Transformer winding fault simulation device and fault detection method

Abstract

The invention discloses a transformer winding fault simulation device and a transformer winding fault simulation method. A firm basic platform is provided for subsequent fault simulation operation. The annular lifting platform can drive the mechanical arm system to move in the radial direction and the axial direction, and accurate positioning of the mechanical arm system in the circumferential direction and the height direction of the transformer winding is achieved. A clamping mechanical arm in the mechanical arm system is used for clamping and extracting a transformer coil pressing piece, a block placing mechanical arm is used for inserting and withdrawing a wedge block, the clamping mechanical arm and the block placing mechanical arm cooperate with each other, the axial loosening fault of the transformer winding can be accurately simulated at different positions, and the accuracy and repeatability of fault simulation are improved. Besides, the transformer winding fault simulation method provided by the invention not only can be used for quantitatively judging the axial loosening degree of the winding, but also can be used for accurately positioning a specific area where the fault occurs according to the comparison of the energy module values of the partitions, thereby providing a reliable diagnosis basis for the preventive maintenance of the transformer.

Description

Technical Field

[0001] The invention relates to the technical field of transformer manufacturing fault detection, and in particular to a transformer winding fault simulation device and a fault detection method. Background Art

[0002] UHV transformers are key equipment for achieving high-voltage power transmission in power systems, and their operating status directly affects the reliability and safety of the system. During operation, UHV transformers are subjected to frequent instantaneous load shocks and occasional short-circuit current shocks, which cause the winding clamps to fall off and cause the windings to loosen. The mechanical bearing capacity of the windings will decrease, which will affect the normal operation of the UHV transformer and ultimately affect the stable operation of the UHV power transmission and power supply system. In order to avoid catastrophic consequences, it is crucial to carry out regular routine inspections of transformer windings. As one of the common types of winding faults, there is currently a lack of research on the correlation between differentiated axial looseness conditions and winding diagnosis methods. Therefore, it is very necessary to diagnose the transformer winding status in a timely manner through winding axial looseness fault simulation. Summary of the invention

[0003] The object of the present invention is to provide a transformer winding fault simulation device and a fault detection method to improve the accuracy and repeatability of fault simulation.

[0004] The present invention discloses a transformer winding fault simulation device, comprising: a transformer winding positioning system, used for rotationally positioning and fixing the transformer winding;

[0005] A positioning mechanism, used to control the annular lifting platform to rotate in the horizontal direction and to control the annular lifting platform to move in the vertical direction;

[0006] A robotic arm system is arranged on the annular lifting platform and is used to perform new deformation operations on the transformer winding; the robotic arm system includes a clamping robotic arm for clamping and extracting the transformer coil clamping piece, and a block placing robotic arm for inserting a wedge block into the transformer winding or recovering the wedge block.

[0007] Furthermore, the transformer winding positioning and fixing system comprises:

[0008] A power transformer winding support platform on which the transformer winding is arranged;

[0009] A transformer rotating motor, used for driving the power transformer winding support platform to rotate in a radial direction;

[0010] The invention discloses a rotating platform for a power transformer winding, on which a telescopic cylinder and a telescopic mechanism for fixing the winding are provided. The telescopic mechanism is used to drive the telescopic cylinder to expand in a radial direction until it abuts against the inner wall of the transformer winding.

[0011] Further, the robotic arm system comprises:

[0012] A multi-degree-of-freedom clamping mechanical arm comprises a movable base, a clamping and pressing piece mechanical arm and a multi-stage clamping arm connected in sequence; the clamping arm farthest from the movable base is used for clamping and extracting the pressing piece in the transformer coil;

[0013] A multi-degree-of-freedom block placement robot arm comprises a movable base, a hydraulic cylinder lifting arm, a multi-stage block placement arm and a winding block placement end connected in sequence; the winding block placement end is used to insert a wedge block into the transformer winding or to recycle the wedge block;

[0014] A guide rail is provided on the surface of the annular lifting platform, and the movable bases of the clamping mechanical arm and the block placing mechanical arm are slidably connected to the guide rail.

[0015] Furthermore, the positioning mechanism includes a radial movement mechanism arranged on both sides of the transformer winding positioning system, and the radial movement mechanism includes:

[0016] A radial slide rail, the radial slide rail is arranged on the bottom plate seat;

[0017] An axial slider seat is slidably connected to the radial slide rail, and bearing seats are respectively provided on both sides of the axial slider seat;

[0018] A roller, arranged on the surface of the axial slider seat, for supporting the annular lifting platform;

[0019] A rotary drive gear, disposed on the surface of the axial slider seat, for meshing with a meshing gear ring disposed on the outer periphery of the annular lifting platform;

[0020] A radial transmission screw rod is rotatably disposed on the axial slider seat and inside the axial slider seat;

[0021] A screw drive motor, used for driving the axial ball screw to rotate along the axis of the axial ball screw;

[0022] The gear drive motor is used to drive the annular lifting platform to rotate in a radial direction.

