Power frequency withstand voltage test device and test method for impregnated paper sleeve core body

Abstract

The invention discloses a power frequency withstand voltage test device and test method for a glue impregnated paper sleeve core body, and relates to the technical field of electric power facilities. The power frequency withstand voltage test device for the impregnated paper sleeve core comprises an insulating workbench, a first electrode, a second electrode, a first conductive bead layer, a second conductive bead layer, a vertical supporting module and a pressing module, a first cavity and a second cavity are formed in the insulating workbench; the top end of the first cavity can communicate with the bottom end of the inner ring gap, and the top end of the second cavity can communicate with the bottom end of the outer ring gap. A first lifting plate is arranged in the first cavity; and a second lifting plate is arranged in the second cavity. The first lifting plate can push the first conductive bead layer to rise and fill the inner ring gap, and the second lifting plate can push the second conductive bead layer to rise and fill the outer ring gap; therefore, the number of electric shock points on the inner and outer side walls of the tested core body is increased; therefore, the problems of incomplete detection area and large detection blind area caused by single-point / strip-shaped contact in the prior art are avoided.

Description

Technical Field

[0001] This invention relates to the field of power facility technology, specifically to a power frequency withstand voltage test device and test method for resin-impregnated paper sleeve cores. Background Technology

[0002] Insulating bushings are mainly used in power systems (such as generators, transformers, reactors, power switches, etc.) as insulation protection devices for wires (cables).

[0003] Insulating bushings are classified according to their core material into gas-impregnated bushings, oil-impregnated paper bushings, adhesive-bonded paper bushings, and resin-impregnated paper bushings. Among them, resin-impregnated paper bushings (also known as epoxy resin impregnated paper bushings) have a paper core impregnated with curable resin as the insulating core, which has excellent insulation properties as well as flame-retardant and explosion-proof properties.

[0004] Before assembling the insulating core, different voltages need to be applied to the inner and outer walls of the core to create a voltage force difference, thereby conducting a withstand voltage test. Existing technology typically inserts cylindrical electrodes into the inner cavity of the core. However, due to dimensional errors during the manufacturing process (such as uneven curing, wear, cutting, etc.), it is difficult for the cylindrical surface of the cylindrical electrode to fit snugly against the cylindrical surface of the inner cavity of the core. That is, it can only achieve single-point or strip contact (and cannot achieve multi-point contact and testing), resulting in a small and incomplete detection area and a large detection blind zone. Summary of the Invention

[0005] To overcome the problem of "inability to achieve multi-point contact between electrodes and core" in the above-mentioned background technology, the present invention provides a power frequency withstand voltage test device and test method for the core of the adhesive-impregnated paper sleeve, which uses a first conductive bead layer and a second conductive bead layer to increase the number of contact points and improve the comprehensiveness of the test.

[0006] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows: A power frequency withstand voltage testing device for a paper-impregnated tubing core includes an insulating workbench, a first electrode erected above the insulating workbench and capable of being raised and lowered, and a second electrode fixedly erected on the top surface of the insulating workbench. The first electrode has a columnar structure, and the second electrode has a cylindrical structure. When the core to be tested is inserted into the inner cavity of the second electrode and sleeved on the outer periphery of the first electrode, an inner ring gap is provided between the inner wall of the core to be tested and the first electrode, and an outer ring gap is provided between the outer wall of the core to be tested and the second electrode. The insulating workbench has a first cavity and a second cavity respectively located on the inner and outer sides of the insulating separator cylinder. The top end of the first cavity can communicate with the bottom end of the inner ring gap, and the top end of the second cavity can communicate with the bottom end of the inner ring gap. The device is connected to the bottom end of the outer ring gap; a first lifting plate is provided in the first cavity; a second lifting plate is provided in the second cavity; it also includes a first conductive bead layer and a second conductive bead layer for increasing the number of contact points of the tested core; when the bottom surface of the tested core is adapted to fit and press against the top surface of the insulating separator, the first lifting plate can push the first conductive bead layer to rise and fill the inner ring gap, and the second lifting plate can push the second conductive bead layer to rise and fill the outer ring gap; it also includes a support module for supporting and lifting the first electrode; it also includes a pressing module; the pressing module can press the tested core downward to prevent the bottom surface of the tested core from separating from the top surface of the insulating separator.

[0007] As a further optimization of the present invention, the first conductive bead layer includes a plurality of first conductive beads, and the second conductive bead layer includes a plurality of second conductive beads; the first conductive bead layer is initially positioned in the first cavity and pressed against the first lifting plate, and the second conductive bead layer is initially positioned in the second cavity and pressed against the second lifting plate.

[0008] As a further optimization of the present invention, the bottom of the first cavity is provided with a first linear driver for driving the first lifting plate to move; the bottom of the second cavity is provided with a second linear driver for driving the second lifting plate to move.

[0009] As a further optimization of the present invention, the support module is fixedly installed above the insulating workbench; the support module includes a column, a top support platform and a vertically arranged third linear actuator; the top and bottom ends of the column are respectively vertically fixedly connected to the top support platform and the insulating workbench; the top support platform and the third linear actuator are connected in a cross shape; the third output shaft of the third linear actuator is connected to the first electrode through an insulating rod.

[0010] As a further optimization of the present invention, the pressing module includes a pressing rod and a fourth linear actuator; the middle part of the pressing rod is hinged to the column; the bottom end of the fourth linear actuator is hinged to the insulating workbench and the top end is hinged to the end of the pressing rod; the fourth linear actuator is used to drive the pressing rod to rotate, and the end of the pressing rod away from the fourth linear actuator is provided with a pressing end, which can apply downward pressure to the top surface of the core being tested.

[0011] As a further optimization of the present invention, the pressing module is provided in two parts and is arranged in a centrally symmetrical manner with the first electrode as the center; when the two pressing ends are rotated to a parallel state, they are respectively located on both sides of the first electrode; when the pressing ends are rotated to a horizontal state, they can abut against the outer wall of the first electrode, and both ends of the bottom surface of the pressing ends are attached to and pressed against the top surface of the core being tested.

[0012] As a further optimization of the present invention, the columns are provided in a matrix arrangement, and the two columns located at opposite corners are respectively connected to the two pressure rods.

[0013] As a further optimization of the present invention, the outer wall of the top of the insulating separator is provided with an outer chamfer structure; an inclined cable is provided in the outer ring gap, and a plurality of the inclined cables are arranged in an inverted conical circumferential array; during the process of the core being tested being inserted downward into the inner cavity of the second electrode, the inclined cable can guide the bottom surface of the core being tested to fit and conform to the top surface of the insulating separator; the bottom end of the inclined cable is fixedly installed on the top of the outer chamfer structure, and the top end of the inclined cable is fixedly installed on the top of the inner wall of the second electrode.

[0014] As a further optimization of the present invention, the bottom surface of the core under test can cover the top surface of the insulating separator cylinder, so as to prevent the first conductive bead and / or the second conductive bead from being stuck at the top surface of the insulating separator cylinder when the first conductive bead layer rises or falls, and when the second conductive bead layer rises or falls.

