Secondary wiring terminal structure of combined mutual inductor for metering

Abstract

According to the secondary wiring terminal structure of the combined type mutual inductor for metering, a special plugging structure is adopted, one-by-one loosening and tightening of screws are reduced, rapid connection and disconnection are achieved, even if mechanical vibration is encountered, stable connection can still be kept, unreliable connection caused by loose connection is greatly reduced, and the service life of the secondary wiring terminal structure is prolonged. The influence of poor contact on the measurement result is reduced, and the stable connection between the combined mutual inductor and the electric energy meter is ensured; the environmental adaptability is improved, the safety protection level is improved through protection of the sealing and insulating layer, and equipment loss and inaccurate metering caused by severe conditions such as a humid environment are effectively prevented; the wiring terminals are locked through the positioning clamping grooves and are aligned one by one, so that misconnection and missed connection are avoided, and the safety of electrical equipment and operators is guaranteed; the secondary wiring terminal structure disclosed by the invention achieves remarkable effects in the aspects of connection reliability, environmental adaptability, electrical performance, safety and the like, and has extremely high application value and market prospect.

Description

Technical Field

[0001] The present invention relates to the technical field of secondary connection of combined instrument transformers, and more specifically, to a secondary wiring terminal structure for a combined instrument transformer used for metering. Background Art

[0002] Combined instrument transformers for metering are widely used in power systems, mainly for electric energy metering and protection. It integrates a current transformer (CT) and a voltage transformer (PT), simplifying installation and maintenance. Combined instrument transformers for metering are particularly important in high-voltage power transmission and distribution systems, capable of accurately measuring current and voltage and providing key data for electric energy metering. The secondary output of the instrument transformer accurately transmits the current and voltage signals on the secondary side of the transformer to the watt-hour meter through secondary wiring. The secondary terminals of the combined instrument transformer involve multiple windings (voltage windings and current windings), with many terminals and complex wiring, making it easy for manual operations to go wrong. At the same time, due to limited installation space and a compact layout of the wiring terminals, the difficulty of manual operation is increased. When the wiring is not secure, it affects the accuracy of electric energy metering; when wrongly wired, it may cause an open circuit or a short circuit, affecting the safety of the power system. In subsequent maintenance and calibration work, there are also related difficulties due to the need to disconnect and reconnect the secondary wiring.

[0003] Currently, screw-fastening type wiring terminals are used for the secondary wiring of combined instrument transformers for metering. In terms of installation and maintenance, screw-fastening type wiring requires the use of tools to perform separate connection operations on each wire, loosening and tightening the screws one by one, which is cumbersome and time-consuming. When tightening, there is a range of force requirements for the operator. If the torque is too small, the connection will be unreliable; if the torque is too large, it may damage the terminal or the wire. In terms of connection reliability, when the screw is not fully tightened or becomes loose, the contact area between the wire and the terminal decreases, resulting in an increase in contact resistance, which may affect the accuracy of electric energy metering. In terms of environmental adaptability. In harsh environments such as humidity and corrosion, the screws and terminals are prone to rusting and corrosion, thus reducing the connection reliability. Summary of the Invention

[0004] In view of this, the present invention provides a secondary wiring terminal structure for a combined transformer for metering, which includes a secondary connection end, a plug, and a connecting cable that are detachably connected in sequence; a first ring is provided on the body of the secondary connection end, and the body of the secondary connection end forms a cylindrical cavity. A plurality of first connection terminals are provided in the cylindrical cavity, and the first connection terminals penetrate and extend to the other side of the body of the secondary connection end; a circular groove corresponding to the first connection terminals is provided at the first end of the plug, and the first end of the plug can be integrally embedded in the cylindrical cavity. At the same time, the first connection terminals are correspondingly inserted into the circular grooves. A copper tube communicating with the circular groove is provided at the second end of the plug and can be connected to the connecting cable; the first end of the connecting cable is of a circular structure, and a plurality of second connection terminals are correspondingly provided thereon and can be correspondingly connected to the copper tube. The second end of the connecting cable is of a square structure, and a plurality of third connection terminals are provided thereon and can be correspondingly connected to the wiring terminals of the meter to be connected. The second connection terminals and the third connection terminals are correspondingly connected wiring terminals that are in one-to-one communication.

[0005] Further, a second ring is also provided on the body of the secondary connection end, which surrounds the first ring and can provide waterproof protection for the first ring.

[0006] Further, a convex block is provided inside the first ring, and a concave rail is correspondingly provided at the first end of the plug. When the first end of the plug is connected inside the first ring, the convex block and the concave rail are correspondingly connected together to play a role in fastening and positioning.

[0007] Preferably, the first connection terminal is a copper connecting wire with a cross-sectional area of 4 mm 2 。

[0008] Preferably, the first connection terminals are arranged in a circular layout method inside the first ring.

