Built-in bus type miniature current transformer

Abstract

The utility model provides a miniature current transformer with a built-in bus. The miniature current transformer with the built-in bus comprises a shell, a bus structure and an induction structure. The shell is provided with a center hole and further provided with through heat dissipation holes annularly arranged around the center hole at intervals. The bus structure is connected with the shell and provided with a center penetrating bus capable of penetrating through the center hole. The induction structure is located in the shell and arranged around the heat dissipation holes, and signal conversion can be achieved. According to the built-in bus type miniature current transformer provided by the utility model, the heat emitted by the cross-core bus can be timely guided out through the plurality of heat dissipation holes, so that the cross-core bus is prevented from being too high in temperature or being in a relatively high temperature environment for a long time, the aging is reduced, the cross-core bus is prevented from being damaged, and the practicability is strong.

Description

TECHNICAL FIELD

[0001] The utility model belongs to current transformer technical field, concretely relates to a built-in busbar type micro current transformer. BACKGROUND

[0002] The micro current transformer is a device for measuring current, which can convert large current into small current or voltage signal based on electromagnetic induction principle, and is convenient for measurement and control. For the built-in busbar type micro current transformer, the through core busbar can be electrically connected with the measured busbar in the switch cabinet and ring network cabinet.

[0003] In the prior art, the through core busbar of the micro current transformer may heat, especially when the current exceeds the rated current (for example, the short-time current exceeds the design value), which may cause high temperature rise. Because of the built-in disadvantage, the heat cannot be discharged in time, so long-term high-temperature operation may occur. For example, if the through core busbar made of copper exceeds 90℃ for a long time, the material around the center conductor may soften, deform, or even carbonize, and the heat dissipation is poor. In addition, the through core busbar is frequently in a cold and hot environment, which may cause surface cracks and cannot be replaced. SUMMARY

[0004] The utility model embodiment provides a built-in busbar type micro current transformer, which aims to solve the poor practicability of the existing built-in busbar type micro current transformer due to poor heat dissipation.

[0005] To achieve the above-mentioned purpose, the utility model adopts the technical scheme of providing a built-in busbar type micro current transformer, which comprises:

[0006] The shell has a center hole and a through hole for heat dissipation arranged annularly and spaced apart around the center hole;

[0007] The busbar structure is connected with the shell and has a through core busbar that can pass through the center hole;

[0008] The induction structure is located in the shell and arranged around each heat dissipation hole for signal conversion.

[0009] In a possible implementation manner, the busbar structure comprises:

[0010] The copper bar is arranged in the center hole, and the copper bar is the through core busbar;

[0011] The end cap is provided with two end caps, each of which is located at the two ends of the center hole and electrically connected with the two ends of the through core busbar;

[0012] The terminal post is provided with two terminal posts, both of which are located on the shell and used for external connection of the busbar.

[0013] The conductive pieces are provided with two, each of the conductive pieces is located at two ends of the center hole, and is fixedly connected with the shell, and two conductive pieces are electrically connected with two terminal posts through wires respectively; two conductive pieces are used for electrically and detachably connecting two end covers respectively.

[0014] In a possible implementation, each of the end covers is threadedly connected with the corresponding conductive piece;

[0015] Each of the conductive pieces has a threaded hole coaxially and communicatively arranged with the center hole.

[0016] In a possible implementation, each of the end covers comprises a metal end head threadedly connected with the conductive piece.

[0017] In a possible implementation, an end of the metal end head is provided with a spring.

[0018] In a possible implementation, the spring is a conical spiral spring.

[0019] In a possible implementation, each of the wires is located in the shell.

[0020] In a possible implementation, the sensing structure comprises:

[0021] A ring-shaped iron core is coaxially arranged with the center hole, and surrounds each of the heat dissipation holes;

[0022] A secondary winding is wound on the ring-shaped iron core.

