Dry bushing test method, breakdown test structure, and flashover test structure
By designing a target test structure for dry bushings and simulating the fault occurrence process, the problem that existing test methods cannot reflect the fault characteristics of dry bushings was solved, and fault data acquisition and structural optimization were achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- WUHAN NARI LIABILITY OF STATE GRID ELECTRIC POWER RES INST
- Filing Date
- 2024-08-28
- Publication Date
- 2026-05-26
AI Technical Summary
Existing dry bushing testing methods cannot directly reflect their characteristics during failure, thus failing to provide a scientific basis for fault prevention and structural optimization.
The design and fabrication of the target test structure for dry bushings aims to obtain the state data of dry bushings during faults by simulating the actual fault occurrence process. This includes the design of test structures for radial breakdown and surface flashover of the core, and the use of the connection method of the conductor and the central guide rod to simulate the current path.
By simulating the fault process, the state data of the dry bushing during the fault is obtained, providing a basis for fault prevention and structural optimization, and reducing the manufacturing cost and cycle of the test structure.
Smart Images
Figure CN119199410B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of transformer bushing technology, specifically to a dry bushing test method, a breakdown test structure, and a flashover test structure. Background Technology
[0002] The operational reliability of bushings is directly related to the operational safety of large power grids and is one of the key pieces of equipment for developing high-voltage transmission and ensuring the safe and stable operation of power systems. In recent years, oil-impregnated paper bushings have experienced numerous defects such as poor sealing, abnormal oil chromatography, oil leakage, and combustion and explosion accidents, seriously affecting the safety and stability of the power grid and the reliability of power supply. The operational reliability and combustion and explosion characteristics of bushings have received great attention. As one of the main alternatives to oil-impregnated paper bushings, the number and proportion of dry bushings used are increasing year by year. Although existing transformer bushings require a series of tests before and after installation to ensure that their performance meets standards and requirements, such as dielectric loss testing, insulation resistance testing, AC withstand voltage testing, and DC withstand voltage testing, these tests cannot directly and specifically reflect the characteristics of dry bushings when faults occur, and therefore cannot provide a scientific basis for bushing fault prevention and structural optimization. Summary of the Invention
[0003] The problem to be solved by the present invention is to provide a dry bushing test method, a breakdown test structure and a flashover test structure. The dry bushing test method can simulate the actual occurrence process of the fault through the test, and then obtain the state data of the dry bushing during the fault, so as to provide a basis for dry bushing fault prevention and structural optimization.
[0004] To address the aforementioned technical problems, the present invention provides a method for testing dry bushings, comprising:
[0005] Based on the target fault to be analyzed in the dry bushing, design and fabricate the corresponding target test structure for the dry bushing;
[0006] The target test structure is used to conduct tests to simulate the actual occurrence process of the target fault, thereby analyzing the characteristics of the dry bushing when the target fault occurs.
[0007] In the above-mentioned dry bushing test method, the test structure is designed and manufactured according to the dry bushing fault, and the test is conducted to simulate the actual occurrence process of the fault. Then, the state data of the dry bushing during the fault is obtained, and the characteristics of the dry bushing during the fault are analyzed, so as to provide a basis for dry bushing fault prevention and structural optimization.
[0008] As an improvement to the dry bushing testing method of the present invention, when the target fault is radial breakdown of the core, the step of designing and fabricating the corresponding target test structure for the dry bushing based on the target fault to be analyzed includes:
[0009] On one side of the core of the dry bushing, a wire is used to pass radially through the insulation structure of the core to connect the central guide rod of the core to the outside of the core.
[0010] By connecting the central guide rod to the outside of the core with a wire, the current is directly passed through the insulation structure to form a conductive channel when the core of the dry bushing undergoes radial breakdown. The test structure of the dry bushing is ingeniously designed and easy to manufacture.
[0011] Furthermore, the step of using a wire to guide the central guide rod of the core to the outside of the core via a conductor passing radially through the insulation structure of the core on one side of the core of the dry bushing includes:
[0012] Remove the upper and lower umbrella skirts from the outside of the core of the dry sleeve;
[0013] A test hole is made radially on the core, with the bottom of the hole located on the central guide rod;
[0014] One end of the wire is extended to the bottom of the test hole, fixed to the central guide rod, and electrically connected, thus completing the design and fabrication of the target test structure for radial breakdown of the core.
[0015] By creating openings in existing dry bushings to place wires, the design and fabrication process is easy, and it significantly reduces the manufacturing cost and time required for experimental structural components.
