in turn, and name each measuring channel according to the serial number marked on each measuring point;

[0036] Enter the digital acquisition interface of the terminal to collect the initial value D1, displacement values D2, D3, D4 and D5 of the dial indicator in each measurement channel in real time, and automatically calculate the elastic deformation value of the measured oil tank wall under the preset pressure: the difference between D2 and D1; the permanent deformation value under the preset pressure: the difference between D4 and D1; the elastic deformation value of the oil tank under the preset vacuum degree: the difference between D3 and D1; and the permanent deformation value of the oil tank under the preset vacuum degree: the difference between D5 and D1.

[0037] Furthermore, in the above-mentioned method for measuring the deformation of the power transformer oil tank, the wireless communication method is Bluetooth, infrared or WiFi.

[0038] In the present invention, a number of fixed-point movable and fixable pole devices are placed correspondingly along the outer sides of the oil tank of the transformer to be tested, and a dial indicator is installed correspondingly on each fixed-point movable and fixable pole device to measure the deformation of each measuring point. This can avoid the influence of factors such as personnel, tooling, and measuring equipment on the measurement accuracy, thereby greatly improving the detection accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present invention. The same reference symbols are used throughout the drawings to represent the same components. In the drawings:

[0040] Figure 1 A schematic flow chart of a method for measuring deformation of a power transformer oil tank provided by an embodiment of the present invention;

[0041] Figure 2 A schematic diagram of a test state of a method for measuring deformation of a power transformer oil tank provided by an embodiment of the present invention;

[0042] Figure 3 A schematic structural diagram of a fixed-point movable fixable pole device used in a method for measuring deformation of a power transformer oil tank provided by an embodiment of the present invention;

[0043] Figure 4 Schematic diagram of the structure of the first bracket of the fixed-point movable fixed pole device in an embodiment of the present invention;

[0044] Figure 5 Schematic diagram of the structure of the second bracket of the fixed-point movable fixable pole device in an embodiment of the present invention. DETAILED DESCRIPTION

[0045] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art. It should be noted that, unless there is a conflict, the embodiments of the present disclosure and the features described in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0046] See Figure 1 and Figure 2 The method for measuring the deformation of the power transformer oil tank according to the embodiment of the present invention comprises the following steps:

[0047] Step S1: Mark a corresponding number of measuring points in a designated area on the wall of the transformer oil tank to be tested.

[0048] Specifically, multiple measurement points can be arranged based on the structural strength of the transformer tank 1. The designated area can be a location on the transformer tank wall where the structural strength is relatively weak. For example, measurement points can be evenly distributed across the weaker areas of the transformer tank wall. The number of measurement points can be determined based on the lengths of the tank wall along its major and minor axes, as well as the amount of reinforcement iron used to reinforce the tank wall.

[0049] Preferably, several measuring points are arranged at half the height of each side of the wall of the transformer oil tank to be tested, in the middle position and on both sides of the length direction of the major axis and the minor axis, or according to the position where the surface strength of the transformer oil tank to be tested is relatively weak.

[0050] Step S2: According to the position of each measuring point, a plurality of fixed-point movable fixed pole devices are placed along the outer side of the oil tank of the transformer to be measured, corresponding to each measuring point, and each fixed-point movable fixed pole device is fixed, and a dial indicator is respectively set on the horizontal benchmark of each fixed-point movable fixed pole device.

[0051] Specifically, a corresponding number of fixed-point movable fixed pole devices 2 can be placed along the outer periphery of the transformer tank 1 to be tested, based on the locations of the aforementioned measurement points. The devices are secured using a pulley locking device on a universal pulley at the bottom of the fixed-point movable fixed pole devices to prevent them from moving relative to the transformer tank to be tested. The first brackets on the vertical poles 21 of the fixed-point movable fixed pole devices are adjusted so that each horizontal marker 22 is at the same height as the corresponding measurement point, and are then secured using a first locking member.

[0052] Step S3: Keep the measuring probe of each dial indicator perpendicular to the area where each measuring point is located on the wall of the transformer tank to be tested, and make the measuring probe of each dial indicator fully contact with the corresponding measuring point.

