Insulated pull rod static load state simulation experiment device

Abstract

The application discloses an insulation pull rod static load state simulation experiment device, and belongs to the technical field of high-voltage electrical equipment detection and test. The device is provided with an air inlet and an air outlet; a mechanical stress loading module and an electric stress loading module are located in a sealed cavity, the mechanical stress loading module comprises two oppositely spaced metal discs and a force loading assembly connected between the two metal discs, and is used for applying axial pressure to an insulation pull rod assembly; the electric stress loading module comprises two lifting ring bolts, two first metal balls and one second metal ball; and a thermal stress loading module is used for heating the sealed cavity. The application has a compact structure, can realize superimposed and combined loading of electric stress, thermal stress and mechanical stress under static load conditions, and the stress is controllable and the loading is repeatable.

Description

Technical Field

[0001] This invention relates to the field of high-voltage electrical equipment testing and experimental technology, and in particular to an experimental device for simulating the static load state of an insulating tie rod. Background Technology

[0002] Insulating tie rods are crucial components in high-voltage circuit breakers and disconnectors, providing both operational force transmission and insulation isolation. During long-term operation, they simultaneously withstand multiple stresses, including electric fields, thermal fields, and mechanical loads. Current research, both domestically and internationally, largely focuses on experimental or simulation analyses of single stresses (electrical, thermal, or mechanical stress). However, under actual operating conditions, insulating tie rods are often subjected to the combined effects of multiple physical fields. This multi-field coupling significantly impacts insulation degradation and mechanical fatigue, contributing significantly to high-voltage equipment failures. Existing multi-physics experimental platforms are primarily used for transient studies of dynamic opening and closing processes, lacking experimental devices capable of accurately superimposing electro-thermal-mechanical stresses under long-term static load conditions. This hinders the controllable and repeatable loading of parameters such as the holding force, ambient temperature, and electric field strength of the insulating tie rod assembly. Summary of the Invention

[0003] This invention aims to at least partially solve one of the technical problems in related technologies. To this end, one objective of this invention is to provide an experimental device for simulating the static load state of an insulating tie rod, which has a compact structure and can achieve superimposed composite loading of electrical stress, thermal stress, and mechanical stress under static load conditions, with controllable stress and repeatable loading.

[0004] An experimental apparatus for simulating the static load state of an insulating tie rod according to an embodiment of the present invention includes:

[0005] A sealed cavity, wherein the sealed cavity is provided with an air inlet and an air outlet; A mechanical stress loading module, located within the sealed cavity, includes two metal discs arranged at relative intervals and a force loading assembly connected between the two metal discs. The force loading assembly is used to apply axial pressure to an insulating tie rod assembly sandwiched between the two metal discs. An electrical stress loading module includes two eye bolts, two first metal balls, and one second metal ball. The two eye bolts pass through the two metal discs respectively. One end of the two eye bolts is connected to both ends of an insulating tie rod assembly. The other end of the two eye bolts is fixed to the two first metal balls located in the sealed cavity respectively. The second metal ball is located outside the sealed cavity and is electrically connected to one of the first metal balls. A thermal stress loading module is used to heat the sealed cavity.

[0006] The loading principle of the static load state simulation experimental device for insulating tie rod in this embodiment of the invention is as follows: A constant axial load on the tie rod can be set through the force loading component to simulate the contact closing holding force. The high-voltage bushing is connected to the second metal ball, and voltage is introduced to the first metal ball. One of the first metal balls (such as the first metal ball at the upper end) is at a high potential, and the other first metal ball is grounded to form a stable electric field. The thermal stress loading module heats the high-voltage insulating gas in the cavity to form a temperature field, and the temperature control system can realize programmed temperature rise.

