A device for testing the withstand voltage of the secondary winding of a current transformer

Abstract

This invention provides a device for testing the withstand voltage of the secondary winding of a current transformer, comprising a first conductive plate, a second conductive plate, and a pair of insulated connecting rods. The first and second conductive plates are arranged parallel to each other via the pair of connecting rods, forming an adjustable clamping area between them. The clamping area is used to simultaneously clamp all secondary winding terminals of a single current transformer. The first conductive plate has a pair of first terminals, and the second conductive plate has a pair of second terminals. This invention, through the parallel conductive plates and the adjustable-gap clamping area design, enables simultaneous short-circuiting of the secondary winding terminals of all current transformers in a single operation, quickly connecting multiple terminals and significantly improving the connection efficiency of the detection circuit.

Description

Technical Field

[0001] The utility model relates to the technical field of current transformer inspection devices, and particularly relates to a withstand voltage inspection device for the secondary winding of a current transformer. Background Technique

[0002] After the production of a current transformer is completed, it needs to undergo a finished product test, and the withstand voltage test of the secondary winding is one of the mandatory safety inspection items. According to relevant requirements, the finished product of the current transformer must pass the power frequency withstand voltage test (such as 3 kV / min) to verify the insulation strength between its primary winding and secondary winding, and between the secondary winding and the ground, and prevent electric shock or equipment explosion caused by insulation breakdown during operation. The existing technology generally conducts a ground insulation test on the finished product of the current transformer through a withstand voltage tester to test whether there is a risk or potential hazard of ground breakdown in the transformer equipment. During the test, the withstand voltage tester applies a test voltage much higher than the working voltage of the transformer to the secondary winding for a certain period of time. If there is no insulation breakdown and the leakage current meets the standard, it is judged to be qualified. The withstand voltage tester has the following key terminals: a high-voltage output terminal and a grounding terminal. The former outputs the test high voltage and is connected to the secondary winding of the tested transformer, and the latter is directly connected to the ground or the equipment shell to provide a reference potential. The traditional method for detecting the withstand voltage of the secondary winding generally requires manually winding multiple secondary terminals with copper wires to short-circuit the secondary winding of the transformer, and then connecting multiple transformers in series with copper wires. The above methods have the following defects: First, the detection personnel directly contact the unshielded high-voltage circuit, which is prone to electric shock accidents; second, the short-circuiting of the terminals of a single transformer takes a long time, the wiring efficiency is low, and the copper wires are prone to breakage, falling off, or winding and knotting; third, the contact resistance of the copper wires is unstable, resulting in the phenomenon that the leakage current exceeds the standard. Therefore, there is an urgent need for a withstand voltage inspection device for the secondary winding of a current transformer with integrated short-circuiting, insulation shielding, and fast series connection. Content of the Utility Model

[0003] The purpose of the utility model is to provide a withstand voltage detection device for the secondary winding of a current transformer, which has the advantages of integrated short-circuiting, insulation shielding to prevent electric shock, and fast series connection of multiple transformers.

[0004] To achieve the above purpose, the utility model proposes the following technical solutions:

[0005] A withstand voltage inspection device for the secondary winding of a current transformer includes a first conductive sheet, a second conductive sheet, and a pair of insulating connecting rods;

[0006] The first conductive sheet and the second conductive sheet are arranged parallel and opposite to each other through a pair of the connecting rods, and a clamping area with adjustable gap is formed between the two;

[0007] The clamping area is used for clamping all secondary winding terminals of a single current transformer simultaneously;

[0008] The first conductive sheet has a pair of first terminals, and the second conductive sheet has a pair of second terminals.

[0009] As a preferred technical solution of this utility model, a pair of connecting rods are arranged in parallel opposite directions, and each connecting rod is provided with a connecting hole arranged along its length;

[0010] The first conductive sheet is vertically connected to the bottom end of the pair of connecting rods;

[0011] The two ends of the second conductive sheet are movably connected to the connection hole.

[0012] As a preferred embodiment of the present invention, the first conductive sheet is connected to the connecting rod by a locking bolt;

[0013] The second conductive sheet is movably connected to the connection hole via an adjusting bolt.

[0014] As a preferred technical solution of this utility model, the physical form of the first terminal and the second terminal is a terminal post or a socket;

[0015] When the first terminal is a terminal block, it is integrated with the locking bolt; when the first terminal is a socket, the socket is opened through the end of the locking bolt.

[0016] When the second terminal is a terminal block, it is integrated with the adjusting bolt; when the second terminal is a socket, the socket is opened through the end of the adjusting bolt.

