Method for additionally installing built-in acoustoelectric joint partial discharge sensing device in converter transformer

Abstract

The invention relates to a method for additionally installing a built-in acoustoelectric combined partial discharge sensing device in a converter transformer, which comprises the following steps of: forming a through hole at the geometric center of a manhole cover plate in the converter transformer, and welding and installing a flange at the through hole; before the converter transformer is vacuumized, the built-in acoustoelectric combined partial discharge sensing device is in sealed connection with the mounting flange through the valve; by arranging the valve, the communication state of the built-in acoustoelectric combined partial discharge sensing device and the converter transformer can be adjusted through the valve, and when the valve is closed, the built-in acoustoelectric combined partial discharge sensing device is allowed to be detached for maintenance and replacement during operation of the converter transformer; the influence of the operation and maintenance of the built-in acoustoelectric combined partial discharge sensing device on the reliable operation of the converter transformer is greatly reduced; and the sensitivity and the anti-interference capability of the built-in acoustic-electric combined partial discharge sensing device are improved.

Description

Technical Field

[0001] The invention relates to the technical field of converter transformers, and in particular to a method for installing a built-in acoustic-electric combined partial discharge sensor device in a converter transformer. Background Art

[0002] At present, the sudden discharge of converter transformers is developing rapidly and has a high degree of harm, which should be given high attention. Effectively monitoring partial discharge signals during the occurrence and development of discharge and timely fault warning are of positive significance to improving the operational reliability of converter transformers. Existing partial discharge monitoring mainly includes ultra-high frequency, ultrasonic, high-frequency current and other technical means. Limited by the structure of converter transformers and the characteristics of multi-physical field distribution, various partial discharge sensors used on site are installed externally, which are seriously interfered and have low sensitivity. The effectiveness of sudden discharge monitoring needs to be improved.

[0003] Through experimental verification, it was found that the built-in partial discharge sensor has significant advantages in improving the sensitivity of the sensor device and enhancing the anti-interference ability. The use of built-in ultra-high frequency partial discharge sensors, built-in acoustic sensors and built-in pressure sensors can effectively cover the partial discharge signal monitoring needs of the entire process of insulation defect occurrence and development.

[0004] However, constrained by the converter transformer structure and the requirements for safe operation, there is currently a lack of suitable locations for installing built-in sensors in operating converter transformers. To install built-in sensors, holes need to be drilled in the converter transformer body, which changes the structure of the converter transformer body and poses a hidden danger to the safe operation of the converter transformer. In addition, after the built-in sensor is installed and connected to the converter transformer body, if the built-in sensor is damaged, the converter transformer needs to be shut down, unloaded, and then disassembled and replaced, which greatly increases the pressure on the operation and inspection of the converter transformer and lacks reasonable operation and maintenance methods. Summary of the invention

[0005] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a method for installing a built-in acoustic-electric combined partial discharge sensor device in a converter transformer. The method has the advantage of being able to connect the built-in sensor with the converter transformer body without changing the structure of the converter transformer body, and being able to effectively sense the ultra-high frequency, acoustic and pressure partial discharge signals inside the converter transformer, thereby significantly improving the sensitivity and anti-interference ability of the built-in sensor.

[0006] The above-mentioned invention object of the present invention is achieved through the following technical solution: A method for installing a built-in acoustic-electric combined partial discharge sensor device in a converter transformer comprises the following steps:

[0007] A through hole is opened at the geometric center of the manhole cover plate in the converter transformer, and a mounting flange is welded at the through hole;

[0008] Before the converter transformer is evacuated, the built-in acoustic-electric combined partial discharge sensor is sealed and connected to the mounting flange through a valve.

[0009] Preferably, in the method for installing a built-in acoustic-electric combined partial discharge sensor device in a converter transformer provided by the present invention, the manhole cover is checked for need of additional thickening or reinforcement based on the overall weight of the built-in acoustic-electric combined partial discharge sensor device.

[0010] Preferably, in the method for installing a built-in acoustic-electric combined partial discharge sensor device in a converter transformer provided by the present invention, the valve type is selected according to the structure of the converter transformer and on-site operation and maintenance conditions, wherein the valve type is one of a butterfly valve, a ball valve and a gate valve.

[0011] Preferably, in the method for installing a built-in acoustic-electric combined partial discharge sensor device in a converter transformer provided by the present invention, the mounting flange is provided with a raised platform, and the aperture of the raised platform is consistent with the size of the through hole.