[0023] In the implementation, the bus structure is arranged on the shell, and the through bus passes through the center hole to realize the built-in bus structure. The ring-shaped interval arranged outside the center hole and each of the heat dissipation holes can ensure that the heat generated by the through bus is promptly dissipated, thereby avoiding that the temperature of the through bus is too high or that the through bus is long-term in a high-temperature environment, reducing aging, avoiding damage of the through bus, and having high practicability. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 A structure schematic diagram of the built-in bus type miniature current transformer is provided in the embodiment of the utility model;

[0025] Figure 2 A structure schematic diagram of the built-in bus type miniature current transformer is provided in the embodiment of the utility model;

[0026] Explanation of reference signs:

[0027] 10, housing; 11, center hole; 12, heat dissipation hole; 20, busbar structure; 21, copper bar; 22, end cap; 221, metal end; 23, terminal post; 24, conductive part; 25, wire; 26, spring; 30, induction structure; 31, ring-shaped iron core; 32, secondary winding. DETAILED DESCRIPTION

[0028] In order to make the technical problems, technical solutions and beneficial effects of the utility model clearer, the utility model will be described in further detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the utility model and do not limit the utility model.

[0029] Please refer to Figure 1 and Figure 2 , the built-in busbar type miniature current transformer provided by the utility model will be described. The built-in busbar type miniature current transformer comprises a housing 10, a busbar structure 20 and an induction structure 30. The housing 10 has a center hole 11 and also has through heat dissipation holes 12 arranged annularly and spaced apart around the center hole 11. The busbar structure 20 is connected with the housing 10 and has a through busbar that can pass through the center hole 11. The induction structure 30 is located in the housing 10 and is arranged around each heat dissipation hole and can perform signal conversion.

[0030] The built-in busbar type miniature current transformer provided by the embodiment has the following advantages compared with the prior art. The busbar structure 20 is arranged on the housing 10 and passes through the center hole 11 through the through busbar, so that the built-in busbar type structure is realized. The heat dissipation holes 12 arranged annularly and spaced apart outside the center hole 11 can ensure that the heat generated by the through busbar is promptly dissipated, so that the temperature of the through busbar is prevented from being too high or the through busbar is prevented from being in a high-temperature environment for a long time, aging is reduced, the through busbar is prevented from being damaged, and the utility model has high practicability.

[0031] In the embodiment, the housing 10 can be molded by using PBT-GF30 composite material, so that the flame retardation requirement can be met, and the induction structure 30 is directly arranged in the housing 10 during molding. The diameter of the center hole 11 can be controlled to be 12±0.5 mm.

[0032] In some embodiments, the busbar structure 20 can have the structure shown in Figures 1 to 2 . Referring to Figures 1 to 2The busbar structure 20 includes a copper rod 21, end caps 22, terminals 23, and conductive elements 24. The copper rod 21 is disposed in the central hole 11 and serves as a through-core busbar. Two end caps 22 are provided, each located at one end of the central hole 11 and electrically connected to both ends of the through-core busbar. Two terminals 23 are provided, both located on the outer casing 10, and can be connected to external busbars. Two conductive elements 24 are provided, each located at one end of the central hole 11 and fixedly connected to the outer casing 10. The two conductive elements 24 are electrically connected to the two terminals 23 via wires 25. The two conductive elements 24 can provide electrical and detachable connections to the two end caps 22 respectively.

[0033] The copper rod 21 is clamped at both ends of the central hole 11 by two end caps 22, which realizes electrical connection and also ensures the fixation of the copper rod 21. This method can ensure convenient replacement of the copper rod 21 after surface cracks appear, thereby extending its service life.

[0034] In addition, the two end caps 22 are detachably connected to the conductive elements 24 embedded at both ends of the central hole 11, and the two conductive elements 24 are electrically connected to the two terminals 23 through wires 25. This structure can ensure that the end caps 22 and the corresponding conductive elements 24 can be electrically connected at the same time.

[0035] It should be noted that the conductive component 24 can also be made of copper.

[0036] In this embodiment, the outer casing 10 can directly enclose the terminal 23 and the wire 25 during the molding process.

[0037] Correspondingly, regarding each heat dissipation hole 12, 11 holes are distributed at equal angles along the circumference, with the center line of the central hole 11 as a reference. The angle between any two heat dissipation holes 12 is 30°, but the angle between two adjacent heat dissipation holes 12 is 60° to provide space for the wires 25 to pass through and avoid interference. The diameter of each central hole 11 can be 18±0.5mm.

[0038] In some embodiments, the end cap 22 and the conductive element 24 may be adopted as follows: Figure 2 The structure shown. See also Figure 2 Each end cap 22 is threadedly connected to the corresponding conductive element 24.

[0039] Specifically, each conductive element 24 has a threaded hole that is coaxial with and connected to the central hole 11.

