Testing device for low-voltage side of transformer

Abstract

The utility model provides a test device used for a low voltage side of a transformer, the transformer is provided with a box body and a plug head seat arranged on the box body, a conductive element of the plug head seat is electrically connected to a coil lead in the box body, the test device is characterized by comprising a sleeve, a plug pin and a plug pin, the sleeve is installed on a box body through an installation hand hole in the box body of the transformer and is provided with a conductive end extending into the box body and a test end arranged on the outer side of the box body. And the transition connecting piece is arranged in the box body, the first end of the transition connecting piece is electrically connected to the conductive end of the sleeve, and the second end of the transition connecting piece is electrically connected to the conductive element of the plug head seat, so that the sleeve is indirectly and electrically connected to the coil lead. According to the test device, high capital cost and time cost are not needed, and factory test of the low-voltage side of the transformer can be simply and efficiently completed with low cost.

Description

Technical Field

[0001] The utility model belongs to the technical field of transformers, and particularly relates to a test device for the low-voltage side of a transformer. Background Art

[0002] In order to ensure that the transformer meets all technical specifications and performance requirements before leaving the factory and to guarantee the safe operation and reliability of the transformer, a series of factory tests need to be carried out on the transformer. For example, the factory high-voltage tests of the transformer (power frequency test, lightning impulse, partial discharge test, etc.). Among the factory test items on the low-voltage side of the transformer, the 35kV plug-in head seat is a commonly used test device. At present, the form of plug-in head seat and XLPE cable is generally adopted on the low-voltage 35kV side of offshore wind power transformers or onshore wind power / solar photovoltaic transformers. Common plug-in head seats include L-shaped or straight-hole types, and there are also single-hole, double-hole or four-hole types, etc.

[0003] Since the object of the test is a high-voltage electrical product such as a transformer, during the test process, it is necessary to strictly ensure the safety and accuracy of the operation. According to relevant standards and specifications, the personnel conducting the 35kV plug-in head seat test should be professional personnel with corresponding qualifications and skills. These professional personnel need to hold a nationally recognized qualification certificate, be able to operate the test equipment proficiently, and be familiar with the safety regulations and operation standards of high-voltage tests. In addition, special test components are usually required during the test, including test bushings, test cables or socket simulation plugs, etc. For example, when conducting a transformer temperature rise test, a special current test connector is also required.

[0004] The above requirements make it necessary for transformer manufacturers to not only rent the above various special test components from the suppliers of the test devices when conducting factory tests on transformers, but also wait for the professional personnel of the suppliers to come to the site to operate the test equipment for the test. Therefore, the factory test of each transformer requires high rental costs and also needs to consider the schedule of the suppliers' test equipment and professional installation workers, resulting in a long cycle and high time costs.

[0005] Therefore, the inventor believes it is necessary to provide a test device for the low-voltage side of a transformer, which can complete the factory test of the low-voltage side of the transformer simply, at low cost and efficiently without high capital costs and time costs. Summary of the Utility Model

[0006] The present disclosure aims to provide a test device for the low-voltage side of a transformer, which at least partially eliminates the defects existing in the prior art.

[0007] An object of the present disclosure is to provide a test device for the low-voltage side of a transformer, which can complete the factory test of the low-voltage side of the transformer at low cost.

[0008] Another object of the present disclosure is to provide a test device for the low-voltage side of a transformer, which can efficiently complete the factory test of the low-voltage side of the transformer.

[0009] Yet another object of the present disclosure is to provide a test device for the low-voltage side of a transformer, which can simply and conveniently complete the factory test of the low-voltage side of the transformer.

[0010] To solve the above technical problems, according to one aspect of the present disclosure, there is provided a test device for the low-voltage side of a transformer. The transformer has a box body and a plug-in head seat provided on the box body. The conductive element of the plug-in head seat is electrically connected to the coil lead in the box body. The test device is characterized in that it includes: a bushing, which is installed on the box body through an installation hand hole on the box body of the transformer, and has a conductive end extending into the box body and a test end provided outside the box body; and a transition connector, which is provided in the box body. The first end of the transition connector is electrically connected to the conductive end of the bushing, and the second end is electrically connected to the conductive element of the plug-in head seat, thereby indirectly electrically connecting the bushing to the coil lead.