[0053] Specifically, step S3 is performed one by one with reference to each measuring point. By adjusting the angle of the second bracket on the horizontal pole, the dial indicator measuring probe on the horizontal pole is perpendicular to the tank wall, and the measuring probe maintains full contact with the tank wall measuring point to avoid measurement errors.

[0054] After step S3, the following steps S4 to S6 are performed, or the following steps S4, S7, and S8 are performed; that is, after step S3, only the pressure deformation test of steps S4 to S6 may be performed, or only the vacuum deformation test of steps S4, S7, and S8 may be performed; the pressure deformation test of steps S4 to S6 may be performed first, and then the vacuum deformation test of steps S4, S7, and S8 may be performed; or the vacuum deformation test of steps S4, S7, and S8 may be performed first, and then the pressure deformation test of steps S4 to S6 may be performed.

[0055] Step S4: performing a zero check operation on the dial indicator and adjusting the dial indicator to an initial value D1 of the estimated deformation amount.

[0056] Specifically, the initial value of the estimated deformation can be determined based on the empirical deformation of the transformer tank to be tested. After determining the initial value, the initial value can be recorded. In this step, by adjusting the dial indicator to the initial value of the estimated deformation, it is possible to avoid the problem of the measuring probe of dial indicator 3 being unable to reach the transformer tank wall due to bulging of the transformer tank to be tested and depression of other deformed parts, thereby preventing the dial indicator from properly detecting the transformer tank. In this step, the initial values of the estimated deformation of each dial indicator can be the same or different. For ease of calculation, the initial values of the estimated deformation of each dial indicator can be set to the same value.

[0057] Step S5: applying a preset pressure value to the transformer oil tank 1 to be tested, and after the pressure stabilizes for a period of time, recording the reading D2 in each of the dial indicators. The difference between D2 and D1 is the elastic deformation of the oil tank corresponding to the preset pressure value.

[0058] Specifically, a preset pressure value can be applied to the transformer tank 1 using the inflation method or the liquid column method. The preset pressure value can be determined according to Article 11.10 of GB / 1094.1-2013. In practice, after the readings of the dial indicators are stable, the corresponding D2 is read and recorded.

[0059] Step S6, releasing the pressure in the oil tank of the transformer to be tested, leaving it to stand for a period of time, and recording the reading D4 in each dial indicator again. The difference between D4 and D1 is the permanent deformation of the oil tank corresponding to the preset pressure value.

[0060] Specifically, after the pressure is released, until the readings of each dial indicator stabilize, read and record the corresponding reading D4, and determine the difference between D4 and D1 as the permanent deformation of the fuel tank under the preset pressure value.

[0061] Step S7: evacuate the pressure in the transformer tank to a preset vacuum degree. After the vacuum pressure stabilizes for a period of time, record the reading D3 on the dial indicator. The difference between D3 and D1 is the elastic deformation of the tank corresponding to the preset vacuum degree.

[0062] Specifically, the preset vacuum degree can be determined according to the product technical agreement or relevant standard requirements.

[0063] Step S8, releasing the preset vacuum degree in the oil tank of the transformer to be tested, leaving it to stand for a period of time, and then reading the reading D5 on the dial indicator again. The difference between D5 and D1 is the permanent deformation of the oil tank corresponding to the preset vacuum degree.

[0064] Specifically, the standing time can be determined based on the condition that the dial indicator reading is stable and hardly changes.

[0065] The operations of steps S2 to S4 above must be performed before pressurization for positive pressure deformation or before vacuum extraction for vacuum deformation to avoid displacement of the dial indicator relative to each measuring point.

[0066] It can be clearly concluded from the above that the method for measuring the deformation of the transformer oil tank provided in this embodiment, by placing a number of fixed-point movable and fixed pole devices corresponding to the outer sides of the transformer oil tank to be measured, and installing a dial indicator on each fixed-point movable and fixed pole device to measure the deformation of each measuring point, can avoid the influence of factors such as personnel, tooling, and measuring equipment on the measurement accuracy, thereby greatly improving the detection accuracy.