[0015] A method for conducting a power frequency withstand voltage test on a paper-impregnated sleeve core, using a power frequency withstand voltage test device for a paper-impregnated sleeve core, includes the following steps: S1, inserting the core under test into the inner cavity of the second electrode, and pressing the bottom surface of the core under test against the top surface of the insulating separator cylinder; S2, moving the first electrode downwards until it is inserted into the inner cavity of the core under test; S3, rotating the pressing rod of the pressing module until the pressing end presses against the top surface of the core under test; S4, the first lifting plate pushes the first conductive bead layer upwards and fills the inner ring gap, and the second lifting plate pushes the second conductive bead layer upwards and fills the outer ring gap; S5, ... S6. The pressure rod rotates until the crimping end is removed from above the core being tested; S7. Power is supplied to the first electrode and the second electrode respectively, so that there is a voltage difference between the first electrode and the second electrode; S8. Power is de-energized to the first electrode and the second electrode respectively; S9. The first lifting plate descends, causing the first conductive bead layer to descend, until the top surface of the first conductive bead layer is lower than the top surface of the insulating separator cylinder; the second lifting plate descends, causing the second conductive bead layer to descend, until the top surface of the second conductive bead layer is lower than the top surface of the insulating separator cylinder; S10. The first electrode rises; S11. The core being tested is removed from the inner cavity of the second electrode.

[0016] In summary, the present invention has at least one of the following advantages: (1) In this invention, a first conductive bead layer is filled between the first electrode and the core under test, thereby increasing the number of contact points on the inner wall of the core under test; a second conductive bead layer is filled between the second electrode and the core under test, thereby increasing the number of contact points on the outer wall of the core under test; thereby avoiding the problem of incomplete detection area and large detection blind zone caused by single point / strip contact in traditional technology, and ultimately increasing the comprehensiveness of withstand voltage test and improving product quality.

[0017] (2) Under the push of the first lifting plate / second lifting plate, the first conductive bead layer is filled between the first electrode and the core under test in an "upward moving form", and the second conductive bead layer is filled between the second electrode and the core under test in an "upward moving form". During the process, the bottom surface of the core under test is used to cover and press against the top surface of the insulating separator cylinder, which can avoid the problem of the first conductive bead and / or the second conductive bead being stuck at the top surface of the insulating separator cylinder (on the one hand, if the core under test is inserted downward into the first conductive bead layer / second conductive bead layer, due to the downward moving form, the first conductive bead and / or the second conductive bead are not properly positioned). If the bottom surface of the test core is flat and the top surface of the insulating separator is flat, some of the first conductive beads / second conductive beads will be stuck between the bottom surface of the test core and the top surface of the insulating separator and will not be able to move out laterally. On the other hand, if the test core is not used to cover and press the top surface of the insulating separator during the descent of the first conductive bead layer / second conductive bead layer, some of the first conductive beads / second conductive beads will be supported on the top surface of the insulating separator and will not be able to move down automatically. In both cases, "the first conductive bead and / or the second conductive bead is stuck at the position of the top surface of the insulating separator".

[0018] (3) Apply downward pressure to the core under test using the pressing module so that the core under test is stably pressed against the top surface of the insulating separator and the two are kept coaxial. On the one hand, this prevents the core under test from tilting (or even falling over) during the non-uniform descent of the first conductive bead layer / second conductive bead layer. On the other hand, it prevents the core under test from tilting (or even falling over) or separating from the top surface of the insulating separator during the non-uniform ascent of the first conductive bead layer / second conductive bead layer.

[0019] (4) Two crimping ends are located on the left and right sides of the first electrode; each crimping end is located close to the first electrode, thus forming two crimping surfaces with the core being tested. In total, four crimping surfaces are evenly distributed on the top surface of the core being tested, thereby applying uniform pressure to the core being tested and improving the crimping stability of the core being tested.

[0020] (5) The inclined cables can guide the core being tested on the one hand, and will not hinder the rise and fall of the first conductive bead layer / second conductive bead layer on the other hand. During the process of the core being tested moving downward and inserting into the inner cavity of the second electrode, the several inclined cables arranged in an inverted cone shape can guide the core being tested, so that the core being tested is aligned with the insulating separator cylinder. The first conductive bead / second conductive bead can smoothly penetrate the gap between two adjacent inclined cables, that is, during the rise of the first conductive bead layer / second conductive bead layer, it can smoothly pass through the inclined cables (lower middle part), and during the descent of the first conductive bead layer / second conductive bead layer, there will be no problem that (partial) first conductive bead / second conductive bead is blocked by the inclined cables (and cannot descend).

[0021] (6) The first electromagnet / second electromagnet arranged in a circular array can be energized one by one to generate a variable magnetic attraction force in the horizontal direction. The first conductive bead / second conductive bead will be displaced in the horizontal direction when subjected to the variable magnetic attraction force in the horizontal direction, thus greatly reducing the probability of it getting stuck when moving vertically. Attached Figure Description

[0022] The present application will be further explained below with reference to the accompanying drawings: Figure 1 This is a front view of the overall structure of the present invention. Figure 2 This is a front view schematic diagram showing the initial positions of the first and second conductive bead layers. Figure 3 This is a schematic diagram of the location of the inner and outer ring gaps and the front view of the structural elevation section. Figure 4 A front view of the first conductive bead layer rising and filling the inner ring gap; Figure 5 This is a front view of the vertical section showing the position and structure of the housing and conductive beads. Figure 6 A schematic diagram showing the core under test inserted downwards into the cavity of the second electrode. Figure 7 This is a front view schematic diagram showing the positions and structures of the first and second linear actuators. Figure 8 This is a front view diagram showing the location and structure of the support module. Figure 9 A top-view diagram showing the positions of the columns and the top support platform; Figure 10 A front view diagram showing the state of the pressing module pressing against the top surface of the core under test; Figure 11 This is a front view diagram showing the pressure rod being removed from the top surface of the core being tested. Figure 12 A top view diagram showing the positions of the four pressing surfaces; Figure 13 This is a front view diagram showing the location of the reinforcing rod and the structure. Figure 14 A front view diagram showing the positions of the top and bottom ends of the stay cables; Figure 15 This is a schematic diagram showing the location of the stay cables and the oblique top view of the structure; Figure 16 This is a schematic diagram showing the spacing between two adjacent stay cables; Figure 17 This is a front view diagram showing the connection point between the bottom end of the stay cable and the outer chamfer structure. Figure 18 A front view schematic diagram of the first and second conductive bead layers in their descending state; Figure 19 A front view diagram showing the positions of the first and second electromagnets. Figure 20 Top view of the positions of the first and second electromagnets; Figure 21 This is a schematic diagram of the cross-section where the strip-shaped contact surface is formed.

