Transformer partial discharge dynamic simulation electrode and simulation test device

Abstract

The invention discloses a transformer partial discharge dynamic simulation electrode and simulation test device, and the electrode comprises an electrode body, the end part of the electrode body extends to form a conical thorn part, and the cross section size of the conical thorn part is gradually reduced from the connection part of the conical thorn part and the electrode body to the end part until a tip is formed; the electrode body located at the cone thorn part is sleeved with an arc top piece in a sealing mode, a sealed cavity is formed between the arc top piece and the outer wall face of the cone thorn part, and the inner wall face of the arc top piece makes contact with the tip end. An air channel structure is formed in the electrode body, the outer end of the air channel structure communicates with an external air extractor, and the inner end of the air channel structure communicates with the cavity; in an actual test, the air extractor works to extract air into the cavity through the air passage structure, so that the arc top piece deforms towards the conical thorn part under the action of internal and external pressure difference until the arc top piece is attached to the conical thorn part, the continuous evolution process from the initial state of partial discharge to the final height sharpening into the sharp thorn is dynamically simulated, complete research on discharge is greatly facilitated, and the electrode is simple in structure and convenient to operate. Installation and use are convenient, and different test requirements are met.

Description

Technical Field

[0001] This invention relates to the field of power equipment testing devices, and in particular to a dynamic simulation electrode and simulation test device for partial discharge of transformers. Background Technology

[0002] Power transformers are critical equipment in power systems, and their stability is crucial to the safety of the entire power grid. Large transformers widely employ oil-paper composite insulation structures, which are susceptible to localized insulation defects during manufacturing, installation, and operation due to various factors. These defects can induce partial discharges in high electric fields. Continuous partial discharges lead to the gradual deterioration of the insulation material and eventual breakdown, causing significant safety failures.

[0003] Most internal defect discharges in transformers are not sudden. The basic process is as follows: Tiny metal burrs and edge warping formed during the manufacturing, assembly, or operational vibration and friction of components such as windings, cores, or switches are subjected to continuous weak partial discharge etching within the transformer's high electric and magnetic field environment. The high-energy electrons and ions generated by the discharge slowly corrode the surface of nearby metals and insulating materials, entering a vicious cycle of continuous deterioration of insulation performance. Eventually, this gradually "carves" sharper burrs or spherical protrusions, producing obvious partial discharges.

[0004] Therefore, effectively simulating the continuous dynamic process of insulation defects from initial weak partial discharge to obvious discharge after insulation deterioration and failure is beneficial for analyzing and summarizing the laws of discharge development and evolution. It is of key significance for identifying and blocking defects / faults, constructing active protection schemes, and ensuring the long-term safe and stable operation of equipment.

[0005] In existing technologies, while electrode structures such as needle-plate, needle-needle, or ball-plate can effectively simulate the discharge patterns of typical internal defects in transformers in traditional partial discharge tests, they still have significant limitations. The electrodes in existing partial discharge tests use fixed structures, which simplifies the simulation of the final morphology after insulation degradation and fails to reflect the dynamic process of continuous electrode morphology evolution in actual operation. Therefore, the discharge data obtained from existing partial discharge tests only represent the static characteristics of already formed sharp defects and cannot reflect the influence of gradual electrode morphology changes on discharge behavior during continuous insulation degradation, making it difficult to fully reveal the complete development law of partial discharge. Summary of the Invention

[0006] To address the aforementioned issues, this application provides a transformer partial discharge dynamic simulation electrode and simulation test device with a reasonable structure, thereby realizing the dynamic simulation of the continuous evolution process from the initial stage of partial discharge to the final highly sharpened spike, which greatly assists in the complete study of discharge. The electrode structure is simple, easy to install and use, and suitable for different test requirements.

[0007] The technical solution adopted in this invention is as follows: A transformer partial discharge dynamic simulation electrode includes an electrode body, the end of which extends to form a conical spike, the cross-sectional size of which gradually decreases from the connection point with the electrode body toward the end until it forms a sharp point; an arc-shaped top is sealed on the electrode body at the conical spike, and a sealed cavity is formed between the arc-shaped top and the outer wall of the conical spike, the inner wall of the arc-shaped top being in contact with the sharp point; an air passage structure is provided inside the electrode body, the outer end of which is connected to an external air extraction device, and the inner end of which is connected to the cavity.