[0067] In the above embodiment, the dial indicator in step 3 is a digital dial indicator with an accuracy of 0.01mm based on the wireless communication function. Its measurement accuracy can reach 0.01mm, which greatly improves the detection accuracy and is far superior to the 1mm level in the existing technology.

[0068] Furthermore, the use process of each dial indicator includes the following steps:

[0069] Step a: Turn on each of the dial indicators and enable the wireless communication module in each of the dial indicators to communicate wirelessly with the terminal. In practice, press the power button on the digital dial indicator panel to turn on the power, and long press the send button on the panel to enter the Bluetooth pairing state.

[0070] Specifically, the wireless communication method is Bluetooth, infrared or WiFi. Preferably, Bluetooth. The dial indicator is provided with a Bluetooth module.

[0071] Step b: turn on the terminal, make it wirelessly connected to the corresponding dial indicators arranged at each of the measuring points in sequence, and name each measuring channel according to the serial number marked on each of the measuring points.

[0072] Specifically, the terminal is a mobile phone app or PC. In actual use, turn on the Bluetooth module on the mobile phone app or PC, select pairing in the Bluetooth search dialog box, and connect to the corresponding digital dial indicators arranged at the measurement points on each side of the fuel tank wall. Name each measurement channel according to the serial number marked on the fuel tank wall measurement point.

[0073] Step c: Accessing the digital acquisition interface of the terminal, collecting the initial value D1, displacement values D2, D3, D4, and D5 of the dial indicator in each measurement channel in real time, and automatically calculating the difference between the elastic deformation value D2 and D1 of the measured oil tank wall under a preset pressure, the permanent deformation value D4 and D1 under the preset pressure, the elastic deformation value D3 and D1 of the oil tank under a preset vacuum degree, and the permanent deformation value D5 and D1 of the oil tank under the preset vacuum degree.

[0074] As can be seen, the initial value D1 of each dial indicator can be consistent, facilitating subsequent recording or calculation. By using a digital dial indicator with wireless communication, fuel tank deformation can be remotely monitored in real time, enabling the early prediction of tank cracking and explosion risks, ensuring the safety of equipment and on-site inspection personnel.

[0075] In this embodiment, after measuring the elastic deformation and permanent deformation values of each measuring point, it is possible to determine whether the deformation meets the requirements based on the values specified in the corresponding standards or technical protocols, so that timely measures can be taken when the deformation exceeds the standard to ensure the safety of the operators.

[0076] See Figure 3 In the above embodiments, the fixed-point movable fixed pole device 2 includes: a vertical pole 21, a horizontal mark pole 22, a first bracket 23, a second bracket 24 and a movable base 25; wherein, the bottom of the vertical pole 21 is connected to the movable base 25; the horizontal mark pole 22 is rotatably connected to the vertical pole 21 through the first bracket 23, and a first shaft sleeve is provided on the upper frame of the first bracket 23 in the horizontal direction. The vertical pole 21 is passed through the first shaft sleeve to adjust the height of the horizontal mark pole 22 in the vertical direction; the second bracket 24 is installed at one end of the horizontal mark pole 22, and the second bracket 24 is rotatably connected to the horizontal mark pole 22 to make the measuring probe of the dial indicator perpendicular to the wall surface of the oil tank of the transformer to be tested.

[0077] Specifically, the movable base 25 includes a base 251 and a plurality of pulleys 252. A fastener is provided at the top center of the base 251 to secure the vertical pole 21 to the base. Each pulley is mounted below the base, and a locking mechanism 253 is provided on each pulley 252 to lock the movable base 25 when the movable base is moved to the target location. More specifically, the base 251 can be a hollow frustum with a threaded hole at its center. The fastener can be an adjustment nut with a connection hole in the middle to facilitate adjusting the height of the vertical pole 21 relative to the base. The connection between the vertical pole 21 and the base can be achieved through rivets. The locking mechanism can be a brake pad.