[0023] Furthermore, the axial motion mechanism comprises:

[0024] An axially movable support is arranged on the surface of the axial slider seat; the roller and the rotary drive gear are both arranged on the axially movable support;

[0025] An axial ball screw is arranged in an axial movable support; the axial movable support is transmission-connected to the axial ball screw;

[0026] The screw drive motor is used to drive the axial ball screw to rotate along the axis of the axial ball screw.

[0027] The present invention also discloses a transformer winding fault detection method, the method comprising:

[0028] Excite the vibration of transformer windings;

[0029] Collect vibration signals of the transformer winding at preset measuring points to obtain a vibration signal matrix composed of a plurality of the vibration signals;

[0030] Analyzing the vibration signal to obtain a vibration energy spectrum feature matrix;

[0031] Calculate the overall vibration energy modulus and the partitioned vibration energy modulus according to the vibration energy spectrum characteristic matrix;

[0032] After comparing the overall vibration energy modulus and the partitioned vibration energy modulus with different standard values ​​respectively, the fault degree and fault location of the axial looseness of the transformer winding are determined according to the comparison results.

[0033] Furthermore, the vibration energy spectrum characteristic matrix obtained by analyzing the vibration signal includes:

[0034] Performing high-pass and low-pass filtering decomposition and reconstruction on the vibration signal;

[0035] The signals after high-pass and low-pass filtering decomposition and reconstruction are subjected to Fourier transform, and the vibration energy spectrum characteristic matrix is ​​established according to the Fourier transform results.

[0036] Further, calculating the overall vibration energy modulus and the partitioned vibration energy modulus according to the vibration energy spectrum characteristic matrix includes:

[0037] After extracting the energy value of each frequency band in the vibration energy spectrum characteristic matrix, the energy values ​​of several frequency points with the largest energy values ​​are selected to form a characteristic vector; and the norm of the characteristic vector is calculated.

[0038] Further, calculating the overall vibration energy modulus and the partitioned vibration energy modulus according to the vibration energy spectrum characteristic matrix includes:

[0039] Arranging the norms according to the measurement point positions to form an eigenvalue norm matrix;

[0040] Dividing the transformer winding into a plurality of regions;

[0041] Dividing the eigenvalue norm matrix into a plurality of block matrices corresponding to a plurality of the regions;

[0042] The overall vibration energy modulus corresponding to the eigenvalue norm matrix and the partition vibration energy modulus corresponding to the block matrix are calculated.

[0043] Further, after comparing the overall vibration energy modulus and the partitioned vibration energy modulus with different standard values, judging the fault degree and fault location of the axial looseness of the transformer winding according to the comparison results includes:

[0044] Comparing the overall vibration energy modulus with a preset reference value;

[0045] When the overall vibration energy modulus is less than the preset reference value, it is determined that the transformer winding is slightly loose;

[0046] When the overall vibration energy modulus is greater than the preset reference value, it is determined that the transformer winding is obviously loose;

[0047] The magnitudes of the vibration energy moduli of each partition are compared to determine the fault location of the loose transformer winding.

[0048] Compared with the prior art, the present invention has at least the following technical effects:

[0049] The transformer winding positioning and fixing system disclosed in the present invention can stably and reliably support and fix the transformer winding, providing a solid basic platform for subsequent fault simulation operations. The annular lifting platform can drive the mechanical arm system to move in the radial and axial directions, realizing the precise positioning of the mechanical arm system in the circumferential and height directions of the transformer winding. The clamping mechanical arm in the mechanical arm system is used to clamp and extract the transformer coil clamping parts, and the block placing mechanical arm is used to insert and retract the wedge block. The two cooperate with each other and can accurately simulate the axial looseness fault of the transformer winding at different positions, thereby improving the accuracy and repeatability of the fault simulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 Schematic diagram of the structure of a transformer winding fault simulation device in Embodiment 1 of the present invention;

[0051] Figure 2 A top view of a transformer winding fault simulation device in Embodiment 1 of the present invention;

[0052] Figure 3 It is a front view of a high voltage transformer winding fault simulation device in Embodiment 1 of the present invention;

[0053] Figure 4 It is a partial enlarged view of the annular lifting platform of the high-voltage transformer winding fault simulation device in the first embodiment of the present invention;

[0054] Figure 5 This is a schematic structural diagram of a six-degree-of-freedom clamping mechanical arm of a high-voltage transformer winding fault simulation device in Embodiment 1 of the present invention;