[0009] Further, an insulating insert is provided at the bottom of the cylindrical cavity.

[0010] Preferably, the insulating insert is a green part.

[0011] Preferably, the secondary connection end is an epoxy casting molded part, preferably a red part.

[0012] Further, the body of the plug is an insulating crimping part, preferably a blue part.

[0013] Furthermore, a cable fixing tube is correspondingly provided at the connection between the plug and the connection cable. The cable fixing tube is provided with internal threads and can be threadedly connected to the plug. At the same time, the plug and the secondary connection end are fastened. The outer part of the cable tube has external threads and can be connected to the cable fixing tube and the connection cable through a set lock.

[0014] Furthermore, the cable fixing tube is made of iron metal and its surface is nickel-plated.

[0015] Furthermore, an annular sealing ring is provided at the internal thread of the cable fixing tube.

[0016] Furthermore, the lock is made of steel metal and its surface is nickel-plated.

[0017] Furthermore, a positioning block is provided at the second end of the connection cable for accurately connecting the third connection terminal to the electricity meter.

[0018] Preferably, two positioning blocks are provided.

[0019] Furthermore, a, b, and c terminal voltage display lights are provided at the second end of the connection cable.

[0020] Furthermore, a special screw for connecting to the ground is provided at the second end of the connection cable, and a ground terminal mark is provided.

[0021] The third connection terminal is a single-core round copper cable.

[0022] The secondary wiring terminal structure of the combined transformer for metering provided by the present invention has the following advantages: The present invention adopts a special plug-and-play structure, reducing the need to loosen and tighten screws one by one, enabling quick connection and disconnection. Even in the face of mechanical vibration, it can still maintain a stable connection, greatly reducing the unreliable connection caused by loose connection, reducing the impact on measurement results due to poor contact, and ensuring the stable connection between the combined transformer and the electricity meter; improving environmental adaptability, protected by a seal and an insulating layer, improving the safety protection level, and effectively preventing equipment loss and inaccurate metering caused by harsh conditions such as a humid environment; improving the safety of installation and maintenance, locking the wiring terminals through positioning slots to align them one by one, avoiding wrong connection and missed connection, and ensuring the safety of electrical equipment and operators; the secondary wiring terminal structure of the combined transformer for metering of the present invention has achieved remarkable improvement effects in terms of connection reliability, environmental adaptability, electrical performance, and safety through innovative designs in multiple aspects, can better meet the requirements of the new power system, is convenient for front-line operators to install and maintain, and has extremely high application value and market prospects. Description of the Drawings

[0023] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the following detailed description of the preferred embodiments. The drawings are only for the purpose of showing the preferred embodiments and are not considered to be a limitation of the present invention. Also, throughout the drawings, the same reference numerals are used to denote the same components. In the drawings: Figure 1 This is the general assembly drawing of the secondary wiring terminal structure provided by the embodiment of the present invention; Figure 2 This is the schematic diagram (1)-(2) of the structure of the secondary connection end provided by the embodiment of the present invention; Figure 3 This is the schematic diagram (1)-(2) of the structure of the plug provided by the embodiment of the present invention; Figure 4 This is the schematic diagram (1)-(2) of the structure of the cable fixing tube provided by the embodiment of the present invention; Figure 5 This is the schematic diagram (1)-(2) of the structure of the buckle provided by the embodiment of the present invention; Figure 6 This is the schematic diagram of the structure of the connecting cable provided by the embodiment of the present invention Figure 1 ; Figure 7 This is the schematic diagram of the structure of the connecting cable provided by the embodiment of the present invention Figure 2 In the figure, 1 is the secondary wiring terminal, 2 is the plug, 3 is the cable fixing tube, 4 is the buckle, 5 is the connecting cable, and 6 is the electricity meter; 11 is the secondary connection end body, 12 is the first ring, 13 is the second ring, 14 is the first connection terminal, 15 is the insulating insert, 16 is the bump, 21 is the circular groove, 22 is the copper tube, 23 is the plug thread, 24 is the groove, 31 is the internal thread, 32 is the external thread, 33 is the sealing ring, 51 is the second connection terminal, 52 is the third connection terminal, 53 is the positioning block, 54 is the abc terminal voltage display lamp, and 55 is the dedicated grounding screw. Detailed Embodiments

[0024] Hereinafter, exemplary embodiments of the present disclosure will be described in more detail with reference to the drawings. Although the exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present disclosure can be more thoroughly understood and the scope of the present disclosure can be fully conveyed to those skilled in the art. It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other. Hereinafter, the present invention will be described in detail with reference to the drawings and in combination with the embodiments.

