Primary terminal of current transformer
By designing rectangular sheet-shaped primary terminals, using the structure of busbar connection grooves and inserts, the connection process is simplified and the stability is improved, and the problems of complex and safety hazards of traditional primary terminals are solved, achieving lower cost and better High safety current transformer design.
Patent Information
- Application Number
- CN202420481142.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-12
- Publication Date
- 2025-02-11
- Estimated Expiration
- 2034-03-12
AI Technical Summary
The production process of the primary terminal of traditional current transformers is complex, with high material use and processing costs, and there are safety hazards in crimping processing and insulation.
Design a rectangular sheet-shaped primary terminal, set up several busbar connecting grooves and inserts, fix the busbar conductor by pressing and twisting inserts, simplify the connection process, and connect it to the primary winding wire through welding to avoid crimping deal with.
It reduces the complexity of the production process and the cost of material, improves the stability of the connection and the simplicity of operation, avoids the conductor discharge, and enhances safety.
Smart Images
Figure CN222462567U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of current transformers, and in particular relates to a primary terminal of a current transformer. Background Art
[0002] As we all know, the current transformer is an instrument that converts the large current on the primary side into the small current on the secondary side for measurement based on the principle of electromagnetic induction. The current in the power generation, transformation, transmission, distribution and power consumption lines varies greatly, ranging from a few amperes to tens of thousands of amperes. In order to facilitate measurement, protection and control, it needs to be converted into a relatively uniform current. In addition, the voltage on the line is generally high, and direct measurement is very dangerous. The current transformer plays the role of current conversion and electrical isolation. The welding quality of the primary terminal and the primary winding during the production process of the current transformer determines the performance and quality of the current transformer.
[0003] At present, the primary terminal of the traditional current transformer is an L-shaped terminal with 2-3 through holes on the short side of the L-shaped terminal. During the manufacturing process of the current transformer, the primary winding wire of the current transformer is passed through the through hole for winding. After the winding is completed, the primary terminal and the primary winding wire are fixed by crimping. During the crimping, copper wire is also needed for caulking, which results in a thicker interface and a thinner insulating resin wrapping the interface.
[0004] However, it was found during the use that the traditional technology still has the following defects:
[0005] First, the manufacturing process of L-shaped terminals is complicated, and the material and processing costs are high;
[0006] Second, the crimping process requires the use of copper wire to fill the gap, which is a complex process, difficult to operate, and takes more time;
[0007] Third, the insulating resin at the crimping point is relatively thin, which may easily lead to conductor discharge during the power frequency withstand voltage test or in use, posing a safety hazard. Utility Model Content
[0008] The utility model aims to provide a primary terminal of a current transformer to solve the technical problems of the L-shaped terminal proposed in the above background technology, such as the complex manufacturing process, high material and processing costs, and the crimping process and insulation.
[0009] In order to achieve the above purpose, the utility model provides the following technical solutions:
[0010] A primary terminal of a current transformer, wherein the primary current of the current transformer is less than or equal to 400A, and the primary winding conductor of the current transformer is connected to the primary terminal; the primary terminal is a rectangular sheet structure, and a plurality of busbar connection grooves are arranged on the primary terminal, and inserts are arranged in the busbar connection grooves. When connecting the busbar conductor to the primary terminal, the busbar connection conductor is pressed against the bottom of the busbar connection groove, and the inserts are tightened to fix it; one end of the primary terminal is welded to the primary winding conductor, and the primary terminal and the primary winding conductor are perpendicular to each other.
[0011] Preferably, the ratio of the length to the width of the primary terminal is 69:49; the ratio of the width to the thickness of the primary terminal is 49:6.
[0012] Preferably, there are two busbar connection slots on each primary terminal to provide more busbar connection options, allowing connection of multiple wires or devices, thereby increasing flexibility and improving functionality of the primary terminal.
[0013] Preferably, the busbar connection groove is a threaded groove that is open at the lower end and closed at the upper end, which is used to ensure a reliable connection for the insert, avoid loosening of the insert during operation, and ensure the firmness and stability of the connection between the busbar conductor and the primary terminal.
[0014] Preferably, a thread is provided on the upper end of the insert for matching with a busbar connection groove having a thread, thereby ensuring a stable connection between the busbar conductor and the primary terminal.
[0015] Preferably, the insert includes an upper half connected to the connecting groove and a lower half located outside the busbar connecting groove. The diameter of the lower half is larger than the inner diameter of the busbar connecting groove. The lower half of the insert with a larger diameter can block the busbar connecting groove to prevent the resin from entering the busbar connecting groove when pouring the insulating resin, thereby increasing the resistance at the connection between the busbar conductor and the primary terminal and causing a safety accident.