[0011] In the present disclosure, by adopting the test device with the above-described embodiment, the need to connect test components such as test cables using the plug-in head seat for testing is eliminated. Instead, only a conventional bushing can be used to connect test components for necessary tests. This not only eliminates the rent for renting specific test components (such as special test bushings, test cables, current test connectors, socket simulation plugs, etc.), but also does not require professional personnel from the supplier to come to the site for installation. Compared with the original test device, the capital, labor, and time costs for testing are greatly reduced.

[0012] Furthermore, the transition connector is flexible, which is beneficial for the transition connector to adapt to various application scenarios with different connection distances.

[0013] Optionally, the transition connector includes a rigid extension part and a flexible extension part connected to at least one end of the rigid extension part. The rigid extension part has a shape adapted to the insulating space of its installation position. The presence of the rigid extension part ensures the overall stability of the connector to a certain extent, helps to ensure the safety and stability during the use of the device, and makes the rigid extension part have a shape adapted to the insulating space of its installation position. In this way, in the assembled state, the rigid extension part is not likely to move, thus ensuring the insulation performance during use.

[0014] Specifically, according to the shape of the insulating space, the rigid extension part can have a two-dimensional bending shape or a three-dimensional bending shape.

[0015] Optionally, the flexible extension part is a flexible connection piece and is detachably connected to the rigid extension part, which not only enhances the adaptability of the transition connection piece but also facilitates disassembly, changing the structural relationship, and reuse.

[0016] Optionally, the rigid extension part is a copper busbar.

[0017] Optionally, the flexible extension part is a flexible connection piece, and the flexible connection piece includes flexible copper sheets and copper blocks welded to both ends of the flexible copper sheets.

[0018] Optionally, the rigid extension part and the flexible extension part are connected by bolts, and the rigid extension part has a redundant number of oblong bolt holes. The bolt holes are oblong and redundant in number, which allows reducing the assembly difficulty when connecting by bolts and also reduces the requirements for the machining accuracy and fitting accuracy of each component.

[0019] Alternatively, the transition connection piece is composed of a single flexible connection piece, which allows the transition connection piece to have increased flexibility. The single flexible connection piece has a first connection terminal forming the first end of the transition connection piece, a second connection terminal forming the second end of the transition connection piece, and a flexible conductor connecting the first connection terminal and the second connection terminal.

[0020] Optionally, the single flexible connection piece is a transition cable, and the transition cable includes: a first terminal lug as the first connection terminal; a second terminal lug as the second connection terminal; and a cable part as the flexible conductor, and both ends of the cable part are respectively connected to the first terminal lug and the second terminal lug.

[0021] Or optionally, the single flexible connection piece is a flexible connection piece, and the flexible connection piece includes: a first copper block as the first connection terminal; a second copper block as the second connection terminal; and a flexible copper sheet as the flexible conductor, and both ends of the flexible copper sheet are respectively welded to the first copper block and the second copper block.

[0022] The transition connection piece structure composed of a single flexible connection piece is simpler and easier to install.

[0023] Furthermore, the first end and the second end of the transition connection piece are respectively detachably electrically connected to the sleeve and the plug socket, so it is easy to disassemble and assemble.

[0024] Furthermore, the transition connection piece is made of copper, with low cost and simple production.

[0025] Alternatively, the material of the transition connection piece can also be selected from conductive materials such as aluminum, silver, gold, tin, graphite, carbon fiber, and conductive polymer materials.

[0026] Furthermore, the structure and installation orientation of the transition connector can be adaptively adjusted according to the insulation space at the installation position. On the one hand, it helps to ensure the insulation performance during use, and on the other hand, it will be more conducive to the recycling of the transition connector, thereby saving costs.

[0027] In the present disclosure, a conventional pure magnetic bushing (vertically or horizontally installed) can be used as the test bushing, which reduces costs. Moreover, the transition connectors (such as copper bars and flexible connectors) are easy to process and manufacture and are inexpensive. The installation of the test device does not require external professionals and can simultaneously meet the high-voltage test and temperature rise test during the transformer's factory production without switching. In practical applications, multiple conventional bushings and matching transition connectors can be purchased at one time. In this way, the installation and testing of more than two transformers can be simultaneously satisfied without excessive cost, and these components can be recycled, saving a large amount of test device rental costs and time costs. Therefore, the test device for the low-voltage side of the transformer in the present disclosure can simply, inexpensively, and efficiently complete the factory test of the low-voltage side of the transformer. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Through the following description with reference to the drawings, the features and advantages of one or several embodiments of the present utility model will become more easily understood. The drawings described herein are only for illustrative purposes and are not intended to limit the scope of the present utility model in any way. The drawings are not drawn to scale, and some features may be enlarged or reduced to show the details of specific components. In the drawings:

[0029] Figure 1 is a schematic diagram of the working state of a test device for the low-voltage side of a transformer according to the prior art;

[0030] Figure 2 is a schematic diagram of a test device for the low-voltage side of a transformer according to the first embodiment of the present disclosure;

[0031] Figure 3 is a schematic diagram of the rigid extension part in the test device according to the first embodiment of the present disclosure;

[0032] Figure 4 is a schematic diagram of a test device for the low-voltage side of a transformer according to the second embodiment of the present disclosure;

[0033] Figure 5 is a schematic diagram of a test device for the low-voltage side of a transformer according to the third embodiment of the present disclosure; and

[0034] Figure 6 is Figure 5 a partial enlarged schematic diagram of part A of the square box.

[0035] Explanation of the reference numerals in the drawings:

[0036] 1 Box body, 2 Side wall, 5 Cable

[0037] 3 Plug - in head seat, 3a Conductive element, C Flexible connection piece

[0038] 4 Coil lead wire, 4a Copper bar

[0039] 10 Box body, 101 Box cover, 102 Side wall

[0040] 103 Installation hand hole for plug - in head seat lead wire, 14 Coil lead wire, 14a Copper bar

[0041] 20 Plug - in head seat, 20a Copper bar, C1 Flexible connection piece

[0042] 22 Seat part, 24 Rod part

[0043] 30 Sleeve, 32 Conductive end, 34 Copper block

[0044] 36 Test end, 40 Copper busbar, 40c Bolt hole

[0045] 42 Flexible connection piece, 105 Busbar box, 50 Test transition cable

[0046] 52 First wiring nose, 54 Second wiring nose, 56 Cable part

[0047] 60 Plug - in head seat, 60a Copper conductive plate, 70 Flexible connection piece

[0048] 72 First copper block, 74 Second copper block, 76 Copper sheet Detailed implementation manners

[0049] Next, the technical solutions in the embodiments of the present disclosure will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and in no way restrictive of the present disclosure and its application or use. Based on the embodiments in the present disclosure, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present disclosure.

[0050] It should be noted that the terms used here are only for describing the specific implementation manners and are not intended to limit the exemplary implementation manners according to the present disclosure. As used here, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form.

[0051] Figure 1It is a schematic diagram of the working state of a test device for the low-voltage side of a transformer according to the prior art. As shown in the figure, a plug-and-socket base 3 for testing is installed on the low-voltage side of the transformer. In this example, the plug-and-socket base 3 is a common L-shaped four-hole plug-and-socket base, which is installed on the side wall 2 of the transformer box 1, and its end extends into the box 1 and has a conductive element 3a for connecting the coil. The seat part fixed outside the box 1 has four connection holes, and these holes are used to connect test elements such as special test cables 5 or test bushings for relevant tests. When conducting tests, the unused connection holes need to be tightly plugged with socket mock plugs to ensure insulation. In this example, the conductive element 3a of the plug-and-socket base 3 is a copper rod, and its electrical connection with the end copper rod 4a of the coil lead 4 is achieved through a flexible connector C. In this existing test device, test elements such as the cable 5 and socket mock plugs need to be rented, and inserting the cable 5 into the plug-and-socket base 3 requires high safety and accuracy, and needs to be completed by professional personnel with corresponding qualifications and skills.

[0052] In view of this, aiming at the deficiencies of the above prior art, the applicant provides a test device for the low-voltage side of a transformer as described in the following embodiments, and this test device will greatly reduce the capital, labor and time costs spent on factory inspection.

[0053] Figure 2 It is a schematic diagram of a test device for the low-voltage side of a transformer according to the first embodiment of the present disclosure.