[0023] Explanation of reference numerals in the attached figures: In the picture, 1. Insulated workbench; 101. First cavity; 1011. First lifting plate; 1012. First insulating column; 1013. First linear actuator; 10131. First output shaft; 102. Second cavity; 1021. Second lifting plate; 1022. Second insulating column; 1023. Second linear actuator; 10231. Second output shaft; 103. Insulated separator cylinder; 1031. Outer chamfer structure; 1032. Inner chamfer structure; 104. First electromagnet; 105. Second electromagnet; 2. First electrode; 3. Second electrode; 31. Fin mounting; 32. Stay cable; 4. Test core; 401. Inner ring gap; 402. Outer ring gap; 41. Housing; 42. Conductive bead; 43. Electrode A; 44. Electrode B; 5. First conductive bead layer; 51. First conductive bead; 6. Second conductive bead layer; 61. Second conductive bead; 7. Support module; 71. Column; 711. Crimping end; 7111. Crimping surface; 72. Top support platform; 73. Third linear actuator; 731. Third output shaft; 74. Insulating pole; 8. Pressing module; 81. Pressing rod; 82. Fourth linear actuator; 821. Fourth output shaft; 83. Reinforcing rod; 9. Cylindrical electrode; 91. Strip contact surface; 92. Non-contact surface. Detailed Implementation

[0024] Reference Figure 21 In traditional technology, only one strip-shaped contact surface 91 can usually be formed between the cylindrical electrode 9 and the core 4 under test, resulting in a large non-contact surface 92, which leads to a small and incomplete detection area and a large detection blind zone.

[0025] The following provides further details on the implementation methods of this application: Reference Figures 1-2This embodiment provides a power frequency withstand voltage test device for a paper-impregnated tube core, including an insulating workbench 1, a first electrode 2 erected above the insulating workbench 1 and capable of being raised and lowered, and a second electrode 3 fixedly erected on the top surface of the insulating workbench 1. The first electrode and the second electrode 3 are used to create a voltage difference between the inner and outer sides of the core 4 under test, thereby detecting the insulation performance of the core 4 under test.

[0026] Reference Figures 1-3 The first electrode 2 has a columnar structure, and the second electrode 3 has a cylindrical structure. When the core to be tested 4 is inserted into the inner cavity of the second electrode 3 and sleeved on the outer periphery of the first electrode 2 (i.e., the core to be tested 4 is sleeved on the outer periphery of the first electrode 2, and the second electrode 3 is sleeved on the outer periphery of the core to be tested 4), an inner ring gap 401 is provided between the inner sidewall of the core to be tested 4 and the outer sidewall of the first electrode 2, and an outer ring gap 402 is provided between the outer sidewall of the core to be tested 4 and the inner sidewall of the second electrode 3. The first electrode 2 has a straight cylindrical structure with a constant diameter, the core to be tested 4 has a straight cylindrical structure with a constant diameter and open at both ends, the second electrode 3 has a straight cylindrical structure with a constant diameter and open at both ends, the inner ring gap 401 has a straight cylindrical structure with a constant diameter and open at both ends, and the outer ring gap 402 has a straight cylindrical structure with a constant diameter and open at both ends.

[0027] Reference Figure 5 In traditional techniques, to increase the contact area between electrode A43 and the core under test 4, as well as the contact area between electrode B44 and the core under test 4, it is usually necessary to: vertically insert and fix electrode A43 in the middle of the bottom plate of housing 41, vertically insert and fix electrode B44 in the edge of the bottom plate of housing 41, then pour several conductive beads 42 (e.g., steel balls) into the inner cavity of housing 41 to form a layer of conductive beads 42, and then vertically insert the core under test 4 into the layer of conductive beads 42 until the bottom surface of the core under test 4 and the bottom surface of the inner cavity of housing 41 are in contact with each other. This allows the conductive beads 42 in the inner cavity of the core under test 4 to be completely isolated from the outer core under test 4, so that different voltages can be applied to electrode A43 and electrode B44 respectively, and a voltage difference can be formed between the inner and outer walls of the core under test 4 for insulation testing. However, this method has significant problems: when the bottom surface of the core under test 4 is close to the bottom surface of the inner cavity of the housing 41, some conductive beads 42 will be stuck between the bottom surface of the core under test 4 and the bottom surface of the inner cavity of the housing 41. (On the one hand, based on the cutting process of the core under test 4, both ends of the core under test 4, namely the top and bottom surfaces, are planar, so when the core under test 4 moves along the axial direction, it cannot apply a lateral or oblique pushing force to the conductive beads 42 that are in contact with its end surfaces; on the other hand, the core under test 4 is set vertically, so based on the requirement of placement stability, the bottom surface of the core under test 4 needs to be planar in order to fit with the bottom surface of the inner cavity of the housing 41 to achieve stable placement.) This makes it difficult for the conductive beads 42 at the inner and outer wall positions to be completely separated and form a passage, so a voltage difference cannot be formed between the inner and outer walls of the core under test 4.

[0028] Reference Figures 1-4 To avoid the aforementioned problems, the insulating workbench 1 of this invention is provided with a first cavity 101 and a second cavity 102 respectively located on the inner and outer sides of the insulating separator 103; the top end of the first cavity 101 can communicate with the bottom end of the inner ring gap 401, and the top end of the second cavity 102 can communicate with the bottom end of the outer ring gap 402; a first lifting plate 1011 is provided in the first cavity 101; and a second lifting plate 1021 is provided in the second cavity 102. The power frequency withstand voltage test device for the resin-impregnated paper sleeve core also includes a first conductive bead layer 5 (the first conductive bead layer 5 includes a plurality of first conductive beads 51) and a second conductive bead layer 6 (the second conductive bead layer 6 includes a plurality of second conductive beads 61). (Refer to...) Figure 4 When the bottom surface of the core under test 4 is fitted and pressed against the top surface of the insulating separator 103, the first lifting plate 1011 can push the first conductive bead layer 5 to rise and fill the inner ring gap 401 (to form a passage between the first electrode 2, the first conductive bead layer 5, and the inner wall of the core under test 4), and the second lifting plate 1021 can push the second conductive bead layer 6 to rise and fill the outer ring gap 402 (to form a passage between the second electrode 3, the second conductive bead layer 6, and the outer wall of the core under test 4). When different voltages are supplied to the first electrode 2 and the second electrode 3 respectively, a voltage difference will be formed between the inner wall and the outer wall of the core under test 4, which is used for the insulation test of the core under test 4.

[0029] Compared to the direct contact between the first electrode 2 / second electrode 3 and the core under test 4, this invention utilizes the first conductive bead layer 5 / second conductive bead layer 6 to achieve indirect contact between the core under test 4 and the electrodes (including the first electrode 2 and the second electrode 3). Multiple contact points (for conduction) are formed between the first conductive bead layer 5 and the core under test 4 (when the first conductive bead layer 5 is energized, the contact point is the electric contact point), and multiple contact points (for conduction) are formed between the second conductive bead layer 6 and the core under test 4 (when the second conductive bead layer 6 is energized, the contact point is the electric contact point). This avoids the problems of insufficient number of electric contact points on the inner and outer walls of the core under test 4, incomplete detection, and large detection blind spots.

