Test tool for high-voltage isolation transformer

Abstract

The utility model relates to the technical field of transformer detection devices, in particular to a test tool for a high-voltage isolation transformer. The device comprises a voltage doubling rectifying device connected to the output end of a secondary coil of a transformer, and a voltage dividing device and a sampling device are sequentially connected between the high-voltage end and the low-voltage end of the voltage doubling rectifying device. According to the testing tool of the high-voltage isolation transformer, boosting is achieved through the transformer and the voltage doubling rectifying device, the voltage dividing device and the sampling device are arranged between the high-voltage end and the low-voltage end of the testing tool, accurate measurement of the output voltage is achieved, and therefore detection of the output high voltage of the testing tool is achieved. Therefore, the performance of the test tool can effectively meet the detection requirements of the current high-voltage isolation transformer.

Description

TECHNICAL FIELD

[0001] The utility model relates to transformer detection device technical field, specifically a kind of test tool of high-voltage isolation transformer. BACKGROUND

[0002] In the manufacturing field of high-voltage electrical equipment, as a key component, the withstand voltage performance of high-voltage isolation transformer is directly related to the safe and stable operation of the entire electrical system. Especially in high-voltage power transmission, power distribution and special industrial applications, high-voltage isolation transformer needs to withstand extremely high voltage stress, so strict detection of its withstand voltage performance is an indispensable link to ensure product quality and performance stability.

[0003] Traditional withstand voltage test equipment often faces many challenges when facing high-voltage isolation transformer. On the one hand, as the withstand voltage level of the transformer increases, such as reaching a high voltage level of 300KV, the test equipment needs to have higher voltage output capability and more accurate control precision to ensure the accuracy and reliability of the test results. On the other hand, safety protection, operation convenience and test efficiency during high-voltage testing are also important factors that cannot be ignored.

[0004] Therefore, the traditional withstand voltage test equipment at the present stage still needs to be further improved to better meet the actual production needs. SUMMARY

[0005] In order to avoid and overcome the technical problems existing in the prior art, the utility model provides a kind of test tool of high-voltage isolation transformer. The utility model can effectively meet the detection needs of current high-voltage isolation transformer.

[0006] To achieve the above-mentioned purpose, the utility model provides the following technical scheme:

[0007] A kind of test tool of high-voltage isolation transformer, including insulating cylinder, transformer and voltage doubler rectifier device, the transformer and the voltage doubler rectifier device are arranged in the insulating cylinder with interval, the insulating cylinder contains insulating liquid, the primary side of the transformer is used to connect to power supply, the voltage doubler rectifier device is connected to the secondary side of the transformer, voltage divider and sampling device are sequentially connected between the high-voltage end and the low-voltage end of the voltage doubler rectifier device, the sampling device is close to the low-voltage end to collect the electrical signal of the output end of the voltage divider.

[0008] According to the scheme, the test tool of high-voltage isolation transformer realizes voltage boosting through transformer and voltage doubler rectifier device, and sets voltage divider and sampling device between its high-voltage end and low-voltage end, which realizes accurate measurement of output voltage.

[0009] Further, the voltage dividing device comprises a plurality of voltage dividing plates connected in series, the plurality of voltage dividing plates are distributed with a set insulation distance in the height direction of the insulation cylinder, and the voltage dividing plate close to the bottom of the insulation cylinder is connected to the low-voltage end of the voltage doubling rectifying device.

[0010] According to the present solution, the structure of the plurality of voltage dividing plates connected in series and spaced with a set insulation distance in the height direction can effectively prevent electrical short circuit in high-voltage environment, and improve the insulation performance and safety performance of the test tool; and the voltage dividing device is designed as a plurality of voltage dividing plates connected in series, which can reduce the volume of the whole test tool.