[0007] The static load simulation experimental device for insulating tie rods in this invention has the following advantages: First, it can simultaneously apply superimposed composite loading of electrical stress, thermal stress, and mechanical stress to the insulating tie rod assembly. Specifically, by setting up a sealed cavity and utilizing the coordinated mechanical stress loading module, electrical stress loading module, and thermal stress loading module, the insulating tie rod assembly can simultaneously withstand the high-voltage insulating gas environment simulated by the sealed cavity, the constant axial mechanical stress from the mechanical stress loading module, the power frequency high-voltage electric field stress applied by the electrical stress module, and the thermal stress applied by the thermal stress loading module through an adjustable temperature field. This achieves composite loading of the electrical, thermal, and mechanical fields, providing an experimental platform for studying the electrical performance, mechanical stability, and aging behavior of insulating tie rods in circuit breakers and disconnectors. Second, it simulates the actual operating conditions. Specifically, by introducing high-voltage insulating gas (such as sulfur hexafluoride) into a sealed cavity, it simulates the high-voltage, highly insulating environment of the real engineering operation of the insulating tie rod assembly, making the experimental environment close to the actual engineering operating conditions (such as the internal operating conditions of gas-insulated switchgear). The sealed cavity physically isolates the internal high-voltage insulating gas from the outside, preventing high-voltage insulating gas leakage and pollution, avoiding the threat of high voltage to operators, and ensuring experimental safety. Third, the stress parameters are controllable, ensuring experimental reliability. Specifically, the pressure of the mechanical stress loading module on the insulating tie rod assembly is adjustable, and the sealed cavity and thermal stress loading module achieve precise temperature setting and long-term stable maintenance. The electrical stress loading module controls the electric field strength on the first metal ball, ensuring that the experimental voltage parameters are controllable. In other words, the loading parameters (voltage, temperature, force) can be independently adjusted and maintained stably, and the experiment has strong repeatability and controllability. Fourth, it has a compact and integrated structure.

[0008] In some embodiments, the metal disk is a disc.

[0009] In some embodiments, the outer edge of the metal disk is provided with rounded corners.

[0010] In some embodiments, the force loading assembly includes insulating columns and threaded components. The insulating columns are evenly distributed circumferentially between two metal discs. The threaded components correspond one-to-one with the two ends of the insulating columns and pass through the corresponding metal discs to be threadedly connected to the insulating columns. The length of the insulating columns is less than the length of the insulating tie rod assembly.

[0011] In some embodiments, the mechanical stress loading module further includes an insulating plate, wherein another of the first metal balls is located within the insulating plate.

[0012] In some embodiments, one end of the eye bolt is connected to the end insert of the insulating tie rod assembly via a pin.

[0013] In some embodiments, the second metal ball is connected to the first metal ball by a metal rod passing through the wall of the sealed cavity, the outer periphery of the metal rod being wrapped with an insulating layer and fixed to the sealed cavity by a flange.

[0014] In some embodiments, the metal rod includes a first threaded rod and a second threaded rod, one end of the first threaded rod is fixed to one of the first metal balls, one end of the second threaded rod is fixed to the second metal ball, and the other end of the first threaded rod is threadedly engaged with the other end of the second threaded rod.

[0015] In some embodiments, the thermal stress loading module includes a heating element attached to the outer surface of the sealed cavity.

[0016] In some embodiments, the sealed cavity is provided with a pressure gauge and an observation window.

[0017] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the experimental device for simulating the static load state of an insulating tie rod according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the mechanical stress loading module according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the sealed cavity structure according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the mechanical force path of the insulating tie rod assembly according to an embodiment of the present invention.

[0019] Figure Labels The experimental device for simulating static load state of an insulating tie rod includes: a sealed cavity 1; a cavity shell 101; a top cover 102; an air inlet 103; an air outlet 104; an insulating layer 105; a flange 106; a pressure gauge 107; an observation window 108; an insulating plate 203; a mechanical stress loading module 2; a metal disc 201; a through hole 2011; a force loading component 202; an insulating column 2021; a threaded component 2022; an electrical stress loading module 3; a first metal ball 301; a second metal ball 302; a lifting eye bolt 303; a metal rod 304; a second threaded rod 3041; an insulating tie rod assembly 4; an end insert 401; and an insulating tube 402. Detailed Implementation

[0020] Embodiments of the present invention are described in detail below. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0021] The following is combined Figures 1 to 4 The present invention describes the static load state simulation experimental device 1000 for insulating tie rods according to an embodiment of the present invention.

