Acoustic online monitoring device and method for installing acoustic sensor on converter transformer

Abstract

The invention provides an acoustic online monitoring device and a method for installing an acoustic sensor on a converter transformer. The device comprises a tool shell which is hollow and has two open ends; and the acoustic sensing assembly is arranged in the tool shell. According to the acoustic on-line monitoring device, the necessary chromatography pipeline connector on the converter transformer is fully utilized, an oil chromatography pipeline connecting structure is modified, and on the premise that normal operation of an oil chromatography device is not affected, the tool shell is additionally arranged between the oil chromatography connector and the oil chromatography pipeline, so that the acoustic on-line monitoring device can be mounted and dismounted on line; normal operation of the converter transformer and the oil chromatography device is not influenced; on the premise that an original converter transformer body structure is not changed, the built-in acoustic sensor is communicated with the converter transformer body, acoustic partial discharge signals in the converter transformer can be effectively sensed, the sensitivity of the acoustic sensor is remarkably improved, and the effective monitoring range of the acoustic sensor is remarkably widened. The problem that a converter transformer lacks a built-in acoustic sensor installation position in operation is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of converter transformers, in particular to an acoustic online monitoring device and a method for adding an acoustic sensor to a converter transformer. BACKGROUND

[0002] Converter transformers are key core equipment of extra-high voltage direct current transmission. Ultrasonic partial discharge online monitoring can timely find defects and hidden dangers of converter transformers and timely perform fault early warning, which has positive significance for improving safe and reliable operation of converter transformers. Limited by the structure of converter transformers and the distribution characteristics of multiple physical fields, the ultrasonic partial discharge sensors applied in the field are all externally installed, and the effective range of detection is very limited. The monitoring effect of defects and faults far from the sensor installation needs to be improved.

[0003] It is found through test verification that the built-in partial discharge sensor has significant advantages in enhancing the sensitivity of the acoustic sensing device and improving the effective range. At the same time, the built-in acoustic sensor can effectively represent the whole process of the development of insulation defects, meeting the needs of state monitoring of converter transformers. In addition, acoustic partial discharge monitoring combined with oil chromatographic monitoring can effectively improve the timeliness and accuracy of state monitoring of converter transformers.

[0004] Due to the structure of converter transformers and the requirements of safe operation, there is currently no suitable installation position for built-in sensors in the converter transformers in operation. The installation of built-in sensors usually needs to change the original structure of the converter transformer, which may cause hidden dangers to the safe operation of the converter transformer. In addition, once the built-in sensor is damaged, the converter transformer needs to be shut down and the oil needs to be removed for disassembly and replacement, which greatly increases the inspection pressure of the converter transformer, and there is a lack of reasonable operation and maintenance method. SUMMARY

[0005] In view of this, the present application provides an acoustic online monitoring device and a method for adding an acoustic sensor to a converter transformer, aiming to solve the problems that the installation of the built-in acoustic sensor on the existing converter transformer needs to change the original structure of the converter transformer, which may cause hidden dangers to the safe operation of the converter transformer, and the sensor needs to be replaced after the converter transformer is shut down and the oil is removed, which increases the inspection pressure of the converter transformer.

[0006] On one hand, the present application provides an acoustic online monitoring device, which comprises: a tool shell, which is hollow inside and has two open ends, the two open ends are used for being detachably connected to an oil chromatographic interface and an oil chromatographic pipeline of the converter transformer respectively, so as to realize the communication between the oil chromatographic interface and the oil chromatographic pipeline, so that the insulating oil in the oil tank of the converter transformer can flow through the oil chromatographic interface and the tool shell in turn and flow into the oil chromatographic pipeline; and an acoustic sensing assembly, which is arranged in the tool shell and is used for monitoring acoustic partial discharge signals inside the converter transformer.