[0025] See Figure 1-7As shown in the figure, it is the secondary wiring terminal structure of the combined transformer for metering provided by the embodiment of the present invention, including a secondary connection end 1, a plug 2 and a connection cable 5 that are detachably connected in sequence; a first ring 12 is provided on the body 11 of the secondary connection end 1, and the body 11 of the secondary connection end forms a cylindrical cavity. A plurality of first connection terminals 14 are arranged in the cylindrical cavity, and the first connection terminals 14 penetrate and extend to the other side of the secondary connection end body 11; a circular groove 21 corresponding to the first connection terminals 14 is provided at the first end of the plug 2. The first end of the plug 2 can be integrally embedded in the cylindrical cavity, and at the same time the first connection terminals 14 are correspondingly inserted into the circular groove 21. A copper tube 22 communicating with the circular groove 21 is provided at the second end of the plug 2, and the copper tube 22 can be connected to the connection cable 5. The first end of the connection cable 5 is of a circular structure, and a plurality of second connection terminals 51 are correspondingly arranged thereon, which can be correspondingly connected to the copper tube 22. The second end of the connection cable 5 is of a square structure, and a plurality of third connection terminals 52 are arranged thereon, which can be correspondingly connected to the wiring terminals of the meter 6 to be connected. Among them, the second connection terminals 51 and the third connection terminals 52 are corresponding and communicating wiring terminals. In this embodiment, the traditional screw-tightening wiring method is abandoned, and a plug-and-play connection structure is adopted. This design makes the wiring process simpler and faster. The operator does not need to use additional tools, which greatly shortens the installation and disassembly time. For example, during the on-site installation of the transformer, it may take 5-10 minutes to complete the connection of a wiring terminal in the traditional way, while the new plug-and-play structure only takes about 1 minute, which greatly improves the work efficiency.

[0026] Refer to Figure 2 As shown in the figure, a second ring 13 is further provided on the body 11 of the secondary connection end 1. It surrounds the first ring 12 and can provide waterproof protection for the first ring 12 and the plug 2 inserted therein. The overall appearance of the secondary wiring terminal 1 is that one end is a hexagonal circle with first connection terminals extending outside it, and the other end is two rings perpendicular to the hexagonal circle, namely the first ring 12 and the second ring 13. The first ring 12 is arranged inside the second ring 13, and a plurality of ground connection terminals 14 are arranged inside the first ring 12.

[0027] Refer to Figure 2-3 As shown in the figure, a convex block 16 is provided on the inner side of the first ring 12, and a groove 24 is correspondingly provided at the first end of the plug 2. When the first end of the plug 2 is inserted into the first ring 12, the convex block 16 and the groove 24 are correspondingly connected together, playing a role of fastening and positioning, realizing accurate positioning and avoiding the situation of incorrect connection of the terminals.

[0028] In this embodiment, the first connection terminal 14 is a copper connecting wire with a cross-sectional area of 4mm 2 .

[0029] Continue to refer to Figure 1 As shown, the first connection terminal 14 is arranged in a circular layout within the first circular ring 12. An insulating insert 15 is provided at the bottom of the cylindrical cavity, and the insulating insert 15 is a green part. In this embodiment, the secondary connection terminal 1 is an epoxy casting part, preferably a red part.

[0030] In this embodiment, the plug 2 body is an insulating crimping part, preferably a blue part.

[0031] Refer to Figure 1 、 4 As shown, a cable fixing tube 3 is also correspondingly provided at the connection between the plug 2 and the connecting cable 3. An internal thread 31 is provided inside the cable fixing tube 3, which can be threadedly connected to the plug 2, and at the same time fasten the plug 2 and the secondary connection terminal 1. An external thread 32 corresponds to the outside of the cable fixing tube 3, and through the provided lock 4, the cable fixing tube 3 and the connecting cable 5 can be connected.

[0032] In this embodiment, the cable fixing tube 3 is a ferrous metal part with a nickel plating treatment on its surface.

[0033] Refer to Figure 4 As shown, an annular sealing ring 33 is provided at the internal thread 31 of the cable fixing tube 3.

[0034] In this embodiment, the lock 4 is a steel metal part with a nickel plating treatment on its surface. One end of the lock 4 is a tightening opening, and the other end has an internal thread. Refer to Figure 5 As shown, it can correspondingly lock the connecting cable 5 and the cable fixing tube 3.

[0035] Refer to Figure 6-7 As shown, a positioning block 53 is provided at the second end of the connecting cable 5 for accurately connecting the third connection terminal 52 to the electricity meter 6. In this embodiment, two positioning blocks 53 are provided and are arranged on the same side of its square structure to ensure accurate connection between the electricity meter and the wiring terminal.