[0011] Further, the voltage dividing plate is in the shape of a spiral plate, and each voltage dividing plate is connected in series in sequence to form a spiral rising structure; or

[0012] The voltage dividing plate is in the shape of an annular plate with a notch, the notches of adjacent two voltage dividing plates are aligned, and each voltage dividing plate is connected in series in sequence to form a spiral rising structure.

[0013] According to the present solution, the voltage dividing device forms a spiral rising structure, which can optimize the electric field distribution in the insulation cylinder, reduce the possibility of partial discharge, and further improve the stability and safety of the test tool.

[0014] Further, the voltage dividing device further comprises a voltage dividing insulation support frame for mounting the voltage dividing plates, the voltage dividing insulation support frame comprises a second insulation support rod extending in the height direction, and the second insulation support rod has at least three rods, and each second insulation support rod is distributed with a set interval around the axis of the spiral rising structure.

[0015] According to the present solution, the mechanical strength and stability of the voltage dividing device can be ensured.

[0016] Further, the voltage dividing plate is detachably mounted to the second insulation support rod; or

[0017] Each voltage dividing plate and the second insulation support rod are configured as a voltage dividing member formed integrally, and adjacent two voltage dividing members are connected in series through the second insulation support rod to constitute the voltage dividing device.

[0018] According to the present solution, the voltage dividing device is very convenient to disassemble and assemble, and the number of voltage dividing plates can be adjusted according to actual use requirements.

[0019] Further, the cylinder wall of the insulation cylinder is embedded with a wiring terminal for connecting to the transformer and the sampling device.

[0020] According to the scheme, by embedding the wiring terminal on the insulating cylinder, the detection equipment is connected outside the insulating cylinder, and the detection of the output parameters of the test tool is realized.

[0021] Further, the voltage doubling rectifier device comprises a first insulating support rod extending in the height direction, a plurality of voltage doubling rectifier plates are sequentially and spacedly installed on the first insulating support rod from bottom to top, and each voltage doubling rectifier plate is sequentially connected in series, and the voltage doubling rectifier plate close to the bottom of the first insulating support rod is connected to the secondary side of the transformer.

[0022] According to the scheme, the voltage doubling rectifier device is designed to have a plurality of voltage doubling rectifier plates connected in series, and the voltage doubling rectifier plates are sequentially and spacedly arranged in the insulating cylinder along the height direction, so as to reduce the volume of the entire test tool.

[0023] Further, the sampling device comprises a first sampling device and a second sampling device, the first sampling device and the voltage dividing device are connected in series at the output end of the voltage doubling rectifier device to form a voltage dividing sampling loop, the first sampling device is arranged close to the low-voltage end of the voltage doubling rectifier device, and is used for collecting the voltage signal of the voltage dividing sampling loop.

[0024] The second sampling device is arranged in the total loop close to the low-voltage end of the voltage doubling rectifier device, and is used for collecting the current signal of the total loop.

[0025] According to the scheme, the first sampling device can be used for detecting the output voltage of the test tool, and the second sampling device can be used for detecting the current of the total loop.

[0026] Further, a sparking current limiting device is further connected to the high-voltage end of the voltage doubling rectifier device, and the sparking current limiting device is immersed in the insulating liquid filled in the insulating cylinder.

[0027] The sparking current limiting device is installed on the top of the voltage dividing device and comprises a third insulating support rod and a plurality of current limiting plates sequentially and spacedly installed on the third insulating support rod from bottom to top, and the sparking current limiting device is arranged above the voltage dividing device.

[0028] According to the scheme, the overall size of the test tool can be further controlled, and the space occupation can be reduced.

[0029] Further, a high-voltage lead terminal connected to the output end of the sparking current limiting device is installed on the top cover of the insulating cylinder; the high-voltage lead terminal comprises a wiring post installed on the top cover, an insulating column is wrapped outside the wiring post, and an insulating arch is integrally and insulatively connected to at least one of the outer surface of the insulating column and the top surface of the top cover.