[0007] Further, the acoustic on-line monitoring device, the acoustic sensing assembly comprises: an acoustic sensing fixing base arranged in the tool shell; an acoustic sensor arranged on the acoustic sensing fixing base for monitoring the acoustic local discharge signal inside the converter transformer; and a pressing strip arranged on the acoustic sensing fixing base, and the acoustic sensor is clamped between the pressing strip and the acoustic sensing fixing base.

[0008] Further, the acoustic on-line monitoring device, the acoustic sensing fixing base comprises: a fixing support plate provided with a groove at the top for carrying the acoustic sensor; and a fixing connecting block arranged at the bottom of the fixing support plate for detachably mounting on the inner wall of the tool shell.

[0009] Further, the acoustic on-line monitoring device, an extension channel is communicated on the tool shell, and an end of the extension channel is provided with a support disc provided with a fiber through device for leading out the optical fiber connected with the acoustic sensor.

[0010] Further, the acoustic on-line monitoring device, the support disc is a flange disc which is detachably connected with the end of the extension channel through a flange interface.

[0011] Further, the acoustic on-line monitoring device, a sealing ring is arranged at the flange interface of the support disc, between the fiber through device and the support disc, and / or at the butt flange arranged at the two open ends of the tool shell.

[0012] Further, the acoustic on-line monitoring device, a support base is arranged in the tool shell and detachably connected with the acoustic sensing assembly.

[0013] Further, the acoustic on-line monitoring device, butt flanges are arranged at the two open ends of the tool shell for respectively detachably connecting with the oil chromatographic interface and the oil chromatographic pipeline.

[0014] Further, the acoustic on-line monitoring device, an exhaust valve is arranged on the tool shell.

[0015] In another aspect, the application also provides a method for installing an acoustic sensor in a converter transformer, which comprises the following steps: closing an oil chromatograph valve arranged on an oil chromatograph interface of the converter transformer, and disconnecting the oil chromatograph interface from an oil chromatograph pipeline; installing the acoustic online monitoring device between the oil chromatograph interface and the oil chromatograph pipeline, and connecting and fixing two open ends of a tool shell of the acoustic online monitoring device to the oil chromatograph interface and the oil chromatograph pipeline respectively, to complete the installation of the acoustic online monitoring device; and opening the oil chromatograph valve, so that the insulating oil in the oil tank of the converter transformer flows through the acoustic online monitoring device and into the oil chromatograph pipeline, to monitor the acoustic partial discharge signal inside the converter transformer through the acoustic sensor of the online monitoring device, and monitor the oil chromatograph information of the converter transformer through the oil chromatograph monitor connected to the oil chromatograph pipeline.

[0016] The acoustic online monitoring device and the method for installing an acoustic sensor in a converter transformer provided by the application make full use of the necessary chromatograph pipeline interface of the converter transformer, and the oil chromatograph pipeline connection structure is reformed, so that the acoustic online monitoring device is installed between the oil chromatograph interface and the oil chromatograph pipeline without affecting the normal operation of the oil chromatograph device. In particular, the acoustic online monitoring device can be installed and removed online without affecting the normal operation of the converter transformer and the oil chromatograph device. The acoustic sensor assembly in the tool shell can effectively monitor the acoustic partial discharge signal inside the converter transformer, and significantly improve the sensitivity and monitoring coverage of the acoustic sensor assembly. The device realizes the communication between the built-in acoustic sensor and the converter transformer without changing the original structure of the converter transformer, can effectively sense the acoustic partial discharge signal inside the converter transformer, significantly improves the sensitivity and effective monitoring range of the acoustic sensor, solves the problem of lack of suitable installation position for the built-in acoustic sensor in the converter transformer in operation, and solves the problem that the installation of the built-in acoustic sensor in the existing converter transformer changes the original structure of the converter transformer, which poses a hidden danger to the safe operation of the converter transformer, and the converter transformer needs to be shut down and the oil needs to be removed for disassembly and replacement of the sensor when the sensor is damaged, which increases the inspection pressure of the converter transformer. In addition, the communication state between the built-in acoustic sensor device and the converter transformer can be adjusted through the oil chromatograph valve. When the oil chromatograph valve is closed, the acoustic online monitoring device can be removed for maintenance under the operating state of the converter transformer, which greatly reduces the influence of the acoustic online monitoring device on the reliable operation of the converter transformer. BRIEF DESCRIPTION OF DRAWINGS