[0012] Preferably, in the method for installing a built-in acoustic-electric combined partial discharge sensor device in a converter transformer provided by the present invention, the manhole cover plate and the mounting flange are welded by an internal and external full welding process.

[0013] Preferably, the method for installing a built-in acoustic-electric combined partial discharge sensor device in a converter transformer provided by the present invention further includes: assembling the built-in acoustic-electric combined partial discharge sensor device before opening a through hole at the geometric center of a manhole cover in the converter transformer and welding a mounting flange at the through hole.

[0014] Preferably, the method for adding a built-in acoustic-electric combined partial discharge sensor device to a converter transformer provided by the present invention, the built-in acoustic-electric combined partial discharge sensor device includes an acoustic sensor, a pressure sensor, a mounting assembly and an ultra-high frequency sensor, a mounting platform is provided in the mounting assembly, the acoustic sensor and the pressure sensor are both fixed to the mounting platform by insulating fastening screws, one end of the mounting assembly is sealed with the valve, and the other end of the mounting assembly is sealed with the ultra-high frequency sensor by a fixed flange; the mounting assembly includes a first flange, a connecting sleeve, a second flange, an exhaust valve, an oil drain valve, a first optical fiber through-hole and a second optical fiber through-hole, the first flange is connected to the second flange through the connecting sleeve, the mounting platform is provided in the connecting sleeve, an exhaust hole, an oil drain hole, a first optical fiber through-hole and a second optical fiber through-hole are provided on the outer peripheral wall of the connecting sleeve, the exhaust hole, the exhaust valve, the first optical fiber through-hole and the second optical fiber through-hole are provided, The oil hole, the first optical fiber through-threaded hole and the second optical fiber through-threaded hole are all connected to the cavity of the connecting sleeve, the first optical fiber through-threaded hole and the second optical fiber through-threaded hole are arranged correspondingly, and the exhaust hole, the first optical fiber through-threaded hole, the oil drain hole and the second optical fiber through-threaded hole are arranged at equal intervals around the circumference of the connecting sleeve; the exhaust hole is adapted to the exhaust valve, the oil drain valve is adapted to the oil drain hole, the first optical fiber through-threaded hole is adapted to the first optical fiber through-device, the second optical fiber through-threaded hole is adapted to the second optical fiber through-device, the exhaust valve is fixed in the exhaust hole, the oil drain valve is fixed in the oil drain hole, the first optical fiber through-device is installed in the first optical fiber tube through hole, and the second optical fiber through-device is installed in the second optical fiber through-threaded hole; the first flange is sealed and connected to the valve, and the second flange is sealed and connected to the fixed flange.

[0015] Preferably, the method for installing a built-in acoustic-electric combined partial discharge sensor device in a converter transformer provided by the present invention further comprises: assembling the built-in acoustic-electric combined partial discharge sensor device before opening a through hole at the geometric center of a manhole cover plate in the converter transformer and welding a mounting flange at the through hole; wherein, assembling the built-in acoustic-electric combined partial discharge sensor device comprises:

[0016] Fully weld the exhaust valve into the exhaust hole, and fully weld the oil drain valve into the oil drain hole;

[0017] The acoustic sensor is fixed on the mounting platform by means of an insulating fastening screw, and the optical fiber of the acoustic sensor is connected to the first optical fiber feedthrough;

[0018] The pressure sensor is fixed on the mounting platform by means of insulating fastening screws, and the optical fiber of the pressure sensor is connected to the second optical fiber feedthrough;

[0019] The side of the fixed flange facing away from the UHF sensor is sealed and connected to the second flange.

[0020] Preferably, the method for installing a built-in acoustic-electric combined partial discharge sensor device in a converter transformer provided by the present invention comprises: before the converter transformer is evacuated, the built-in acoustic-electric combined partial discharge sensor device is sealed and connected to the mounting flange through a valve, comprising:

[0021] One end of the valve is sealed and connected to the mounting flange;

[0022] Before the commutation transformer is evacuated, the first flange in the built-in acoustic-electric combined partial discharge sensor device is sealed and connected to the end of the valve away from the mounting flange.