[0055] Figure 6 This is a schematic structural diagram of a six-degree-of-freedom block-setting mechanical arm of a high-voltage transformer winding fault simulation device in Embodiment 1 of the present invention;

[0056] Figure 7 This is a wiring diagram of a high voltage transformer in Embodiment 2 of the present invention;

[0057] Figure 8 A simplified flowchart of a transformer winding fault detection method in Embodiment 2 of the present invention;

[0058] Fig. 9 The figure is a simplified flowchart of the transformer winding fault simulation method and detection method in Embodiment 1 and Embodiment 2 of the present invention. DETAILED DESCRIPTION

[0059] A transformer winding fault simulation device and a transformer winding fault detection method of the present invention will be described below in conjunction with a schematic diagram, wherein a preferred embodiment of the present invention is shown. It should be understood that those skilled in the art can modify the present invention described herein and still achieve the advantageous effects of the present invention. Therefore, the following description should be understood as being widely known to those skilled in the art and not as a limitation of the present invention.

[0060] The present invention is described in more detail in the following paragraphs by way of example with reference to the accompanying drawings. The advantages and features of the present invention will become more apparent from the following description. It should be noted that the accompanying drawings are in very simplified form and in non-precise proportions, and are only used to facilitate and clearly assist in illustrating the purpose of the embodiments of the present invention.

[0061] Embodiment 1

[0062] Please refer to Figure 1-Figure 6 This embodiment discloses a transformer winding fault simulation device, comprising:

[0063] Transformer winding positioning and fixing system, used for rotational positioning and fixing of transformer windings;

[0064] A positioning mechanism, used to control the annular lifting platform to rotate in the horizontal direction and to control the annular lifting platform to move in the vertical direction;

[0065] A robotic arm system is arranged on the annular lifting platform 21 and is used to perform new deformation operations on the transformer winding; the robotic arm system includes a clamping robotic arm for clamping and extracting the transformer coil clamping piece, and a block placing robotic arm for inserting a wedge block into the transformer winding or recovering the wedge block.

[0066] In this embodiment, the transformer winding positioning and fixing system can stably and reliably support and fix the transformer winding, providing a solid basic platform for subsequent fault simulation operations. The annular lifting platform 21 can drive the mechanical arm system to move in the radial and axial directions, realizing the precise positioning of the mechanical arm system in the circumferential and height directions of the transformer winding. The clamping mechanical arm in the mechanical arm system is used to clamp and extract the transformer coil clamping parts, and the block placing mechanical arm is used to insert and retract the wedge block. The two cooperate with each other to accurately simulate the axial looseness fault of the transformer winding at different positions, thereby improving the accuracy and repeatability of the fault simulation.

[0067] Specifically, the transformer winding support system includes a power transformer winding support platform 8 and a transformer rotating motor 9. The transformer winding is fixed on the power transformer winding support platform 8; the transformer rotating motor 9 is used to drive the power transformer winding support platform 8 to rotate in the radial direction.

[0068] In a specific embodiment, a transformer rotating motor 9 is fixedly installed on the power transformer winding support platform 8 by bolts. The output shaft of the transformer rotating motor 9 is fixedly connected to the central axis of the transformer rotating driving gear 11 through a coupling. A transformer winding rotating transmission gear 12 is fixedly installed at the center position of the lower surface of the power transformer winding rotating platform 10 by bolts, and the transmission gear is precisely meshed with the transformer rotating driving gear 11. When the motor is running, the entire power transformer winding rotating platform 10 and the transformer winding thereon can be driven to rotate through the gear transmission chain, thereby realizing the rotation positioning of the transformer winding.

[0069] In addition, the power transformer winding rotating platform 10 is provided with a telescopic cylinder 44 and a telescopic mechanism for fixing the transformer winding, and the telescopic mechanism is used to drive the telescopic cylinder 44 to expand in the radial direction until it abuts against the inner wall of the transformer winding.

[0070] In a specific embodiment, the power transformer winding rotating platform 10 is made of high-strength steel, the surface of which is treated for corrosion resistance, and has sufficient rigidity and stability. The power transformer winding rotating platform 10 is provided with positioning holes and mounting grooves for fixing other components.

[0071] In another specific embodiment, the telescopic mechanism driving motor 40 is fixed on the telescopic mechanism fixing seat 43 through a motor seat, and the motor shaft is connected to the telescopic mechanism driving gear 41 through a key. The telescopic mechanism driving gear 41 is meshed with the telescopic mechanism transmission gear 42, and the transmission gear 42 is connected to the telescopic cylinder 44 through a spline. The telescopic cylinder 44 is installed in the telescopic mechanism fixing seat 43 through a linear bearing, can be extended and retracted in the axial direction, and is used to support and fix the transformer winding.