[0040] The end cap 22 and the conductive component 24 are connected by threads, which can ensure the adjustment of the screw-in length of the end cap 22, and also ensure the connection strength, thereby ensuring the support effect on the copper rod 21 in the center hole 11, which is highly practical.

[0041] In some embodiments, the end cap 22 can adopt the structure as shown in Figure 2 FIG. 2. Figure 2 Each end cap 22 comprises a metal end 221 threadedly connected with the conductive part 24, which can ensure electrical connection after being threadedly connected with the conductive part 24.

[0042] In this embodiment, the metal end 221 can have a cylindrical outer shape structure, and an insulating cover is integrally connected at the tail end. Specifically, interference fit or key connection structure can be adopted to avoid electric leakage. In addition, the outer periphery of the metal end 221 can be provided with external threads matched with the conductive part 24.

[0043] The insulating cover can be made of PA66+30%GF, and the insulating creepage distance is ≥8mm.

[0044] In some embodiments, the end cap 22 can adopt the structure as shown in Figure 2 FIG. 3. Figure 2 The end of the metal end 221 is provided with a spring 26, which can avoid rigid contact between the copper bar 21 and the two end caps 22, thereby avoiding large axial stress on the copper bar 21. This structure can also ensure stable electrical connection between the copper bar 21 and the end cap 22, thereby ensuring the reliability of the work.

[0045] In some embodiments, the spring 26 can adopt the structure as shown in Figure 2 FIG. 4. Figure 2 The spring 26 is a conical spiral spring 26, which has a large compression space, thereby ensuring the length of the copper bar 21.

[0046] In some embodiments, the shell 10 and the wire 25 can adopt the structure as shown in Figure 2 FIG. 5. Figure 2 Each wire 25 is located in the shell 10 and is embedded in the shell 10, which can avoid electric leakage and also protect the wire 25.

[0047] In some embodiments, the induction structure 30 can adopt the structure as shown in Figure 2 FIG. 6. Figure 2 Figure 2 The induction structure 30 comprises a ring-shaped core 31 and a secondary winding 32. The ring-shaped core 31 is coaxially arranged with the center hole 11 and surrounds each heat dissipation hole 12. The secondary winding 32 is wound on the ring-shaped core 31.

[0048] The ring-shaped core 31 and the secondary winding 32 mainly realize signal conversion.

[0049] The ring-shaped core 31 and the secondary winding 32 can adopt the prior art, and the two connection terminals of the corresponding secondary winding 32 are led out in the shell 10.

[0050] The above merely describes the preferred embodiments of the present application, and is not intended to limit the present application, and any modification, equivalent replacement and improvement within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A miniature current transformer with built-in bus, characterized in that, The utility model relates to a kind of induction coil, including: Shell, with central hole, also with through heat dissipation hole annularly spaced around the central hole; Bus structure, connected with the shell, with through central hole through bus bar; Induction structure, in the shell, and around each heat dissipation hole is arranged, for signal conversion.

2. The internal bus bar type miniature current transformer as claimed in claim 1, wherein The bus structure includes: Copper bar, arranged in the central hole, the copper bar is the through bus bar; End cap, provided with two, each end cap is located at the both ends of the central hole respectively, and the both ends of the through bus bar are electrically connected; Binding post, provided with two, two binding posts are located on the shell, for external bus bar; Conductive piece, provided with two, each conductive piece is located at the both ends of the central hole respectively, and the shell is fixedly connected, two conductive pieces are electrically connected by wire with two binding posts respectively;Two conductive pieces are used for respectively for two end caps electrically and detachably connected.

3. The PT with built-in bus-bar type current transformer as claimed in claim 2, wherein, Each end cap and corresponding conductive piece are threadedly connected; Wherein, each conductive piece has threaded hole coaxially and continuously arranged with the central hole.

4. The PT with built-in busbars according to claim 3, characterized in that, Each end cap includes metal end, which is threadedly connected with the conductive piece.

5. The PT with built-in busbars according to claim 4, characterized in that, The end of the metal end is provided with spring.

6. The PT with built-in busbars according to claim 5, characterized in that, The spring is conical spiral spring.

7. The PT with built-in bus-bar type current transformer as claimed in claim 2, wherein, Each wire is located in the shell.

8. The PT with built-in busbars according to claim 1, characterized in that, The induction structure includes: Annular core, coaxially arranged with the central hole, and around each heat dissipation hole is arranged; Secondary winding, wound on the annular core.

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