[0017] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The accompanying drawings are included to provide a description of the preferred embodiments and are not intended to limit the scope of the application. Moreover, the same reference numerals are used throughout the same figures. In the drawings: Figure 1The exploded view of the acoustic online monitoring device provided by the embodiment of the present application is installed on the oil tank of the converter transformer; Figure 2 The structural schematic view between the acoustic online monitoring device provided by the embodiment of the present application and the oil tank of the converter transformer; Figure 3 The structural schematic view of the acoustic online monitoring device provided by the embodiment of the present application; Figure 4 The sectional view of the acoustic online monitoring device provided by the embodiment of the present application; Figure 5 The structural schematic view of the acoustic sensing assembly provided by the embodiment of the present application; Figure 6 The top view of the acoustic sensing assembly provided by the embodiment of the present application; Figure 7 The side view of the acoustic sensing assembly provided by the embodiment of the present application; Figure 8 The structural schematic view of the acoustic sensing fixing table provided by the embodiment of the present application; Figure 9 The flow chart of the method for adding the acoustic sensor to the converter transformer provided by the embodiment of the present application; Figure 10 The acoustic signal pulse waveform in the experimental verification of the acoustic online monitoring device provided by the embodiment of the present application; Figure 11 The average amplitude change graph of the acoustic signal in the experimental verification process of the acoustic online monitoring device provided by the embodiment of the present application; Mark explanation: 1-frock shell, 11-butted flange, 111-sealing groove, 12-extended channel, 13-supporting disc, 14-optical fiber through device, 15-supporting base, 151-table connecting hole, 2-acoustic sensing assembly, 21-acoustic sensing fixing table, 211-fixing supporting plate, 2111-groove, 2112-base connecting hole, 212-fixing connecting block, 2121-base connecting hole, 22-acoustic sensor, 23-pressing strip, 231-pressing fixing connecting hole, 3-oil chromatogram interface, 4-oil chromatogram pipeline, 5-oil chromatogram valve, 6-converter transformer oil tank, 7-exhaust valve. DETAILED DESCRIPTION

[0018] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it is to be understood that the present disclosure can be embodied in various forms without being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present disclosure to those skilled in the art. It should be noted that the embodiments in the present disclosure and the features in the embodiments can be combined with each other without conflict. The present disclosure will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

[0019] Device embodiments: Referring to Figures 1 to 4 , which shows the preferred structure of the acoustic online monitoring device provided by the embodiments of the present disclosure. As shown in the figure, the device comprises a tool shell 1 and an acoustic sensing assembly 2.

[0020] The tool shell 1 is hollow inside and open at both ends, and the two open ends are respectively detachably connected to the oil chromatography interface 3 and the oil chromatography pipeline 4 of the converter transformer, realizing the communication between the oil chromatography interface 3 and the oil chromatography pipeline 4, so that the insulating oil in the oil tank 6 of the converter transformer can flow through the oil chromatography interface 3 and the tool shell 1 in turn and flow into the oil chromatography pipeline 4.