[0016] Furthermore, the step of conducting experiments using the target test structure to simulate the actual occurrence process of the target fault includes:
[0017] Connect the other end of the wire and either end of the central guide rod to the test equipment for testing.
[0018] The other end of the conductor and either end of the central conductor rod serve as the input and output terminals, respectively. Either can be used as the input or output terminal; one can be used as the high-voltage or high-current input, and the other as grounded. The testing equipment has one high-voltage or high-current output terminal and one grounded terminal.
[0019] Preferably, before connecting the other end of the conductor and either end of the central guide rod to the test equipment for testing, the method further includes fixing the dry bushing through the flange of the dry bushing.
[0020] The test structure of the dry bushing is fixed in place by the flange, preferably in the installation state as it is in actual operation. This prevents the test structure from shaking during the test, which would affect the results, and also facilitates test wiring, monitoring and other operations.
[0021] Furthermore, the test hole is located on the side of the flange of the dry bushing near the upper terminal block.
[0022] Furthermore, one end of the wire is fixed to the central guide rod with a screw. The screw secures the wire to the central guide rod, ensuring a stable and reliable connection and electrical conductivity.
[0023] As another improvement to the dry bushing test method of the present invention, when the target fault is surface flashover, the step of designing and fabricating the corresponding target test structure for the dry bushing based on the target fault to be analyzed includes:
[0024] On the core surface of the dry bushing, a wire is used to electrically connect either the flange of the dry bushing and either end of the central guide rod of the core, and the main body of the wire is arranged in close contact with the outer surface of the core along the axial direction of the core.
[0025] By laying the conductor radially along the outer surface of the core and connecting one end of the central guide rod to the flange, the phenomenon of gas or liquid dielectric around the core being broken down and discharging along the surface of the core when a surface flashover occurs in a dry bushing is simulated.
[0026] Furthermore, the step of electrically connecting the flange of the dry bushing and either end of the central guide rod of the core body using a wire on the surface of the dry bushing core, wherein the main body of the wire is arranged axially along the outer surface of the core body, includes:
[0027] Remove the upper and lower umbrella skirts from the outside of the core of the dry sleeve;
[0028] One end of the conductor is fixed and electrically connected to the oil end terminal of the dry bushing, and the other end is fixed and electrically connected to the flange of the dry bushing. The main body of the conductor is laid on the surface of the core along the core axis; thus, the design and fabrication of the target test structure corresponding to surface flashover is completed.
[0029] By arranging wires on existing dry bushing products, the design and fabrication are easy, and the manufacturing cost and cycle of experimental structural components are greatly reduced.
[0030] Furthermore, the main body of the conductor is bonded and fixed to the surface of the core. Preferably, bonding points are evenly spaced along the main body of the conductor, and each bonding point is bonded and fixed to the surface of the core with epoxy adhesive.
[0031] Furthermore, the step of conducting experiments using the target test structure to simulate the actual occurrence process of the target fault includes:
[0032] Connect either end of the flange and the central guide rod to the test equipment for testing.
[0033] Either end of the flange and the central guide rod can serve as the input and output terminals, respectively. Either can be used as the input or output terminal; one can be used as the high-voltage or high-current input, and the other as grounded. The testing equipment has one high-voltage or high-current output terminal and one grounding terminal.
[0034] Preferably, before connecting either end of the flange and the central guide rod to the test equipment for testing, the method further includes: fixing the dry sleeve through the flange.
[0035] The test structure of the dry bushing is fixed in place by the flange, preferably in the actual working installation state. This prevents the test structure from shaking during the test, which would affect the results, and also facilitates test wiring, monitoring and other operations.
[0036] As an improvement to the dry bushing test method of the present invention, the step of conducting the test using the target test structure to simulate the actual occurrence process of the target fault and thereby analyze the characteristics of the dry bushing when the target fault occurs includes: analyzing the characteristics of the dry bushing when the target fault occurs by recording the state parameters during the dry bushing test.
[0037] Preferably, the state parameters include voltage, current, pressure, temperature, images, etc.
[0038] To address the aforementioned technical problems, another aspect of the present invention provides a breakdown test structure for use in the aforementioned dry bushing test method, comprising a core, a conductor, a flange, an upper terminal block, and an oil terminal block; the core includes a central guide rod and an insulating structure sleeved on the central guide rod; a test hole is radially formed on the core, the test hole passes through the insulating structure, and the bottom of the hole is located on the central guide rod; one end of the conductor extends to the bottom of the test hole, is fixed to the central guide rod, and is electrically conductive.