[0022] The static load simulation experimental device 1000 for insulating tie rods is used to conduct experiments on the superimposed loading of electrical, thermal, and mechanical triple stresses on the insulating tie rod assembly 4 in equipment such as circuit breakers and disconnectors under static load conditions. It belongs to the experimental equipment technology for high voltage insulation performance evaluation and reliability research.

[0023] like Figures 1 to 4 As shown, the static load simulation experimental device 1000 for insulating tie rods in this embodiment of the invention includes a sealed cavity 1, a mechanical stress loading module 2, an electrical stress loading module 3, and a thermal stress loading module (not shown in the figure).

[0024] The sealed chamber 1 is also known as the high-voltage test chamber. The sealed chamber 1 is equipped with an air inlet 103 and an air outlet 104. The air inlet 103 and the air outlet 104 are used to control the entry and exit of insulating gas (such as sulfur hexafluoride) into and out of the sealed chamber 1. The sealed chamber 1 is used to simulate the high-voltage insulation environment of the actual operation of the insulating tie rod assembly 4, while preventing the impact on the external environment.

[0025] Specifically, the sealed cavity 1 is made of metal and includes a cavity shell 101 and a top cover 102. The top cover 102 is detachably fixed to the top opening of the cavity shell 101. More specifically, the cavity shell 101 is cylindrical, and the top cover 102 is disc-shaped. The top cover 102 and the cavity shell 101 are connected by fixing bolts.

[0026] The mechanical stress loading module 2 is located inside the sealed cavity 1 and includes two metal disks 201 arranged at relative intervals and a force loading assembly 202 connected between the two metal disks 201. The force loading assembly 202 is used to apply axial pressure to the insulating tie rod assembly 4 sandwiched between the two disks. The direction of the axial pressure is as follows: Figure 4 As shown. The force loading component 202 can precisely control the magnitude of the axial pressure applied to the insulating tie rod assembly 4. On the one hand, it can simulate the contact holding force under real working conditions, and on the other hand, it can test the deformation, strength, and insulation performance changes of the insulating tie rod assembly 4 under mechanical stress.

[0027] Specifically, the two metal discs 201 are arranged vertically at intervals, the insulating tie rod assembly 4 is arranged vertically and sandwiched between the two metal discs 201, and the force loading assembly 202 is connected between the two metal discs 201 to apply downward axial pressure to the insulating tie rod assembly 4.

[0028] The electrical stress loading module 3 includes two eye bolts 303, two first metal balls 301, and one second metal ball 302. The two eye bolts 303 pass through two metal discs 201 respectively. One end of each eye bolt 303 is connected to both ends of the insulating tie rod assembly 4, and the other end of each eye bolt 303 is fixed to the two first metal balls 301 located inside the sealed cavity 1. The second metal ball 302 is located outside the sealed cavity 1 and is electrically connected to one of the first metal balls 301. For example, the second metal ball 302 is located above the top cover 102 of the sealed cavity 1, and one of the first metal balls 301 is located... Figure 2 and Figure 4 The upper middle part, and another first metal ball 301 is located in Figure 2 and Figure 4 The lower middle part (obscured and not shown in the figure). The first metal ball 301 and the second metal ball 302 are copper balls. An external power supply can apply a power frequency high voltage to the second metal ball 302 through a high-voltage bushing (not shown in the figure), and the second metal ball 302 transmits the high voltage to one of the first metal balls 301 (i.e., Figure 2 and Figure 4 The first metal ball 301 located at the top is then transferred to the insulating tie rod assembly 4, so that the insulating tie rod assembly 4 is placed in a high voltage electric field to apply electrical stress to the insulating tie rod assembly 4, thereby testing the insulation withstand capability of the insulating tie rod assembly 4 (such as whether it breaks down, the size of the leakage current, etc.).

[0029] A thermal stress loading module (not shown in the figure) is used to heat the sealed cavity 1. The thermal stress loading module realizes temperature control, which can heat and control the temperature of the sealed cavity 1, so as to keep the insulating tie rod assembly 4 in a stable temperature field, so as to apply thermal stress to the insulating tie rod assembly 4 for testing the thermal performance of the insulating tie rod assembly 4.