[0078] See Figure 4 The first bracket 23 includes: a first shaft sleeve 231, a second shaft sleeve 232 and a first locking piece 233; wherein the first shaft sleeve 231 and the second shaft sleeve are arranged at an angle; a first shaft sleeve 231 is provided with a first shaft hole for passing the vertical pole 21; a plurality of first connecting holes are provided on the end of the first shaft sleeve 231 away from the first shaft hole for passing the first locking piece 233; a second shaft sleeve 232 is provided with a second shaft hole for passing the horizontal pole 22; a first threaded hole is also provided on the second shaft sleeve 232 for passing the first locking piece 233; the first locking piece passes through the first connecting hole and the first threaded hole in sequence to lock the first shaft sleeve 231 and the second shaft sleeve 232.

[0079] The first axial hole is arranged along the vertical direction, the first connecting hole is arranged along the horizontal direction, and the first threaded hole is arranged perpendicular to the second axial hole.

[0080] Furthermore, the first sleeve 231 includes: a first main body portion 2311 and two first connecting portions 2312 connected to each other; wherein, a first axial hole is opened at one end of the first main body portion 2311, and a first adjustment channel 2313 passing through the first axial hole is opened in the horizontal direction on the side of the first main body portion 2311 away from the first axial hole; the two first connecting portions 2312 are relatively arranged at the two ends of the first adjustment channel 2313, and the two first connecting portions are correspondingly opened with first connecting holes in the horizontal direction for passing the first locking member 233.

[0081] Specifically, the first body portion can be a rectangular block-shaped structure, with an arc-shaped edge near the first axial hole. The first connecting portion can be a semicircular arc-shaped structure, with the semicircular edge facing outward. The width of the adjustment channel can be determined based on actual conditions to lock the vertical rod 21 when the first locking member 233 is tightened. There can be two first connecting holes, and the two first connecting holes can be arranged opposite each other.

[0082] The first locking member 233 includes: a first screw and a first knob connected to each other; wherein the first screw is arranged in a horizontal direction, and the first knob is arranged at one end of the first screw.

[0083] The second shaft sleeve 232 is cylindrical, and a second shaft hole is opened in the middle thereof along the horizontal direction. The second shaft hole is perpendicular to the first connecting hole.

[0084] The second sleeve 232 is threadedly connected to the first locking piece 233, that is, threadedly connected through the first screw. On the one hand, when the first locking piece is screwed, the horizontal mark rod 22 can be rotated relative to the second axis hole, thereby adjusting the rotation angle of the horizontal mark rod 22; on the other hand, it is also convenient for the first screw to tighten the horizontal mark rod 22.

[0085] See Figure 5 The second bracket 24 includes: a third shaft sleeve 241, a fourth shaft sleeve 242 and a second locking piece 243; wherein the third shaft sleeve 241 and the fourth shaft sleeve 242 are arranged at an angle; the third shaft sleeve 241 is provided with a third axial hole for passing the horizontal mark rod 22; the third shaft sleeve 241 is provided with a plurality of second connecting holes at one end away from the third axial hole for passing the second locking piece 243; the fourth shaft sleeve 242 is provided with a fourth axial hole for passing the fixing rod of the dial indicator 3; the fourth shaft sleeve 242 is also provided with a second threaded hole for cooperating with the second locking piece 243; the second locking piece passes through the connecting hole and the second threaded hole in sequence to lock the third shaft sleeve 241 and the fourth shaft sleeve 242.

[0086] Specifically, the fourth sleeve 242 can be a columnar structure with fourth axial holes defined on opposite sides of its sidewalls to allow the fastening rod of the dial indicator 3 to pass through and rotate relative to the fourth axial hole. A second threaded hole is also defined at one end of the fourth sleeve 242 to facilitate connection with the second screw of the second locking member 243. This second threaded hole and the fourth axial hole can be perpendicularly disposed.

[0087] In this embodiment, the third shaft sleeve 241 has the same structure as the first shaft sleeve 231, and the third shaft sleeve 241 includes: a second main body portion (not shown in the figure) and two second connecting portions (not shown in the figure) connected to each other; wherein, a third axial hole is opened at one end of the second main body portion, and a second adjustment channel passing through the third axial hole is opened in the horizontal direction on the side of the second main body portion away from the first axial hole; the two second connecting portions are relatively arranged at the two ends of the second adjustment channel, and the two second connecting portions are correspondingly opened with second connecting holes in the horizontal direction for passing the second locking member 243.