[0039] In the above-mentioned breakdown test structure, the central guide rod is connected to the outside of the core through a wire. When the dry bushing experiences radial breakdown of the core, the current directly passes through the insulation structure to form a conductive channel. Then, by loading the test, the occurrence of radial breakdown fault of the core can be simulated, and the characteristics of the dry bushing when radial breakdown of the core is analyzed. This provides a basis for dry bushing fault prevention and structural optimization. Moreover, the breakdown test structure is ingeniously designed and easy to manufacture.
[0040] To solve the above-mentioned technical problems, the present invention also provides a flashover test structure for the above-mentioned dry bushing test method, including a core, a wire, a flange, an upper terminal and an oil terminal; one end of the wire is fixed to the oil terminal and electrically conductive, and the other end is fixed to the flange and electrically conductive, and the main body is laid on the surface of the core along the axial direction of the core.
[0041] In the above-mentioned flashover test structure, by laying the conductor radially along the outer surface of the core and connecting one end of the central guide rod to the flange, the phenomenon of gas or liquid dielectric around the core being broken down and discharging along the surface of the core when a surface flashover occurs in a dry bushing is simulated. Furthermore, the occurrence of surface flashover can be simulated by test loading, and the characteristics of surface flashover in dry bushings can be analyzed, providing a basis for fault prevention and structural optimization of dry bushings. Moreover, this breakdown test structure is ingeniously designed and easy to manufacture.
[0042] In summary, by employing the aforementioned dry bushing test method, breakdown test structure, and flashover test structure, this dry bushing test method can simulate the actual fault occurrence process through testing, thereby obtaining the state data of the dry bushing during a fault, and providing a basis for dry bushing fault prevention and structural optimization. Attached Figure Description
[0043] In the attached diagram:
[0044] Figure 1 This is a flowchart of the dry sleeve test method of the present invention.
[0045] Figure 2 This is a schematic diagram of the breakdown test structure of the present invention.
[0046] Figure 3 This is a schematic diagram of the flashover test structure of the present invention.
[0047] In the diagram, 1 is the core; 11 is the central guide rod; 12 is the insulation structure; 13 is the test hole; 2 is the wire; 3 is the flange; 4 is the upper terminal; and 5 is the oil terminal. Detailed Implementation
[0048] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings. It should be noted that these descriptions of the embodiments are for the purpose of helping to understand the present invention, but do not constitute a limitation thereof.
[0049] Example 1
[0050] Figure 1 This invention illustrates a dry bushing testing method. In this embodiment, the target fault to be analyzed in the dry bushing is radial breakdown of the core, such as... Figure 1 As shown, the dry casing test method includes the following steps S10 and S20.
[0051] Radial breakdown of the core is a relatively serious type of transformer fault. Its causes can involve multiple factors, such as the aging of the insulation material during long-term use, which significantly reduces insulation strength. Overvoltage and overcurrent are among the main causes of transformer bushing breakdown. When the strength of the insulating medium is insufficient to withstand the voltage, an electric arc may penetrate the bushing surface, leading to radial breakdown. For example, when the transformer is affected by external factors such as lightning strikes or operational errors, overvoltage or overcurrent may occur, impacting the bushing.
[0052] Step S10: Based on the target fault to be analyzed in the dry bushing, design and fabricate the corresponding target test structure for the dry bushing.
[0053] Combined with appendix Figure 2 First, the target test structure is designed and fabricated to simulate the radial breakdown of the core of a dry bushing, where current directly passes through the insulation structure 12 to form a conductive channel. Specifically, it only needs to meet the following structural requirements: On one side of the core 1 of the dry bushing, a wire 2 is used to radially pass through the insulation structure 12 of the core 1, connecting the central guide rod 11 of the core 1 to the outside of the core 1. Many structures can meet the above requirements; a feasible design and fabrication process is given below, including steps a1-a3.
[0054] Step a1: Remove the upper and lower umbel skirts from the outside of the core 1 of the dry bushing. Use an existing dry bushing as the raw material, removing the upper and lower umbel skirts to facilitate subsequent processing. Furthermore, these two structures are not needed during the simulated radial breakdown test of the core.
[0055] Step a2: Make a test hole 13 radially on the core 1, with the bottom of the hole located on the central guide rod 11.