[0021] Specifically, the tool shell 1 is a hollow long tube structure as a whole, and is made of Q235 carbon steel. The two ends of the tool shell 1 are open ends, and the two open ends can be provided with butt flanges 11 for detachable connection with the oil chromatographic interface 3 and the oil chromatographic pipeline 4 respectively. In the embodiment, the oil chromatographic interface 3 and the end of the oil chromatographic pipeline 4 can be provided with corresponding flange structures, and are detachably connected with the corresponding butt flanges 11 through bolts, so as to facilitate the online disassembly of the device. The two ends of the tool shell 1 are communicated with the oil chromatographic interface 3 and the oil chromatographic pipeline 4 respectively, the oil chromatographic interface 3 is detachably connected at the oil chromatographic connection hole of the converter transformer oil tank 6, and the oil chromatographic interface 3 and the oil chromatographic connection hole can be detachably connected through a flange interface. The corresponding flange structures on the oil chromatographic pipeline 4 and the oil chromatographic interface 3 are connected through bolts, and the flange interfaces on the two sides are matched, and the corresponding flange structures on the oil chromatographic pipeline 4 and the oil chromatographic interface 3 are also matched, and the two can be directly connected through bolts. In the embodiment, the oil chromatographic valve 5 is arranged on the oil chromatographic interface 3 to control the on-off of the oil chromatographic interface 3, thereby facilitating the disassembly of the device, especially the tool shell 1. In order to avoid leakage of insulating oil, preferably, a sealing groove 111 can be arranged at the butt joint surface of the butt flange 11 and the corresponding flange structure, and a sealing ring is arranged in the sealing groove 111. The sealing ring can be a rubber sealing ring. The cavity length between the two butt flanges 11 of the tool shell 1 can be 150 mm, or other gears, which are not limited in the embodiment. The butt flange 11 can be a dn50 flange, that is, a flange structure with an outer diameter of 50 mm.

[0022] The acoustic sensing assembly 2 is arranged in the tool shell 1 to monitor the acoustic partial discharge signal inside the converter transformer. Specifically, the acoustic sensing assembly 2 is arranged inside the tool shell 1, which can effectively monitor the acoustic partial discharge signal inside the converter transformer, and significantly improve the sensitivity and monitoring coverage of the acoustic sensing assembly 2. In the embodiment, in order to facilitate the installation of the acoustic sensing assembly 2, the tool shell 1 can be an axial split structure, that is, the tool shell 1 is divided into two parts along the axial cutting surface, and the two parts are detachably connected through bolts, and a sealing structure can be arranged at the connection. Of course, when the acoustic sensing assembly 2 is small, it can also be directly installed through the open end.

[0023] Continuing to refer to Figures 1 to 4 In the embodiment, the tool shell 1 is provided with an exhaust valve 7, which can be arranged at the top of the tool shell 1 to facilitate the exhaust of the tool shell 1. The tool shell 1 is provided with an exhaust hole with a hole diameter matched with the exhaust valve 7, and the exhaust hole and the exhaust valve 7 are welded by inner and outer full welding process.

[0024] Continuing to refer to Figures 1 to 4In this embodiment, to facilitate the transmission of signals acquired by the acoustic sensing component 2, preferably, the fixture housing 1 has an extension channel 12, and the end of the extension channel 12 is provided with a support plate 13, on which an optical fiber connector 14 is provided for the optical fiber connected to the acoustic sensor 22 to be led out. Specifically, the bottom of the fixture housing 1 may be provided with an extension channel 12 arranged perpendicular to the fixture housing 1 (e.g., Figure 3 The extension channel 12 (vertically arranged as shown) is connected to the tooling housing 1, and the extension channel 12 and the tooling housing 1 can be an integral structure. The bottom end of the extension channel 12 is an open end, equipped with a fiber optic through flange, that is, the open end is connected to the support plate 13 through the flange interface. The support plate 13 is a flange structure, which is bolted to the flange interface of the open end of the extension channel 12. The flange interface of the support plate 13, that is, the mating surface of the flange structure and the flange interface of the open end of the extension channel 12, has a sealing groove 111. A sealing ring is provided in the sealing groove 111 to achieve sealing at the connection and prevent leakage of insulating oil. For example, the connection between the flange 11 and the oil chromatography interface 3, and the oil chromatography pipeline 4 can also refer to the sealing structure of the flange structure and the flange interface of the open end of the extension channel 12 for sealing. In this embodiment, a mounting hole may be provided at the center of the support plate 13. The fiber optic connector 14 is detachably inserted through the mounting hole. The fiber optic connector also has a fiber optic mounting hole for the fiber optic cable from the acoustic sensing component 2, enabling the transmission of the fiber optic signal, i.e., the acoustic partial discharge signal inside the converter transformer. The mounting hole can be a threaded hole, i.e., it has an internal thread, and the outer wall of the fiber optic connector 14 has a matching external thread, connecting it to the mounting hole via threads. In this embodiment, a sealing ring may also be provided between the fiber optic connector 14 and the support plate 13.