[0088] The second body portion can be a rectangular block-shaped structure, with an arc-shaped edge near the third axial hole. The second connecting portion can be a semicircular arc-shaped structure, with the semicircular edge facing outward. The width of the second adjustment channel can be determined based on actual conditions, so that when the second locking member 243 is tightened, the second bracket is locked to the horizontal pole 22.

[0089] The third axial hole opened on the third shaft sleeve 241 is arranged in the horizontal direction so as to pass the horizontal mark rod 22; there can be two second connecting holes, and the center line connecting the two second connecting holes can be an oblique line, that is, the two second connecting holes arranged on the connecting part of the third shaft sleeve 241 are arranged at an angle, so that the second locking member 243 passes through the two second connecting holes in sequence at a preset angle.

[0090] The second locking member 243 is the same as the first locking member 233. The second locking member includes: a second screw and a second knob connected to each other; wherein the second screw is arranged in a horizontal direction, and the second knob is arranged at one end of the second screw.

[0091] In summary, the method for measuring the deformation of the power transformer oil tank provided by the present invention can avoid the influence of factors such as personnel, tooling, and measuring equipment on the measurement accuracy, greatly improving the detection accuracy. Its measurement accuracy can reach 0.01mm, which is far better than the current 1mm level. By adopting a digital dial indicator with wireless communication function, the deformation of the oil tank can be monitored remotely in real time, and the risk of oil tank cracking and explosion can be predicted in advance to ensure the safety of equipment and on-site inspection personnel.

[0092] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A method for measuring the deformation of a power transformer oil tank, characterized in that: The following steps are involved: Step 1: Mark a corresponding number of measuring points on a designated area on the outer surface of the oil tank wall of the transformer to be tested; Step 2: According to the position of each measuring point, a plurality of fixed-point movable fixed pole devices are placed along the outer side of the transformer tank to be measured, corresponding to each measuring point, and each fixed-point movable fixed pole device is fixed, and a dial indicator is respectively set on the horizontal pole of each fixed-point movable fixed pole device; The fixed-point movable fixed pole device comprises: a vertical pole, a horizontal pole, a first bracket, a second bracket and a movable base; wherein the bottom of the vertical pole is connected to the movable base; The horizontal mark rod is rotatably connected to the vertical rod via a first bracket, a first sleeve is provided on the first bracket in the horizontal direction, and the vertical rod is passed through the first sleeve for adjusting the height of the horizontal mark rod in the vertical direction; a second bracket is mounted on one end of the horizontal mark rod, and the second bracket is rotatably connected to the horizontal mark rod for ensuring that the measuring probe of the dial indicator is perpendicular to the wall surface of the transformer tank to be tested; Step 3: Keep the measuring probe of each dial indicator perpendicular to the area where each measuring point on the wall of the transformer tank to be tested is located, and fully contact the measuring probe of each dial indicator with the corresponding measuring point; Follow steps 4 to 6 below, or follow steps 4, 7, and 8 below. Step 4: performing a zero check operation on each of the dial indicators and adjusting each of the dial indicators to an initial value D1 of the estimated deformation; Step 5: applying a preset pressure value to the oil tank of the transformer to be tested, and after the pressure stabilizes for a period of time, recording the reading D2 in each of the dial indicators, and the difference between D2 and D1 is the elastic deformation of the oil tank corresponding to the preset pressure value; Step 6, releasing the pressure in the oil tank of the transformer to be tested, leaving it to stand for a period of time, and then recording the reading D4 in each dial indicator again. The difference between D4 and D1 is the permanent deformation of the oil tank corresponding to the preset pressure value; Step 7: evacuate the pressure in the transformer tank to be tested to a preset vacuum degree, wait for the vacuum pressure to stabilize for a period of time, and then record the reading D3 on the dial indicator. The difference between D3 and D1 is the elastic deformation of the tank corresponding to the preset vacuum degree. Step 8: Release the preset vacuum degree in the oil tank of the transformer to be tested, let it stand for a period of time, and then read the reading D5 in each dial indicator again. The difference between D5 and D1 is the permanent deformation of the oil tank corresponding to the preset vacuum degree.