[0072] Furthermore, in this embodiment, the positioning mechanism includes a radial movement mechanism, and the radial movement mechanism includes: a radial slide rail, an axial slide seat 17 and a radial transmission screw.

[0073] Specifically, the radial slide rail is arranged on the bottom plate seat 13 and is slidably connected with the radial slide rail; bearing seats are respectively arranged on both sides of the axial slider seat 17; the axial slider seat 17 is rotatably arranged on the axial slider seat 17 and inside the axial slider seat 17. The screw drive motor 19 controls the radial transmission screw to drive the axial slider seat 17 located on the radial moving slide rail 14 and the radial transmission screw to move radially to the middle position of the radial moving slide rail 14, and the roller 24 slightly lifts the annular lifting platform 21 so that the rotating drive gear 23 is correctly meshed with the annular lifting platform 21.

[0074] In a specific embodiment, the base plate seat 13 is used as a basic support member and is fixed on the ground by anchor bolts. A groove is processed on the upper end surface of the base plate seat 13, and the groove is used to install the radial moving slide rail 14.

[0075] In another specific embodiment, the bearing seat 15 is fixed to the end of the radial movable slide rail 14 by bolts, and is used to support the radial transmission screw 16. Both ends of the radial transmission screw 16 are supported by angular contact ball bearings in the bearing seat 15.

[0076] In another specific embodiment, a linear guide slider is installed at the bottom of the axial slider seat 17 to form a sliding pair with the radial movable slide rail 14. At the same time, a ball nut is arranged inside the axial slider seat 17 to form a spiral pair with the radial transmission screw 16.

[0077] In another specific embodiment, the gear drive motor 22 is fixed on the annular lifting platform 21 through a motor seat, and the output shaft of the gear drive motor 22 is connected to the rotary drive gear 23 through a coupling. The rotary drive gear 23 is meshed with the meshing gear ring on the outer periphery of the annular lifting platform 21.

[0078] Furthermore, in this embodiment, the positioning mechanism also includes: an axial motion mechanism.

[0079] Specifically, an axially movable support 20 is arranged on the surface of the axial slider seat 17; the roller 24 and the rotating drive gear 23 are both arranged on the axially movable support 20; the axial ball screw 18 is arranged in the axially movable support 20; the axially movable support 20 is transmission-connected to the axial ball screw 18; and the screw drive motor 19 is used to drive the axial ball screw 18 to rotate along the axis of the axial ball screw 18.

[0080] Furthermore, in this embodiment, the robotic arm system includes: a multi-degree-of-freedom block-placing robotic arm, which includes a robotic arm mobile base 29, a hydraulic cylinder lifting arm 30 and a multi-stage block-placing arm connected in sequence, and the block-placing arm farthest from the mobile base is used to insert and retract the wedge blocks located in the transformer winding.

[0081] In this embodiment, the multi-stage block placing arm includes a first-stage block placing mechanical arm 35, a second-stage block placing mechanical arm 36 and a third-stage block placing mechanical arm 37 which are connected in sequence. The multi-stage block placing arm, the mechanical arm moving base 29, the hydraulic cylinder lifting arm 30 and the winding block placing end 38 together form a six-degree-of-freedom clamping mechanical arm.

[0082] In a specific embodiment, the robot arm moving base 29 is installed on the guide rail of the annular lifting platform 21 through a linear guide slider, and can move along the annular track; a locking mechanism is provided on the base, which can be locked at any position. The guide rail adopts a V-groove structure. The bottom of the hydraulic cylinder lifting arm 30 is connected to the robot arm moving base 29 through a double-ear hinge. One end of the first-stage block robot arm 35 is hingedly connected to the hydraulic cylinder lifting arm 30, and the other end is connected to one end of the second-stage block robot arm 36 through a slewing bearing. The other end of the second-stage block robot arm 36 is movably connected to one end of the third-stage block robot arm 37 through a slewing bearing, and the other end of the third-stage block robot arm 37 is provided with a winding block terminal 38.

[0083] Furthermore, in this embodiment, the clamping robot arm includes a robot arm mobile base 29, a clamping and pressing piece robot arm 34 and a multi-stage clamping arm connected in sequence; the clamping arm farthest from the mobile base is used to clamp and extract the pressing piece 7 in the transformer coil.

[0084] In this embodiment, the multi-stage block placing arm includes a first-level clamping robot arm 31, a second-level clamping robot arm 32, a third-level clamping robot arm 33 and a fourth-level clamping robot arm 34. The multi-stage block placing arm, the movable base and the clamping and pressing member robot arm 34 together constitute a six-degree-of-freedom clamping robot arm.