[0036] Continue to refer to Figure 6-7 As shown, a, b, and c terminal voltage display lights 54 are provided at the second end of the connecting cable 5. A dedicated screw 55 for connecting to the ground is provided at the second end of the connecting cable 5, and a ground terminal mark is provided to facilitate identification by workers and improve work efficiency.

[0037] In this embodiment, the third connection terminal 52 is a single-core round copper cable.

[0038] The secondary wiring terminal structure of a combined transformer for metering provided by the present invention has the following beneficial technical effects: The present invention adopts a special plug-and-play structure, reducing the need to loosen and tighten screws one by one, enabling quick connection and disconnection. Even in the face of mechanical vibration, it can still maintain a stable connection, greatly reducing the unreliable connection caused by loose connection, reducing the impact on measurement results due to poor contact, and ensuring a stable connection between the combined transformer and the electricity meter; enhancing environmental adaptability, protecting through sealing and insulating layers, improving the safety protection level, and effectively preventing equipment loss and inaccurate metering caused by harsh conditions such as a humid environment; improving the safety of installation and maintenance, locking the wiring terminals through positioning slots to align them one by one, avoiding incorrect connection and missed connection, and ensuring the safety of electrical equipment and operators; The secondary wiring terminal structure of the combined transformer for metering of the present invention has achieved remarkable improvement effects in terms of connection reliability, environmental adaptability, electrical performance, and safety through various innovative designs, can better meet the requirements of the new power system, is convenient for front-line operators to install and maintain, and has extremely high application value and market prospects.

[0039] It should be noted that in the description of the present invention, the terms indicating directions or positional relationships such as "upper", "lower", "left", "right", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings. This is only for the convenience of description and does not indicate or imply that the device or component must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0040] In addition, it should also be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installation", "connection", and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, and can be the communication inside two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0041] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and its equivalent technologies, the present invention also intends to include these changes and modifications.

Claims

1. A secondary terminal structure of a combined transformer for metering, characterized in that: The utility model comprises a secondary connection end, a plug and a connection cable which can be detachably connected in sequence; a first ring is provided on the main body of the secondary connection end, and the main body of the secondary connection end forms a cylindrical cavity, a plurality of first connection terminals are provided in the cylindrical cavity, and the first connection terminal penetrates and extends to the other side of the main body of the secondary connection end; a circular groove corresponding to the first connection terminal is provided at the first end of the plug, and the first end of the plug can be integrally embedded in the cylindrical cavity, and the first connection terminal is correspondingly inserted in the circular groove, and a copper tube connected thereto is provided at the second end of the plug corresponding to the circular groove, and can be connected to the connection cable; the first end of the connection cable is a circular structure, and a plurality of second connection terminals are correspondingly provided thereon, and can be correspondingly connected to the copper tube; the second end of the connection cable is a square structure, and a plurality of third connection terminals are provided thereon, and can be correspondingly connected to the connection terminal of the electric meter to be connected, and the second connection terminal and the third connection terminal are one-to-one corresponding connection terminals.

2. The secondary terminal structure of the combined transformer for metering according to claim 1 is characterized in that: A second ring is also provided on the body of the secondary connection end, which is arranged around the first ring and can provide waterproof protection for the first ring and the plug inserted therein.

3. The secondary terminal structure of the combined transformer for metering according to claim 1 is characterized in that: A convex block is provided on the inner side of the first circular ring, and a groove is correspondingly provided on the first end of the plug. When the first end of the plug is connected to the first circular ring, the convex block and the groove are correspondingly engaged together.

4. The secondary terminal structure of the combined transformer for metering according to claim 1 is characterized in that: An insulating insert is provided at the bottom of the cylindrical cavity.

5. The secondary terminal structure of the combined transformer for metering according to claim 1 is characterized in that: The plug body is an insulating crimping piece.

6. The secondary terminal structure of the combined transformer for metering according to any one of claims 1 to 5, characterized in that: A cable fixing tube is also provided at the connection point between the plug and the connecting cable. The cable fixing tube is provided with an internal thread, which can be threadedly connected to the plug. The cable tube is provided with an external thread on the outside, and the cable fixing tube and the connecting cable can be connected by a set lock.

7. The secondary terminal structure of the combined transformer for metering according to claim 6 is characterized in that: The cable fixing tube is an iron metal part with a nickel-plated surface.

8. The secondary terminal structure of the combined transformer for metering according to claim 6, characterized in that: An annular sealing ring is arranged at the internal thread of the cable fixing tube.

9. The secondary terminal structure of the combined transformer for metering according to claim 6, characterized in that: The lock buckle is a metal part with a nickel-plated surface.

10. The secondary terminal structure of the combined transformer for metering according to claim 6, characterized in that: A positioning block is provided at the second end of the connecting cable for accurately connecting the third connecting terminal to the electric meter.

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