[0030] According to the scheme, the design of the high-voltage lead-out terminal enables the test tool to be conveniently connected with the transformer to be tested. The combination of the insulating base column and the insulating arch can improve the insulation withstand performance and thus improve the safety, so that the test tool is more suitable for long-term stable operation in a high-voltage environment. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 It is a schematic diagram of the overall structure of the utility model.

[0032] Figure 2 It is a schematic diagram of the structure of the striking current limiting device in the utility model.

[0033] Figure 3 It is a schematic diagram of the structure of the voltage dividing device in the utility model.

[0034] Figure 4 It is an electrical schematic diagram of the utility model.

[0035] In the figure: 1, insulating cylinder; 11, base; 12, positioning ring; 13, top cover; 14, high-voltage lead-out terminal; 141, insulating base plate; 142, terminal post; 143, insulating base column; 144, convex disc; 145, insulating sleeve; 15, transformer input terminal; 16, current sampling terminal; 17, voltage sampling terminal; 18, shell grounding terminal; 19, output low-voltage terminal; 2, voltage doubling rectifier device; 21, first insulating support rod; 22, voltage doubling rectifier plate; 3, voltage dividing device; 31, second insulating support rod; 32, voltage dividing plate; 4, sampling device; 41, first sampling device; 42, second sampling device; 5, striking current limiting device; 51, third insulating support rod; 52, current limiting plate; 6, transformer. DETAILED DESCRIPTION

[0036] In the following description, a large number of specific details are given to provide a more thorough understanding of the utility model. However, it is obvious for those skilled in the art that the utility model embodiments can be implemented without one or more of these details. In other examples, some technical features known in the art are not described in order not to obscure the utility model embodiments.

[0037] In order to thoroughly understand the utility model embodiments, detailed structures will be proposed in the following description. Obviously, the implementation of the utility model embodiments is not limited to the special details familiar to those skilled in the art. The preferred embodiments of the utility model are described in detail as follows, however, in addition to these detailed descriptions, the utility model can also have other embodiments, and should not be interpreted as being limited to the embodiments proposed here.

[0038] It is to be understood that the terms used herein are for the purpose of describing particular embodiments and are not intended to be limiting of the present application, as the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. When the terms "comprises" and / or "comprising" are used in this specification, they are taken to specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. The term "upper," "lower," "front," "back," "right," "left," and similar terms are used herein only to facilitate description of the embodiments, and do not connote limitations.

[0039] The ordinal numbers such as "first" and "second" used in the present application merely identify the names, and do not have any other meanings, such as a particular order. Also, for example, the term "first component" itself does not imply the existence of a "second component," and the term "second component" itself does not imply the existence of a "first component."

[0040] In this document, "approximately," "about," and the like are used to describe and account for small fluctuations, such as can be expected in manufacturing or other processes, which are within the scope of those of ordinary skill in the art.

[0041] Unless otherwise indicated, numerical ranges herein are inclusive of the recited two endpoints in their entirety. Also, unless otherwise indicated, individual values in a range are inclusive.

[0042] The technical solutions in the embodiments of the present application will be clearly and completely described with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of the present application.

[0043] A test tool for a high-voltage isolation transformer includes an insulating cylinder 1, a transformer 6, and a voltage doubling rectifier device 2. The transformer 6 and the voltage doubling rectifier device 2 are arranged in the insulating cylinder 1 with a spacing therebetween.

[0044] The insulating cylinder 1 contains an insulating liquid. The primary side of the transformer 6 is connected to a power supply (not shown). The voltage doubling rectifier device 2 is connected to the secondary side of the transformer 6. A voltage dividing device 3 and a sampling device 4 are connected in sequence between the high-voltage end and the low-voltage end of the voltage doubling rectifier device 2. The sampling device 4 is arranged close to the low-voltage end to collect the electrical signal at the output end of the voltage dividing device 3.