[0085] In a specific embodiment, the robot arm moving base 29 is installed on the guide rail of the annular lifting platform 21 through a linear guide slider and can move along the annular track. A locking mechanism is provided on the base, which can be locked at any position. The bottom of the hydraulic cylinder lifting arm 30 is connected to the robot arm moving base 29 through a double-ear hinge. The first-level clamping robot arm 31 is connected to the top of the hydraulic cylinder lifting arm 30 through a rotating shaft, and a deep groove ball bearing is installed at the rotating shaft to improve the flexibility of rotation. The second-level clamping robot arm 32 is connected to the first-level clamping robot arm 31 through a joint bearing, the outer ring of the joint bearing is fixed on the first-level arm, and the inner ring is connected to the second-level arm. The connection method between the third-level clamping robot arm 33 and the second-level clamping robot arm 32 is the same as the connection between the second-level arm and the first-level arm, and joint bearings are also used. The clamping and pressing member robot arm 34 is fixed to the end of the third-level clamping robot arm 33, and they are connected by flanges and bolts.

[0086] In a specific embodiment, a first six-degree-of-freedom clamping robot 25 , a second six-degree-of-freedom blocking robot 26 , a third six-degree-of-freedom clamping robot 27 and a fourth six-degree-of-freedom blocking robot 28 are sequentially distributed in the circumferential direction of the annular lifting platform 21 .

[0087] In a specific embodiment, the transformer includes a first high-voltage winding 1, a second low-voltage winding 2, a third high-voltage winding 3, a fourth low-voltage winding 4, a fifth high-voltage winding 5 and a sixth low-voltage winding 6 which are coaxially arranged in sequence, and a plurality of coil clamping parts are evenly arranged on the outer surface of each winding, and a corresponding first upper end sleeve 45, a second upper end sleeve 46, a third upper end sleeve 47, a fourth upper end sleeve 48, a fifth upper end sleeve 49 and a sixth upper end sleeve 50 are respectively arranged at the top of each winding.

[0088] In a specific embodiment, taking the deformation of the first high-voltage winding 1 and the second low-voltage winding 2 as an example, the specific operation steps of the above transformer winding fault simulation device are as follows:

[0089] S100. Place the transformer winding on the center of the power transformer winding rotating platform 10 on the power transformer winding supporting platform 8, and axially install the gear-driven circular telescopic mechanism 39 on the inner side of the winding on the power transformer winding rotating platform 10. The telescopic mechanism driving motor located on the telescopic mechanism fixing seat 43 rotates to drive the telescopic mechanism driving gear 41 and the telescopic mechanism transmission gear to pull the telescopic cylinder 44 to expand to the inner wall of the second low-voltage winding 2, so as to achieve radial fixation of the winding.

[0090] S200. Operate the transformer rotating motor 9 located on the power transformer winding support platform 8 to drive the transformer rotating driving gear 11 and the transformer winding rotating transmission gear 12 to drive the transformer winding rotating platform to rotate the first high-voltage winding 1 and the second low-voltage winding 2 of the power transformer to a suitable position. The screw drive motor 19 controls the axial ball screw 18 to drive the axial movable support 20 located on the axial slider seat 17 and the axial ball screw 18 to descend to the bottom.

[0091] S300. The screw drive motor 19 controls the radial transmission screw drive to radially move the axial slider seat 17 located on the radial movable slide rail 14 and the radial transmission screw to the middle position of the radial movable slide rail 14, and the roller 24 slightly lifts the annular lifting platform 21 so that the rotating drive gear 23 is correctly engaged with the annular lifting platform 21.

[0092] S400. The screw drive motor 19 controls the axial ball screw 18 to transmit so that the axial movable support 20 located on the axial slider seat 17 and the axial ball screw 18 drives the annular lifting platform 21 to reach the fault simulation axial height.

[0093] S500. The block placing robot arm moves to the winding clamp loose fault simulation position along the guide rail of the circular lifting platform 21 through the robot arm moving base 29, controls the hydraulic cylinder lifting arm 30, the first-level block placing robot arm 35, the second-level block placing robot arm 36, and the third-level block placing robot arm 37 to move the winding block end 38 to the front of the coil clamp, and the winding block end 38 pushes out the wedge block and inserts it into the middle of the winding coil cakes at both ends of the coil clamp to cause looseness, the robot arm is retracted, and the block placing robot arm is reset along the guide rail of the circular lifting platform 21 through the robot arm moving base 29.