[0030] Compared to the aforementioned traditional technologies, referencing Figures 1-4 The present invention uses a method in which the core under test 4 is stationary and the first conductive bead layer 5 / second conductive bead layer 6 is driven to rise to fill the gap (including the inner ring gap 401 and the outer ring gap 402) between the core under test 4 and the electrodes (including the first electrode 2 and the second electrode 3). This avoids the problem in the traditional technology (where the conductive beads 42 are stationary and the core under test 4 is inserted downward) where the bottom surface of the core under test 4 is blocked by the conductive beads 42 and it is difficult to fit with the bottom surface of the inner cavity of the housing 41 (i.e., the core under test 4 cannot completely separate the conductive beads 42 on the inner and outer walls). This also avoids the problem of the conductive beads 42 on the inner and outer walls (bypassing the core under test 4) directly forming a passage.

[0031] Reference Figure 6 If the present invention adopts the form of keeping the first conductive bead layer 5 / second conductive bead layer 6 stationary and inserting the core under test 4 downward, the same problem as the conventional technology will still occur: some of the first conductive beads 51 / second conductive beads 61 will be stuck between the bottom surface of the core under test 4 and the top surface of the insulating separator 103 (and difficult to move laterally). On the one hand, this makes it difficult for the core under test 4 to continue to move downward, and on the other hand, it causes the first conductive bead layer 5 / second conductive bead layer 6 (bypassing the core under test 4) to directly form a passage. Therefore, the present invention needs to adopt the form of keeping the core under test 4 stationary and driving the first conductive bead layer 5 / second conductive bead layer 6 to rise to fill the inner ring gap 401 / outer ring gap 402.

[0032] Reference Figure 2 The first conductive bead layer 5 is initially positioned inside the first cavity 101 and pressed against the first lifting plate 1011; when the first lifting plate 1011 rises, it can push the first conductive bead layer 5 upward; when the first lifting plate 1011 descends, the first conductive bead layer 5 descends under its own weight. The second conductive bead layer 6 is initially positioned inside the second cavity 102 and pressed against the second lifting plate 1021; when the second lifting plate 1021 rises, it can push the second conductive bead layer 6 upward; when the second lifting plate 1021 descends, the second conductive bead layer 6 descends under its own weight.

[0033] Reference Figure 2 The first conductive bead 51 has a spherical structure, which has excellent rolling and moving performance, so that the first conductive bead layer 5 can rise and fall smoothly without getting stuck; the second conductive bead 61 has a spherical structure, which has excellent rolling and moving performance, so that the second conductive bead layer 6 can rise and fall smoothly without getting stuck.

[0034] The first conductive bead 51 is, for example, a steel bead (which may be plated with silver or copper on its outer surface if necessary to increase conductivity), and the second conductive bead 61 is, for example, a steel bead (which may be plated with silver or copper on its outer surface if necessary to increase conductivity).

[0035] Reference Figure 7The bottom of the first cavity 101 is provided with a first linear actuator 1013 for driving the first lifting plate 1011 to move. The first linear actuator 1013 is vertically arranged, and the bottom end of the housing of the first linear actuator 1013 is fixedly connected to the insulating workbench 1 (e.g., by bolts). The top end of the first output shaft 10131 of the first linear actuator 1013 is fixedly connected to the first lifting plate 1011 through a first insulating post 1012; the bottom end of the first insulating post 1012 is coaxially arranged with and fixedly connected to the first output shaft 10131 (e.g., by bolts), and the top end is vertically fixedly connected to the bottom surface of the lifting plate (e.g., by bolts). The bottom of the second cavity 102 is provided with a second linear actuator 1023 for driving the second lifting plate 1021 to move. The second linear actuator 1023 is vertically arranged. The bottom end of the housing of the second linear actuator 1023 is fixedly connected to the insulating workbench 1 (e.g., by bolts). The top end of the second output shaft 10231 of the second linear actuator 1023 is fixedly connected to the second lifting plate 1021 through the second insulating post 1022. The bottom end of the second insulating post 1022 is coaxially arranged and fixedly connected to the second output shaft 10231 (e.g., by bolts), and the top end is vertically fixedly connected to the bottom surface of the lifting plate (e.g., by bolts).

[0036] Reference Figure 8 The support module 7 of the power frequency withstand voltage test device for the impregnated paper sleeve core is fixedly mounted above the insulating workbench 1. The support module 7 includes a column 71, a top support platform 72, and a vertically arranged third linear actuator 73. The top and bottom ends of the column 71 are vertically and fixedly connected to the top support platform 72 and the insulating workbench 1 respectively (e.g., by bolts). The top support platform 72 and the third linear actuator 73 are connected in a cross shape. The top support platform 72 is horizontally positioned, and the third linear actuator 73 is vertically positioned. The housing of the third linear actuator 73 is fixedly connected to the top support platform 72 by bolts, and the third output shaft 731 of the third linear actuator 73 is connected to the first electrode 2 via an insulating rod 74. The top end of the insulating rod 74 is coaxially and fixedly connected to the third output shaft 731 (e.g., by bolts), and the bottom end is coaxially and fixedly connected to the first electrode 2 (e.g., by bolts).

[0037] The first electrode 2 is connected to a transformer via a power supply wire, and the transformer is connected to an external power source. The second electrode 3 is connected to the ground via a grounding wire, with an ammeter connected in series in the middle of the grounding wire. The user uses the transformer to boost the voltage of the external power source to the power frequency voltage (common power frequency voltages include 10V, 220V, 380V, 1000V, 750kV, etc.), then applies the power frequency voltage to the first electrode 2 and records the leakage current data displayed on the ammeter in real time, thereby detecting the insulation performance of the core 4 under test.

[0038] Reference Figure 4During the upward / downward movement of the first conductive bead layer 5 / second conductive bead layer 6, an upward / downward thrust (and a horizontal thrust, generated by compression) is applied to the tested core 4 through friction. This may cause the tested core 4 to tilt or even fall over due to uneven force (the first conductive bead 51 / second conductive bead 61 rolls while moving, making it difficult to apply equal upward / downward / horizontal thrust to the tested core 4 within a 360-degree range). (The tested core 4 is made of resin material, with low density and light weight). In this case, the bottom surface of the tested core 4 (which was originally pressed together) may separate from the top surface of the insulating separator 103, and the first conductive bead 51 and / or the second conductive bead 61 may take the opportunity to roll into the gap between the bottom surface of the tested core 4 and the top surface of the insulating separator 103, resulting in the first conductive bead layer 5 / second conductive bead layer 6 (bypassing the tested core 4) directly forming a circuit.

[0039] Reference Figure 10 To avoid the above problems, the power frequency withstand voltage test device for the impregnated paper sleeve core also includes a pressing module 8. During the upward movement of the first conductive bead layer 5 and / or the second conductive bead layer 6, the pressing module 8 is used to apply downward pressure to the core 4 under test, thereby pressing the bottom surface of the core 4 under test against the top surface of the insulating separator 103 to prevent them from separating.