[0008] As a further improvement to the above technical solution: The arc-shaped top component is made of a thin layer of metal. Under the action of the air extraction device, the arc-shaped top component deforms toward the cone-shaped part until it gradually approaches and fits. The arc-shaped top component has an outwardly convex smooth curved surface structure, and / or the outer wall surface of the cone-shaped part connecting the tip and the electrode body has an inwardly concave smooth curved surface structure.

[0009] The tip of the cone-shaped part is located in the axial direction of the electrode body, and the end of the arc-shaped part is located in the axial direction of the electrode body, with the tip contacting the inner side of the end of the arc-shaped part; the cone-shaped part and the arc-shaped part fitted onto the cone-shaped part form a mirror-symmetrical structure in any axial cross section.

[0010] The arc top component is integrally molded from copper foil using a rolling process, and the thickness of the arc top component is 0.1mm-0.3mm; the electrode body is made of copper rod to form a conical spike, and the radius of curvature of the tip of the spike is not greater than 0.3mm.

[0011] The axial dimension of the cone-shaped part from the connection point with the electrode body to the tip is consistent with the axial dimension of the arc-shaped part. The size of the opening end of the arc-shaped part is adapted to the cross-sectional size of the electrode body. The edge of the opening end of the arc-shaped part is attached to the connection point between the cone-shaped part and the electrode body. The arc-shaped part is formed by welding to create a sealed connection at the cone-shaped part.

[0012] The air passage structure has two or more air extraction ports facing the cavity, arranged at intervals along the circumference of the electrode body. The distance between the air extraction port and the tip in the axial direction of the electrode body is greater than 2 / 3 of the height of the cone in the axial direction of the electrode body.

[0013] The airway structure includes an axial airway opened along the axial center of the electrode body. The end of the axial airway facing the tip extends towards the outer wall of the cone-shaped part and has two or more branch airways. Each branch airway forms an air extraction port on the outer wall of the cone-shaped part. The end of the axial airway away from the tip connects to a concave structure opened on the end face of the electrode body. A plug is installed at the axial airway port in the concave structure. The axial airway runs radially through the electrode body to form a main airway, which is connected to an external air extraction device.

[0014] The inner diameter of the bronchial airway does not exceed 1 / 10 of the diameter of the electrode body, and the inner diameter of the axial airway is 1.5-2 times the inner diameter of the bronchial airway; the main airway connection is located at the center of the axial airway length, and the inner diameter of the main airway is the same as that of the axial airway.

[0015] The main air passage opening is provided with an internal thread one, and the internal thread one is used to install a connector and connect to an external air extraction device through a pipeline; the axial air passage opening is provided with an internal thread two, and a plug is fitted through the internal thread two; the diameter of the concave structure is 1 / 3 to 1 / 2 of the diameter of the electrode body, and the depth of the concave structure is 1 / 6 to 1 / 4 of the total length of the electrode body including the cone-shaped part.

[0016] A transformer partial discharge dynamic simulation test device includes a simulated electrode as described above, wherein a lead wire is installed at the end of the electrode body away from the tip of the simulated electrode via a connector; it also includes a circular plate electrode, one side of which is directly opposite the tip of the simulated electrode, and the center of the other side of which extends to form a connecting part, wherein a lead wire is installed at the connecting part via a connector; one of the lead wires is connected to an external excitation source to form a high-voltage end, and the other is connected to a ground wire to form a low-voltage end; the air passage structure is connected to an external air extraction device via a pipe.