[0056] The test hole 13 allows the insulation structure 12 to pass radially through the core 1. The insulation structure 12 is generally a layered structure, including layers of insulating material and a shielding layer. The insulating material can be epoxy resin, glass fiber, resin-impregnated paper, etc., and the shielding layer can be aluminum foil, copper foil, etc. The central guide rod 11 can be a copper rod, etc. These structures can be processed by drilling to obtain the test hole 13. Alternatively, a hole can be pre-drilled during the production of the dry bushing as the test hole 13. The diameter of the test hole 13 should be as small as possible, provided it can accommodate the conductor 2.
[0057] In addition, the test hole 13 can theoretically be opened at any radial position, since the radial breakdown of the core can occur at any position. However, for the convenience of actual processing, it can be determined that the test hole 13 is opened on the side of the flange 3 near the upper terminal 4, with a larger processing surface, so that the distance between the test hole 13 and the flange 3 is 20-60mm.
[0058] Step a3: Extend one end of the wire 2 to the bottom of the test hole 13, fix it to the central guide rod 11 and make it electrically conductive, thus completing the design and fabrication of the target test structure for radial penetration of the core.
[0059] For better simulation results, the smaller the diameter of the wire 2, the better; for example, a copper wire with a diameter of 0.5 mm can be used. After fixing one end of the wire 2 to the central guide rod 11, the test hole 13 can be filled with insulating material, taking care to ensure that the portion of the wire 2 inside the hole runs radially along the core 1.
[0060] In addition, in order to better achieve a fixed connection between one end of the wire 2 and the central guide rod 11, one end of the wire 2 can be fixed with a screw first, and then the screw can be inserted into the test hole 13 and tightened to fix it on the central guide rod 11. This is convenient to operate, and the fixing and electrical conduction structure is stable and reliable.
[0061] Step S20: Conduct tests using the target test structure to simulate the actual occurrence process of the target fault, thereby analyzing the characteristics of the dry bushing when the target fault occurs. The test is conducted using the pre-fabricated test structure for radial breakdown faults in the core, specifically including the following steps b1 and b2.
[0062] Step b1: Secure the dry bushing using flange 3. Secure the test structure of the dry bushing using flange 3, ideally maintaining its actual working installation position. This prevents the test structure from shaking during testing, which could affect the results, and also facilitates test wiring, monitoring, and other operations.
[0063] Step b2: Connect the other end of the wire 2 and any end of the central guide rod 11 to the test equipment for testing.
[0064] Since the other end of conductor 2 and either end of the central guide rod 11 serve as the input and output terminals respectively, either can be used as the input or output terminal; one can be used as the input for high voltage or high current, and the other can be grounded. The test equipment has a high voltage or high current output terminal and a grounding terminal. Therefore, by connecting the other end of conductor 2 and either end of the central guide rod 11 to the test equipment, the test can be conducted.
[0065] In addition, to analyze the characteristics of a dry bushing when a radial breakdown fault occurs in the core, it is necessary to connect monitoring equipment during the experiment and record the state parameters of the dry bushing during the test, such as voltage, current, pressure, temperature, and images, in order to analyze the characteristics of the dry bushing when the target fault occurs.
[0066] Example 2
[0067] The target fault to be analyzed in the dry bushing of this embodiment is surface flashover. The dry bushing test method includes the following steps P10 and P20.
[0068] Surface flashover is also a relatively serious type of transformer fault. Under high voltage, the discharge along the surface of the insulator is called flashover. Surface flashover is most severe when the environment is humid and heavily polluted.
[0069] Step P10: Based on the target fault to be analyzed in the dry bushing, design and fabricate the corresponding target test structure for the dry bushing.
[0070] Combination Figure 3 First, the target test structure is designed and fabricated to simulate the phenomenon where, during a surface flashover of a dry bushing, the gas or liquid dielectric surrounding the core 1 is broken down, resulting in discharge along the surface of the core 1. Specifically, the following structural requirements need to be met: On the surface of the core 1 of the dry bushing, a conductor 2 is used to electrically connect either the flange 3 of the dry bushing or one end of the central guide rod 11 of the core 1, with the main body of the conductor 2 axially attached to the outer surface of the core 1. Many structures can meet these requirements; a feasible design and fabrication process is given below, including steps c1 and c2.
[0071] Step c1: Remove the upper and lower umbel skirts from the outside of the core 1 of the dry bushing. Use an existing dry bushing as the raw material, removing the upper and lower umbel skirts to facilitate subsequent processing. Furthermore, these two structures are not needed during the simulated surface flashover test.