[0025] See also Figure 4 To support and secure the acoustic sensing component 2, the tooling housing 1 preferably includes a support base 15 internally, which is detachably connected to the acoustic sensing component 2. Specifically, the two ends of the support base 15 can be connected to the inner wall of the tooling housing 1 by welding or other methods, particularly by full internal and external welding. The support base 15 can be a cuboid structure with a length of 60mm, a width of 40mm, and a height of 5mm. In this embodiment, the support base 15 may have a base connection hole 151 for connecting the acoustic sensing component 2.

[0026] See Figures 5 to 7The figure illustrates a preferred structure of the acoustic sensing component 2 provided in an embodiment of the present invention. As shown, the acoustic sensing component 2 includes: an acoustic sensing mounting platform 21, an acoustic sensor 22, and a pressure strip 23. The acoustic sensing mounting platform 21 is disposed within the tooling housing 1. The acoustic sensor 22 is disposed on the acoustic sensing mounting platform 21 and is used to monitor acoustic partial discharge signals inside the converter transformer; the pressure strip 23 is disposed on the acoustic sensing mounting platform 21, and the acoustic sensor 22 is sandwiched between the pressure strip 23 and the acoustic sensing mounting platform 21.

[0027] Specifically, the acoustic sensor mounting platform 21 can be bolted to the support base 15. The acoustic sensor 22 can be embedded in the top wall of the acoustic sensor mounting platform 21, and the acoustic sensor 22 is at least partially exposed, that is, exposed inside the tooling housing 1. There can be two pressure strips 23, which are respectively pressed and fixed to the left and right ends above the acoustic sensor 22 (relative to the left and right ends). Figure 5 (As shown in the diagram), the length of the pressure strip 23 can be greater than the width of the acoustic sensor 22, so that both ends press against the top wall of the acoustic sensor mounting platform 21, and the middle presses against the top wall of the acoustic sensor 22. Of course, there can also be a gap between the acoustic sensor 22 and the pressure strip 23; this embodiment does not impose any limitations on it. In this embodiment, both ends of the pressure strip 23 can be provided with clamping connection holes 231 for connecting bolts, so as to fix it to the top wall of the acoustic sensor mounting platform 21 by bolts, thereby fixing the pressure strip 23, and then clamping the acoustic sensor 22 onto the acoustic sensor mounting platform 21 by the pressure strip 23. That is, the acoustic sensor 22 is installed between the acoustic sensor mounting platform 21 and the pressure strip 23, and is clamped by the pressure strip 23. The acoustic sensor 22 can be a built-in fiber optic acoustic sensor 22 with a fully insulated structure, and the sensor volume can be 50mm long, 25mm wide, and 2mm high.

[0028] See also Figures 5 to 8 The acoustic sensor mounting platform 21 may include a fixed support plate 211 and a fixed connecting block 212; wherein, the top of the fixed support plate 211 is provided with a groove 2111 for supporting the acoustic sensor 22; the fixed connecting block 212 is disposed at the bottom of the fixed support plate 211 for detachably mounting on the inner wall of the tooling housing 1.