[0045] According to the scheme, the test tool of the high-voltage isolation transformer realizes voltage boosting through the transformer and the voltage doubling rectifier device, and sets the voltage dividing device and the sampling device between the high-voltage end and the low-voltage end of the test tool, so that the output voltage of the test tool can be accurately measured.

[0046] Please refer to Figures 1-4 , the test tool of the high-voltage isolation transformer according to a preferred embodiment of the utility model. The test tool includes a two-end sealed insulating cylinder 1, and a voltage doubling rectifier device 2, a voltage dividing device 3, a sampling device 4, a sparking current limiting device 5 and a transformer 6 located inside the insulating cylinder 1.

[0047] The insulating cylinder 1 is made of insulating material. It can be set to be transparent to observe the working condition of each device placed inside it in time.

[0048] Please refer to Figure 1 , the bottom of the insulating cylinder 1 is provided with a base 11 made of insulating material. The base 11 can be directly placed on the ground, or a plurality of lockable universal wheels can be installed on the bottom of the base 11 to quickly move the entire test tool to the corresponding working area for test work.

[0049] A positioning ring 12 made of insulating material is installed on the upper surface of the base 11, and the lower ring surface of the positioning ring 12 and the upper surface of the base 11 are sealed and fitted with each other. A sealing ring can also be provided between the lower ring surface of the positioning ring 12 and the base 11. The bottom of the insulating cylinder 1 is coaxially inserted into the positioning ring 12, and the insulating cylinder 1 and the positioning ring 12 are sealed and fitted with each other through a sealing element to avoid leakage at the joint gap between the two.

[0050] As shown in Figure 1 , in order to further improve the connection tightness of the insulating cylinder 1 and the positioning ring 12, a plurality of through holes are opened on the outer surface of the positioning ring 12 along the ring direction of the positioning ring 12, and at the same time a plurality of threaded blind holes are also opened on the outer surface of the bottom of the insulating cylinder 1. Then the insulating cylinder 1 is firmly installed on the positioning ring 12 through the threaded cooperation of the screws and the threaded blind holes. Similarly, the same way is adopted to install a positioning ring 12 on the top end of the insulating cylinder 1, and at the same time a top cover 13 is sealed and covered on the positioning ring 12.

[0051] So far, through the cooperation of the base 11, the top cover 13 and the two positioning rings 12, the packaging of the two ends of the insulating cylinder 1 is completed, and a sealed cavity is formed in the inside of the insulating cylinder 1. The sealed cavity is filled with insulating liquid, and the rest of the devices are immersed in the insulating liquid. Since the test tool of the embodiment of the utility model is used for detecting the high-voltage isolation transformer, the inside of the insulating cylinder 1 is a high-voltage environment, and high-voltage insulation performance is required to ensure safety in use, therefore, transformer oil is selected as the insulating liquid, which can absorb the heat generated in the test tool on the one hand, and can improve the high insulation performance of the test tool on the other hand.

[0052] Referring to Figure 1 , the high-voltage lead terminal 14 for load connection is also arranged on the top cover 13. It can be understood that the test tool of the utility model is a device for testing the withstand voltage performance of the high-voltage isolation transformer, therefore, the high-voltage lead terminal 14 is actually used for connecting to the high-voltage isolation transformer to be tested.

[0053] In order to improve the withstand voltage insulation performance of the test tool, the high-voltage lead terminal 14 is provided with an insulating structure. Specifically, the insulating structure includes an insulating column 143 coaxially sleeved outside the high-voltage lead terminal 14. The insulating structure also includes an insulating base plate 141 arranged at the bottom of the insulating column 143 and used for mounting on the top cover 13 (see Figure 1 ). For example, the insulating base plate 141 can be fixed with the top cover 13 through threaded fasteners. A through hole can be formed in the insulating base plate 141 for inserting and keeping the wiring vertical, and a threading hole is formed in the top cover 13 correspondingly, and the bottom end of the wiring column 142 is sequentially threaded through the through hole and the threading hole, and is connected with the output end of the sparking current limiting device 5. At the same time, the wiring column 142 and the threading hole are sealingly connected, so as to effectively protect the sealing performance of the insulating cylinder 1.

