Three-phase common-box cable drum and combined electric appliance device

Abstract

The invention relates to a three-phase common-box cable cylinder and a combined electric appliance device, the three-phase common-box cable cylinder comprises a cylinder body, a cable joint and a combined electric appliance connecting conductor, an isolating switch is arranged between the cable joint and the combined electric appliance connecting conductor, and the opening distance of the isolating switch is matched with the insulation distance required when the cable joint and a combined electric appliance are subjected to a withstand voltage test; after improvement, the cable joint and the isolation switch are always kept in a connection state in the whole test process, and when a worker carries out a power frequency withstand voltage test on a cable, because the opening distance of the isolation switch is matched with the insulation distance required by the withstand voltage test on the cable joint and a combined electric appliance, the insulation distance is not required. If the cable joint and the disconnecting switch do not meet the voltage withstanding requirement, the condition of unqualified voltage withstanding near the cable joint can be observed; in this way, a plurality of components and connection parts among the components can be judged at the same time in one-time cable power frequency withstand voltage test, and therefore the problem that test blind spots exist in the prior art is solved.

Description

Technical Field

[0001] This invention relates to the field of equipment specifically for installing, maintaining, repairing or dismantling cables, and more particularly to a three-phase common-box cable drum and combined electrical device. Background Technology

[0002] GIS, as a common type of combined electrical equipment, is one of the important electrical devices. GIS typically includes circuit breakers, disconnect switches, grounding switches, instrument transformers, surge arresters, busbars, incoming and outgoing bushings, and cable terminals. Chinese utility model patent CN207053156U discloses a miniaturized cable terminal structure for three-phase common-enclosure combined electrical equipment. This cable terminal structure is filled with sulfur hexafluoride gas to improve insulation performance. The cable terminal structure also includes a three-position disconnect switch, a three-position connecting conductor, a cable terminal, and a cable head. The three-position connecting conductor inside the three-position disconnect switch is connected to the cable head of the cable terminal, thereby realizing the circuit connection.

[0003] When workers conduct power frequency withstand voltage tests to check the insulation performance of electrical appliances or cables, the withstand voltage requirements for the electrical appliances and cables are inconsistent. Workers must first slowly collect sulfur hexafluoride gas inside the cable terminal structure. After the internal pressure gradually drops to zero, the connecting conductor above the cable head is removed, and power frequency withstand voltage tests are performed on both the cable and the electrical appliance separately. After the tests, the connecting conductor is reinstalled and sulfur hexafluoride gas is refilled. This entire process is not only extremely cumbersome, but also creates a testing blind spot because the connection between the cable head and the connecting conductor is never tested for withstand voltage during the test. Summary of the Invention

[0004] The purpose of this invention is to provide a three-phase common-box cable drum to solve the problem that existing cable terminal devices require disassembly and separate testing of their internal components during withstand voltage testing, which makes it impossible to test the interconnected parts and thus creates testing blind spots; the purpose of this invention is to provide a combined electrical appliance that uses the above-mentioned three-phase common-box cable drum.

[0005] To solve the above problems, the three-phase common-box cable drum of the present invention adopts the following technical solution: The present invention provides a three-phase common-box cable drum comprising a drum body, a cable connector, and a combined electrical appliance connecting conductor. A disconnecting switch is provided between the cable connector and the combined electrical appliance connecting conductor. The opening distance of the disconnecting switch matches the insulation distance required for the cable connector and the combined electrical appliance to undergo withstand voltage testing.

[0006] Furthermore, the contact base of the disconnecting switch is provided with a deflection structure, or a corresponding deflection structure is provided between the contact base and the cable joint or the connecting conductor of the combined electrical appliance, so that the three-phase contacts of the disconnecting switch are arranged in a straight line inside the cylinder.

[0007] Furthermore, the steering structure is formed by a bent structure on the contact seat of the disconnecting switch or by a corresponding steering conductor.

[0008] Furthermore, an operating mechanism for controlling the disconnect switch is provided on the outside of the cylinder. The operating mechanism is connected to the disconnect switch via an insulated rotating shaft, and the insulated rotating shaft is sealed to the cylinder.