[0023] Preferably, the method for installing a built-in acoustic-electric combined partial discharge sensor device in a converter transformer provided by the present invention, before evacuating the converter transformer, after the built-in acoustic-electric combined partial discharge sensor device is sealed to the mounting flange via a valve, further comprises: after the built-in acoustic-electric combined partial discharge sensor device is installed on the valve, the built-in acoustic-electric combined partial discharge sensor device is subjected to vacuum evacuation, oil filling and related tests along with the converter transformer, and after the tests are passed, the built-in acoustic-electric combined partial discharge sensor device is put into operation along with the converter transformer.

[0024] To sum up, the beneficial technical effects of the present invention are as follows: the method for installing a built-in acoustic-electric combined partial discharge sensor device in a converter transformer provided in the present application comprises the following steps: opening a through hole at the geometric center of the manhole cover in the converter transformer, and welding a mounting flange at the through hole; before evacuating the converter transformer, sealingly connecting the built-in acoustic-electric combined partial discharge sensor device to the mounting flange through a valve; by setting the valve, the valve can adjust the connectivity between the built-in acoustic-electric combined partial discharge sensor device and the converter transformer, and when the valve is closed, the built-in acoustic-electric combined partial discharge sensor device is allowed to be removed for inspection and replacement while the converter transformer is running, which greatly reduces the impact of the operation and maintenance of the built-in acoustic-electric combined partial discharge sensor device on the reliable operation of the converter transformer; and improves the sensitivity and anti-interference capability of the built-in acoustic-electric combined partial discharge sensor device. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a flow chart of a method for installing a built-in acoustic-electric combined partial discharge sensor device in a converter transformer provided by an embodiment of the present invention.

[0026] Figure 2 It is a schematic diagram of the installation structure of a built-in acoustic-electric combined partial discharge sensor device installed in a converter transformer provided by an embodiment of the present invention.

[0027] Figure 3It is a structural schematic diagram of a built-in acoustic-electric combined partial discharge sensor device in a method for adding a built-in acoustic-electric combined partial discharge sensor device in a converter transformer provided in an embodiment of the present invention.

[0028] Figure 4 It is a structural schematic diagram of an installation flange in a method for adding a built-in acoustic-electric combined partial discharge sensor device in a converter transformer provided in an embodiment of the present invention.

[0029] Figure 5 It is a front view of the installation flange in the method for installing a built-in acoustic-electric combined partial discharge sensor device in a converter transformer provided by an embodiment of the present invention.

[0030] Figure 6 It is a side view of a mounting flange in a method for adding a built-in acoustic-electric combined partial discharge sensor device in a converter transformer provided in an embodiment of the present invention.

[0031] Figure 7 It is a structural schematic diagram of the installation components in the method for installing a built-in acoustic-electric combined partial discharge sensor device in a converter transformer provided by an embodiment of the present invention.

[0032] Figure 8 It is a front view of the installation components in the method for installing a built-in acoustic-electric combined partial discharge sensor device in a converter transformer provided by an embodiment of the present invention.

[0033] Fig. 9 The side view of the installation component in the method for installing a built-in acoustic-electric combined partial discharge sensor device in a converter transformer provided by an embodiment of the present invention Figure 1 .

[0034] Fig.10 The side view of the installation component in the method for installing a built-in acoustic-electric combined partial discharge sensor device in a converter transformer provided by an embodiment of the present invention Figure 2 .

[0035] Fig.11 It is a schematic diagram of the connection structure between the ultra-high frequency sensor and the fixed flange in the method for installing a built-in acoustic-electric combined partial discharge sensor device in a converter transformer provided by an embodiment of the present invention.

[0036] Fig.12 It is the signal of the ultra-high frequency sensor unit of the built-in acoustic-electric combined partial discharge sensor device when the internal defect of the transformer discharges slightly in the method for adding a built-in acoustic-electric combined partial discharge sensor device in the converter transformer provided by the embodiment of the present invention.

[0037] Fig.13 It is the acoustic sensor unit signal of the built-in acoustic-electric combined partial discharge sensor device when the internal defect of the transformer discharges slightly in the method for installing the built-in acoustic-electric combined partial discharge sensor device in the converter transformer provided by the embodiment of the present invention.

[0038] Fig.14It is the signal of the pressure sensing unit of the built-in acoustic-electric combined partial discharge sensing device when a high-energy arc discharge occurs inside the transformer in the method for adding a built-in acoustic-electric combined partial discharge sensing device in the converter transformer provided by the embodiment of the present invention.