[0040] Reference Figure 10 The pressing module 8 includes a pressing rod 81 and a fourth linear actuator 82. The middle part of the pressing rod 81 is hinged to the column 71. The housing at the bottom of the fourth linear actuator 82 is hinged to the insulating workbench 1, and the fourth output shaft 821 at the top is hinged to the end of the pressing rod 81. The end of the pressing rod 81 away from the fourth linear actuator 82 is provided with a crimping end 711 (e.g., fixed by bolts or by an integral fixed connection). When the fourth output shaft 821 of the fourth linear actuator 82 extends or retracts, it can drive the pressing rod 81 to rotate; when the fourth output shaft 821 extends, it can drive the lower extension rod to rotate until the bottom surface of the crimping end 711 is in contact with the top surface of the core 4 under test and applies downward pressure to the core 4 under test.

[0041] Reference Figure 9 The column 71 has four columns arranged in a matrix, and the top support platform 72 has a rectangular plate structure. The four columns 71 are located at the four right-angle positions of the top support platform 72, thereby achieving stable support for the top support platform 72. The third linear actuator 73 is plugged and fixed at the center of the top support platform 72.

[0042] Reference Figure 10 , Figure 11 and Figure 12The pressing module 8 has two parts, arranged symmetrically around the first electrode 2. When the two pressing rods 81 rotate to a parallel state, both pressing ends 711 are adapted to press against the top surface of the core 4 under test, and at this time, the two pressing ends 711 are located on both sides of the first electrode 2. The pressing ends 711 have a strip-shaped structure. When the pressing ends 711 rotate to a horizontal state, they can abut against the outer wall of the first electrode 2, and both ends of the bottom surface of the pressing ends 711 are in contact with and pressed against the top surface of the core 4 under test. Since the two pressing ends 711 are located on both sides of the first electrode 2, a total of four pressing surfaces 7111 are formed (between the bottom surface of the pressing ends 711 and the top surface of the core 4 under test), and the four pressing surfaces 7111 are arranged in a matrix, thereby pressing the core 4 under test evenly and stably, avoiding off-center loading.

[0043] Reference Figure 9 and Figure 12 The column 71 is provided in a matrix arrangement. The two columns 71 located at the diagonal positions are connected to the two pressing rods 81 respectively. When the two pressing rods 81 are rotated to a parallel state, the first electrode 2 and the two pressing rods 81 are arranged in a Z-shape to press the core 4 under test evenly and stably, avoiding off-center loading.

[0044] Reference Figure 13 An L-shaped reinforcing rod 83 is provided above the pressure rod 81, and both ends of the reinforcing rod 83 are fixedly connected to both ends of the pressure rod 81 (e.g., by bolts or by an integral fixing connection). The pressure rod 81 has a straight rod structure; two pressure rods 81 are connected to two reinforcing rods 83 respectively. The pressure rod 81 and its corresponding reinforcing rod 83 form a triangular structure, which has excellent structural stability and reduces the problem of bending deformation of the pressure rod 81 due to bending moment (bending moment comes from the fourth linear actuator 82 and the core being measured 4).

[0045] Reference Figure 14 and Figure 17 The insulating separator 103 has an outer chamfer structure 1031 on its outer side wall and an inner chamfer structure 1032 on its inner side wall. The outer chamfer structure 1031 is annular; the inner chamfer structure 1032 is annular. The outer chamfer structure 1031 and the inner chamfer structure 1032 are used to make the top surface of the insulating separator 103 have the smallest possible area, thereby preventing the outer edge of the top surface of the insulating separator 103 from being outwardly curved. This prevents the first conductive bead 51 / second conductive bead 61 from being trapped at the outer edge of the top surface of the insulating separator 103 when the first conductive bead layer 5 / second conductive bead layer 6 descends (i.e., preventing the first conductive bead 51 / second conductive bead 61 from being stuck at the outer edge of the top surface of the insulating separator 103 and unable to descend).

[0046] The inner diameter of the top surface of the insulating separator 103 is equal to the inner diameter of the bottom surface of the core 4 under test; the outer diameter of the top surface of the insulating separator 103 is equal to the outer diameter of the bottom surface of the core 4 under test. When the insulating separator 103 and the core 4 under test are coaxially arranged, the top surface of the insulating separator 103 can fit and conform to the bottom surface of the core 4 under test.

[0047] Reference Figure 14 and Figure 15 An inclined cable 32 is provided within the outer ring gap 402. Several inclined cables 32 are arranged in a circumferential array (inverted cone or inverted frustum shape); several inclined cables 32 are arranged radially. During the process of inserting the core 4 under test downward into the inner cavity of the second electrode 3, the inclined cable 32 can guide the bottom surface of the core 4 under test to fit and conform to the top surface of the insulating separator 103 (the outer edge of the bottom surface of the core 4 under test can hit the inclined cable 32 and slide downward along the inclined cable 32 until the bottom surface of the core 4 under test is aligned with the top surface of the insulating separator 103).

[0048] Several inclined cables 32 are arranged in a circular array with equal spacing and angles along the inner wall of the second electrode 3. Since the inclined cables 32 are arranged radially and there is a gap between two adjacent inclined cables 32, the second conductive bead 61 can pass through the gap and move smoothly up and down; that is, the inclined cables 32 can provide a guiding function for the core 4 under test, while avoiding obstructing the movement of the second conductive bead layer 6.

[0049] Reference Figure 14 and Figure 15 The bottom end of the stay cable 32 is fixedly installed on the top of the outer chamfer structure 1031 (e.g., by anchoring), and the top end of the stay cable 32 is fixedly installed on the top of the inner side wall of the second electrode 3 (e.g., by anchoring).

[0050] Reference Figure 16 Because several stay cables 32 are arranged in an inverted cone shape, the distance between two adjacent stay cables 32 is an isosceles trapezoidal shape, meaning the distance between two adjacent stay cables 32 is non-uniform. The diameter of the second conductive bead 61 is smaller than the minimum distance H1 between two adjacent stay cables 32 (for example, 1 / 3 of H1), allowing the second conductive bead 61 to pass smoothly through the gap between two adjacent stay cables 32. The outer diameter of the core 4 under test is larger than the maximum distance H2 between two adjacent stay cables 32, preventing the core 4 under test from passing through the gap between two adjacent stay cables 32, thus ensuring the smooth guiding function of the stay cables 32 for the core 4 under test.

[0051] The cable 32 is a straight structure with an incline; the cable 32 is straightened.

[0052] Reference Figure 17If the bottom end of the inclined cable 32 is located on the top surface of the insulating separator 103, the bottom end of the inclined cable 32 will be squeezed between the top surface of the insulating separator 103 and the bottom surface of the core 4 under test. Since the inclined cable 32 has a certain diameter and therefore occupies a certain amount of space, the top surface of the insulating separator 103 and the bottom surface of the core 4 under test cannot fit together properly, resulting in reduced stability of the core 4 under test. Therefore, in this invention, the bottom end of the inclined cable 32 is located at the top of the outer chamfer structure 1031 (i.e., near the bottom surface of the core 4 under test) to avoid reduced stability of the core 4 under test. However, this arrangement introduces a new problem: since there is no direct contact between the core 4 under test and the inclined cable 32, the inclined cable 32 cannot replace the second conductive bead layer 6 (which acts as a conductor between the outer wall of the core 4 under test and the second electrode 3). Therefore, the presence of the second conductive bead layer 6 is essential.