[0009] Furthermore, the disconnecting switch also includes a moving contact, a rack and gears. The rack is located on the moving contact, and the insulating shaft is connected to three gears to drive the gears to rotate, so that the three moving contacts can engage or disengage with the stationary contacts on the three cable joints in cooperation with the rack and gears.

[0010] Furthermore, the cylinder is equipped with insulators, the combined electrical appliance connecting conductors are located on the insulators, and the disconnecting switch is connected to the insulators through the combined electrical appliance connecting conductors.

[0011] Furthermore, the connection between the contact seat and the moving contact, as well as the interior of the stationary contact, are equipped with elastic contact fingers.

[0012] Furthermore, the cylinder sidewall is provided with a hand hole for easy internal installation and a hand hole cover that can be sealed with the hand hole. The position of the hand hole opening is perpendicular to the axial direction of the insulating shaft.

[0013] Furthermore, a pressure valve and a density gauge are installed on the outside of the cylinder to monitor the air pressure inside the cylinder.

[0014] Beneficial effects: This invention improves upon existing cable termination structures. When conducting withstand voltage tests on cables or combined electrical appliances, operators only need to operate the disconnecting switch to maintain a certain distance between the combined electrical appliance's connecting conductor and the cable joint, eliminating the need to remove the connecting conductor between the internal cable joint and the combined electrical appliance conductor. Furthermore, after the improvement, the cable joint and disconnecting switch remain connected throughout the entire testing process. When conducting power frequency withstand voltage tests on the cable, because the opening distance of the disconnecting switch matches the insulation distance required for the withstand voltage test between the cable joint and the combined electrical appliance, if the cable joint and disconnecting switch do not meet the withstand voltage requirements, the operator will observe a failure near the cable joint. This method allows for simultaneous evaluation of multiple components and their connections in a single power frequency withstand voltage test, eliminating testing blind spots in existing technologies and solving the aforementioned technical problems.

[0015] To solve the above problems, the combined electrical appliance device of the present invention adopts the following technical solution: The present invention provides a combined electrical device comprising a three-phase common-box cable drum and a combined electrical appliance connected to the three-phase common-box cable drum. The three-phase common-box cable drum includes a drum body, a cable connector, and a connecting conductor for the combined electrical appliance. A disconnecting switch is provided between the cable connector and the connecting conductor for the combined electrical appliance. The opening distance of the disconnecting switch matches the insulation distance required for the cable connector and the combined electrical appliance to undergo withstand voltage testing.

[0016] Furthermore, the contact base of the disconnecting switch is provided with a deflection structure, or a corresponding deflection structure is provided between the contact base and the cable joint or the connecting conductor of the combined electrical appliance, so that the three-phase contacts of the disconnecting switch are arranged in a straight line inside the cylinder.

[0017] Furthermore, the steering structure is formed by a bent structure on the contact seat of the disconnecting switch or by a corresponding steering conductor.

[0018] Furthermore, an operating mechanism for controlling the disconnect switch is provided on the outside of the cylinder. The operating mechanism is connected to the disconnect switch via an insulated rotating shaft, and the insulated rotating shaft is sealed to the cylinder.

[0019] Furthermore, the disconnecting switch also includes a moving contact, a rack and gears. The rack is located on the moving contact, and the insulating shaft is connected to three gears to drive the gears to rotate, so that the three moving contacts can engage or disengage with the stationary contacts on the three cable joints in cooperation with the rack and gears.

[0020] Furthermore, the cylinder is equipped with insulators, the combined electrical appliance connecting conductors are located on the insulators, and the disconnecting switch is connected to the insulators through the combined electrical appliance connecting conductors.

[0021] Furthermore, the connection between the contact seat and the moving contact, as well as the interior of the stationary contact, are equipped with elastic contact fingers.

[0022] Furthermore, the cylinder sidewall is provided with a hand hole for easy internal installation and a hand hole cover that can be sealed with the hand hole. The position of the hand hole opening is perpendicular to the axial direction of the insulating shaft.