[0017] Compared with the prior art, the present invention has the following beneficial effects: In actual testing, the present invention uses an air extraction device to extract air into the cavity through the air passage structure, causing the arc-shaped part to deform towards the cone-shaped part due to the internal and external pressure difference until it fits. This achieves dynamic simulation of the continuous evolution process from the initial form of partial discharge to the final sharpening into a spike, which greatly assists in the complete study of discharge. The electrode structure is simple, easy to process, install and use, and suitable for different test requirements. The present invention also includes the following advantages: As the air is pumped out, the arc-shaped top part gradually deforms toward the cone-shaped part, realizing the active change of the electrode end shape until the arc-shaped top part is completely attached to the cone-shaped part, achieving the final sharpening degree of the electrode tip, thereby effectively simulating the continuous evolution process from electrode formation to tip shape during the continuous partial discharge of insulation defects. By combining the continuous operation of the pumping device, the arc apex component is gradually deformed, thereby enabling the dynamic simulation electrode to actively and continuously simulate the changes in the physical morphology of the electrode without interrupting power. This achieves a realistic simulation of the actual evolution process of spike defects in partial discharge faults, effectively solving the problem of the one-sidedness of experimental data in existing static simulations based on fixed structure electrodes. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the simulated electrode of the present invention.

[0019] Figure 2 This is a schematic diagram of the structure of the electrode body of the present invention.

[0020] Figure 3 This is a schematic diagram of the state of the arc-shaped top component facing the electrode body in the initial stage of deformation during the experiment of this invention.

[0021] Figure 4 This is a schematic diagram showing the state of the arc-shaped apex component when it is deformed inward toward the electrode body during the experiment of this invention.

[0022] Figure 5 This is a schematic diagram showing the state of the arc-shaped top component deforming towards the electrode body and fitting together during the experiment of this invention.

[0023] Figure 6 This is a schematic diagram of the layout of the dynamic simulation test device of the present invention.

[0024] Among them: 1. Arc top component; 2. Electrode body; 3. Cavity; 20. Conical part; 21. External thread; 22. Internal concave structure; 23. Air passage structure; 24. Plug; 25. Connector; 26. Internal thread one; 27. Internal thread two; 231. Branch air passage one; 232. Branch air passage two; 233. Axial air passage; 234. Main air passage; 31. Connector 1; 32. Connector 2; 41. Plate electrode; 42. Connecting part; 51. Lead 1; 52. Lead 2; 6. Air extraction device; 61. Pipeline. Detailed Implementation

[0025] The specific embodiments of the present invention will now be described with reference to the accompanying drawings.

[0026] like Figure 1 and Figure 2 As shown, a transformer partial discharge dynamic simulation electrode of this embodiment includes an electrode body 2, with a conical spike 20 extending from the end of the electrode body 2. The cross-sectional size of the conical spike 20 gradually decreases from the connection point with the electrode body 2 toward the end until it forms a sharp point. An arc-shaped top 1 is provided on the electrode body 2 located at the conical spike 20. A sealed cavity 3 is formed between the arc-shaped top 1 and the outer wall of the conical spike 20. The inner wall of the arc-shaped top 1 is in contact with the sharp point. An air passage structure 23 is provided inside the electrode body 2. The outer end of the air passage structure 23 is connected to an external air extraction device 6, and the inner end of the air passage structure 23 is connected to the cavity 3.

[0027] In this embodiment, during the actual test, the air extraction device 6 works, drawing air into the cavity 3 through the air passage structure 23, causing the arc top part 1 to deform toward the cone 20 due to the internal and external pressure difference until it fits, realizing the dynamic simulation of the continuous evolution process from the initial form of partial discharge to the final height sharpening into a spike.

[0028] The dynamic simulation electrode in this embodiment includes an electrode body 2 and an arc-shaped top component 1 covering the outside of its cone-shaped spike 20, forming an integrated structure. This structure is not only easy to process, install, and use, but also helps to ensure the smooth and successful discharge test. It can also be applied to the dynamic partial discharge test requirements at different voltage levels and locations.

[0029] The arc top part 1 is made of a thin layer of metal. Under the action of the suction device 6, the arc top part 1 deforms toward the cone piercing part 20 until it gradually approaches and fits. By setting the arc top part 1 to be made of a thin layer of metal, it can be smoothly deformed and approach the cone piercing part 20 under the action of pressure difference, thus ensuring the smooth progress of the dynamic discharge test.

[0030] The arc-shaped top part 1 has an outwardly convex smooth curved surface structure, and / or the outer wall surface of the cone-shaped part 20 connecting the tip and the electrode body 2 has an inwardly concave smooth curved surface structure.