[0054] Referring to Figure 1 , the outer side of the wiring column 142 on the insulating base plate 141 is coaxially sleeved with the insulating column 143, and the top end of the wiring column 142 protrudes out of the insulating column 143 upward, so as to be connected with the external load. Exemplarily, the insulating column 143 and the insulating base plate 141 can be integrally casted by using a mold and adopting epoxy resin. Although the insulating column 143 has increased the creepage distance, in the preferred embodiment, at least one of the outer surface of the insulating column 143 and the top surface of the top cover 13 is integrally and insulatingly connected with an insulating arch, so as to further increase the creepage distance.

[0055] Specifically, referring to the embodiment shown in Figure 1 , the insulating arch includes a protruding disc 144 and an insulating sleeve 145. The protruding disc 144 is arranged on the outer surface of the insulating column 143, and the insulating sleeve 145 is arranged on the insulating base plate 141.

[0056] The insulating base column 143 is fixedly connected with the top cover 13 through the insulating base plate 141, the insulating base plate 141 is attached to the top cover 13, and the cross-sectional area of the insulating base plate 141 is greater than the cross-sectional area of the insulating base column 143. It is ensured that the high-voltage lead-out terminal 14 can be stably supported on the surface of the top cover 13.

[0057] Referring to Figure 1 A plurality of insulating sleeves 145 coaxially sleeved with the insulating base column 143 are arranged on the insulating base plate 141. Meanwhile, a plurality of insulating protruding discs 144 are coaxially arranged outside the insulating base column 143, and each protruding disc 144 is arranged at equal intervals along the axis of the insulating base column 143. In order to eliminate the fitting gap between the insulating base plate 141, the insulating base column 143, each insulating sleeve 145 and each protruding disc 144, the insulating base plate 141, the insulating base column 143, each insulating sleeve 145 and each protruding disc 144 are integrally formed by pouring through a mold, so as to eliminate the possible fitting gap and further increase the creepage distance.

[0058] In other embodiments not shown in the utility model, a bowl-shaped insulating structure can be designed on the top of the high-voltage lead-out terminal 14 to further increase the creepage distance.

[0059] The primary coil of the transformer 6 is connected with an external power source through a wiring terminal embedded on the insulating cylinder 1. The voltage doubling and rectifying device 2 is installed on the output end of the secondary coil of the transformer 6. The transformer 6 and the voltage doubling and rectifying device 2 are used to increase the voltage of the external power source, so as to reach the detection standard of the high-voltage isolation transformer to be detected.

[0060] Referring to Figure 4 In the embodiment shown, the high-voltage end of the voltage doubling and rectifying device 2 is connected to the voltage dividing device 3 and the spark limiting device 5, and the low-voltage end of the voltage doubling and rectifying device 2 is connected to the secondary coil of the transformer 6. The low-voltage end is also grounded.

[0061] The voltage doubling and rectifying device 2 includes four first insulating support rods 21, and each voltage doubling and rectifying plate 22 is fixed on the four first insulating support rods 21 from bottom to top, and a certain space is left between adjacent voltage doubling and rectifying plates 22, so that the transformer oil can fully contact the surface of the voltage doubling and rectifying plate 22, thereby effectively reducing the temperature of the voltage doubling and rectifying plate 22 and maintaining stable operation. Each voltage doubling and rectifying plate 22 is connected in series to form the entire voltage doubling and rectifying circuit. Each voltage doubling and rectifying plate 22 includes a plurality of diodes and capacitors, and the voltage doubling and rectifying circuit formed by cooperation is as shown in Figure 4 .