[0053] Reference Figure 18 If the core under test 4 is removed first, and then the first conductive bead layer 5 and / or the second conductive bead layer 6 are lowered, some of the first conductive beads 51 and / or the second conductive beads 61 will be stuck on the top surface of the insulating separator 103 and will be difficult to lower automatically. Therefore, the core under test 4, which will be subjected to a withstand voltage test later, will not be stably pressed onto the upper surface of the insulating separator 103. To avoid this problem, in this invention, the first conductive bead layer 5 and / or the second conductive bead layer 6 are lowered first, and then the core under test 4 is removed. That is, the bottom surface of the core under test 4 can cover the top surface of the insulating separator 103, so as to prevent the first conductive beads 51 and / or the second conductive beads 61 from being stuck on the top surface of the insulating separator 103 when the first conductive bead layer 5 rises or falls, and when the second conductive bead layer 6 rises or falls.

[0054] Reference Figure 4 The bottom surface of the first electrode 2 has a downwardly convex hemispherical structure or an inverted conical structure, thereby reducing the resistance to the upward movement of the first conductive bead layer 5.

[0055] Reference Figure 2 and Figure 15 The bottom of the outer wall of the second electrode 3 is fixedly provided with mounting fins 31 (for example, by integral fixed connection or by bolt fixed connection); the mounting fins 31 are in the form of annular plate structure; the mounting fins 31 are pressed onto the top surface of the insulating workbench 1 and fixedly connected to the insulating workbench 1 by bolts, thereby realizing the fixed installation of the second electrode 3.

[0056] Reference Figure 1The insulating separator 103 is fixedly connected to the insulating workbench 1 (e.g., by bolts); the first cavity 101 and the second cavity 102 are coaxially arranged. The first lifting plate 1011 has a circular plate structure and its edge is adapted to the inner wall of the first cavity 101; the second lifting plate 1021 has an annular plate structure and its edge is adapted to the inner wall of the second cavity 102.

[0057] Reference Figure 7 Four second linear actuators 1023 are provided and arranged in parallel to each other. The four second linear actuators 1023 are arranged in a circular array with equal angles and equal spacing along the second cavity 102. The second output shafts 10231 of the four second linear actuators 1023 extend and retract synchronously (at the same time, at the same speed, and in the same direction) to keep the second lifting plate 1021 in a horizontal state during the lifting process.

[0058] In this invention, the insulating workbench 1, insulating partition cylinder 103, first lifting plate 1011, second lifting plate 1021, insulating upright 74, first insulating column 1012, second insulating column 1022, and column 71 are all made of insulating materials (such as unsaturated polyester resin glass fiber reinforced molding compound, Teflon, nylon, epoxy resin glass fiber, and alumina ceramic, etc.). The first electrode 2 and the second electrode 3 are both conductive electrodes (such as metal electrodes made of copper, silver, platinum, titanium, etc.).

[0059] The height of the tested core 4 (its own) is greater than the height of the second electrode 3 (its own); the top surface of the insulating separator 103 is coplanar with the bottom surface of the second electrode 3; therefore, when the tested core 4 is pressed onto the top surface of the insulating separator 103, the height of the top surface of the tested core 4 is higher than the height of the top surface of the second electrode 3. Thus, the pressing end 711 can be pressed onto the top surface of the tested core 4 (not the top surface of the second electrode 3, see reference). Figure 10 Furthermore, excess second conductive beads 61 can overflow from the top of the inner cavity of the second electrode 3 and roll off to the outside of the second electrode 3 (see reference). Figure 4 ).

[0060] The height position of the second electrode 3 is adapted to the height position of the pressure module 8; the height position of the second electrode 3 is adapted to the height position of the insulating separator 103.

[0061] Reference Figure 1 The inner wall of the second electrode 3 and the outer wall of the second cavity 102 are adapted to be arranged on the same (arc) surface.

[0062] Reference Figure 19 and Figure 20An insulating separator 103 contains a first electromagnet 104, which is arranged in a circular array (equally spaced and at equal angles) along the inner wall of the insulating separator 103. An insulating workbench 1 contains a second electromagnet 105, which is also arranged in a circular array (equally spaced and at equal angles) along the inner wall of the insulating separator 103. When any one of the first electromagnets 104 is energized, the others are de-energized; when any one of the second electromagnets 105 is energized, the others are de-energized; that is, at any given time, only one first electromagnet 104 and one second electromagnet 105 are energized (and generate magnetic attraction). Several first electromagnets 104 are energized one by one in a clockwise direction (from a top view), and several second electromagnets 105 are energized one by one in a counterclockwise direction (from a top view). This is used to apply a horizontally variable magnetic attraction force to the first conductive bead 51 and / or the second conductive bead 61, so as to reduce the probability of the first conductive bead 51 and / or the second conductive bead 61 getting stuck during the lifting and lowering process (after long-term use, the first conductive bead 51, the second conductive bead 61, the outer wall of the first electrode 2, the inner wall of the second electrode 3, the inner wall of the first cavity 101, and the inner and outer walls of the second cavity 102 will wear down, resulting in increased surface roughness, which will increase the probability of getting stuck).

[0063] like Figure 20 As shown, since the first conductive bead 51 / second conductive bead 61 is subjected to a variable magnetic attraction force in the horizontal direction, the first conductive bead 51 / second conductive bead 61 near the position of the first electromagnet 104 / second electromagnet 105 will undergo a slight displacement in the horizontal direction; since the first conductive bead 51 / second conductive bead 61 can be slightly displaced in the horizontal direction, the probability of them getting stuck when moving vertically can be greatly reduced.

[0064] After repeated use of the first electromagnet 104 and the second electromagnet 105, the first conductive bead 51 / second conductive bead 61 will become significantly magnetized, causing them to clump together and become difficult to fit and fill the inner ring gap 401 / outer ring gap 402 and make full contact with the core 4 under test, further increasing the risk of jamming. Therefore, users need to periodically replace the first conductive bead 51 / second conductive bead 61 with new ones, or remove the first conductive bead 51 / second conductive bead 61 and demagnetize it before putting it back into the first cavity 101 / second cavity 102. By periodically (using a sampling survey) removing some of the first conductive beads 51 / second conductive beads 61 and performing magnetic susceptibility testing (e.g., using a magnetic susceptibility meter), users can assess whether they need to be replaced / demagnetized.

[0065] Both the first electromagnet 104 and the second electromagnet 105 are strip-shaped structures and are arranged vertically.

[0066] The first linear actuator 1013, the second linear actuator 1023, the third linear actuator 73, and the fourth linear actuator 82 are all electric actuators, pneumatic actuators, hydraulic actuators, or combinations thereof (e.g., electro-hydraulic actuators).