[0017] As a preferred embodiment of the present invention, both the outer surface of the first conductive sheet and the outer surface of the second conductive sheet are covered with an insulating shell.

[0018] The insulating outer shell covers the non-contact area of ​​the conductive sheet, and through windows are opened on opposite sides of the clamping area;

[0019] The through window exposes the clamping surface of the conductive sheet, forming a conductive area for direct contact with the secondary winding terminals.

[0020] As can be seen from the above technical solution, the present invention provides a device for testing the withstand voltage of the secondary winding of a current transformer. Compared with the traditional method of connecting copper wires by winding them point by point, the present invention, through the design of parallel conductive plates and an adjustable gap clamping area, enables simultaneous short-circuiting of the secondary winding terminals of all current transformers in a single operation, quickly connecting multiple terminals and significantly improving the connection efficiency of the testing circuit. Furthermore, the standardized design of the first and second terminals supports the rapid series connection of multiple testing devices. When testing a single current transformer, the withstand voltage tester is directly connected to the second terminal; when testing multiple transformers, the first terminals of adjacent testing devices are cascaded through short-circuit wires to form a series circuit, resulting in fast operation and high efficiency.

[0021] It should be understood that all combinations of the foregoing concepts and the additional concepts described in more detail below can be considered as part of the utility model subject matter of this disclosure, provided that such concepts do not contradict each other.

[0022] The foregoing and other aspects, embodiments, and features of the present invention will be more fully understood from the following description in conjunction with the accompanying drawings. Other additional aspects of the present invention, such as features and / or beneficial effects of exemplary embodiments, will become apparent from the following description or may be learned through practice of specific embodiments according to the teachings of the present invention. Attached Figure Description

[0023] The accompanying drawings are not drawn to scale according to a true reference numeral. In the drawings, each identical or nearly identical component shown in the various figures can be denoted by the same reference numeral. For clarity, not every component is labeled in each figure. Embodiments of various aspects of the present invention will now be described by way of example and with reference to the accompanying drawings, wherein:

[0024] Figure 1 This is a front view of the detection device structure according to an embodiment of the present utility model;

[0025] Figure 2 This is a first side view of the detection device structure according to an embodiment of the present utility model;

[0026] Figure 3 This is a second side view of the detection device structure according to an embodiment of the present utility model.

[0027] The meanings of the reference numerals in the figure are as follows:

[0028] 1-First conductive sheet; 2-Second conductive sheet; 3-Connecting rod; 301-Connecting hole; 4-Clamping area; 5-Locking bolt; 501-Insertion hole; 6-Adjusting bolt; 7-Insulating shell. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the described embodiments of this utility model without creative effort are within the scope of protection of this utility model. Unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by those skilled in the art to which this utility model pertains.

[0030] The terms "first," "second," and similar words used in this utility model patent application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, unless the context clearly indicates otherwise, the singular forms of "an," "a," or "the," etc., do not indicate a quantity limitation, but rather indicate the presence of at least one. Terms such as "comprising" or "including" indicate that the element or object preceding "comprising" encompasses the features, integrals, steps, operations, elements, and / or components listed following "comprising" or "including," and do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or collections thereof. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0031] Traditionally, when testing the secondary winding withstand voltage of current transformers, copper wire is typically used as the conductive connection to connect each winding. For transformers with multiple pairs of secondary winding terminals, this connection method is cumbersome, inefficient, and prone to problems such as copper wire detaching from the terminals, tangling, or breaking. Furthermore, these exposed copper wires often pose a safety hazard, such as electric shock. Therefore, this invention provides a device for testing the secondary winding withstand voltage of current transformers, enabling more efficient and safer testing.

[0032] like Figure 1 As shown, the secondary winding withstand voltage testing device of this utility model embodiment includes a first conductive sheet 1, a second conductive sheet 2, and a pair of insulated connecting rods 3. The first conductive sheet 1 and the second conductive sheet 2 are both made of copper sheets with good conductivity; while the connecting rods 3 are made of materials with excellent insulation properties, such as phenolic fiber plastic.

[0033] To facilitate rapid connection to the detection circuit, the first conductive plate 1 and the second conductive plate 2 are arranged parallel to each other via a pair of connecting rods 3, forming an adjustable clamping area 4 between them. The clamping area 4 is used to simultaneously clamp all secondary winding terminals of a single current transformer. Opening the distance between the first conductive plate 1 and the second conductive plate 2 expands the clamping area 4, allowing the secondary winding terminals of the current transformer to be placed within it. Then, pulling the first conductive plate 1 and the second conductive plate 2 closer together clamps the secondary winding terminals, achieving an electrical short circuit between them, thus quickly completing the connection of the detection circuit. Traditional copper wire wiring methods require winding and connecting each secondary winding terminal individually, which is inefficient.