[0054] Combined with Figure 1, A test device for the low-voltage side of a transformer according to the first embodiment of the present disclosure. The transformer has a box body 10 and a plug-in head seat 20 provided on the box body 10. Specifically, the plug-in head seat 20 is provided on the side wall 102 of the box body 10 and has a seat portion 22 exposed outside the box body 10 and a rod portion 24 extending into the inside of the box body 10. At the end of the rod portion 24, there is a protruding conductive element, which is implemented as an elongated copper rod 20a, and it is electrically connected to the coil lead 14 through a flexible connection C1 inside the box body 10. Specifically, the copper rod 20a is electrically connected to a copper rod 14a led out from the coil lead 14 through the flexible connection C1. On this basis, the test device includes a bushing 30, which does not need to be specially rented and can be a conventional medium- and low-voltage bushing, such as a 40.5 kV - 4000 A pure magnetic bushing. The bushing 30 is installed on the cover 101 of the box body 10 in the vertical direction through a plug-in head seat lead installation hand hole 103 on the transformer box body 10. The conductive end 32 of the bushing 30 extends into the box body for electrical connection to the coil, and the test end 36 of the bushing 30 is exposed outside the box body 10, and this test end 36 can be used to connect various test elements (such as test cables) to conduct corresponding tests. The test device according to this embodiment further includes a transition connector. The first end of the transition connector is electrically connected to the conductive end 32 of the bushing 30, and the second end of the transition connector is electrically connected to the copper rod 20a of the plug-in head seat 20, thereby indirectly electrically connecting the bushing 30 to the coil lead 14.

[0055] In the present disclosure, by adopting the test device with the above-described implementation manner, the need to connect test elements such as test cables using the plug-in head seat for testing is eliminated. Instead, only by means of a conventional bushing can test elements be connected to conduct necessary tests, which not only eliminates the rent for renting specific test elements (such as special test bushings, test cables, current test connectors, socket simulation plugs, etc.), but also does not require professional personnel from the supplier to come to the site for installation. Compared with the original test device, the capital, labor, and time costs for testing are greatly reduced. Moreover, the test device of the present disclosure itself does not require additional equipment costs and also has the advantages of low cost, simple structure, and easy operation.

[0056] Preferably, the transition connector is flexible as a whole. As Figure 2As shown, in the test device according to the first embodiment of the present application, the transition connector includes a copper busbar 40 as a rigid extension part and a soft connector 42 as a flexible extension part, wherein the copper busbar 40 has a bent shape, and one end of the copper busbar 40 is rigidly connected to the conductive copper rod 20a of the plug header 20 by bolts. Specifically, a copper plate is clamped on the outside of the copper rod 20a, and the end of the copper busbar 40 is rigidly connected to the copper plate by bolts; the other end of the copper busbar 40 is connected to the soft connector 42 and is electrically connected to the copper block 34 on the conductive end 32 of the sleeve 30 via the soft connector 42.

[0057] The above design is advantageous because in a transformer, live components are dense and complex, and insulation space is not sufficient. If the transition connector moves during use, it is easy to cause a short circuit. The rigidity of the rigid extension part makes it difficult to deform or move after being fixed, which ensures the overall stability and insulation of the connector to a certain extent, thereby ensuring the safety of the device during use.

[0058] Preferably, the rigid extension has a shape adapted to the insulating space in which it is installed. Figure 2 and Figure 3 As shown, the curved shape of the copper busbar 40 includes an angled structure, which is provided to adapt to the insulation space of the installation location, in other words, to bypass the area where a short circuit may occur. In this way, in the assembled state, the rigid extension part is not easy to deform and move, thereby ensuring insulation during use.

[0059] In this embodiment, the flexible extension portion is a soft connector 42, which can have the same structure as the soft connector C1 between the plug header 20 and the coil lead 14. For example, the soft connector includes two copper blocks and a flexible conductor welded between the two copper blocks. The flexible conductor is, for example, a flexible copper sheet that is easy to bend. The flexible copper sheet is composed of multiple layers of ultra-thin copper sheets. The copper blocks on both sides can be fixed to the end of the copper busbar 40 and the copper block 34 on the conductive end 32 of the sleeve 30 by bolts, respectively. On the one hand, the flexible conductor realizes electrical conduction, and on the other hand, it can compensate for the distance deviation between the end of the copper busbar 40 and the copper block 34 on the conductive end 32, and can also be used in other positions with different connection distances.