[0067] The invention also includes an electrical cabinet, which is bolted to the workshop floor. The first linear actuator 1013, the second linear actuator 1023, the third linear actuator 73, the fourth linear actuator 82, the transformer, the ammeter, the first electromagnet 104, and the second electromagnet 105 are connected to the electrical cabinet via wires and signal lines. The electrical cabinet is connected to an external power supply and an external controller (e.g., a computer or a PLC programmable logic controller) via wires and signal lines. The external controller controls the start-stop and other operating states of the first linear actuator 1013, the second linear actuator 1023, the third linear actuator 73, the fourth linear actuator 82, the transformer, the ammeter, the first electromagnet 104, and the second electromagnet 105 through the electrical cabinet. The insulated workbench 1 has wiring holes for routing wires and signal lines (connected to the first linear actuator 1013 and the second linear actuator 1023), and for routing wires and signal lines (connected to the first electromagnet 104 and the second electromagnet 105).

[0068] The power frequency withstand voltage test method for the paper-impregnated sleeve core, which involves using a power frequency withstand voltage test device for the paper-impregnated sleeve core to perform a withstand voltage test on the core 4 under test, includes the following steps: S1. The user manually inserts the core to be tested 4 into the inner cavity of the second electrode 3 and presses the bottom surface of the core to be tested 4 onto the top surface of the insulating separator 103. During the process, the inclined cable 32 guides the bottom end of the core to be tested 4, so that the core to be tested 4 can be easily aligned with the insulating separator 103.

[0069] S2. The first electrode 2 moves downwards until it is inserted into the middle of the inner cavity of the core 4 being tested.

[0070] S3. The pressing rod 81 of the pressing module 8 rotates until the pressing end 711 presses against the top surface of the core 4 under test, thereby making the core 4 under test fit tightly against the insulating separator 103.

[0071] S4. The first lifting plate 1011 pushes the first conductive bead layer 5 up and fills the inner ring gap 401, and the second lifting plate 1021 pushes the second conductive bead layer 6 up and fills the outer ring gap 402. During the process, the core under test 4 will not detach from the insulating separator 103 due to the pressure from the lowering module 8, nor will it tilt. Furthermore, some of the second conductive beads 61 can pass through the gap between adjacent stay cables 32, so the second conductive bead layer 6 can cover the lower middle part of the stay cable 32. By setting the rising stroke of the first lifting plate 1011, the starting height of the first lifting plate 1011, the rising stroke of the second lifting plate 1021, and the starting height of the second lifting plate 1021 to a fixed value, the appropriate number of the first conductive beads 51 and the second conductive beads 61 can be evaluated through a limited number of experiments, so that the first conductive bead layer 5 and the second conductive bead layer 6 can fill the inner ring gap 401 and the outer ring gap 402, and avoid the first conductive beads 51 and the second conductive beads 61 from overflowing.

[0072] S5. The pressure rod 81 rotates until the crimping end 711 is removed from above the core being tested 4.

[0073] S6. Power is supplied to the first electrode 2 and the second electrode 3 respectively, so that there is a voltage difference between the first electrode 2 and the second electrode 3, thereby testing the voltage withstand performance of the core 4 under test.

[0074] S7. Stop supplying power to the first electrode 2 and the second electrode 3 respectively.

[0075] S8. The first lifting plate 1011 descends, causing the first conductive bead layer 5 to descend until the top surface of the first conductive bead layer 5 is lower than the top surface of the insulating separator cylinder 103; the second lifting plate 1021 descends, causing the second conductive bead layer 6 to descend until the top surface of the second conductive bead layer 6 is lower than the top surface of the insulating separator cylinder 103.

[0076] S9. The first electrode 2 rises until the height difference between the bottom of the first electrode 2 and the top of the second electrode 3 is greater than the height of the core 4 under test (its own), so that the core 4 under test can be removed from the inner cavity of the second electrode 3.

[0077] S10, the core to be tested 4 is extracted from the inner cavity of the second electrode 3 and removed.

[0078] S11. After rotating the core 4 to be tested 180 degrees, insert it vertically back into the cavity of the second electrode 3 and repeat steps S1 to S10 (refer to...). Figure 4Since the top surfaces of the first conductive bead layer 5 and the second conductive bead layer 6 cannot cover the top of the core under test 4, the top of the core under test 4 is a detection blind zone. Therefore, after the first detection of the core under test 4, it is necessary to rotate it 180 degrees and insert the detection blind zone into the cavity of the second electrode 3 for a second detection. Alternatively, the detection blind zone can be treated as waste and its insulation performance can be ignored, in which case a second detection is not required.

[0079] This invention has a simple structure and reliable function. The first conductive bead layer 5 is filled between the first electrode 2 and the core under test 4, thereby increasing the number of contact points on the inner wall of the core under test 4. The second conductive bead layer 6 is filled between the second electrode 3 and the core under test 4, thereby increasing the number of contact points on the outer wall of the core under test 4. This avoids the problems of incomplete detection area and large detection blind spots caused by single-point / strip contact in traditional technology, and ultimately increases the comprehensiveness of withstand voltage testing and improves product quality.

[0080] Under the pushing action of the first lifting plate 1011 / second lifting plate 1021, the first conductive bead layer 5 fills the space between the first electrode 2 and the core under test 4 in an "upward moving form," and the second conductive bead layer 6 fills the space between the second electrode 3 and the core under test 4 in an "upward moving form." During this process, the bottom surface of the core under test 4 covers and presses against the top surface of the insulating separator 103, thus avoiding the problem of the first conductive bead 51 and / or the second conductive bead 61 being stuck on the top surface of the insulating separator 103 (on the one hand, referring to...). Figure 6 If the core under test 4 is inserted downwards into the first conductive bead layer 5 / second conductive bead layer 6, since the bottom surface of the core under test 4 is planar and the top surface of the insulating separator 103 is planar, some of the first conductive beads 51 / second conductive beads 61 will be stuck between the bottom surface of the core under test 4 and the top surface of the insulating separator 103 and cannot be moved out laterally; on the other hand, referring to Figure 18 If the top surface of the insulating separator 103 is not covered and pressed by the core under test 4 during the descent of the first conductive bead layer 5 / second conductive bead layer 6, the first conductive bead 51 / second conductive bead 61 will be supported on the top surface of the insulating separator 103 and will not be able to move downward automatically; in both cases, "the first conductive bead 51 and / or the second conductive bead 61 will be stuck at the top surface of the insulating separator 103".