[0072] Step c2: Fix one end of the wire 2 to the oil end terminal 5 of the dry bushing and make it electrically conductive, and fix the other end to the flange 3 of the dry bushing and make it electrically conductive. The main body of the wire 2 is laid on the surface of the core 1 along the axial direction of the core 1; that is, the design and fabrication of the target test structure corresponding to the surface flashover is completed.
[0073] One end of the wire 2 can be fixed to the oil terminal 5 by screwing it in, and the other end can be fixed to the flange 3 by welding. During the laying of the wire 2, it is fixed with epoxy adhesive at certain intervals. For better simulation effect, the smaller the diameter of the wire 2, the better. For example, a copper wire with a diameter of 0.5mm can be used.
[0074] Step P20: Conduct tests using the target test structure to simulate the actual occurrence process of the target fault, thereby analyzing the characteristics of the dry bushing when the target fault occurs. The test is conducted using the pre-fabricated surface flashover fault test structure, specifically including the following steps d1 and d2.
[0075] Step d1: Secure the dry bushing using flange 3. Secure the test structure of the dry bushing using flange 3, ideally maintaining its actual working installation position. This prevents the test structure from shaking during testing, which could affect the results, and also facilitates test wiring, monitoring, and other operations.
[0076] Step d2: Connect either end of flange 3 and center guide rod 11 to the test equipment for testing.
[0077] Since the other end of conductor 2 is connected to flange 3, either flange 3 or the center guide rod 11 can be used as the input and output terminals, respectively. It doesn't matter which one is used as the input or output terminal; one can be used as the high-voltage or high-current input, and the other as ground. The test equipment has a high-voltage or high-current output terminal and a grounding terminal. Therefore, by connecting either flange 3 or the center guide rod 11 to the test equipment, the test can be performed.
[0078] In addition, to analyze the characteristics of a dry bushing when it experiences a surface flashover fault, it is necessary to connect monitoring equipment during the experiment and record the state parameters of the dry bushing during the test, such as voltage, current, pressure, temperature, and images, in order to analyze the characteristics of the dry bushing when it experiences the target fault.
[0079] Example 3
[0080] Figure 2 This invention illustrates a breakdown test structure for the dry bushing test method of Embodiment 1 described above, comprising a core 1, a conductor 2, a flange 3, an upper terminal block 4, and an oil terminal block 5. The core 1 includes a central guide rod 11 and an insulating structure 12 sleeved on the central guide rod 11. A test hole 13 is radially formed on the core 1, passing through the insulating structure 12, with the bottom of the hole located on the central guide rod 11. One end of the conductor 2 extends to the bottom of the test hole 13, is fixed to the central guide rod 11, and is electrically connected. The two ends of the central guide rod 11 are electrically connected to the upper terminal block 4 and the oil terminal block 5, respectively.
[0081] During the test, the other end of the conductor 2 and any end of the central guide rod 11 are connected to the test equipment, and the monitoring equipment is connected to obtain the state parameters such as voltage, current, pressure, temperature, and images of the dry bushing. Then, high voltage or high current is applied through the test equipment to simulate the radial breakdown fault of the dry bushing core, and the state parameters in the actual process are obtained. Then, the characteristics of the dry bushing core radial breakdown are analyzed, providing a basis for dry bushing fault prevention and structural optimization.
[0082] Example 4
[0083] Figure 3This invention illustrates a flashover test structure for the dry bushing test method of Embodiment 2 described above, comprising a core 1, a conductor 2, a flange 3, an upper terminal block 4, and an oil terminal block 5. One end of the conductor 2 is fixed to and electrically connected to the oil terminal block 5, and the other end is fixed to and electrically connected to the flange 3. The main body is laid axially along the surface of the core 1. The core 1 includes a central guide rod 11 and an insulating structure 12 sleeved on the central guide rod 11. The two ends of the central guide rod 11 are electrically connected to the upper terminal block 4 and the oil terminal block 5, respectively.
[0084] During the test, either end of flange 3 and center guide rod 11 is connected to the test equipment, and monitoring equipment is connected to obtain the state parameters of the dry bushing, such as voltage, current, pressure, temperature, and images. Then, high voltage or high current is applied through the test equipment to simulate the surface flashover fault of the dry bushing, and the state parameters in the actual process are obtained. The characteristics of the dry bushing when it experiences surface flashover are then analyzed, providing a basis for dry bushing fault prevention and structural optimization.