[0023] Furthermore, a pressure valve and a density gauge are installed on the outside of the cylinder to monitor the air pressure inside the cylinder.

[0024] Beneficial Effects: This invention improves upon existing combined electrical appliances. When conducting withstand voltage tests on cables or combined electrical appliances, operators only need to operate the disconnecting switch to maintain a certain distance between the connecting conductors of the combined electrical appliances and the cable joints, eliminating the need to disconnect the internal cable joints from the conductors of the combined electrical appliances. Furthermore, after the improvement, the cable joints and the disconnecting switch remain connected throughout the entire testing process. When conducting power frequency withstand voltage tests on cables, because the opening distance of the disconnecting switch matches the insulation distance required for the withstand voltage test between the cable joints and the combined electrical appliances, if the cable joints and the disconnecting switch do not meet the withstand voltage requirements, the operator will observe a failure in withstand voltage near the cable joints. This method allows for the simultaneous assessment of multiple components and their connections in a single power frequency withstand voltage test, eliminating testing blind spots in existing technologies and solving the aforementioned technical problems. Attached Figure Description

[0025] Figure 1 A three-dimensional structural schematic diagram of one embodiment of a three-phase common-box cable drum; Figure 2 This is a first cross-sectional schematic diagram of an embodiment of a three-phase common-enclosure cable drum; Figure 3 This is a second cross-sectional schematic diagram of one embodiment of a three-phase common-enclosure cable drum; Figure 4 for Figure 2 A magnified view of a section at point A; Figure 5 This is a schematic diagram of the connection structure between the insulator and the disconnecting switch in one embodiment of a three-phase common-box cable drum.

[0026] In the diagram: 1. Cylinder; 2. Insulator; 3. Operating mechanism; 4. Handhole; 5. Density gauge; 6. Air pressure valve; 7. Cable connector; 8. Stationary contact; 9. Insulating shaft; 10. Combined electrical conductor; 11. Moving contact; 12. Steering conductor; 13. Gear; 14. Rack; 15. Contact seat. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] In a first aspect, the present invention provides a three-phase common-enclosure cable drum, such as... Figures 1 to 5As shown, the device includes a cylindrical body 1, a cable connector 7, and a combined electrical appliance connecting conductor 10. The cylindrical body 1 is a cylindrical body that is smaller at the top and larger at the bottom. The bottom plate of the cylindrical body 1 is equipped with a square flange, and the four corners of the flange are chamfered to avoid sharp corners affecting the nearby electric field. The combined electrical appliance connecting conductor 10 is connected from the smaller opening at the top of the cylindrical body 1, and the three-phase cable is connected from the larger opening at the bottom of the cylindrical body 1. A disconnecting switch is provided between the cable connector 7 and the combined electrical appliance connecting conductor 10. The opening distance of the disconnecting switch matches the insulation distance required when the cable connector 7 and the combined electrical appliance are tested for withstand voltage. At this opening distance, the required insulation requirements can be met.

[0029] In practical engineering, since the three-phase conductors of three-phase cables and combined electrical appliances are usually arranged in a triangular pattern, in order to facilitate the control of the disconnecting switch and simplify the internal structure of the cylinder 1, in a preferred embodiment, the contact seat 15 of the disconnecting switch is provided with a turning structure, or the contact seat 15 and the cable joint 7 or the connecting conductor 10 of the combined electrical appliance are correspondingly provided with a turning structure, so that the three-phase contacts of the disconnecting switch are arranged in a straight line inside the cylinder 1, which facilitates the connection or disconnection of the disconnecting switch.

[0030] Therefore, in one embodiment, the steering structure is disposed between the contact seat 15 and the combined electrical appliance connecting conductor 10, realizing that the three-phase contacts are arranged in a straight line inside the cylinder 1; however, in order to further simplify the internal structure and reduce the connection gaps between components, in a preferred embodiment, such as Figures 2 to 4 As shown, the deflection structure is formed by the bending structure on the contact seat 15 of the disconnecting switch. By changing the shape of the contact seat 15 itself, the need to add additional components is avoided. A deflection conductor 12 is also provided on the cable connector 7, which reduces the extent of modification required for the contact seat 15.