[0029] Specifically, the fixed support plate 211 is a plate structure, which is horizontally arranged. The top wall of the fixed support plate 211 is provided with a groove 2111 matched with the acoustic sensor 22, in particular, the depth of the groove 2111 can be matched with the thickness of the acoustic sensor 22, in particular, the depth of the groove 2111 can be matched with the thickness of the acoustic sensor 22, and the outer contour can also be matched, so that the acoustic sensor 22 can be placed in the groove 2111, and the top wall of the acoustic sensor 22 can be arranged flush with the top wall of the fixed support plate 211. The fixed support plate 211 can also be provided with a base connecting hole 2112, which can be four, corresponding to the base connecting hole 2112 provided on the two pressing strips 23 respectively, so as to be fixed by bolt connection. The fixed connecting block 212 can be a block structure, which is arranged below the fixed support plate 211, and the two can be connected as an integral structure by welding or other means. The fixed connecting block 212 is provided with a plurality of base connecting holes 2121 along the length direction (such as the horizontal direction shown in the figure) thereof, which correspond to the pedestal connecting holes 151 one by one, so as to be fixed by bolts, so that the acoustic sensor fixing table 21 can be fixedly installed on the support base 15. Figure 6

[0030] In this embodiment, the assembly process of the acoustic online monitoring device is as follows: first, the acoustic sensor 22 is installed on the acoustic sensor 22 fixing table, the pressing strip 23 is installed to fix the acoustic sensor 22, and the acoustic sensor 22 fixing table and the support base 15 at the cavity in the tool shell 1 are tightly connected by bolts; then, the acoustic sensor 22 signal line, i.e. the optical fiber, is led out through the optical fiber through-hole 14 at the support disc 13, the support disc 13, i.e. the optical fiber through-hole flange, is fixed to the bottom of the tool shell 1, the flange abutting surface is fixed by bolts, and the sealing groove 111 structure is arranged between the abutting flanges, which is matched with a complete set of sealing rings.

[0031] ​In summary, the acoustic online monitoring device provided in the embodiment makes full use of the chromatographic pipeline interface necessary on the converter transformer, transforms the connection structure of the oil chromatographic pipeline 4, and under the premise of not affecting the normal operation of the oil chromatographic device, communicates the oil chromatographic interface 3 and the oil chromatographic pipeline 4 by installing the tool shell 1 therebetween, and in particular, the acoustic online monitoring device can be installed and disassembled online without affecting the normal operation of the converter transformer and the oil chromatographic device, and the acoustic sensing assembly 2 in the tool shell 1 can effectively monitor the acoustic partial discharge signals inside the converter transformer, and significantly improve the sensitivity and monitoring coverage of the acoustic sensing assembly 2. The device realizes the communication between the built-in acoustic sensor 22 and the converter transformer body without changing the original structure of the converter transformer, can effectively sense the acoustic partial discharge signals inside the converter transformer, significantly improve the sensitivity and effective monitoring range of the acoustic sensor 22, solve the problem of lack of suitable installation position of the built-in acoustic sensor 22 on the running converter transformer, and solve the problem that the installation of the built-in acoustic sensor 22 on the existing converter transformer changes the original structure of the converter transformer, which poses a hidden danger to the safe operation of the converter transformer, and the sensor needs to be disassembled and replaced after the converter transformer is shut down and the oil is removed, which increases the operation and inspection pressure of the converter transformer. At the same time, the communication state between the built-in acoustic sensing device and the converter transformer can also be adjusted through the oil chromatographic valve 5. When the oil chromatographic valve 5 is closed, the acoustic online monitoring device can be disassembled and repaired under the running state of the converter transformer, which greatly reduces the influence of the acoustic online monitoring device on the reliable operation of the converter transformer.

[0032] Method embodiment Referring to Figure 6 which is a flow chart of the method for installing an acoustic sensor on a converter transformer provided in the embodiment. As shown in the figure, the method comprises the following steps: Step S1, close the oil chromatographic valve provided on the oil chromatographic interface of the converter transformer, and disassemble the oil chromatographic interface from the oil chromatographic pipeline.