[0016] Preferably, the diameter of the busbar connecting groove is 12.5 mm.
[0017] Preferably, the upper end surface of the primary winding wire is welded to one end of the lower bottom surface of the primary terminal, thereby ensuring the reliability and stability of current transmission.
[0018] Preferably, the welding material is brass, which has good electrical conductivity and thermal conductivity, helps to improve the conduction efficiency of current and ensure the stability of the welding part.
[0019] Preferably, the four corners of the primary terminal are rounded to improve the safety of operators during welding work.
[0020] Compared with the prior art, the beneficial effects of the utility model are:
[0021] The utility model solves the technical problems of the complicated manufacturing process, high material and processing cost, and crimping treatment and insulation of the L-shaped terminal in the traditional technology by setting a primary terminal of a current transformer; the primary terminal is a rectangular sheet structure, which is simpler in structure than the L-shaped terminal, has a simpler production process, and has lower material and processing cost; a plurality of busbar connection grooves are arranged on the primary terminal, and inserts are arranged in the busbar connection grooves. When connecting the busbar wire and the primary terminal, the busbar connection wire is pressed against the bottom of the busbar connection groove, and the insert is tightened to fix it. Compared with the L-shaped terminal, the connection between the busbar wire and the primary terminal in the utility model is more stable, does not require additional crimping treatment, and is simple to operate; one end of the primary terminal is welded to the primary winding wire, and the welding connection method has a mature process, does not require caulking treatment, and the interface thickness is normal, which will not affect the normal operation of the insulation layer and avoid conductor discharge. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Figure 1 It is a front view of a preferred embodiment of the utility model;
[0023] Figure 2 A top view of a preferred embodiment of the utility model;
[0024] Figure 3 This is a welding schematic diagram of a preferred embodiment of the utility model.
[0025] In the figure: 1. Primary terminal; 2. Busbar connection slot; 3. Insert; 4. Primary winding wire. DETAILED DESCRIPTION
[0026] The technical solutions in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. All other embodiments obtained by ordinary technicians in the field without creative work based on the embodiments of the utility model shall fall within the scope of protection of the utility model.
[0027] like Figure 1-Figure 3 As shown:
[0028] The first embodiment: a primary terminal of a current transformer, the primary current of the current transformer is less than or equal to 400A, the primary winding conductor 4 of the current transformer is connected to the primary terminal 1; the primary terminal 1 is a rectangular sheet structure; two busbar connection grooves 2 are arranged on the primary terminal 1, wherein the distance from the center of one busbar connection groove 2 to the wide side of the primary terminal 1 is 19mm, and the distance from the center of the other busbar connection groove 2 to the other wide side of the primary terminal 1 is 18mm, and the error during production is less than 0.1mm; an insert 3 is arranged in the busbar connection groove 2, when connecting the busbar conductor and the primary terminal 1, the busbar connection conductor is pressed against the bottom of the busbar connection groove 2, and the insert 3 is tightened to fix it; one end of the primary terminal 1 is welded to the primary winding conductor 4, and the primary terminal 1 and the primary winding conductor 4 are perpendicular to each other.
[0029] Second embodiment: Based on the above-mentioned first embodiment, the ratio of the length and width of the primary terminal 1 is 69:49; the ratio of the width and thickness of the primary terminal 1 is 49:6; preferably, the length of the primary terminal 1 is 69mm, the width is 49mm, and the height is 6mm, and the error is less than 0.1mm.
[0030] The third embodiment: on the basis of the above-mentioned first embodiment, in order to provide more busbar connection options on the primary terminal 1 so as to be able to connect multiple wires or devices, there are two busbar connection slots 2 on each primary terminal 1, thereby improving the functionality of the primary terminal 1.
[0031] Fourth embodiment: On the basis of the above-mentioned first embodiment, in order to ensure a reliable connection for the insert 3 and prevent the insert 3 from loosening during operation, the busbar connection groove 2 is a threaded groove with an open lower end and a closed upper end. The chamfer in the busbar connection groove 2 is 45°, leaving some space for connecting the busbar wire at the bottom of the groove, while ensuring the firmness and stability of the connection between the busbar wire and the primary terminal 1.
[0032] Fifth embodiment: Based on the first embodiment, in order to match the busbar connection slot 2 with threads, threads are provided on the upper end of the insert 3 to ensure a stable connection between the busbar conductor and the primary terminal 1 .
[0033] Sixth embodiment: On the basis of the above-mentioned first embodiment, the insert 3 includes an upper half connected to the busbar connection groove 2 and a lower half located outside the busbar connection groove 2, and the diameter of the lower half is larger than the inner diameter of the busbar connection groove 2. The lower half of the insert 3 with a larger diameter can block the busbar connection groove 2 to prevent the resin from entering the busbar connection groove 2 when pouring the insulating resin, thereby increasing the resistance at the connection between the busbar conductor and the primary terminal and causing a safety accident.