[0085] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit its scope of protection. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that after reading the present invention, they can still make various changes, modifications or equivalent substitutions to the specific implementation of the invention, but these changes, modifications or equivalent substitutions are all within the scope of protection of the pending claims of the invention.
Claims
1. A method for testing dry casing, characterized in that, include: Based on the target fault to be analyzed in the dry bushing, design and fabricate the corresponding target test structure for the dry bushing; The target test structure is used to conduct tests to simulate the actual occurrence process of the target fault, thereby analyzing the characteristics of the dry bushing when the target fault occurs. In the case where the target fault is radial breakdown of the core, the step of designing and fabricating the corresponding target test structure for the dry bushing based on the target fault to be analyzed includes: On one side of the core (1) of the dry bushing, a wire (2) is used to pass through the insulation structure (12) of the core (1) radially along the core (1) to conduct the central guide rod (11) of the core (1) to the outside of the core (1).
2. The dry casing test method according to claim 1, characterized in that, The method of using a wire (2) to pass radially through the insulation structure (12) of the core (1) on one side of the core (1) of the dry bushing to conduct the central guide rod (11) of the core (1) to the outside of the core (1) includes: Remove the upper and lower umbrella skirts from the outside of the core (1) of the dry sleeve; A test hole (13) is made radially on the core (1), with the bottom of the hole located on the central guide rod (11); One end of the wire (2) is extended to the bottom of the test hole (13) and fixed to the central guide rod (11) and electrically connected.
3. The dry sleeve test method according to claim 2, characterized in that, The step of conducting experiments using the target test structure to simulate the actual occurrence process of the target fault includes: Connect the other end of the wire (2) and any one end of the central guide rod (11) to the test equipment for testing.
4. The dry casing test method according to claim 2, characterized in that, The test hole (13) is located on the side of the flange (3) of the dry bushing near the upper terminal (4).
5. The dry casing test method according to claim 1, characterized in that, In the case that the target fault is a surface flashover, the step of designing and fabricating the corresponding target test structure for the dry bushing based on the target fault to be analyzed includes: On the surface of the core (1) of the dry bushing, a wire (2) is used to electrically connect the flange (3) of the dry bushing and either end of the central guide rod (11) of the core (1), and the main body of the wire (2) is arranged in close contact with the outer surface of the core (1) along the axial direction of the core (1).
6. The dry casing test method according to claim 5, characterized in that, The method of electrically connecting the flange (3) of the dry bushing and either end of the central guide rod (11) of the core (1) of the core (1) using a wire (2) on the surface of the core (1) of the dry bushing, and the main body of the wire (2) being arranged in axial fit on the outer surface of the core (1) includes: Remove the upper and lower umbrella skirts from the outside of the core (1) of the dry sleeve; One end of the wire (2) is fixed and electrically connected to the oil end terminal (5) of the dry bushing, and the other end is fixed and electrically connected to the flange (3) of the dry bushing. The main body is laid on the surface of the core (1) along the axial direction of the core (1).
7. The dry casing test method according to claim 6, characterized in that, The step of conducting experiments using the target test structure to simulate the actual occurrence process of the target fault includes: Connect either end of the flange (3) or the center guide rod (11) to the test equipment for testing.
8. The dry casing test method according to claim 1, characterized in that, The process of conducting tests using the target test structure to simulate the actual occurrence of the target fault, and thereby analyzing the characteristics of the dry bushing when the target fault occurs, includes: By recording the state parameters during the dry bushing test, the characteristics of the dry bushing when the target fault occurs are analyzed.
9. A breakdown test structure for use in the dry sleeve test method according to any one of claims 1-4, characterized in that, It includes a core (1), a wire (2), a flange (3), an upper terminal (4), and an oil terminal (5); the core (1) includes a central guide rod (11) and an insulating structure (12) sleeved on the central guide rod (11); a test hole (13) is opened radially on the core (1), the test hole (13) passes through the insulating structure (12), and the bottom of the hole is located on the central guide rod (11); one end of the wire (2) extends to the bottom of the test hole (13), is fixed to the central guide rod (11), and is electrically conductive.
10. A flashover test structure for use in the dry bushing test method according to any one of claims 5-7, characterized in that, It includes a core (1), a wire (2), a flange (3), an upper terminal (4), and an oil terminal (5); one end of the wire (2) is fixed to the oil terminal (5) and electrically connected, and the other end is fixed to the flange (3) and electrically connected. The main body is laid on the surface of the core (1) along the axial direction of the core (1).