[0030] The loading principle of the static load state simulation experimental device 1000 for insulating tie rod in this embodiment of the invention is as follows: A constant axial load on the tie rod can be set through the force loading component 202 to simulate the contact closing holding force. The high-voltage bushing is connected to the second metal ball 302, and voltage is introduced to the first metal ball 301. One of the first metal balls 301 (such as the first metal ball 301 at the upper end) is at a high potential, and the other first metal ball 301 is grounded to form a stable electric field. The thermal stress loading module heats the high-voltage insulating gas in the cavity to form a temperature field, and the temperature control system can realize programmed temperature rise.

[0031] The static load simulation experimental device 1000 for insulating tie rods in this embodiment of the invention has the following advantages: First, it can simultaneously apply superimposed composite loading of electrical stress, thermal stress, and mechanical stress to the insulating tie rod assembly 4. Specifically, by setting up a sealed cavity 1 and utilizing the mechanical stress loading module 2, the electrical stress loading module 3, and the thermal stress loading module in coordination, the insulating tie rod assembly 4 can simultaneously withstand the high-voltage insulating gas environment simulated by the sealed cavity 1, the constant axial mechanical stress of the mechanical stress loading module 2, the power frequency high-voltage electric field stress applied by the electrical stress loading module 3, and the thermal stress applied by the thermal stress loading module through an adjustable temperature field. This achieves composite loading of the three fields of electricity, heat, and force, providing an experimental platform for the study of the electrical performance, mechanical stability, and aging behavior of insulating tie rods in circuit breakers and disconnectors. Second, it simulates the actual operating conditions. Specifically, by introducing high-voltage insulating gas (such as sulfur hexafluoride) into the sealed cavity 1, it simulates the high-voltage, strong-insulation environment of the real engineering operation of the insulating tie rod assembly 4, making the experimental environment close to the actual engineering operating conditions (such as the internal operating conditions of gas-insulated switchgear). The sealed cavity 1 physically isolates the internal high-voltage insulating gas from the outside, preventing high-voltage insulating gas leakage and pollution, avoiding the threat of high voltage to operators, and ensuring experimental safety. Third, the stress parameters are controllable, ensuring experimental reliability. Specifically, the pressure of the mechanical stress loading module 2 on the insulating tie rod assembly 4 is adjustable, and the sealed cavity 1 and the thermal stress loading module achieve precise temperature setting and long-term stable maintenance. The electrical stress loading module 3 controls the electric field strength on the first metal ball 301, which can ensure that the experimental voltage parameters are controllable. In other words, the loading parameters (voltage, temperature, force) can be independently adjusted and maintained stably, and the experiment has strong repeatability and controllability. Fourth, it has a compact and integrated structure.

[0032] In some embodiments, such as Figure 2 and Figure 4 As shown, the metal disk 201 is a circular disk. The circular shape of the metal disk 201 is beneficial for uniform stress distribution and also facilitates processing.

[0033] In some embodiments, such as Figure 2 As shown, the outer edge of the metal disk 201 is rounded. The rounded corners on the outer edge of the metal disk 201 help suppress corona discharge.

[0034] In some embodiments, such as Figure 4 As shown, the metal disc 201 has a through hole 2011 in the middle for the eye bolt 303 to pass through. The eye bolt 303 passes through the through hole 2011, ensuring that high voltage electricity can be led from the second metal ball 302 to the insulating tie rod assembly 4, while also facilitating installation and creating a compact structure.

[0035] In some embodiments, such as Figure 2 and Figure 4 As shown, the force loading assembly 202 includes insulating posts 2021 and threaded components 2022. The insulating posts 2021 are evenly distributed circumferentially between two metal discs 201. The threaded components 2022 correspond one-to-one with the ends of the insulating posts 2021 and pass through the corresponding metal discs 201 to be threadedly connected to the insulating posts 2021. The length of the insulating posts 2021 is less than the length of the insulating tie rod assembly 4. The insulating posts 2021 are made of insulating material, providing structural support and electrical isolation. The threaded components 2022 (such as bolts) apply a preload to the insulating tie rod assembly 4 by connecting the metal discs 201 and the insulating posts 2021.