[0033] In particular, the acoustic online monitoring device can be installed under the normal running state of the converter transformer, and the oil chromatographic valve 5 can be closed first, and the oil chromatographic valve 5 is separated from the oil chromatographic pipeline 4.

[0034] Step S2, install the acoustic online monitoring device between the oil chromatographic interface and the oil chromatographic pipeline, and connect and fix the two open ends of the tool shell of the acoustic online monitoring device with the oil chromatographic interface and the oil chromatographic pipeline respectively, and complete the installation of the acoustic online monitoring device.

[0035] Specifically, the two butt flanges 11 of the tool shell 1 at the two open ends are respectively connected with the flange of the oil chromatography valve 5 on the oil chromatography interface 3 and the flange of the oil chromatography pipeline 4 on the oil chromatography pipeline 4 through bolt fixation, and a sealing groove 111 structure is arranged between the butt surfaces to match a complete set of sealing rings.

[0036] Step S3, open the oil chromatography valve to make the insulating oil in the converter transformer tank flow into the oil chromatography pipeline through the acoustic online monitoring device, so as to online monitor the acoustic partial discharge signal inside the converter transformer through the acoustic sensor of the online monitoring device and online monitor the oil chromatography information of the converter transformer through the oil chromatography monitor connected by the oil chromatography pipeline.

[0037] Specifically, the oil chromatography valve 5 is opened, the insulating oil in the converter transformer tank 6 flows into the oil chromatography pipeline 4 through the tool shell 1, and the acoustic partial discharge sensor and the oil chromatography device work normally.

[0038] In this embodiment, test verification is carried out on a real converter transformer experimental platform, the acoustic online monitoring device can effectively perceive the defect partial discharge signal inside the converter transformer, the oil chromatography device can normally monitor the oil chromatography information, the acoustic signal pulse waveform can be as shown in Figure 10 , and the average amplitude change of the acoustic signal during the test process can be as shown in Figure 11 .

[0039] In this embodiment, the acoustic online monitoring device can be disassembled under the normal running state of the converter transformer, and the disassembly method can refer to the method of adding an acoustic sensor 22 to the converter transformer. The oil chromatography valve 5 is closed first, the optical fiber through flange at the bottom of the tool shell 1, i.e. the support disc 13, is removed, the tool shell 1 is disassembled after oil discharge; the oil chromatography pipeline 4 is reinstalled to the oil chromatography interface 3; the oil chromatography valve 5 is opened, and the oil chromatography device works normally.

[0040] In summary, the method for adding an acoustic sensor to the converter transformer provided in the embodiment makes full use of the necessary chromatography pipeline interface on the converter transformer, and the oil chromatography pipeline 4 connection structure is modified. On the premise of not affecting the normal operation of the oil chromatography device, the tool shell 1 is added between the oil chromatography interface 3 and the oil chromatography pipeline 4 to make them communicate, and the acoustic sensor assembly 2 inside the tool shell 1 is used to monitor the acoustic partial discharge signals inside the converter transformer. On the premise of not changing the original structure of the converter transformer, the built-in acoustic sensor 22 is connected to the converter transformer, which can effectively sense the acoustic partial discharge signals inside the converter transformer, significantly improve the sensitivity and effective monitoring range of the acoustic sensor 22, solve the problem of lack of suitable installation position of the built-in acoustic sensor 22 in the running converter transformer, and solve the problem of changing the original structure of the converter transformer to install the built-in acoustic sensor 22, which poses a hidden danger to the safe operation of the converter transformer, and the converter transformer needs to be shut down and the oil needs to be removed for disassembly and replacement when the sensor is damaged, which increases the inspection pressure of the converter transformer. At the same time, the communication state of the built-in acoustic sensor device and the converter transformer can also be adjusted through the oil chromatography valve 5. When the oil chromatography valve 5 is closed, the acoustic online monitoring device can be removed for maintenance under the running state of the converter transformer, which greatly reduces the influence of the acoustic online monitoring device on the reliable operation of the converter transformer.