[0031] In this embodiment, by setting the arc top part 1 as an outwardly convex curved surface structure, the electrode shape in the early stage of partial discharge is effectively simulated. Combined with the concave curved surface structure and tip structure of the cone thorn part 20, the electrode shape in the later stage of partial discharge is effectively simulated, thereby realizing and ensuring the accuracy and authenticity of dynamic simulation.

[0032] In one embodiment, the arc top 1 is configured as an outwardly convex smooth curved surface structure, and the cone 20 is configured as an inwardly concave smooth curved surface structure connecting the electrode body 2 and the tip in the circumferential direction, so that when the arc top 1 finally fits towards the cone 20, it can effectively ensure the fit and guarantee the test results.

[0033] In this embodiment, the dynamic simulation electrode, while ensuring that the arc top part 1 and the cone burr part 20 are smooth curved surfaces, also needs to have its exposed edges rounded to avoid the presence of burrs and other defects that could affect the test results.

[0034] In one embodiment, the surface roughness of the arc-shaped top part 1 and the cone-shaped burr part 20 can be set, for example, not higher than 0.8 μm.

[0035] The tip of the cone-shaped part 20 is located in the axial direction of the electrode body 2, and the end of the arc-shaped part 1 is located in the axial direction of the electrode body 2. The tip of the arc-shaped part 1 contacts the inner side of the end of the arc-shaped part 1, so that the center of the end of the arc-shaped part 1 is accurately aligned with the tip of the cone-shaped part 20, avoiding significant offset and misalignment during the test and affecting the accuracy of the test, thus helping to ensure the smooth and successful conduct of the test.

[0036] The cone-shaped part 20 and the arc-shaped top part 1 fitted onto the cone-shaped part 20 form a mirror-symmetrical structure in any axial section, which effectively ensures the degree of fit when the arc-shaped top part 1 is attached to the cone-shaped part 20, and helps to meet and ensure the final curvature requirements of the electrode.

[0037] The arc top part 1 is integrally molded from copper foil by rolling, and the thickness of the arc top part 1 is 0.1mm-0.3mm; the electrode body 2 is made of copper rod to form a cone-shaped part 20, and the tip curvature radius of the cone-shaped part 20 is not greater than 0.3mm.

[0038] In this embodiment, the arc top part 1 is molded from copper foil, which is thin and effectively ensures that the arc top part 1 can smoothly deform and fit towards the cone-shaped part 20 under the action of internal and external pressure difference.

[0039] In this embodiment, by limiting the radius of curvature of the tip of the cone-shaped part 20 to no more than 0.3 mm, and combining this with the thickness limitation of the arc-shaped part 1, the electrode size at the tip can still be controlled within 0.6 mm after the arc-shaped part 1 is finally attached to the cone-shaped part 20, effectively ensuring that the final sharpness of the electrode in the dynamic test meets the size evaluation standard of the spike electrode.

[0040] In this embodiment, the arc top part 1 is integrally molded by calendering, which effectively ensures the smoothness of the surface of the arc top part 1 and avoids affecting the test due to the presence of protruding structures such as welds.

[0041] The axial dimension of the cone-shaped part 20 from the connection point with the electrode body 2 to the tip is consistent with the axial dimension of the arc-shaped part 1. The opening end dimension of the arc-shaped part 1 is adapted to the cross-sectional dimension of the electrode body 2. The edge of the opening end of the arc-shaped part 1 is attached to the connection point between the cone-shaped part 20 and the electrode body 2. The arc-shaped part 1 is welded to form a sealed connection at the cone-shaped part 20, which effectively ensures the sealing of the cavity 3.

[0042] In this embodiment, by setting the size of the opening end of the arc top component 1 to be compatible with and consistent with the cross-sectional size of the electrode body 2, the welding sealing quality of the arc top component 1 when it is welded to the cone-shaped burr portion 20 of the electrode body 2 is effectively guaranteed.

[0043] The air passage structure 23 has two or more air extraction ports facing the cavity 3, which are arranged at intervals along the circumference of the electrode body 2. The distance between the air extraction port and the tip in the axial direction of the electrode body 2 is greater than 2 / 3 of the height of the cone 20 in the axial direction of the electrode body 2.

[0044] In this embodiment, by opening the air extraction port away from the tip, it helps to ensure the integrity of the tip shape of the cone-shaped part 20.