2. The method for measuring the deformation of the power transformer oil tank according to claim 1, characterized in that: In step 1, several measuring points are arranged at half the height of each side of the wall of the transformer oil tank to be tested, along the middle position of the long axis and the short axis and on both sides thereof in the length direction, or the measuring points are arranged according to the position where the surface strength of the transformer oil tank to be tested is relatively weak.

3. The method for measuring the deformation of the power transformer oil tank according to claim 1, characterized in that: The first bracket includes: a first sleeve, a second sleeve and a first locking member; wherein, The first shaft sleeve and the second shaft sleeve are arranged at an angle; The first sleeve is provided with a first axial hole for passing the vertical rod; the first sleeve is provided with a plurality of first connecting holes at one end away from the first axial hole for passing the first locking member; the second sleeve is provided with a second axial hole for passing the horizontal rod; the second sleeve is further provided with a first threaded hole for passing the first locking member; The first locking member passes through the first connecting hole and the first threaded hole in sequence to lock the first shaft sleeve and the second shaft sleeve.

4. The method for measuring the deformation of the power transformer oil tank according to claim 3, characterized in that: The first sleeve includes: a first main body portion and two first connecting portions connected to each other; wherein, A first axial hole is formed at one end of the first body portion, and a first adjustment channel is formed in the horizontal direction on a side of the first body portion away from the first axial hole and passing through the first axial hole; The two first connection parts are oppositely arranged at two ends of the first adjustment channel, and the two first connection parts are correspondingly provided with first connection holes along the horizontal direction for passing the first locking member.

5. The method for measuring the deformation of the power transformer oil tank according to claim 3, characterized in that: The second shaft sleeve is cylindrical, and a second shaft hole is opened in the middle thereof along the horizontal direction. The second shaft hole is perpendicularly arranged to the first connecting hole.

6. The method for measuring the deformation of the power transformer oil tank according to claim 3, characterized in that: The second bracket includes: a third shaft sleeve, a fourth shaft sleeve and a second locking member; wherein, The third shaft sleeve and the fourth shaft sleeve are arranged at an angle; The third shaft sleeve is provided with a third axial hole for passing the horizontal mark rod; the third shaft sleeve is provided with a plurality of second connecting holes at one end away from the third axial hole for passing the second locking member; the fourth shaft sleeve is provided with a fourth axial hole for passing the fixing rod of the dial indicator; the fourth shaft sleeve is also provided with a second threaded hole for cooperating with the second locking member; The second locking member passes through the second connecting hole and the second threaded hole in sequence to lock the third sleeve and the fourth sleeve.

7. The method for measuring deformation of a power transformer oil tank according to claim 1, characterized in that: The dial indicator in step 3 is a digital dial indicator with an accuracy of 0.01 mm based on wireless communication function.

8. The method for measuring the deformation of the power transformer oil tank according to claim 1, characterized in that: The use process of each dial indicator includes the following steps: Turning on each of the dial indicators and turning on the wireless communication module in each of the dial indicators to perform wireless communication with the terminal; Turn on the terminal, connect it wirelessly to the corresponding dial indicators arranged at each measuring point in turn, and name each measuring channel according to the serial number marked on each measuring point; Enter the digital acquisition interface of the terminal to collect the initial value D1, displacement values D2, D3, D4 and D5 of the dial indicator in each measurement channel in real time, and automatically calculate the elastic deformation value of the measured oil tank wall under the preset pressure: the difference between D2 and D1, the permanent deformation value under the preset pressure: the difference between D4 and D1; the elastic deformation value of the oil tank under the preset vacuum degree: the difference between D3 and D1; the permanent deformation value of the oil tank under the preset vacuum degree: the difference between D5 and D1.

9. The method for measuring the deformation of the power transformer oil tank according to claim 8, characterized in that: The wireless communication method is Bluetooth, infrared or WiFi.

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