[0036] Specifically, because the length of the insulating column 2021 is manufactured to be less than the length of the insulating tie rod assembly 4, the two end faces of the insulating column 2021 do not contact the two metal discs 201, maintaining a gap, for example, a gap of 4-6 mm. When connected to the insulating column 2021 via the threaded fitting 2022, the two metal discs 201 press against the insulating tie rod assembly 4, applying a constant axial pressure to the insulating tie rod assembly 4. At this time, the insulating column 2021 only serves as a structural positioning and support function, and does not bear the surface pressure, i.e., the main compressive load. The mechanical stress applied to the insulating tie rod assembly 4 can be finely adjusted by precisely adjusting the torque of the threaded fitting 2022. In this way, by utilizing the difference in geometric dimensions, a constant and adjustable (by controlling the tightening torque) static mechanical load can be generated on the insulating tie rod assembly 4 without the need for complex external loading equipment. The structure is simple, reliable, and low in cost.

[0037] The following is a specific embodiment: Two metal discs 201 are 200 mm in diameter and 15 mm thick; the outer edge of the metal discs 201 is rounded with a 7.5 mm radius to suppress corona discharge; a 10 mm diameter hole is opened in the center for the eye bolt 303 to pass through; the insulating posts 2021 are four identical cylinders, each 205 mm long and 20 mm in diameter, with internal threads at both ends; correspondingly, four 8 mm threaded holes are pre-drilled on the two metal discs 201, distributed on a pitch circle with a radius of 70 mm, and arranged at 90° intervals. The central insulating tie rod assembly 4 has a total length of 210 mm, including an insulating tube 402 with a length of 130 mm and a diameter of 40 mm, and two end inserts 401 with a total length of 80 mm; the central insulating tie rod assembly 4 is 5 mm longer than the insulating posts 2021, thus forming a 5 mm mechanical preload difference to achieve a constant axial clamping force. By controlling the tightening torque of the threaded part 2022, the constant axial load on the insulating tie rod assembly 4 can be set to simulate the contact holding force under real working conditions.

[0038] In some embodiments, the mechanical stress loading module 2 further includes an insulating plate 203, wherein another first metal ball 301 is located within the insulating plate 203. The bottom of the insulating plate 203 is flat, so that the mechanical stress loading module 2 forms a stable platform and prevents shaking.

[0039] In some embodiments, one end of the eye bolt 303 is connected to the end insert 401 of the insulating tie rod assembly 4 via a pin (not shown). The pin connection is more convenient and has a more compact structure.

[0040] In some embodiments, the second metal ball 302 is connected to the first metal ball 301 via a metal rod 304 passing through the wall of the sealed cavity 1. The outer periphery of the metal rod 304 is wrapped with an insulating layer 105 and fixed to the sealed cavity 1 via a flange 106. The metal rod 304 is a conductor, and the insulating layer 105 can be wrapped with an insulating material such as epoxy resin for leakage protection. The flange 106 is used to securely seal and fix the entire bushing assembly to the cavity wall to prevent leakage of insulating gas.

[0041] In some embodiments, the metal rod 304 includes a first threaded rod (not shown) and a second threaded rod 3041. One end of the first threaded rod is fixed to one of the first metal balls 301, one end of the second threaded rod 3041 is fixed to the second metal ball 302, and the other end of the first threaded rod is threadedly engaged with the other end of the second threaded rod 3041. The use of a threaded connection between the first threaded rod and the second threaded rod 3041 facilitates manufacturing, assembly, and maintenance. The entire assembly constitutes a standard high-voltage bushing, ensuring that high voltage is safely introduced from the second metal ball 302 outside the cavity into the first metal ball 301302 inside the cavity.

[0042] In some embodiments, the thermal stress loading module includes a heating element (not shown in the figure), which is attached to the outer surface of the sealed cavity 1. Attaching the heating element to the outer wall of the cavity and heating the insulated tie rod static load simulation experimental device 1000 through heat conduction is a simple and effective heating method that does not occupy internal space and does not affect the internal electric field distribution.