[0062] The voltage dividing device 3 comprises four second insulating support rods 31 and a plurality of voltage dividing plates 32 which can be mounted on the voltage dividing insulating support frame. Each voltage dividing plate 32 is annular plate-shaped and has less than one turn, forming a circular ring plate with an opening. Four sleeve holes are formed on the surface of each voltage dividing plate 32 for sleeving the second insulating support rods 31. Each voltage dividing plate 32 is mounted on the second insulating support rod 31 through the sleeve holes and the plug-in cooperation of the second insulating support rods 31, and the adjacent voltage dividing plates 32 are spaced apart from each other by a set insulation distance under the action of the limiting member, thereby forming a spiral rising structure. In order to further improve the stability of the second insulating support rods 31, the top ends of the second insulating support rods 31 are inclined to the axis of the spiral rising structure, and the corresponding voltage dividing plates 32 are also correspondingly reduced in size, thereby forming a tower-shaped frame structure.

[0063] The openings of the voltage dividing plates 32 are aligned from top to bottom, and the adjacent two voltage dividing plates 32 are connected in series through wires at the upper and lower openings, thereby forming a voltage dividing circuit. Each voltage dividing plate 32 comprises a plurality of resistors and capacitors which are connected to each other to form a voltage dividing circuit as shown in FIG. Figure 4

[0064] The striking current limiting device 5 comprises a plurality of annular plate-shaped current limiting plates 52 which are sequentially and spaced apart mounted on the third insulating support rods 51 from bottom to top, and the current limiting plates 52 are sequentially connected in series. That is, the overall structure of the striking current limiting device 5 is similar to that of the voltage dividing device 3, and finally a tower-shaped frame structure is also formed.

[0065] In the voltage dividing device 3, the voltage doubling rectifying device 2 and the striking current limiting device 5, support rods and plates are used, and sleeve holes are formed on the plates. The support rods and the sleeve holes are matched to complete the construction of the devices. The striking current limiting device 5 is erected above the voltage dividing device 3, and the output end of the striking current limiting device 5 is connected to the high-voltage lead-out terminal 14. In this way, the connection and cooperation between the modules in the test tool are more reasonable, the circuit is simple and avoids complex winding, the electric field distribution in the insulating cylinder 1 is optimized through the tower-shaped structure, the possibility of partial discharge is reduced, the insulation performance is improved, the overall size of the test tool is reduced, and the stability and safety of the test tool are further improved.

[0066] In actual use, the matching mode of the support rods and the plates mainly includes two types. One is that the support rods are segmented, and the upper segment and the lower segment can be plugged or screwed together to form a complete support rod. Two positioning holes are formed on each rod body, and when the plate is slid between the two positioning holes on the rod body, two positioning pins as limiting members are inserted into the two positioning holes. At this time, the plate is clamped between the two positioning pins, and the positioning of the plate is achieved. ​

[0067] When installing the voltage dividing device 3, the voltage doubling rectifier device 2 and the striking current limiting device 5 in the insulating cylinder 1, three similar tower-shaped frame structures can be placed on the base 11 and spaced apart from each other, or can be stacked one after another. In the embodiment, the voltage dividing device 3 and the voltage doubling rectifier device 2 are installed on the base 11, and the striking current limiting device 5 is stacked above the voltage dividing device 3, that is, the third insulating support rod 51 is inserted on the second insulating support rod 31, and the upper and lower stacking of the two is completed through the insertion and cooperation of the rods. On the one hand, the upper and lower stacking can reduce the occupied area, and on the other hand, it is convenient for the striking current limiting module to be connected to the high-voltage output terminal through the lead wire; in addition, it can efficiently utilize the space in the sealed cavity, and realize better electrical insulation effect in combination with the tower-shaped structure.