[0045] The airway structure 23 includes an axial airway 233 opened along the axial center of the electrode body 2. The end of the axial airway 233 facing the tip extends toward the outer wall of the cone-shaped part 20 and has two or more branch airways. Each branch airway forms an air extraction port on the outer wall of the cone-shaped part 20. The end of the axial airway 233 away from the tip is connected to a concave structure 22 opened on the end face of the electrode body 2. A plug 24 is installed at the port of the axial airway 233 in the concave structure 22. The axial airway 233 passes through the electrode body 2 radially to form a main airway 234, which is connected to the external air extraction device 6.

[0046] In one embodiment, two or more branch air channels are evenly spaced in the circumferential direction with the axial direction of the electrode body 2 as the center, which effectively ensures the consistency of air being drawn into the cavity 3 through each air extraction port and ensures the stability of the deformation of the arc top component 1.

[0047] exist Figure 1 In the embodiment shown, the end of the axial airway 233 extends into two branch airways, namely branch airway 1 231 and branch airway 232. Branch airway 1 231 and branch airway 232 extend from the end of the axial airway 233 in opposite directions and connect to the outer wall of the cone-shaped part 20 and communicate with the cavity 3.

[0048] In this embodiment, the end of the axial air passage 233 extends into the concave structure 22 on the end face of the electrode body 2, which facilitates the processing of the axial air passage 233 on the electrode body 2. In actual use, the end of the axial air passage 233 located in the concave structure 22 is sealed with a plug 24. For the air extraction in this embodiment, the air passage structure 23 can be connected from the main air passage 234 to the axial air passage 233 and the branch air passage.

[0049] Of course, the through-type setting of the axial air passage 233 toward the concave structure 22 not only facilitates processing, but also allows for operations such as clearing blockages by extending the end of the plug 24 installed in the axial air passage 233 inward, according to actual needs.

[0050] The inner diameter of the bronchus does not exceed 1 / 10 of the diameter of the electrode body 2, and the inner diameter of the axial airway 233 is 1.5-2 times the inner diameter of the bronchus. The main airway 234 is connected at the center of the length of the axial airway 233, and the inner diameter of the main airway 234 is the same as that of the axial airway 233. Thus, while effectively realizing and ensuring the air extraction operation, the structural strength of the electrode itself is also effectively taken into account.

[0051] An internal thread 26 is provided at the orifice of the main air passage 234, and a connector 25 is installed through the internal thread 26 and connected to the external air extraction device 6 via a pipeline; an internal thread 27 is provided at the orifice of the axial air passage 233, and a plug 24 is fitted through the internal thread 27; the diameter of the concave structure 22 is 1 / 3 to 1 / 2 of the diameter of the electrode body 2, and the depth of the concave structure 22 is 1 / 6 to 1 / 4 of the total length of the electrode body 2 including the cone 20, so that the plug 24 can be effectively accommodated through the concave structure 22 without affecting the installation between the end of the dynamic simulation electrode and the external object.

[0052] In actual operation, the length of the internal thread 26 at the opening of the main air passage 234 can be set, for example, not less than 1 / 5 of the length of the main air passage 234, to ensure reliable installation between the main air passage 234 and the connector 25.

[0053] In this embodiment, an external thread 21 can be provided on the end of the electrode body 2 away from the tip, so that the dynamic simulation electrode can be easily adapted and installed in an external test scenario.

[0054] like Figure 1 , Figure 3 , Figure 4 , Figure 5 The diagram illustrates the dynamic change process of the simulated electrode. As the air is pumped out, the internal pressure of the cavity 3 gradually decreases. The arc-shaped part 1 is subjected to the pressure difference between the inside and outside and gradually deforms towards the cone-shaped part 20. This causes the shape of the simulated electrode to gradually change and become closer to the cone-shaped part, thus realizing the active change of the electrode end shape until the arc-shaped part 1 is completely attached to the cone-shaped part 20, achieving the final sharpening degree of the electrode tip. This effectively simulates the continuous evolution process of the electrode from formation to tip shape during the continuous partial discharge of insulation defects.

[0055] In actual operation, the evacuation speed of the external evacuation device 6 can be set according to different actual test requirements.