[0043] In some embodiments, the sealed cavity 1 is equipped with a pressure gauge 107 and an observation window 108. The pressure gauge 107 is used to monitor the pressure inside the sealed cavity in real time to ensure that the experiment is carried out safely under the set pressure. The observation window 108 is used to conveniently observe the state of the insulating tie rod assembly 4 during the experiment, such as whether there is corona discharge, arcing, cracks or abnormal deformation.

[0044] The following reference Figures 1 to 4 The following is a specific method for using the static load simulation experimental device 1000 for insulating tie rods according to an embodiment of the present invention: Step 1: First, assemble and position the insulating column 2021 and the lower metal plate 201; Step 2: Install the center insulating tie rod assembly 4 and adjust the position of the upper metal disc 201; Step 3: Tighten the bolts diagonally to set the target holding force; Step 4: Connect the high-voltage line (the second metal ball 302 is at high potential, and the lower metal plate 201 is grounded). Step 5: After adjusting the temperature control system of the thermal stress loading module, start the test.

[0045] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A simulation experimental device for static load state of an insulating tie rod, characterized in that, include: A sealed cavity, wherein the sealed cavity is provided with an air inlet and an air outlet; A mechanical stress loading module, located within the sealed cavity, includes two metal discs arranged at relative intervals and a force loading assembly connected between the two metal discs. The force loading assembly is used to apply axial pressure to an insulating tie rod assembly sandwiched between the two metal discs. An electrical stress loading module includes two eye bolts, two first metal balls, and one second metal ball. The two eye bolts pass through two metal discs respectively. One end of each eye bolt is connected to both ends of an insulating tie rod assembly. The other ends of each eye bolt are fixed to two first metal balls located inside the sealed cavity. The second metal ball is located outside the sealed cavity and is electrically connected to one of the first metal balls. A thermal stress loading module is used to heat the sealed cavity.

2. The experimental apparatus for simulating the static load state of an insulating tie rod according to claim 1, characterized in that, The metal disk is a round disk.

3. The experimental apparatus for simulating the static load state of an insulating tie rod according to claim 2, characterized in that, The outer edge of the metal disk is rounded.

4. The experimental apparatus for simulating the static load state of an insulating tie rod according to claim 1, characterized in that, The force loading component includes insulating columns and threaded components. The insulating columns are evenly distributed circumferentially between the two metal discs. The threaded components correspond one-to-one with the two ends of the insulating columns and pass through the corresponding metal discs to be threadedly connected to the insulating columns. The length of the insulating columns is less than the length of the insulating tie rod assembly.

5. The experimental apparatus for simulating the static load state of an insulating tie rod according to claim 1, characterized in that, The mechanical stress loading module also includes an insulating plate, wherein another of the first metal balls is located inside the insulating plate.

6. The experimental apparatus for simulating the static load state of an insulating tie rod according to claim 1, characterized in that, One end of the eye bolt is connected to the end insert of the insulating tie rod assembly via a pin.

7. The experimental apparatus for simulating the static load state of an insulating tie rod according to claim 1, characterized in that, The second metal ball is connected to the first metal ball by a metal rod that passes through the wall of the sealed cavity. The outer periphery of the metal rod is wrapped with an insulating layer and fixed to the sealed cavity by a flange.

8. The experimental apparatus for simulating the static load state of an insulating tie rod according to claim 7, characterized in that, The metal rod includes a first threaded rod and a second threaded rod. One end of the first threaded rod is fixed to one of the first metal balls, one end of the second threaded rod is fixed to the second metal ball, and the other end of the first threaded rod is threadedly engaged with the other end of the second threaded rod.

9. The experimental apparatus for simulating the static load state of an insulating tie rod according to claim 1, characterized in that, The thermal stress loading module includes a heating element, which is attached to the outer surface of the sealed cavity.

10. The experimental apparatus for simulating the static load state of an insulating tie rod according to claim 1, characterized in that, The sealed cavity is equipped with a pressure gauge and an observation window.

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