[0039] In the figure, 1, manhole cover; 2, mounting flange; 21, lifting platform; 3, valve; 4, built-in acoustic-electric combined partial discharge sensor; 41, fixed flange; 42, UHF sensor; 43, mounting assembly; 431, first flange; 432, connecting sleeve; 433, second flange; 434, exhaust valve; 435, oil drain valve; 436, mounting platform; 4361, first mounting position; 4362, second mounting position; 437, first optical fiber through-threaded hole; 438, second optical fiber through-threaded hole; 5, sealing ring; 6, sealing rubber ring; 7, sealing rubber ring. DETAILED DESCRIPTION

[0040] The present invention is further described in detail below in conjunction with the accompanying drawings.

[0041] Reference Figure 1 , is a method for installing a built-in acoustic-electric combined partial discharge sensor device 4 in a converter transformer disclosed in the present invention, comprising the following steps:

[0042] S101, a through hole is opened at the geometric center of the manhole cover plate 1 in the converter transformer, and a mounting flange 2 is welded at the through hole.

[0043] S102. Before evacuating the converter transformer, the built-in acoustic-electric combined partial discharge sensor device 4 is sealed and connected to the mounting flange 2 through the valve 3. By setting the valve 3, the valve 3 can adjust the connection state between the built-in acoustic-electric combined partial discharge sensor device 4 and the converter transformer. When the valve 3 is closed, the built-in acoustic-electric combined partial discharge sensor device 4 is allowed to be removed for inspection and replacement when the converter transformer is running, which greatly reduces the influence of the operation and maintenance of the built-in acoustic-electric combined partial discharge sensor device 4 on the reliable operation of the converter transformer.

[0044] The manhole cover 1 is checked for need of additional thickening or reinforcement based on the overall weight of the built-in acoustic-electric combined partial discharge sensor device 4 .

[0045] Specifically, the type of valve 3 is selected according to the structure of the converter transformer and the on-site operation and maintenance conditions, wherein the type of valve 3 is one of a butterfly valve, a ball valve and a gate valve. If conditions permit, a gate valve is preferably selected. In this embodiment, valve 3 uses a DN150 standard butterfly valve made of Q235 carbon steel, one end of the butterfly valve is welded to the mounting flange 2, and the other end of the butterfly valve is bolted to the built-in acoustic-electric combined partial discharge sensor device 4.

[0046] It should be noted that one end of the ball valve or gate valve is connected to the mounting flange 2 by bolts.

[0047] Continue to refer to Figures 2 to 6 In this embodiment, a raised platform 21 is provided on the mounting flange 2, the aperture of the raised platform 21 is consistent with the size of the through hole, and the height of the raised platform 21 can meet the rotating part of the valve 3 when the valve 3 is open or closed. Among them, the manhole cover plate 1 and the mounting flange 2 are welded by the internal and external full welding process.

[0048] In this embodiment, the aperture size of the mounting flange 2 is a standard DN150 flange, the total length of the mounting flange 2 along the X direction is 112 mm, the material of the mounting flange 2 is Q235 carbon steel, and the thickness of the manhole cover 1 is 20 mm, which is sufficient to support the weight of the built-in acoustic-electric combined partial discharge sensor device 4.

[0049] It should be noted that the X direction is the centerline direction of the mounting flange 2 .

[0050] A sealing groove is provided on the side of the mounting flange 2 facing away from the manhole cover plate 1 , and a sealing ring 5 made of rubber material is installed in the sealing groove to achieve a sealed connection between the mounting flange 2 and the valve 3 .

[0051] Furthermore, in the present embodiment, S102, before the converter transformer is evacuated, after the built-in acoustic-electric combined partial discharge sensor device 4 is sealed and connected to the mounting flange 2 through the valve 3, it also includes: after the built-in acoustic-electric combined partial discharge sensor device 4 is installed on the valve 3, the built-in acoustic-electric combined partial discharge sensor device 4 is evacuated, oiled and subjected to related tests along with the converter transformer, and after the tests are passed, the built-in acoustic-electric combined partial discharge sensor device 4 is put into operation along with the converter transformer.

[0052] During the operation of the converter transformer, the connection and isolation between the built-in acoustic-electric combined partial discharge sensor device 4 and the converter transformer body are controlled by the valve 3. When the valve 3 is opened, the built-in acoustic-electric combined partial discharge sensor device 4 is connected to the converter transformer body to monitor the partial discharge signal inside the converter transformer; when the valve 3 is closed, the built-in acoustic-electric combined partial discharge sensor device 4 is isolated from the converter transformer body, and the built-in acoustic-electric combined partial discharge sensor device 4 exits the working state.