[0041] It should be noted that in the description of the present application, the terms "upper", "lower", "left", "right", "inner", "outer" and the like indicate the direction or positional relationship of the terms based on the direction or positional relationship shown in the drawings, which is only for the convenience of description, and does not indicate or imply that the device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0042] In addition, it should be noted that in the description of the present application, unless otherwise specified and limited, the terms "mounting", "connecting", "connecting" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be directly connected, or indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0043] Obviously, those skilled in the art can make various modifications and variations to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application also intends to include these modifications and variations.

Claims

1. An acoustic on-line monitoring device, characterized in that It comprises: a tool shell, which is hollow inside and open at both ends, and the two open ends are respectively detachably connected to the oil chromatography interface and the oil chromatography pipeline of the converter transformer, so as to realize the communication between the oil chromatography interface and the oil chromatography pipeline, so that the insulating oil in the oil tank of the converter transformer can flow through the oil chromatography interface and the tool shell in turn and flow into the oil chromatography pipeline; an acoustic sensing assembly arranged in the tool shell for monitoring the acoustic partial discharge signal inside the converter transformer.

2. The acoustic on-line monitoring device according to claim 1, characterized in that The acoustic sensing assembly comprises: an acoustic sensing fixed table arranged in the tool shell; an acoustic sensor arranged on the acoustic sensing fixed table for monitoring the acoustic partial discharge signal inside the converter transformer; a pressing strip arranged on the acoustic sensing fixed table, and the acoustic sensor is clamped between the pressing strip and the acoustic sensing fixed table.

3. An acoustic on-line monitoring device according to claim 2, characterized in that The acoustic sensing fixed table comprises: a fixed support plate provided with a groove at the top for carrying the acoustic sensor; a fixed connecting block arranged at the bottom of the fixed support plate for detachable installation on the inner wall of the tool shell.

4. The acoustic online monitoring device according to any one of claims 1 to 3, wherein an extension channel is communicated on the tool shell, and an end of the extension channel is provided with a support disc, and an optical fiber through device is arranged on the support disc for leading out the optical fiber connected with the acoustic sensor.

5. The acoustic online monitoring device according to claim 4, wherein the support disc is a flange disc, and the end of the extension channel is detachably connected with the flange interface of the support disc.

6. The acoustic online monitoring device according to claim 5, wherein a sealing ring is arranged at the flange interface of the support disc, between the optical fiber through device and the support disc, and / or at the butt flange arranged at the two open ends of the tool shell.

7. The acoustic online monitoring device according to any one of claims 1 to 3, wherein a support base is arranged in the tool shell, and the acoustic sensing assembly is detachably connected between the support base.

8. The acoustic online monitoring device according to any one of claims 1 to 3, wherein butt flanges are arranged at the two open ends of the tool shell for respectively detachable connection with the oil chromatography interface and the oil chromatography pipeline.

9. An acoustic on-line monitoring device according to any one of claims 1 to 3, characterized in that an exhaust valve is arranged on the tool shell.

10. A method of retrofitting an acoustic sensor to a converter transformer, characterized by, It comprises the following steps: close the oil chromatography valve arranged on the oil chromatography interface of the converter transformer, and detach the oil chromatography interface from the oil chromatography pipeline; install the acoustic online monitoring device according to any one of claims 1 to 9 between the oil chromatography interface and the oil chromatography pipeline, and connect and fix the two open ends of the tool shell of the acoustic online monitoring device with the oil chromatography interface and the oil chromatography pipeline respectively, to complete the installation of the acoustic online monitoring device; open the oil chromatography valve, so that the insulating oil in the oil tank of the converter transformer flows through the acoustic online monitoring device and flows into the oil chromatography pipeline, so as to online monitor the acoustic partial discharge signal inside the converter transformer through the acoustic sensor of the online monitoring device, and online monitor the oil chromatography information of the converter transformer through the oil chromatography monitor connected with the oil chromatography pipeline.

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