[0068] The sampling device 4 includes a first sampling device 41 and a second sampling device 42 which sequentially collect the output electrical signal of the voltage dividing device 3. The first sampling device 41 and the voltage dividing device 3 are connected in series between the high-voltage end and the low-voltage end of the voltage doubling rectifier device 2, forming a voltage dividing sampling loop. And the first sampling device 41 is arranged close to the low-voltage end of the voltage doubling rectifier device 2. By collecting the voltage signal at both ends of the first sampling device 41, the voltage between the high-voltage end and the low-voltage end of the voltage doubling rectifier device 2 (i.e. the no-load output voltage of the test tool, which is also the load voltage) can be obtained.

[0069] The second sampling device 42 is arranged close to the low-voltage end of the voltage doubling rectifier device 2 in the total loop, and by collecting the current signal of the second sampling device 42, the current signal of the total loop can be obtained. When the withstand voltage test of the transformer to be tested is performed, the current (load current) of the transformer to be tested can be obtained through the second sampling device 42.

[0070] As shown in the first sampling device 41 in Figure 4 The first sampling device 41 includes three resistors, two of which are connected in series and connected in parallel with the third resistor, forming a first sampling circuit.

[0071] As shown in the second sampling device 42 in Figure 4 The second sampling device 42 includes one resistor, two capacitors and one bidirectional thyristor, and the resistor, the capacitor and the bidirectional thyristor are connected to each other in parallel, forming a second sampling circuit.

[0072] The transformer 6, the voltage dividing device 3, the voltage doubling rectifier device 2, the sampling device 4 and the striking current limiting device 5 are sequentially installed in the insulating cylinder 1, and are arranged according to Figure 4The electrical schematic diagram is connected. After the connection is completed, the output end of the spark current limiting device 5 and the terminal 142 are connected with each other. The terminal of the transformer primary coil and the transformer input terminal 15 on the wall of the insulating cylinder 1 are connected with each other, and the transformer input terminal 15 is used for external power supply. The terminal of the first sampling device 41 and the voltage sampling terminal 17 on the wall of the insulating cylinder 1 are connected, and the voltage sampling terminal 17 is used for determining the output voltage of the high voltage output terminal, so as to ensure that the high voltage output value reaches the test requirement in the no-load state. The terminal of the second sampling device 42 and the current sampling terminal 16 on the wall of the insulating cylinder 1 are connected with each other, and the current sampling terminal 16 is used for collecting the relevant test data of the transformer to be tested in the withstand voltage test.

[0073] The insulating cylinder 1 is also provided with a shell grounding terminal 18 which is conductively connected with the metal structure in the insulating cylinder 1.

[0074] The low voltage end of the voltage doubling and rectifying device 2 and the output low voltage terminal 19 are connected with each other. In actual use, the output low voltage terminal 19 is grounded.

[0075] The actual products of the voltage dividing plate 32, the voltage doubling and rectifying plate 22 and the current limiting plate 52 are all in the form of printed boards, and the various parts of the circuit are arranged on the voltage dividing plate 32, the voltage doubling and rectifying plate 22 and the current limiting plate 52. Figure 4

[0076] The above is only the preferred specific implementation manner of the present application, but the protection scope of the present application is not limited to this. Any skilled person in the art can make equivalent replacement or change according to the technical scheme and the inventive concept of the present application within the technical range disclosed by the present application, and all of them should be covered in the protection scope of the present application.​

Claims

1. A test fixture for a high voltage isolation transformer, characterized by, The device comprises an insulating cylinder (1), a transformer and a voltage doubling rectifier device (2) which are arranged in the insulating cylinder (1) with a certain interval, the insulating cylinder (1) contains insulating liquid, the primary side of the transformer is connected to a power supply, the voltage doubling rectifier device (2) is connected to the secondary side of the transformer, a voltage dividing device (3) and a sampling device (4) are connected in sequence between the high voltage end and the low voltage end of the voltage doubling rectifier device (2), and the sampling device (4) is arranged close to the low voltage end to collect the electrical signal at the output end of the voltage dividing device (3).