Claims

1. A power frequency voltage withstand test device for a gum-dipped paper bushing core, characterized in that: The application relates to an electrode testing device, which comprises an insulating workbench (1), a first electrode (2) vertically arranged above the insulating workbench (1) and capable of being lifted, and a second electrode (3) fixedly arranged on the top surface of the insulating workbench (1). The first electrode (2) is in a columnar structure, the second electrode (3) is in a cylindrical structure, and when a measured core (4) is inserted into the inner cavity of the second electrode (3) and sleeved on the outer periphery of the first electrode (2), an inner ring gap (401) is arranged between the inner wall of the measured core (4) and the first electrode (2), and an outer ring gap (402) is arranged between the outer wall of the measured core (4) and the second electrode (3). The insulating workbench (1) is internally provided with a first cavity (101) and a second cavity (102) arranged on the inner and outer sides of an insulating separation cylinder (103); the top end of the first cavity (101) can be in communication with the bottom end of the inner ring gap (401), and the top end of the second cavity (102) can be in communication with the bottom end of the outer ring gap (402); the first cavity (101) is internally provided with a first lifting plate (1011); and the second cavity (102) is internally provided with a second lifting plate (1021). The electrode testing device further comprises a first conductive bead layer (5) and a second conductive bead layer (6) for increasing the number of electric contact points of the measured core (4). When the bottom surface of the measured core (4) is adaptively attached to and crimped with the top surface of the insulating separation cylinder (103), the first lifting plate (1011) can push the first conductive bead layer (5) to ascend and fill the inner ring gap (401), and the second lifting plate (1021) can push the second conductive bead layer (6) to ascend and fill the outer ring gap (402). The electrode testing device further comprises a vertical support module (7) for supporting and lifting the first electrode (2). The electrode testing device further comprises a pressing module (8) which can press the measured core (4) downward to avoid the bottom surface of the measured core (4) from being separated from the top surface of the insulating separation cylinder (103).

2. The power frequency voltage withstand test device for a gum-dipped paper bushing core body according to claim 1, characterized in that: The first conductive bead layer (5) comprises a plurality of first conductive beads (51), and the second conductive bead layer (6) comprises a plurality of second conductive beads (61). The first conductive bead layer (5) is arranged in the first cavity (101) and is crimped on the first lifting plate (1011) in an initial position, and the second conductive bead layer (6) is arranged in the second cavity (102) and is crimped on the second lifting plate (1021) in an initial position.

3. The power frequency voltage withstand test device for a gum-dipped paper bushing core body according to claim 2, characterized in that: The bottom part of the first cavity (101) is provided with a first linear driver (1013) for driving the first lifting plate (1011) to move, and the bottom part of the second cavity (102) is provided with a second linear driver (1023) for driving the second lifting plate (1021) to move.

4. The power frequency voltage withstand test device for a gum-dipped paper bushing core body according to claim 3, characterized in that: The vertical support module (7) is fixedly arranged above the insulating workbench (1). The vertical support module (7) comprises a vertical column (71), a top support horizontal table (72) and a vertically arranged third linear driver (73); the vertical column (71) is vertically and fixedly connected with the top support horizontal table (72) and the insulation workbench (1) at the top and bottom ends respectively; the top support horizontal table (72) is cross-shaped connected with the third linear driver (73); the third output shaft (731) of the third linear driver (73) is connected with the first electrode (2) through an insulation vertical rod (74).

5. The power frequency voltage withstand test device for a gum-dipped paper bushing core body according to claim 4, characterized in that: The downward pressing module (8) comprises a downward pressing rod (81) and a fourth linear driver (82); the middle part of the downward pressing rod (81) is hingedly connected with the vertical column (71); the bottom end of the fourth linear driver (82) is hingedly connected with the insulation workbench (1), and the top end is hingedly connected with the end part of the downward pressing rod (81); the fourth linear driver (82) is used for driving the downward pressing rod (81) to rotate; the end part of the downward pressing rod (81) away from the fourth linear driver (82) is provided with a pressing end (711), and the pressing end (711) can apply downward pressure to the top surface of the measured core body (4).

6. The power frequency voltage withstand test device for a gum-dipped paper bushing core body according to claim 5, characterized in that: The downward pressing module (8) is provided with two and is centrally symmetrically arranged with the first electrode (2) as the center; when the two pressing ends (711) are rotated to be parallel to each other, they are respectively arranged on the two sides of the first electrode (2); When the pressing end (711) is rotated to be horizontal, it can abut against the outer side wall of the first electrode (2), and the bottom surface of the pressing end (711) is in close contact with and is pressed against the top surface of the measured core body (4).

7. The power frequency voltage withstand test device for a gum-dipped paper bushing core body according to claim 6, characterized in that: The vertical column (71) is provided with four and is arranged in a matrix shape, and the two vertical columns (71) located at the diagonal positions are respectively connected with the two downward pressing rods (81).

8. The power frequency voltage withstand test device for a gum-dipped paper bushing core body according to claim 7, characterized in that: An outer chamfer structure (1031) is arranged at the top end of the outer side wall of the insulation separation cylinder (103); A diagonal cable (32) is arranged in the outer ring gap (402) in an inclined manner; the diagonal cable (32) is provided with a plurality of and is arranged in a reverse tapered circumferential array; during the process that the measured core body (4) is inserted into the inner cavity of the second electrode (3), the diagonal cable (32) can guide the bottom surface of the measured core body (4) to be in close contact with the top surface of the insulation separation cylinder (103); The bottom end of the diagonal cable (32) is fixedly installed at the top end of the outer chamfer structure (1031), and the top end of the diagonal cable (32) is fixedly installed at the top end of the inner side wall of the second electrode (3).

9. The power frequency voltage withstand test device for a gum-dipped paper bushing core body according to claim 8, characterized in that: The bottom surface of the measured core body (4) can cover the top surface of the insulation separation cylinder (103), so as to avoid the first conductive beads (51) and / or the second conductive beads (61) being stranded at the top surface of the insulation separation cylinder (103) when the first conductive bead layer (5) rises or falls and when the second conductive bead layer (6) rises or falls.

10. A power frequency voltage withstand test method for a gum-dipped paper bushing core body, characterized by, The power frequency withstand voltage test device for the impregnated paper sleeve core body of claim 9 is used to perform the steps of the power frequency withstand voltage test on the measured core body (4). S1, insert the measured core (4) into the inner cavity of the second electrode (3), and make the bottom surface of the measured core (4) adapt to be pressed on the top surface of the insulating separation cylinder (103); S2, the first electrode (2) moves downward to be inserted into the inner cavity of the measured core (4); S3, the lower pressing rod (81) of the lower pressing module (8) rotates until the pressing end (711) is pressed on the top surface of the measured core (4); S4, the first lifting plate (1011) pushes the first conductive bead layer (5) to rise and fill the inner ring gap (401), and the second lifting plate (1021) pushes the second conductive bead layer (6) to rise and fill the outer ring gap (402); S5, the lower pressing rod (81) rotates until the pressing end (711) is removed from above the measured core (4); S6, the first electrode (2) and the second electrode (3) are powered respectively, so that the first electrode (2) and the second electrode (3) have a voltage difference; S7, the first electrode (2) and the second electrode (3) are powered off respectively; S8, the first lifting plate (1011) descends, driving the first conductive bead layer (5) to descend, until the top surface of the first conductive bead layer (5) is lower than the top surface of the insulating separation cylinder (103); the second lifting plate (1021) descends, driving the second conductive bead layer (6) to descend, until the top surface of the second conductive bead layer (6) is lower than the top surface of the insulating separation cylinder (103); S9, the first electrode (2) rises; S10, the measured core (4) is removed from the inner cavity of the second electrode (3).

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