[0031] Based on the above design concept, such as Figures 2 to 4 As shown, in a preferred embodiment, an operating mechanism 3 for controlling the disconnect switch is provided on the outside of the cylinder 1. The operating mechanism 3 is connected to the disconnect switch via an insulated rotating shaft 9, which reduces the sliding loss during rack and pinion transmission and improves working efficiency. A sealing ring is provided between the insulated rotating shaft 9 and the cylinder 1 to achieve a sealed fit and prevent leakage of sulfur hexafluoride gas inside.

[0032] Preferably, such as Figures 1 to 3 As shown, the disconnecting switch also includes a moving contact 11, a rack 14, and a gear 13. The three gears 13 are aligned and their central axes are on the same straight line so that the insulating shaft 9 can be connected to the three gears 13 simultaneously. The rack 14 is located on the moving contact 11. When the insulating shaft 9 drives the three gears 13 to rotate, the three moving contacts 11 are engaged or disengaged with the stationary contacts 8 on the three cable connectors by the cooperation of the rack 14 and the gears 13. Therefore, the circuit can be switched on and off using only the insulating shaft 9. It is ingenious, convenient, and easy to implement.

[0033] The assembly site for GIS is quite complex. To facilitate on-site installation and subsequent disassembly and maintenance, in a preferred embodiment, as follows: Figure 1 and Figure 5 As shown, the cylinder 1 is equipped with an insulator 2, which is a disc insulator that fits the shape of the cylinder opening. The combined electrical appliance connecting conductor 10 is located on the insulator 2, and the disconnecting switch is connected to the insulator 2 through the combined electrical appliance connecting conductor 10. Through integrated design, the operator only needs to pull out the insulating shaft 9 and then pull out the disc insulator to take out the combined electrical appliance connecting conductor 10 and the contact seat 15 together. During installation, the operator only needs to fix the combined electrical appliance connecting conductor 10 and the contact seat 15 on the insulator 2, and then insert the assembled insulator 2 into the cylinder 1. This reduces the difficulty of on-site disassembly and installation for the operator, improves work efficiency, and also reduces the connection gaps caused by the assembly of multiple components, making it easier for the cylinder 1 to maintain a sealed state.

[0034] To ensure the conductivity between the contact seat 15 and the cable connector 7, in a preferred embodiment, the connection between the contact seat 15 and the moving contact 11, as well as the interior of the stationary contact 8, are equipped with elastic contact fingers. The elastic contact fingers can undergo radial deformation under end face pressure, thereby protecting the inner walls of the contact seat 15 and the stationary contact 8 connected to both sides of the moving contact 11, preventing loosening after long-term use, and improving the overall electrical efficiency and stability.

[0035] With the above design, although the staff does not need to open the cylinder 1 during the pressure test, it is still necessary to disassemble and troubleshoot if internal components malfunction later; for ease of operation, in one embodiment, such as Figures 1 to 3 As shown, the side wall of the cylinder 1 is provided with a hand hole 4 for easy internal installation and a hand hole 4 cover that can be sealed to the hand hole 4 to prevent leakage of sulfur hexafluoride gas inside the cylinder 1; moreover, the opening position of the hand hole 4 is perpendicular to the axial direction of the insulating shaft 9, which makes it convenient for the staff to operate the components near the cable joint 7.

[0036] Furthermore, since sulfur hexafluoride gas has nearly 10 times the insulation properties of air and nearly 100 times the arc-quenching effect, it has wide applications in the field of electrical equipment. However, when the content of sulfur hexafluoride gas in the air is too high, it may cause breathing difficulties or even suffocation for people nearby. Therefore, the cylinder 1 must have high airtightness requirements to avoid leakage. In a preferred embodiment, the cylinder 1 is equipped with a pressure valve 6 and a density gauge 5 on the outside to monitor the internal pressure of the cylinder 1 and prevent excessive internal pressure from causing leakage at some connection points.