[0056] In this embodiment, by combining the continuous operation of the pumping device 6, the arc top component 1 is gradually deformed, thereby realizing that the dynamic simulation electrode can actively and continuously simulate the changes in the physical morphology of the electrode without interrupting power, realizing the actual evolution process of spike defects in partial discharge faults, and effectively solving the problem of the one-sidedness of the experimental data of existing static simulation based on fixed structure electrodes.

[0057] like Figure 6As shown, this embodiment also proposes a transformer partial discharge dynamic simulation test device, including any of the above-mentioned simulation electrodes. The electrode body 2 of the simulation electrode, which is far from the tip, is connected to a lead wire 51 via a connector 31. It also includes a circular plate electrode 41 with one side center facing the tip of the simulation electrode and the other side center extending to form a connecting part 42. The connecting part 42 is connected to a lead wire 52 via a connector 32. One of the lead wires 51 and 52 is connected to an external excitation source to form a high-voltage end, and the other is connected to a ground wire to form a low-voltage end, forming a needle-plate integrated test structure. The air passage structure 23 is connected to an external air extraction device 6 via a pipe 61.

[0058] In one embodiment, connector 31 and connector 32 can each adopt a sleeve structure; one end of connector 31 is screwed onto the end of electrode body 2, and the other end of connector 31 is pressed and fixed to lead wire 51; one end of connector 32 is screwed onto the connecting part 42 of plate electrode 41, and the other end of connector 32 is pressed and fixed to lead wire 52.

[0059] In this embodiment, the pipe 61 is made of hard metal and is connected to the air passage structure 23 via the connector 25, ensuring that the pipe 61 will not block the air extraction operation due to its own deformation during the test.

[0060] In actual operation, the needle-plate integrated test structure consisting of plate electrode 41 and dynamic simulation electrode can be fixedly installed by overlapping existing conventional insulating parts.

[0061] In this embodiment, the plate electrode 41 can adopt a conventional structure that meets the requirements of the discharge test, such as a rounded circular sheet structure.

[0062] In actual operation, the dynamic simulation electrode can be connected to the external excitation source via lead 1 51 to form a high voltage end, and the plate electrode 41 can be connected to the ground via lead 2 52 to form a low voltage end, according to the experimental requirements, to conduct dynamic simulation experiments; of course, it can also be the other way around, with the dynamic simulation electrode connected to the ground via lead 1 51 to form a low voltage end, and the plate electrode 41 connected to the external excitation source via lead 2 52 to form a high voltage end.

[0063] This invention enables dynamic simulation of the continuous evolution process from the initial stage of partial discharge to its final highly sharpened spikes, greatly contributing to the comprehensive study of discharge. The electrode structure is simple, easy to process, install and use, and suitable for different experimental needs.

[0064] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0065] The above description is an explanation of the present invention and not a limitation thereof. The scope of the present invention is defined by the claims. Within the scope of protection of the present invention, any form of modification may be made.

Claims

1. A transformer partial discharge dynamic simulation electrode, comprising an electrode body (2), characterized in that: The electrode body (2) extends to form a cone-shaped part (20) at its end. The cross-sectional size of the cone-shaped part (20) gradually decreases from the connection point with the electrode body (2) toward the end until it forms a tip. The electrode body (2) located at the cone-shaped part (20) is sealed with an arc-shaped top part (1). The arc-shaped top part (1) and the outer wall of the cone-shaped part (20) form a sealed cavity (3). The inner wall of the arc-shaped top part (1) is in contact with the tip. An air passage structure (23) is opened inside the electrode body (2). The outer end of the air passage structure (23) is connected to an external air extraction device (6), and the inner end of the air passage structure (23) is connected to the cavity (3).

2. The transformer partial discharge dynamic simulation electrode as described in claim 1, characterized in that: The arc top part (1) is made of a thin layer of metal. Under the suction action of the suction device (6), the arc top part (1) deforms toward the cone piercing part (20) until it gradually approaches and fits. The arc top part (1) has an outwardly convex smooth curved surface structure, and / or the outer wall surface of the cone piercing part (20) connected between the tip and the electrode body (2) has an inwardly concave smooth curved surface structure.