[0094] S600. The clamping robot arm moves to the winding clamping part loose fault simulation position along the guide rail of the circular lifting platform 21 through the robot arm moving base 29, controls the hydraulic cylinder lifting arm 30, the first-level clamping robot arm 31, the second-level clamping robot arm 32, and the third-level clamping robot arm 33 to move the clamping part robot arm 34 to the front of the coil clamping part, drives the clamping part robot arm 34 to feed so that it clamps the coil clamping part 7, and the robot arm moves to complete the extraction of the coil clamping part 7, and the clamping robot arm is reset along the guide rail of the circular lifting platform 21 through the robot arm moving base 29.

[0095] S700. The block placing robot arm moves to the winding clamp loose fault simulation position along the guide rail of the circular lifting platform 21 through the robot arm moving base 29, controls the hydraulic cylinder lifting arm 30, the first-level block placing robot arm 35, the second-level block placing robot arm 36, and the third-level block placing robot arm 37 to move the winding block end 38 to the front of the coil clamp, the winding block end 38 retracts the wedge block, the robot arm retracts, and the block placing robot arm is reset along the guide rail of the circular lifting platform 21 through the robot arm moving base 29.

[0096] S300. Repeat the operations of S300-S700 to simulate winding axial looseness faults at different positions.

[0097] Embodiment 2

[0098] Please refer to Figure 7-Figure 8 This embodiment discloses a transformer winding fault simulation method, the method comprising the following steps:

[0099] S1. Excite transformer winding vibration;

[0100] S2. Collect the vibration signal of the transformer winding at a preset measuring point to obtain a vibration signal matrix consisting of a plurality of the vibration signals;

[0101] S3. Calculate the overall vibration energy modulus and partition vibration energy modulus according to the vibration energy spectrum characteristic matrix;

[0102] S4. After comparing the overall vibration energy modulus and the partitioned vibration energy modulus with different standard values ​​respectively, the fault degree and fault location of the axial looseness of the transformer winding are determined according to the comparison results.

[0103] In a specific embodiment of step S1, a high-frequency excitation signal is applied between the connection points of the high-voltage winding and the low-voltage winding of the transformer to excite the vibration of the transformer winding. The specific operation is as follows:

[0104] (1) The connection point of the upper bushing 45 of the first high-voltage winding 1 , the upper bushings of the third high-voltage winding 3 , and the fifth high-voltage winding 5 is defined as a connection point A.

[0105] (2) The upper bushing connection point of the second low-voltage winding 2, the fourth low-voltage winding 4, and the sixth low-voltage winding 6 is defined as connection point B.

[0106] (3) Connect the high-frequency high-voltage switch 51 and the high-frequency high-voltage DC power supply 52 to the connection points A and B. The output voltage of the high-frequency high-voltage DC power supply 52 is preferably 50 kV-100 kV, and the frequency is preferably 1 kHz-10 kHz.

[0107] (4) Control the high-frequency high-voltage switch 51 to periodically switch at a frequency of 20 Hz-50 Hz to stimulate the vibration of the transformer body structure.

[0108] In a specific embodiment of step S2, a high-speed camera 53 is used to simultaneously collect vibration characteristics of multiple measuring points on the surface of the UHV transformer oil tank, and a signal acquisition device outputs a transformer vibration signal x(t).

[0109] Arrange multiple measuring points on the surface of the transformer tank. The measuring points at the same horizontal position are recorded as a row, and the measuring points in the same vertical direction are recorded as a column. If there are m rows and n columns of measuring points, then the m×n vibration signal matrix X can be obtained. m*n :

[0110]

[0111] Among them, m and n distributions indicate that there are m rows and n columns of measurement points, x mn (t) represents the vibration signal of the measuring point at the mth row and nth column.

[0112] In step S3, the vibration signal matrix obtained in step S2 is analyzed. The specific analysis steps are as follows:

[0113] S31. Use linear time-frequency analysis method to transform the vibration signal x mn (t) Decompose and reconstruct to improve the signal-to-noise ratio and obtain the denoised signal:

[0114]

[0115]

[0116] Among them, x 2mn (t) is the value after high-pass filter R Z The signal after x 2mn-1 (t) is the value after passing through the low-pass filter L Z The signal after; Z is an integer set; x mn (2t-Z) is the original signal; It is the new signal after noise reduction and decomposition.

[0117] S32. New signal after noise reduction and decomposition of each measuring point Perform Fourier transform and establish the vibration energy spectrum characteristic matrix based on the Fourier transform results.

[0118] In a specific embodiment, the vibration energy distribution of the vibration signal in each frequency band (f = 100 Hz, 200 Hz, ... 1000 Hz) is obtained, defined as u, and the energy distribution of the vibration energy spectrum characteristic matrix is ​​established: U mn =[u 100 u 200 …u 1000 ].

[0119] In step S4, calculating the overall vibration energy modulus and the partitioned vibration energy modulus according to the vibration energy spectrum characteristic matrix includes the following specific steps:

[0120] S41. After extracting the energy value of each frequency band in the vibration energy spectrum characteristic matrix, select the energy values ​​of several frequency points with the largest energy values ​​to form a feature vector; and calculate the norm of the feature vector.