[0060] Therefore, in this embodiment, by providing a transition connector having both a rigid extension part and a flexible extension part, short circuits during application are avoided, and the connection distance is adjustable, and the adaptability is strong. The rigid extension part and the flexible extension part are connected to each other and to the connected parts by bolts, which is convenient for disassembly, structural relationship change and reuse.

[0061] Specifically, see Figure 3, both ends of the copper busbar 40 are respectively provided with a plurality of bolt holes 40c for realizing bolt connection.

[0062] Preferably, the bolt holes are oblong, which allows that when connecting by bolts, the copper busbar and the components connected thereto do not necessarily have a strictly aligned dimensional relationship, reducing the precision and difficulty of processing and assembly.

[0063] Further preferably, the copper busbar 40 may have a redundant number of oblong bolt holes 40c. The so-called "redundant number" means that the number of oblong bolt holes 40c is more than the number of threaded holes required for threaded connection. Refer to Figure 2 , one end of the copper busbar 40 connected to the flexible connector 42 has three oblong bolt holes 40c. In actual installation, only one oblong threaded hole aligned or approximately aligned with the threaded hole of the flexible connector 42 is used to realize the threaded connection. As shown in the figure, only the middle oblong threaded hole 40c is used. The redundant design of the bolt holes 40c further allows installation deviations, dimensional variations or even distance changes of each component, reducing the precision and difficulty of processing and assembly, and enhancing the adaptability of the transition connector.

[0064] Although in this embodiment, the rigid extension part and the flexible extension part of the transition connector are respectively the copper busbar 40 and the flexible connector 42, in actual applications, the rigid extension part and the flexible extension part are not limited thereto. The rigid extension part may not be limited to a two-dimensional bent shape. According to actual needs, the rigid extension part may also be set to have a three-dimensional bent shape extending in three-dimensional space; the rigid extension part and the flexible extension part may also not be made of copper material. For example, they may be common conductive metals such as aluminum, silver, gold, tin, etc., or any suitable highly conductive material such as graphite, carbon fiber, conductive polymer material, etc.

[0065] In addition, according to actual installation needs, both ends of the rigid extension part may be connected with flexible extension parts to facilitate adaptation to complex installation conditions.

[0066] The above is only a specific description of an embodiment of the test device for the low-voltage side of a transformer according to the present invention. It can be understood that the present invention may have various alternative embodiments. For example, as a transition connector, it may be implemented as an integral flexible connector. The flexible connector may have a first connection terminal constituting the first end of the transition connector, a second connection terminal constituting the second end of the transition connector, and a flexible conductor connecting the first connection terminal and the second connection terminal. Such an integral transition connector may have greater flexibility, and the increased flexibility is more conducive to adapting to situations with different connection distances, so the application range is wider.

[0067] Next, reference will be made to Figure 4, a test device for the low-voltage side of a transformer according to a second embodiment of the present disclosure is described, wherein the transition connector is implemented as an integral flexible connector. Hereinafter, only the components with changes will be illustrated and described, and the same content as the first embodiment will not be repeated.

[0068] As Figure 4 shown, in this embodiment, the integral flexible connector is in the form of a test transition cable 50, wherein the transition cable 50 has a first connection nose 52 at the first end and a second connection nose 54 at the second end, and a cable portion 56 connecting the first connection nose 52 and the second connection nose 54. In this transition cable 50, both the first connection nose 52 and the second connection nose 54 can be copper connectors with threaded holes, and the cable portion 56 as a flexible conductor can be two or two groups of flexible cables. Specifically, the cable portion 56 can include stranded copper wires or copper flexible braided tapes. According to the insulation requirement, the outer layer of the cable portion 56 can be coated with an insulating layer to enhance the insulation performance. Both ends of the cable portion 56 can be fixedly connected to the first connection nose 52 and the second connection nose 54 by welding or clamping. The first connection nose 52 as the first connection terminal is connected to the copper block 34 on the conductive end 32 of the bushing 30 via a bolt, and the second connection nose 54 as the second connection terminal is connected to the copper bar 20a of the plug-in socket 20 via a bolt.

[0069] This integral flexible connector in the form of a test transition cable 50 has greater flexibility, and is simple in structure, low in manufacturing cost, easier to install, can adapt to different connection distances, and is convenient for repeated use. Especially in the case of sufficient insulation space and low low-voltage current of the transformer, the advantages of this flexible connector will be more obvious.