3. A transformer partial discharge dynamic simulation electrode as described in claim 1 or 2, characterized in that: The tip of the cone-shaped part (20) is located in the axial direction of the electrode body (2), and the end of the arc-shaped part (1) is located in the axial direction of the electrode body (2), with the tip contacting the inner side of the end of the arc-shaped part (1); the cone-shaped part (20) and the arc-shaped part (1) fitted on the cone-shaped part (20) form a mirror-symmetric structure in any axial section.

4. The transformer partial discharge dynamic simulation electrode as described in claim 2, characterized in that: The arc top part (1) is integrally molded from copper foil by rolling, and the thickness of the arc top part (1) is 0.1mm-0.3mm; the electrode body (2) is made of copper rod to form a cone-shaped part (20), and the radius of curvature of the tip of the cone-shaped part (20) is not greater than 0.3mm.

5. The transformer partial discharge dynamic simulation electrode as described in claim 1, characterized in that: The axial dimension of the cone-shaped part (20) from the connection point with the electrode body (2) to the tip is consistent with the axial dimension of the arc-shaped part (1). The opening end dimension of the arc-shaped part (1) is adapted to the cross-sectional dimension of the electrode body (2). The edge of the opening end of the arc-shaped part (1) is attached to the connection point between the cone-shaped part (20) and the electrode body (2). The arc-shaped part (1) is sealed at the cone-shaped part (20) by welding.

6. The transformer partial discharge dynamic simulation electrode as described in claim 1, characterized in that: The air passage structure (23) has two or more air extraction ports facing the cavity (3) arranged circumferentially along the electrode body (2). The distance between the air extraction port and the tip in the axial direction of the electrode body (2) is greater than 2 / 3 of the height of the cone (20) in the axial direction of the electrode body (2).

7. A transformer partial discharge dynamic simulation electrode as described in claim 1 or 6, characterized in that: The airway structure (23) includes an axial airway (233) opened along the axial center of the electrode body (2). The end of the axial airway (233) facing the tip extends towards the outer wall of the cone (20) with two or more branch airways. Each branch airway forms an air extraction port on the outer wall of the cone (20). The end of the axial airway (233) away from the tip is connected to the concave structure (22) opened on the end face of the electrode body (2). A plug (24) is installed at the port of the axial airway (233) in the concave structure (22). The axial airway (233) passes through the electrode body (2) radially to form a main airway (234). The main airway (234) is connected to the external air extraction device (6).

8. The transformer partial discharge dynamic simulation electrode as described in claim 7, characterized in that: The inner diameter of the bronchus does not exceed 1 / 10 of the diameter of the electrode body (2), and the inner diameter of the axial airway (233) is 1.5-2 times the inner diameter of the bronchus; the main airway (234) is connected at the center of the length of the axial airway (233), and the inner diameter of the main airway (234) is the same as the inner diameter of the axial airway (233).

9. The transformer partial discharge dynamic simulation electrode as described in claim 7, characterized in that: The main air passage (234) has an internal thread (26) at the opening, and the connector (25) is installed through the internal thread (26) and connected to the external air extraction device (6) via a pipeline; the axial air passage (233) has an internal thread (27) at the opening, and the plug (24) is fitted through the internal thread (27); the diameter of the concave structure (22) is 1 / 3 to 1 / 2 of the diameter of the electrode body (2), and the depth of the concave structure (22) is 1 / 6 to 1 / 4 of the total length of the electrode body (2), including the cone-shaped part (20).

10. A dynamic simulation test device for partial discharge of a transformer, characterized in that: The device includes a simulated electrode as described in any one of claims 1-9, wherein the electrode body (2) of the simulated electrode, which is far from the tip, is fitted with a lead wire (51) via a connector (31); it also includes a circular plate electrode (41), one side of which is directly opposite the tip of the simulated electrode, and the other side of which extends to form a connecting portion (42), wherein a lead wire (52) is fitted to the connecting portion (42) via a connector (32); one of the lead wires (51) and the lead wire (52) is connected to an external excitation source to form a high-pressure end, and the other is connected to a ground wire to form a low-pressure end; the air passage structure (23) is connected to an external air extraction device (6) via a pipe (61).

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