[0121] In a specific embodiment, according to the established vibration energy spectrum characteristic matrix U mn =[u 100 u 200 … u 1000 ] In descending order, the new signal Take the first 8 values ​​of the vibration energy distribution in each frequency band, and construct the vibration energy values ​​at these frequency points into a vector E p(mn) =[e1,e2,e3,e4,e5,e6,e7,e8], for vector E p(mn) The vector norm is obtained as the characteristic value of the winding vibration evaluation index at the measuring point, denoted as t mn .

[0122] in,

[0123] S42. Arrange the norms according to the measurement point positions to form an eigenvalue norm matrix; divide the transformer winding into multiple regions; divide the eigenvalue norm matrix into multiple block matrices corresponding to the multiple regions; calculate the overall vibration energy modulus corresponding to the eigenvalue norm matrix and the partitioned vibration energy modulus corresponding to the block matrix.

[0124] In a specific embodiment, the vector norm t of the corresponding measuring point position calculated in step S23 is mn Represented as an eigenvalue norm matrix T m*n ; According to the distribution area of ​​the measuring points on the surface of the fuel tank, the eigenvalue norm matrix T m*n Divided into 3 blocks of matrices [T H T D T L ], corresponding to the upper end area of ​​the transformer winding, the middle area of ​​the winding, and the lower end area of ​​the winding.

[0125] in,

[0126] The overall vibration energy modulus corresponding to the eigenvalue norm matrix is ​​|T m*n |, the partition vibration energy modulus values ​​corresponding to the block matrix are |T H |,|T D |,|T L |.

[0127] In step S5, the overall vibration energy modulus is compared with a preset reference value; when the overall vibration energy modulus is less than the preset reference value, the transformer winding is determined to be slightly loose; when the overall vibration energy modulus is greater than the preset reference value, the transformer winding is determined to be obviously loose; and the magnitudes of the vibration energy modulus of each partition are compared to determine the fault location of the loose transformer winding.

[0128] In a specific embodiment, the eigenvalue norm matrix T calculated in step S4 is m*n The overall vibration energy modulus T m*n |, partition vibration energy modulus T of the block matrix H |,T D |,T L |, compared with the vibration energy modulus under the intact transformer winding operation condition as well as for comparison.

[0129] when It was determined that the transformer winding was slightly axially loose;

[0130] when It is determined that the transformer winding is obviously loose in the axial direction, and the loose area needs to be further determined:

[0131] like It was determined that the upper end area of ​​the transformer winding was loose;

[0132] like It was determined that the middle area of ​​the transformer winding was loose;

[0133] like It was determined that the lower end area of ​​the transformer winding was loose.

[0134] In summary, the method of the present invention achieves accurate diagnosis of transformer winding faults by establishing a vibration energy spectrum feature matrix and calculating the vibration energy modulus by partition. Specifically, firstly, a high-speed camera 53 is used to simultaneously collect the vibration characteristics of multiple measuring points on the surface of the transformer oil tank to obtain a complete vibration signal matrix; then, a linear time-frequency analysis method is used to reduce noise and reconstruct the vibration signal to extract the vibration energy distribution characteristics in each frequency band; finally, by calculating the vibration energy modulus of the eigenvalue norm matrix and comparing it with the standard value, not only can the degree of axial looseness of the winding be quantitatively determined, but also the specific area where the fault occurs can be accurately located according to the comparison of the partition energy modulus, providing a reliable diagnostic basis for the preventive maintenance of the transformer.

[0135] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A transformer winding fault simulation device, characterized in that: include: Transformer winding positioning and fixing system, used for rotational positioning and fixing of transformer windings; A positioning mechanism, used to control the annular lifting platform to rotate in the horizontal direction and to control the annular lifting platform to move in the vertical direction; A robotic arm system is arranged on the annular lifting platform and is used to perform deformation operations on the transformer winding; the robotic arm system includes a device for clamping and extracting a transformer coil clamp, and a device for inserting a wedge block into the transformer winding or recovering the wedge block.

2. The transformer winding fault simulation device according to claim 1, characterized in that: The transformer winding positioning and fixing system comprises: A power transformer winding support platform on which the transformer winding is arranged; A transformer rotating motor, used for driving the power transformer winding support platform to rotate in a radial direction; The invention discloses a rotating platform for a power transformer winding, on which a telescopic cylinder and a telescopic mechanism for fixing the winding are provided. The telescopic mechanism is used to drive the telescopic cylinder to expand in a radial direction until it abuts against the inner wall of the transformer winding.