[0070] In practical applications, the plug-in socket may have different configurations, and the bushing can also have different installation methods. As an example, Figure 5 and Figure 6A third embodiment of a test device for the low-voltage side of a transformer with a different structure is further shown. In this embodiment, the plug-and-socket base 60 is a single-hole plug-and-socket base. A plurality of such plug-and-socket bases 60 are connected to the coil lead 14 via a common conductive element, which is implemented as a copper conductive plate 60a. Since the plug-and-socket base 60 has a straight hole, in order to facilitate the connection of other test elements, the plug is installed in the busbar box 105 on the side wall of the box body 10, and is installed on the bottom surface of the busbar box 105 such that the cable socket faces downward. In this example, a plug-and-socket base lead installation hand hole 103 is provided on the side wall of the busbar box 105, and the bushing 30 is installed on the side wall of the busbar box 105 in a horizontal direction via the plug-and-socket base lead installation hand hole 103. The conductive end 32 of the bushing 30 extends into the box body for electrical connection to the coil, and the test end 36 of the bushing 30 is exposed outside the box body 10 for connecting various test elements (e.g., test cables) to perform corresponding tests. The test device according to this embodiment further includes a transition connector, which is implemented as a single flexible connector.

[0071] Specifically, referring to Figure 6 , this flexible connector is configured in the form of a flexible connector 70, which has a first copper block 72 at the first end and a second copper block 74 at the second end, and a flexible copper sheet 76 connecting the first copper block 72 and the second copper block 74. In this flexible connector 70, the copper sheets 76 can be two sets of multilayer thin copper sheets arranged opposite to each other and easy to bend. The two ends of the copper sheets 76 are welded at appropriate positions on the first copper block 72 and the second copper block 74, such as on the surface or edge of the first copper block 72 and the second copper block 74. The first copper block 72 serves as a first connection terminal and is connected to the copper block 34 on the conductive end 32 of the bushing 30 via a bolt, and the second copper block 74 serves as a second connection terminal and is connected to the copper conductive plate 60a of a plug-and-socket base 60 via a bolt.

[0072] In this embodiment, such a transition connector has advantages similar to those of the aforementioned test transition cable 50, for example, large flexibility, low cost, simple structure, easy disassembly and installation, capable of adapting to different connection distances, and facilitating reuse.

[0073] In the present disclosure, although various conductive components basically use copper materials, according to actual needs, common conductive metals such as aluminum, silver, gold, tin, etc., or any suitable highly conductive materials such as graphite, carbon fiber, conductive polymer materials, etc. can be selected.

[0074] In the present disclosure, as an advantageous aspect, both the structure and the installation orientation of the transition connector can be adaptively adjusted according to the insulation space at the installation position. For example, in the third embodiment, when the insulation space in the longitudinal direction is insufficient, the copper sheets 76 in the flexible connector 70 can be arranged on both sides in the transverse direction where the insulation space is relatively sufficient to ensure the insulation effect. On the one hand, this aspect helps to ensure the insulation performance during use, and on the other hand, it reflects the flexibility in the use of the transition connector of the present application.

[0075] In the present disclosure, a conventional pure magnetic bushing (vertically or horizontally installed) can be used as the test bushing, which reduces the cost. Moreover, the transition connectors (such as copper bars and flexible connectors) are easy to process and manufacture and have low costs. The installation of the test device does not require external professionals and can simultaneously meet the high-voltage test and temperature rise test during the factory production of the transformer without switching. In practical applications, multiple conventional bushings and the supporting transition connectors can be purchased at one time. In this way, the installation and testing of two or more transformers can be simultaneously satisfied without excessive cost, and these components can be recycled, saving a large amount of rental costs and time costs for the test device and improving the detection efficiency.

[0076] Summary: The test device for the low-voltage side of the transformer in the present disclosure mainly includes a bushing and a transition connector. The main improvements compared with the prior art are as follows:

[0077] ① The bushing is installed through the plug-in head seat lead installation hand hole on the transformer box body, and the bushing can be a conventional 40.5 kV - 4000 A pure magnetic bushing.

[0078] ② A transition connector is provided. The first end of the transition connector is electrically connected to the conductive end of the bushing, and the second end is electrically connected to the conductive element of the plug-in head seat, thereby indirectly electrically connecting the bushing to the coil lead through the plug-in head seat.