[0053] Continue to refer to Figure 2 , Figures 7 to 11 In this embodiment, the built-in acoustic-electric combined partial discharge sensor device 4 includes an acoustic sensor, a pressure sensor, a mounting assembly 43 and a UHF sensor 42. A mounting platform 436 is provided in the mounting assembly 43. The acoustic sensor and the pressure sensor are both fixed to the mounting platform 436 by insulating fastening screws. One end of the mounting assembly 43 is sealed with the valve 3, and the other end of the mounting assembly 43 is sealed with the UHF sensor 42 by a fixing flange 41. By providing the acoustic sensor, the pressure sensor and the UHF sensor 42, the UHF, sound, pressure and other partial discharge signals inside the converter transformer can be effectively sensed, and the sensitivity and anti-interference ability of the built-in acoustic-electric combined partial discharge sensor device 4 can be significantly improved.

[0054] Among them, a first installation position 4361 and a second installation position 4362 are set on the installation platform 436. The first installation position 4361 matches the size of the pressure sensor, and the second installation position 4362 matches the size of the acoustic sensor. The pressure sensor is used to be installed at the first installation position 4361, and the acoustic sensor is used to be installed at the second installation position 4362.

[0055] In this embodiment, the mounting platform 436 is made of epoxy resin.

[0056] Specifically, the UHF sensor 42 is disposed on one side of the fixed flange 41 , and the side of the fixed flange 41 facing away from the UHF sensor 42 is in contact with one end of the mounting assembly 43 and is sealed and connected.

[0057] In this embodiment, the UHF sensor 42 is a built-in UHF sensor 42, the sensing unit has a diameter of 100 mm, a height of 80 mm, epoxy casting sealing, and the fixed flange 41 is a standard DN150 flange.

[0058] Furthermore, in the present embodiment, the mounting assembly 43 comprises a first flange 431, a connecting sleeve 432, a second flange 433, an exhaust valve 434, an oil drain valve 435, a first optical fiber through-hole and a second optical fiber through-hole. The first flange 431 is connected to the second flange 433 via the connecting sleeve 432. The mounting platform 436 is disposed in the connecting sleeve 432. An exhaust hole, an oil drain hole, a first optical fiber through-hole 437 and a second optical fiber through-hole 438 are provided on the outer peripheral wall of the connecting sleeve 432. The exhaust hole, the oil drain hole, the first optical fiber through-hole 437 and the second optical fiber through-hole 438 are all connected to the cavity of the connecting sleeve 432. The first optical fiber through-hole 437 and the second optical fiber through-hole 438 are correspondingly disposed. The exhaust hole, the first optical fiber through-hole 437, the oil drain hole and the second optical fiber through-hole 438 are equally spaced around the circumference of the connecting sleeve 432. The air valve 434 is adapted to the oil drain valve 435, the first optical fiber through-threaded hole 437 is adapted to the first optical fiber through-device, the second optical fiber through-threaded hole 438 is adapted to the second optical fiber through-device, the exhaust valve 434 is fixed in the exhaust hole, the oil drain valve 435 is fixed in the oil drain hole, the first optical fiber through-device is installed in the first optical fiber tube through-hole, and the second optical fiber through-device is installed in the second optical fiber through-threaded hole 438; the first flange 431 is sealed and connected to the valve 3, and the second flange 433 is sealed and connected to the fixed flange 41; by setting the exhaust valve 434 and the oil drain valve 435, the connection state between the built-in acoustic-electric combined partial discharge sensor device 4 and the converter transformer can be adjusted through the valve 3, and the exhaust valve 434 and the oil drain valve 435 can be used to realize the disassembly and installation of the built-in acoustic-electric combined partial discharge sensor device 4 when the converter transformer is in operation, which greatly avoids the influence of the maintenance of the built-in acoustic-electric combined partial discharge sensor device 4 on the operation of the converter transformer.

[0059] Specifically, the first optical fiber through-threaded hole 437 and the first optical fiber through-hole as well as the second optical fiber through-threaded hole 438 and the second optical fiber through-hole are sealed and connected via sealing gaskets.