[0037] In practical use, the operator first installs the combined electrical appliance connecting conductor 10 and contact seat 15 onto the insulator 2, then inserts the assembled insulator 2 into the cylinder 1, and then installs the operating mechanism 3 and other external components of the cylinder 1. When a power frequency withstand voltage test is required, the operating mechanism 3 is activated, and the insulating shaft 9 drives the three gears 13 to rotate, thereby separating the moving contact 11 from the stationary contact 8. At this time, the circuit is disconnected, and the operator can perform withstand voltage tests on the cable and the combined electrical appliance respectively, and observe whether there is any failure to withstand voltage near the cable joint 7. After the withstand voltage test is completed, the operating mechanism 3 is activated again, and the insulating shaft 9 is used to connect the moving contact 11 and the stationary contact 8 to form a power supply circuit.

[0038] In a second aspect, the present invention provides a combined electrical appliance device, such as... Figure 1 As shown, it includes a three-phase common-box cable drum and electrical equipment connected to the three-phase common-box cable drum. The three-phase common-box cable drum can be any type of three-phase common-box cable drum in the above design concept. The combined electrical device made using the above-mentioned three-phase common-box cable drum can perform power frequency withstand voltage testing on the cable joint 7 and the stationary contact 8 simultaneously without removing the internal components, thus eliminating the testing blind spots in the prior art.

[0039] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. The scope of patent protection of the present invention shall be determined by the claims. Similarly, any equivalent structural changes made based on the description and drawings of the present invention shall also be included within the scope of protection of the present invention.

Claims

1. A three-phase common enclosure cable drum comprising a drum body, a cable joint and a combined electrical connector conductor, characterized in that, The cable joint and the combined electrical appliance connecting conductor are provided with a disconnecting switch, and the opening distance of the disconnecting switch matches the insulation distance required when the cable joint and the combined electrical appliance are subjected to voltage withstand test.

2. A three-phase common-tank cable drum according to claim 1, characterized in that The contact seat of the disconnecting switch is provided with a turning structure, or the contact seat and the cable joint or the combined electrical appliance connecting conductor are provided with corresponding turning structures, so that the three-phase contact heads of the disconnecting switch are arranged in a linear type in the barrel.

3. A three-phase common-tank cable drum according to claim 2, characterized in that The turning structure is composed of a bending structure on the contact seat of the disconnecting switch or is composed of a corresponding turning conductor.

4. A three-phase common-tank cable drum according to claim 2 or 3, characterised in that, The barrel is externally provided with an operating mechanism capable of controlling the disconnecting switch, the operating mechanism is in transmission connection with the disconnecting switch through an insulating rotating shaft, and the insulating rotating shaft is in sealing fit with the barrel.

5. A three-phase common-tank cable drum according to claim 4, characterized in that The disconnecting switch further comprises moving contact heads, a rack and gears, the rack is located on the moving contact heads, the insulating rotating shaft is connected with the three gears to drive the gears to rotate, so that the three moving contact heads are in butt joint or separation with the static contact heads on the three cable joints under the cooperation of the rack and the gears.

6. A three-phase common-tank cable drum according to claim 4, characterized in that The barrel is provided with an insulator, the combined electrical appliance connecting conductor is arranged on the insulator, and the disconnecting switch is connected with the insulator through the combined electrical appliance connecting conductor.

7. A three-phase common-tank cable drum according to claim 5, characterized in that The connecting part of the contact seat and the moving contact head and the inside of the static contact head are both provided with elastic contact fingers.

8. A three-phase common-tank cable drum according to claim 4, characterized in that, The barrel is provided with a hand hole for facilitating internal installation and a hand hole cover capable of sealing fit with the hand hole, and the hole position of the hand hole is perpendicular to the axial direction of the insulating rotating shaft.

9. A three-phase common-tank cable drum according to claim 1, characterized in that, The barrel is externally provided with an air pressure valve and a density table to monitor the air pressure inside the barrel.

10. A combined electrical apparatus comprising a three-phase common-tank cable drum and a combined electrical apparatus connected to the three-phase common-tank cable drum, characterized in that, The three-phase common-box cable barrel is the three-phase common-box cable barrel according to any one of claims 1 to 9.

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