2. The test fixture for a high-voltage isolation transformer of claim 1, wherein, The voltage dividing device (3) comprises a plurality of voltage dividing plates (32) connected in series, the plurality of voltage dividing plates (32) are arranged at a certain insulating distance in the height direction of the insulating cylinder (1), and the voltage dividing plate (32) close to the bottom of the insulating cylinder (1) is connected to the low voltage end of the voltage doubling rectifier device (2).

3. The test fixture for a high-voltage isolation transformer of claim 2, wherein, The voltage dividing plate (32) is a spiral plate, and each voltage dividing plate (32) is connected in sequence to form a spiral structure; or the voltage dividing plate (32) is configured as an annular plate with a notch, the notches of adjacent two voltage dividing plates are aligned, and each voltage dividing plate (32) is connected in sequence to form a spiral structure through a lead wire.

4. The test fixture for a high-voltage isolation transformer of claim 3, wherein, The voltage dividing device (3) further comprises a voltage dividing insulating support frame for mounting the voltage dividing plate (32), the voltage dividing insulating support frame comprises a second insulating support rod (31) extending in the height direction, and the second insulating support rod (31) has at least three rods, and each second insulating support rod (31) is arranged at an interval around the axis of the spiral structure.

5. The test fixture for a high-voltage isolation transformer of claim 4, wherein, The voltage dividing plate (32) is detachably mounted to the second insulating support rod (31); or each voltage dividing plate (32) and the second insulating support rod (31) are configured as a voltage dividing component formed integrally, and adjacent two voltage dividing components are connected through the second insulating support rod (31) to form the voltage dividing device (3).

6. The test fixture for a high voltage isolation transformer of claim 1, wherein, The cylinder wall of the insulating cylinder (1) is embedded with a wiring terminal for connecting to the transformer and the sampling device.

7. A test fixture for a high voltage isolation transformer as claimed in any one of claims 1 to 6, wherein, The voltage doubling rectifier device (2) comprises a first insulating support rod (21) extending in the height direction, a plurality of voltage doubling rectifier plates (22) are arranged in sequence at an interval from bottom to top on the first insulating support rod (21), and the voltage doubling rectifier plate (22) close to the bottom of the first insulating support rod (21) is connected to the secondary side of the transformer.

8. A test fixture for a high voltage isolation transformer as claimed in any one of claims 1 to 6, wherein, The sampling device (4) comprises a first sampling device (41) and a second sampling device (42), the first sampling device (41) and the voltage dividing device (3) are connected in series at the output end of the voltage doubling rectifier device (2) to form a voltage dividing sampling loop, the first sampling device (41) is arranged close to the low voltage end of the voltage doubling rectifier device (2) to collect the voltage signal of the voltage dividing sampling loop, and the second sampling device (42) is arranged in a total loop close to the low voltage end of the voltage doubling rectifier device (2) to collect the current signal of the total loop.

9. A test fixture for a high voltage isolation transformer as claimed in any one of claims 1 to 6, wherein, The high-voltage end of the voltage doubling rectifier device (2) is further connected with a sparking current limiting device (5) which is immersed in the insulation cylinder (1) filled with insulation liquid; the sparking current limiting device (5) is installed on the top of the voltage dividing device (3) and comprises a third insulation support rod (51) and a plurality of current limiting plates (52) which are sequentially and spacedly installed on the third insulation support rod (51) from bottom to top, and the sparking current limiting device (5) is arranged above the voltage dividing device (3).

10. The test fixture for a high-voltage isolation transformer of claim 9, wherein, The top cover (13) of the insulation cylinder (1) is provided with a high-voltage leading terminal (14) which is connected with the output end of the sparking current limiting device (5); the high-voltage leading terminal (14) comprises a terminal post (142) which is installed on the top cover (13), and the outer side of the terminal post (142) is wrapped with an insulation base column (143), and at least one of the outer surface of the insulation base column (143) and the top surface of the top cover (13) is integrally and insulatively connected with an insulation arch.

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