3. The transformer winding fault simulation device according to claim 1, characterized in that: The robotic arm system comprises: A multi-degree-of-freedom clamping mechanical arm comprises a movable base, a clamping and pressing piece mechanical arm and a multi-stage clamping arm connected in sequence; the clamping arm farthest from the movable base is used for clamping and extracting the pressing piece in the transformer coil; A multi-degree-of-freedom block placement robot arm comprises a movable base, a hydraulic cylinder lifting arm, a multi-stage block placement arm and a winding block placement end connected in sequence; the winding block placement end is used to insert a wedge block into the transformer winding or to recycle the wedge block; A guide rail is provided on the surface of the annular lifting platform, and the movable bases of the clamping mechanical arm and the block placing mechanical arm are slidably connected to the guide rail.

4. The transformer winding fault simulation device according to claim 1, characterized in that: The positioning mechanism includes a radial movement mechanism arranged on both sides of the transformer winding positioning system, and the radial movement mechanism includes: A radial slide rail, the radial slide rail is arranged on the bottom plate seat; An axial slider seat is slidably connected to the radial slide rail, and bearing seats are respectively provided on both sides of the axial slider seat; A roller, arranged on the surface of the axial slider seat, for supporting the annular lifting platform; A rotary drive gear, arranged on the surface of the axial slider seat, for meshing with a meshing gear ring arranged on the outer periphery of the annular lifting platform; A radial transmission screw rod is rotatably disposed on the axial slider seat and inside the axial slider seat; A screw drive motor, used for driving the axial ball screw to rotate along the axis of the axial ball screw; The gear drive motor is used to drive the annular lifting platform to rotate in a radial direction.

5. The transformer winding fault simulation device according to claim 4, characterized in that: The positioning mechanism also includes: an axial motion mechanism; An axially movable support is arranged on the surface of the axial slider seat; the roller and the rotary drive gear are both arranged on the axially movable support; An axial ball screw is arranged in an axial movable support; the axial movable support is transmission-connected to the axial ball screw; The screw drive motor is used to drive the axial ball screw to rotate along the axis of the axial ball screw.

6. A transformer winding fault detection method, characterized in that: The method comprises: Excite vibration of transformer windings; Collect vibration signals of the transformer winding at preset measuring points to obtain a vibration signal matrix composed of a plurality of the vibration signals; Analyzing the vibration signal to obtain a vibration energy spectrum feature matrix; Calculate the overall vibration energy modulus and the partitioned vibration energy modulus according to the vibration energy spectrum characteristic matrix; After comparing the overall vibration energy modulus and the partitioned vibration energy modulus with different standard values ​​respectively, the fault degree and fault location of the axial looseness of the transformer winding are determined according to the comparison results.

7. The transformer winding fault detection method according to claim 6, characterized in that: The vibration energy spectrum characteristic matrix obtained by analyzing the vibration signal includes: Performing high-pass and low-pass filtering decomposition and reconstruction on the vibration signal; The signals after high-pass and low-pass filtering decomposition and reconstruction are subjected to Fourier transform, and the vibration energy spectrum characteristic matrix is ​​established according to the Fourier transform results.

8. The transformer winding fault detection method according to claim 7, characterized in that: Calculating the overall vibration energy modulus and the partitioned vibration energy modulus according to the vibration energy spectrum characteristic matrix includes: After extracting the energy value of each frequency band in the vibration energy spectrum characteristic matrix, the energy values ​​of several frequency points with the largest energy values ​​are selected to form a characteristic vector; and the norm of the characteristic vector is calculated.

9. The transformer winding fault detection method according to claim 8, characterized in that: Calculating the overall vibration energy modulus and the partitioned vibration energy modulus according to the vibration energy spectrum characteristic matrix includes: Arranging the norms according to the measurement point positions to form an eigenvalue norm matrix; Dividing the transformer winding into a plurality of regions; Dividing the eigenvalue norm matrix into a plurality of block matrices corresponding to a plurality of the regions; The overall vibration energy modulus corresponding to the eigenvalue norm matrix and the partition vibration energy modulus corresponding to the block matrix are calculated.

10. The transformer winding fault detection method according to claim 9, characterized in that: After comparing the overall vibration energy modulus and the partitioned vibration energy modulus with different standard values, respectively, judging the fault degree and fault location of the axial looseness of the transformer winding according to the comparison results includes: Comparing the overall vibration energy modulus with a preset reference value; When the overall vibration energy modulus is less than the preset reference value, it is determined that the transformer winding is slightly loose; When the overall vibration energy modulus is greater than the preset reference value, it is determined that the transformer winding is obviously loose; The magnitudes of the vibration energy moduli of each partition are compared to determine the fault location of the loose transformer winding.

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