[0034] Seventh embodiment: the diameter of the busbar connecting groove 2 is 12.5 mm.
[0035] Eighth embodiment: On the basis of the seventh embodiment, in order to ensure the reliability and stability of current transmission, the upper end surface of the primary winding conductor 4 is welded to one end of the lower bottom surface of the primary terminal 1 .
[0036] Ninth embodiment: Based on the above-mentioned eighth embodiment, the welding material is brass. Brass has good electrical conductivity and thermal conductivity, which helps to improve the current conduction efficiency and ensure the stability of the welding part.
[0037] The tenth embodiment: on the basis of the above-mentioned first embodiment, in order to ensure the safety of welding personnel, the four corners of the primary terminal 1 are set to be rounded.
[0038] In the utility model, in order to solve the complex manufacturing process, high material and processing costs, and technical problems in crimping and insulation of L-shaped terminals in traditional technologies, a primary terminal of a current transformer is provided, including a rectangular sheet-shaped primary terminal 1, the length of the primary terminal 1 is 69 mm, the width is 49 mm, the height is 6 mm, and the error during production is less than 0.1 mm; two busbar connection grooves 2 are arranged on the primary terminal 1, the diameter of the busbar connection groove 2 is 12.5 mm, and an insert 3 is arranged in the busbar connection groove 2. When connecting the busbar wire to the primary terminal 1, the busbar connection wire is pressed against the bottom of the busbar connection groove 2, and the insert 3 is tightened to fix it.
[0039] Working principle:
[0040] Step 1: Connect the busbar conductor to the primary terminal 1: The operator inserts the busbar conductor into the bottom of the busbar connection slot 2 of the primary terminal 1, and then inserts the insert 3, tightens the insert 3 so that the lower end of the insert 3 completely closes the busbar connection slot 2. At this time, the busbar conductor is pressed against the bottom of the busbar connection slot 2; proceed to the next step;
[0041] Step 2: Connect the primary terminal 1 to the primary winding wire 4 of the current transformer: With the insert 3 of the primary terminal 1 facing downward, the operator welds the end of the bottom surface of the primary terminal 1 19 cm away from the busbar connection slot 2 to the upper end surface of the primary winding wire 4, and brass is used as the welding material; after welding is completed, proceed to the next step.
[0042] Step 3: Pouring insulating resin The operator pours insulating resin on the primary terminal 1 and the interface between the primary terminal 1 and the primary winding conductor 4. The lower end of the insert 3 completely closes the busbar connection slot 2, effectively preventing the insulating resin from entering the busbar conductor. The operation is completed.
[0043] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.
Claims
1. A primary terminal of a current transformer, wherein the primary current of the current transformer is less than or equal to 400A, and the primary winding conductor (4) of the current transformer is connected to the primary terminal (1); characterized in that: The primary terminal (1) is a rectangular sheet structure, a plurality of busbar connection slots (2) are provided on the primary terminal (1), and an insert (3) is provided in the busbar connection slot (2); one end of the primary terminal (1) is welded to a primary winding conductor (4), and the primary terminal (1) and the primary winding conductor (4) are perpendicular to each other.
2. The primary terminal of the current transformer according to claim 1, characterized in that: The ratio of the length to the width of the primary terminal (1) is 69:49; and the ratio of the width to the thickness of the primary terminal (1) is 49:
6.
3. The primary terminal of the current transformer according to claim 1, characterized in that: There are two busbar connection slots (2) on each primary terminal (1).
4. The primary terminal of the current transformer according to claim 1, characterized in that: The busbar connection groove (2) is a threaded groove with an open lower end and a closed upper end.
5. The primary terminal of the current transformer according to claim 1, characterized in that: The upper end of the insert (3) is provided with a thread.
6. The primary terminal of the current transformer according to claim 1, characterized in that: The insert (3) comprises an upper half section connected to the busbar connection groove (2) and a lower half section located outside the busbar connection groove (2), wherein the diameter of the lower half section is greater than the inner diameter of the busbar connection groove (2).
7. The primary terminal of the current transformer according to claim 1, characterized in that: The diameter of the busbar connection groove (2) is 12.5 mm.
8. The primary terminal of the current transformer according to claim 7, characterized in that: The upper end surface of the primary winding wire (4) is welded to one end of the lower bottom surface of the primary terminal (1).
9. The primary terminal of the current transformer according to claim 8, characterized in that: The welding material is brass.
10. The primary terminal of the current transformer according to claim 1, characterized in that: The four corners of the primary terminal (1) are arranged to be rounded.