[0034] Furthermore, the first conductive sheet 1 is provided with a pair of first terminals for cascading other current transformers. Specifically, it connects the first conductive sheet 1 of adjacent detection devices through a shorting wire to realize the series detection of multiple current transformers. The second conductive sheet 2 is provided with a pair of second terminals for connecting to the terminals of the withstand voltage tester.

[0035] In some specific embodiments of this utility model, such as Figure 1 As shown, a pair of connecting rods 3 are arranged in parallel opposite directions. Each connecting rod 3 has a connecting hole 301 arranged along its length. The first conductive sheet 1 is vertically connected to the bottom end of the pair of connecting rods 3, and the two ends of the second conductive sheet 2 are movably connected to the connecting hole 301. Therefore, the second conductive sheet 2 can move away from or closer to the first conductive sheet 1, thereby creating an opening or clamping effect in the clamping area 4.

[0036] Furthermore, the first conductive sheet 1 is connected to the connecting rod 3 via a locking bolt 5, and the second conductive sheet 2 is movably connected to the connecting hole 301 via an adjusting bolt 6. Both the locking bolt 5 and the adjusting bolt 6 are equipped with corresponding nuts. Specifically, in the following configuration... Figure 2 , 3As shown, the first conductive sheet 1 has first through holes at both ends, and the lower end of the connecting rod 3 also has an opening corresponding to the position of the first through holes. The locking bolt 5 is inserted sequentially through the first through holes and the opening, and then screwed into the nut located on the back side of the connecting rod 3 to secure the first conductive sheet 1 to the lower end of the connecting rod 3. Similarly, the second conductive sheet 2 has second through holes at both ends, but unlike the first conductive sheet 1, it uses the connecting hole 301 as the opening. The adjusting bolt 6 is inserted sequentially through the second through hole and the connecting hole, and then connected to the nut located on the back side of the connecting rod 3. When the adjusting bolt 6 and its matching nut are not tightened, the second conductive sheet 2 can be moved away from or closer to the first conductive sheet 1, adjusting the gap of the clamping area 4 to achieve the function of disconnecting or connecting the detection circuit. When the secondary winding terminals of the current transformer are clamped between the first conductive plate 1 and the second conductive plate 2, tightening the adjusting bolt 6 will fix the second conductive plate 2 at a certain height on the connecting rod, so that it always forms a stable clamping effect with the first conductive plate 1, and establishes a stable detection circuit.

[0037] The physical form of the first terminal and the second terminal is a terminal block or a socket.

[0038] When the first terminal is a terminal block, it is integrated with the locking bolt 5. The connector of the short wire can be designed as a common clip structure. During connection, it is directly clamped to the locking bolt 5, allowing for rapid cascading of detection devices for adjacent current transformers. When the first terminal is a socket, the socket 501 is opened through the end of the locking bolt 5. In this case, the connector of the short wire can be designed as a pin-type structure. During connection, it is directly inserted into the socket, allowing for rapid cascading of adjacent current transformers, significantly improving the connection efficiency of the detection circuit. During testing, the connection can be freely switched according to the scenario, reducing equipment modification costs.

[0039] Similarly, when the second terminal is a terminal block, it is integrated with the adjusting bolt 6. The connector for the conductive wire used to connect the withstand voltage tester is designed as a commonly used clip structure, which is directly clamped to the adjusting bolt 6. When the second terminal is a socket, the socket is opened through the end of the adjusting bolt 6. At this time, the connector for the conductive wire is designed as a pin structure, which is quickly inserted into the socket to complete the circuit connection.

[0040] To avoid the risk of electric shock due to accidental contact with exposed copper wires, as is the case with traditional copper wire connections, some embodiments of this invention, such as... Figure 1As shown, both the first conductive sheet 1 and the second conductive sheet 2 are covered with an insulating shell 7, which can be made of rubber or similar materials with excellent insulating properties. The insulating shell 7 covers the non-contact areas of the conductive sheets and has through windows on opposite sides of the clamping area 4. The through windows expose the clamping surfaces of the conductive sheets, forming conductive areas for direct contact with the secondary winding terminals. Specifically, the first conductive sheet 1, except for the first clamping surface located in the clamping area 4 (i.e., the upper side located between the two connecting rods 3 and opposite to the second conductive sheet 2), is entirely a non-contact area. The insulating shell completely covers the non-contact areas, with through windows only at the first clamping surface to expose a portion of the first conductive sheet 1 to form a conductive area for direct contact with the secondary winding terminals. Similarly, the second conductive sheet 2, except for the second clamping surface located in the clamping area (i.e., the lower side located between the two connecting rods 3 and opposite to the first conductive sheet), is entirely a non-contact area. The insulating shell 7 completely covers the non-contact areas, with through windows only at the second clamping surface to expose a portion of the second conductive sheet 2 to form a conductive area for direct contact with the secondary winding terminals. The insulating shell design reduces the risk of accidental conduction due to the exposure of most of the conductive sheet. The through-window is only opened on the opposite side of the first and second conductive sheets in the clamping area, so the risk of accidental contact is extremely low.