[0060] When the mounting flange 2, the valve 3, the mounting assembly 43 and the fixed flange 41 are installed, the various parts are fastened and connected with each other by bolts and sealed.

[0061] In this embodiment, the apertures of the first flange 431 and the second flange 433 are both standard DN150 flanges, and the total length of the built-in acoustic-electric combined partial discharge sensor device 4 along the X direction is 168 mm, wherein the first flange 431, the connecting sleeve 432 and the second flange 433 are all made of Q235 carbon steel.

[0062] Specifically, the first flange 431 is connected to the valve 3 by bolts, a sealing groove is provided on the side of the valve 3 away from the mounting flange 2 , and a sealing rubber ring 6 is provided in the sealing groove to achieve a sealed connection between the first flange 431 and the valve 3 .

[0063] The second flange 433 is connected to the fixed flange 41 by bolts. A groove is provided on the side of the second flange 433 away from the connecting sleeve 432 . A sealing rubber ring 7 is provided in the groove to achieve a sealed connection between the second flange 433 and the fixed flange 41 .

[0064] Furthermore, in this embodiment, before S101, a through hole is opened at the geometric center of the manhole cover plate 1 in the converter transformer and the mounting flange 2 is welded at the through hole, it also includes: assembling a built-in acoustic-electric combined partial discharge sensor device 4.

[0065] Wherein, the built-in acoustic-electric combined partial discharge sensor device 4 is assembled, including:

[0066] S201, fully weld the exhaust valve 434 into the exhaust hole, and fully weld the oil drain valve 435 into the oil drain hole.

[0067] It should be noted that Fig. 9 Taking the shown orientation as an example, the exhaust valve 434 is located at the upper part of the connecting sleeve 432, and the oil drain valve 435 is located at the lower part of the connecting sleeve 432.

[0068] S202, fixing the acoustic sensor on the mounting platform 436 by means of insulating fastening screws, and connecting the optical fiber of the acoustic sensor to the first optical fiber through-hole.

[0069] In this embodiment, the acoustic sensor adopts a built-in fiber optic acoustic sensor. The built-in fiber optic acoustic sensor has a fully insulating structure and a sensor volume of 50*25*2mm. The built-in fiber optic acoustic sensor is fixed to the mounting platform 436 by insulating fastening screws. The optical signal collected by the built-in fiber optic acoustic sensor is led out through the optical fiber of the built-in fiber optic acoustic sensor and the first optical fiber through-fitter.

[0070] S203, the pressure sensor is fixed on the mounting platform 436 by means of insulating fastening screws, and the optical fiber of the pressure sensor is connected to the second optical fiber through-hole.

[0071] In this embodiment, the pressure sensor adopts a built-in optical fiber pressure sensor. The built-in optical fiber pressure sensor is a fully insulated structure. The sensor diameter is 22 mm and the height is 32 mm. The built-in optical fiber pressure sensor is fixed to the mounting platform 436 by insulating fastening screws. The optical signal collected by the built-in optical fiber pressure sensor is led out through the optical fiber of the built-in optical fiber pressure sensor and the second optical fiber through-fitter.

[0072] S204 , the side of the fixed flange 41 facing away from the UHF sensor 42 is sealed and connected to the second flange 433 .

[0073] Specifically, the second flange 433 is connected to the fixed flange 41 by bolts. A groove is provided on the side of the second flange 433 away from the connecting sleeve 432 . A sealing rubber ring 7 is provided in the groove to achieve a sealed connection between the second flange 433 and the fixed flange 41 .

[0074] Further, in this embodiment, S102, before the commutation transformer is evacuated, the built-in acoustic-electric combined partial discharge sensor device 4 is sealed and connected to the mounting flange 2 through the valve 3, including:

[0075] S1021. One end of the valve 3 is sealed and connected to the mounting flange 2.

[0076] Specifically, one end of the valve 3 is bolted or welded to the mounting flange 2 , and a sealing ring 5 is used to achieve a sealed connection between the valve 3 and the mounting flange 2 .

[0077] S1022. Before evacuating the converter transformer, seal the first flange 431 in the built-in acoustic-electric combined partial discharge sensor 4 with the end of the valve 3 facing away from the mounting flange 2.

[0078] Specifically, the first flange 431 is connected to the valve 3 by bolts, and a sealing rubber ring 6 is used to achieve a sealed connection between the first flange 431 and the valve 3 .