[0079] The advantages of the test device in the present disclosure are as follows:

[0080] ① It eliminates the need to use test components such as test cables connected to the plug-in head seat for testing, but only relies on a conventional bushing to connect test components for necessary tests, saving capital, labor, and time costs.

[0081] ② The bushing and the transition connector have low costs, a simple installation structure, and are easy to operate.

[0082] ③ The flexibility of the transition connector in terms of structure, form, and installation ensures the overall insulation performance of the test device, improves the adaptability of the test device, and allows the test device to be recycled.

[0083] ④ The flexible and redundant design of the transition connector reduces the precision requirements and difficulties in component processing and assembly.

[0084] ⑤ It allows for simultaneous installation and testing of two or more transformers at low cost, greatly improving the detection efficiency.

[0085] The various embodiments and variations of the present invention have been specifically described above. However, those skilled in the art should understand that the present invention is not limited to the above specific embodiments and variations, but may include other various possible combinations and associations. Other variations and modifications can be achieved by those skilled in the art without departing from the essence and scope of the present invention. All such variations and modifications fall within the scope of the present invention. Moreover, all components described herein can be replaced by other technically equivalent components.

Claims

1. A test device for the low-voltage side of a transformer, wherein, The transformer has a box body (10) and plug-in head seats (20, 60) provided on the box body (10). The conductive elements of the plug-in head seats (20, 60) are electrically connected to the coil leads (14) inside the box body (10). It is characterized in that the test device includes: A bushing (30), which is installed on the box body (10) of the transformer through a mounting hand hole on the box body (10), and has a conductive end (32) extending into the box body (10) and a test end (36) provided outside the box body (10). Among them, the conductive end (32) is used to be electrically connected to the coil lead (14), and the test end (36) is used to connect test elements; and A transition connector, which is arranged inside the box body (10). Among them, the first end of the transition connector is electrically connected to the conductive end (32) of the bushing (30), and the second end of the transition connector is electrically connected to the conductive elements of the plug-in head seats (20, 60), so as to indirectly electrically connect the bushing (30) to the coil lead (14).

2. The test device according to claim 1, characterized in that, The transition connector has flexibility.

3. The test device according to claim 2, characterized in that, The transition connector includes a rigid extension part and a flexible extension part connected to at least one end of the rigid part. Among them, the rigid extension part has a shape adapted to the insulating space of its installation position.

4. The test device according to claim 3, characterized in that, The rigid extension part has a two-dimensional bending shape or a three-dimensional bending shape, and the rigid extension part is detachably connected to the flexible extension part.

5. The test device according to claim 3, characterized in that: The rigid extension part is a copper bar (40); and / or The flexible extension part is a flexible connector (42), and the flexible connector (42) includes flexible copper sheets and copper blocks welded to both ends of the flexible copper sheets.

6. The test device according to claim 5, wherein The rigid extension part and the flexible extension part are connected by bolts, and the rigid extension part has a redundant number of oblong bolt holes (40c).

7. The test device according to claim 2, wherein The transition connector is composed of a single flexible connector, and the flexible connector has a first connection terminal constituting the first end, a second connection terminal constituting the second end, and a flexible conductor connecting the first connection terminal and the second connection terminal.

8. The test device according to claim 7, characterized in that, The single flexible connector is a transition cable (50), and the transition cable (50) includes: A first terminal lug (52) as the first connection terminal; A second terminal lug (54) as the second connection terminal; and A cable part (56) as the flexible conductor, and both ends of the cable part (56) are respectively connected to the first terminal lug (52) and the second terminal lug (54).

9. The test device according to claim 7, wherein, The single flexible connector is a flexible connector (70), and the flexible connector (70) includes: A first copper block (72) as the first connection terminal; A second copper block (74) as the second connection terminal; and The flexible copper sheet (76) serving as the flexible conductor, both ends of the flexible copper sheet (76) are welded to the first copper block (72) and the second copper block (74) respectively.

10. The test device according to any one of claims 1 to 9, characterized in that, The first end and the second end of the transition connector are electrically connected to the sleeve (30) and the plug-in head seat (20, 60) in a detachable manner respectively.

11. The test device according to any one of claims 1 to 9, characterized in that, The material of the transition connector is selected from conductive materials such as copper, aluminum, silver, gold, tin, graphite, carbon fiber and conductive polymer materials.

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