[0041] Example 1

[0042] When testing a single current transformer, loosen the adjusting bolts 6 on the two connecting rods 3 to increase the distance between the second conductive plate 2 and the first conductive plate 1. Place the secondary winding terminals of the current transformer in the clamping area 4, then pull the second conductive plate 2 closer to clamp it with the first conductive plate 1, securing the secondary winding terminals. Next, tighten the adjusting bolts 6 to fix the position of the second conductive plate 2, ensuring it does not loosen and maintaining a stable clamping posture. Ensure the testing circuit connection is stable. Finally, connect the high-voltage output terminal of the withstand voltage tester to one of the second terminals of the testing device, and connect the grounding terminal of the withstand voltage tester directly to the other second terminal. After checking and ensuring reliable grounding, the test can proceed. When testing a single current transformer, the second terminal actually serves the same function as the first terminal. In this case, the high-voltage output terminal and grounding terminal of the withstand voltage tester can also be connected to the two first terminals respectively for withstand voltage testing.

[0043] Example 2

[0044] To simultaneously test at least two current transformers, the clamping method of the secondary winding terminals of a single current transformer is the same as in Example 1, and the wiring method of the withstand voltage tester is also the same as in Example 1. There is one and only one withstand voltage tester, which can be connected to the second terminal of any testing device. The difference lies in that the testing devices for adjacent current transformers are connected to their respective first terminals via jumpers. That is, one first terminal of the first testing device is connected to one first terminal of the second testing device via a jumper, the other first terminal of the second testing device is connected to one first terminal of the third testing device, and so on, until the last testing device is connected. There is no need to form a loop between the first and last testing devices. After the wiring is completed and checked for errors, testing can proceed.

[0045] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Those skilled in the art to which this invention pertains can make various modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of this invention shall be determined by the claims.

Claims

1. A device for testing the withstand voltage of the secondary winding of a current transformer, characterized in that, It includes a first conductive sheet (1), a second conductive sheet (2), and a pair of insulated connecting rods (3); The first conductive sheet (1) and the second conductive sheet (2) are arranged in parallel opposite directions through a pair of connecting rods (3), forming a clamping area (4) with an adjustable gap between them; The clamping area (4) is used to simultaneously clamp all the secondary winding terminals of a single current transformer. The first conductive sheet (1) is provided with a pair of first terminals, and the second conductive sheet (2) is provided with a pair of second terminals.

2. The withstand voltage testing device for the secondary winding of a current transformer according to claim 1, characterized in that, A pair of connecting rods (3) are arranged in parallel opposite directions, and each connecting rod (3) is provided with a connecting hole (301) arranged along its length; The first conductive sheet (1) is vertically connected to the bottom end of the pair of connecting rods (3); The two ends of the second conductive sheet (2) are movably connected to the connection hole (301).

3. The withstand voltage testing device for the secondary winding of a current transformer according to claim 2, characterized in that, The first conductive sheet (1) is connected to the connecting rod (3) by a locking bolt (5); The second conductive sheet (2) is movably connected to the connection hole (301) by an adjusting bolt (6).

4. The withstand voltage testing device for the secondary winding of a current transformer according to claim 3, characterized in that, The physical form of the first terminal and the second terminal is a terminal post or a socket; When the first terminal is a terminal block, it is integrated with the locking bolt (5); when the first terminal is a socket, the socket is opened through the end of the locking bolt (5). When the second terminal is a terminal block, it is integrated with the adjusting bolt (6); when the second terminal is a socket, the socket is opened through the end of the adjusting bolt (6).

5. The withstand voltage testing device for the secondary winding of a current transformer according to claim 1, characterized in that, Both the first conductive sheet (1) and the second conductive sheet (2) are covered with an insulating shell (7); The insulating shell (7) covers the non-contact area of ​​the conductive sheet and has through windows on opposite sides of the clamping area (4); The through window exposes the clamping surface of the conductive sheet, forming a conductive area for direct contact with the secondary winding terminals.

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