[0079] When the built-in acoustic-electric combined partial discharge sensor device 4 is in normal operation, the exhaust valve 434 and the oil drain valve 435 should be in the closed position and sealed with lead to prevent accidental opening. When the built-in acoustic-electric combined partial discharge sensor device 4 is activated to monitor the internal partial discharge signal of the converter transformer, the valve 3 should be opened; when the built-in acoustic-electric combined partial discharge sensor device 4 is deactivated, the valve 3 should be closed.

[0080] Continue to refer to Figure 12 to Figure 14 In this embodiment, the converter transformer equipped with a built-in acoustic-electric combined partial discharge sensor device 4 was tested and verified on a real transformer experimental platform. Among them, the ultra-high frequency sensor 42 and the acoustic sensor can effectively sense the partial discharge signal of internal defects of the transformer, and the pressure sensor can effectively sense the pressure change inside the oil tank when the transformer is discharged with high energy.

[0081] Among them, the built-in acoustic-electric combined partial discharge sensor device 4 can be disassembled and installed under the normal operation of the converter transformer. Among them, when the built-in acoustic-electric combined partial discharge sensor device 4 needs to be disassembled, close the valve 3, drain the oil through the oil drain valve 435, and then remove the built-in acoustic-electric combined partial discharge sensor device 4 separately, and install the flange 2 blind plate on the flange 2 surface outside the valve 3 to seal it. When the built-in acoustic-electric combined partial discharge sensor device 4 needs to be reinstalled, remove the flange blind plate and install the built-in acoustic-electric combined partial discharge sensor device 4; after the installation is completed, evacuate the vacuum through the exhaust valve 434 to the vacuum value required by the manufacturer's manual of the installed converter transformer, and close the exhaust valve 434; open the valve 3 to allow the insulating oil in the converter transformer to slowly fill the built-in acoustic-electric combined partial discharge sensor device 4; slowly open the exhaust valve 434 to ensure that all residual gas that may exist in the built-in acoustic-electric combined partial discharge sensor device 4 is discharged; close the exhaust valve 434 and seal it with a lead seal to prevent accidental opening.

[0082] The method for installing a built-in acoustic-electric combined partial discharge sensor device 4 in a converter transformer provided in the present application comprises the following steps: opening a through hole at the geometric center of a manhole cover plate 1 in the converter transformer, and welding a mounting flange 2 at the through hole; before evacuating the converter transformer, sealingly connecting the built-in acoustic-electric combined partial discharge sensor device 4 to the mounting flange 2 through a valve 3; by setting the valve 3, the valve 3 can adjust the connection state between the built-in acoustic-electric combined partial discharge sensor device 4 and the converter transformer, and when the valve 3 is closed, the built-in acoustic-electric combined partial discharge sensor device 4 is allowed to be removed for inspection and replacement when the converter transformer is running, which greatly reduces the influence of the operation and maintenance of the built-in acoustic-electric combined partial discharge sensor device 4 on the reliable operation of the converter transformer; and improves the sensitivity and anti-interference ability of the built-in acoustic-electric combined partial discharge sensor device 4.

[0083] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0084] Finally, it should be noted that: Obviously, the above embodiments are only examples for clearly explaining the present invention, and are not intended to limit the implementation methods. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from this are still within the scope of protection of the present invention.

Claims

1. A method for installing a built-in acoustic-electric combined partial discharge sensor in a converter transformer, characterized in that: The steps include: A through hole is opened at the geometric center of the manhole cover plate in the converter transformer, and a mounting flange is welded at the through hole; Before the converter transformer is evacuated, the built-in acoustic-electric combined partial discharge sensor is sealed and connected to the mounting flange through a valve.

2. The method for installing a built-in acoustic-electric combined partial discharge sensor device in a converter transformer according to claim 1, characterized in that: The manhole cover is checked for need of additional thickening or reinforcement based on the overall weight of the built-in acoustic-electric combined partial discharge sensor device.

3. The method for installing a built-in acoustic-electric combined partial discharge sensor device in a converter transformer according to claim 1, characterized in that: The valve type is selected according to the structure of the converter transformer and on-site operation and maintenance conditions, wherein the valve type is one of a butterfly valve, a ball valve and a gate valve.

4. The method for installing a built-in acoustic-electric combined partial discharge sensor device in a converter transformer according to claim 1, characterized in that: The mounting flange is provided with a raised platform, and the aperture of the raised platform is consistent with the size of the through hole.

5. The method for installing a built-in acoustic-electric combined partial discharge sensor device in a converter transformer according to claim 1, characterized in that: The manhole cover plate and the mounting flange are welded by adopting an inside-outside full welding process.

6. The method for installing a built-in acoustic-electric combined partial discharge sensor device in a converter transformer according to claim 1, characterized in that: Before a through hole is opened at the geometric center of the manhole cover plate in the converter transformer and a mounting flange is welded at the through hole, the method further includes: assembling the built-in acoustic-electric combined partial discharge sensor device.

7. The method for installing a built-in acoustic-electric combined partial discharge sensor device in a converter transformer according to claim 6, characterized in that: The built-in acoustic-electric combined partial discharge sensing device comprises an acoustic sensor, a pressure sensor, a mounting assembly and a UHF sensor. A mounting platform is provided in the mounting assembly. The acoustic sensor and the pressure sensor are both fixed to the mounting platform by insulating fastening screws. One end of the mounting assembly is sealed and connected to the valve, and the other end of the mounting assembly is sealed and connected to the UHF sensor by a fixing flange. The mounting assembly comprises a first flange, a connecting sleeve, a second flange, an exhaust valve, an oil drain valve, a first optical fiber through-hole and a second optical fiber through-hole, the first flange is connected to the second flange through the connecting sleeve, the mounting platform is arranged in the connecting sleeve, an exhaust hole, an oil drain hole, a first optical fiber through-hole and a second optical fiber through-hole are provided on the outer peripheral wall of the connecting sleeve, the exhaust hole, the oil drain hole, the first optical fiber through-hole and the second optical fiber through-hole are all connected to the cavity of the connecting sleeve, the first optical fiber through-hole and the second optical fiber through-hole are arranged correspondingly, and the exhaust hole, the first optical fiber through-hole, the oil drain hole and the second optical fiber through-hole are arranged at equal intervals around the circumference of the connecting sleeve; The exhaust hole is matched with the exhaust valve, the oil drain valve is matched with the oil drain hole, the first optical fiber through-threaded hole is matched with the first optical fiber through-device, the second optical fiber through-threaded hole is matched with the second optical fiber through-device, the exhaust valve is fixed in the exhaust hole, the oil drain valve is fixed in the oil drain hole, the first optical fiber through-device is installed in the first optical fiber tube through hole, and the second optical fiber through-device is installed in the second optical fiber through-threaded hole; The first flange is sealed and connected to the valve, and the second flange is sealed and connected to the fixed flange.

8. The method for installing a built-in acoustic-electric combined partial discharge sensor device in a converter transformer according to claim 7, characterized in that: The assembly of the built-in acoustic-electric combined partial discharge sensor device comprises: Fully weld the exhaust valve into the exhaust hole, and fully weld the oil drain valve into the oil drain hole; The acoustic sensor is fixed on the mounting platform by means of an insulating fastening screw, and the optical fiber of the acoustic sensor is connected to the first optical fiber feedthrough; The pressure sensor is fixed on the mounting platform by means of insulating fastening screws, and the optical fiber of the pressure sensor is connected to the second optical fiber feedthrough; The side of the fixed flange facing away from the UHF sensor is sealed and connected to the second flange.

9. The method for installing a built-in acoustic-electric combined partial discharge sensor device in a converter transformer according to claim 7, characterized in that: Before the commutation transformer is evacuated, the built-in acoustic-electric combined partial discharge sensor is sealed and connected to the mounting flange through a valve, including: One end of the valve is sealed and connected to the mounting flange; Before the commutation transformer is evacuated, the first flange in the built-in acoustic-electric combined partial discharge sensor device is sealed and connected to the end of the valve away from the mounting flange.

10. The method for installing a built-in acoustic-electric combined partial discharge sensor device in a converter transformer according to claim 1, characterized in that: Before the converter transformer is evacuated, the built-in acoustic-electric combined partial discharge sensor is sealed and connected to the mounting flange through a valve, and the method further includes: After the built-in acoustic-electric combined partial discharge sensor device is installed on the valve, the built-in acoustic-electric combined partial discharge sensor device is subjected to vacuuming, oil filling and related tests along with the converter transformer. After the tests are passed, the built-in acoustic-electric combined partial discharge sensor device is put into operation along with the converter transformer.

Images