Single-conduit current-carrying direct-current wall bushing

Abstract

The utility model discloses a single-conduit current-carrying direct-current wall bushing, which comprises a flange, two hollow composite insulators symmetrically arranged at two ends of the flange, a conductive tube coaxially arranged in the flange and the two hollow composite insulators, and a dry-type capacitor core sleeved outside the conductive tube, a plurality of insulating supports are arranged on the conductive tube to ensure that the conductive tube is uniformly separated from the dry-type capacitor core; the dry-type capacitor core penetrates through the flange and is fixed on the flange, and a space formed by the flange, the hollow composite insulator and the end cover is filled with insulating gas; a plurality of layers of capacitor plates are arranged in the dry-type capacitor core, a measuring terminal is mounted on the flange, and the capacitor plate on the outermost layer is connected with the measuring terminal through an end screen lead; a conductive metal sheet is arranged on the inner side of a capacitor plate on the innermost layer of the dry-type capacitor core, an equipotential device is arranged between the conductive metal sheet and a conductive tube, two ends of the equipotential device are respectively connected with the conductive metal sheet and the conductive tube, and equipotential between the capacitor plate on the innermost layer and a high-voltage side is realized.

Description

Technical Field

[0001] The utility model relates to a single-conduit current-carrying DC wall bushing, belonging to the technical field of bushings. Background Art

[0002] At present, there are three main types of DC wall bushings in China: pure gas insulation, pure dry capacitor core insulation, and gas-dry capacitor core composite insulation. Traditional DC wall bushings are mostly pure gas insulation structures, usually using a conductive tube nested structure, and current carrying is achieved through finger connections, expansion joints, and other forms. Since the conductive tube of the wall bushing is long, an insulating support device will be used to support the conductive tube at the flange. This type of bushing is prone to discharge at the nested position or insulation support position, thereby generating harmful gases and affecting the gas insulation performance. DC wall bushings with pure dry capacitor core insulation structure are also used. Due to the low thermal conductivity of the insulation material, insulation aging, insulation performance degradation, and electric field distortion are prone to occur. In recent years, DC wall bushings with gas-dry capacitor core composite insulation structure have been increasingly used, usually with a multi-conduit nested structure and dry capacitor core support. This structure avoids the discharge problem caused by insulation support, but the discharge problem between multiple conduits still exists. Utility Model Content

[0003] The utility model aims to provide a single-conduit current-carrying DC wall bushing to solve the discharge problem between multiple conduits of a DC wall bushing with a composite insulation structure of a gas-dry capacitor core.

[0004] The technical solution adopted by the utility model is:

[0005] A single-conductor current-carrying DC wall bushing comprises a flange and two hollow composite insulators symmetrically mounted at both ends of the flange, and end caps are mounted on the ends of the two hollow composite insulators that are away from each other; a conductive tube is coaxially arranged in the flange and the two hollow composite insulators, and the two ends of the conductive tube abut against the inner side surfaces of the end caps at the corresponding ends; a dry capacitor core is sleeved outside the conductive tube, and a plurality of insulating supports for supporting the dry capacitor core are arranged on the conductive tube; the dry capacitor core is inserted through the flange and fixed on the flange, and the space formed by the flange, the hollow composite insulator and the end caps is filled with insulating gas;

[0006] The dry capacitor core has multiple layers of capacitor plates, and measuring terminals are installed on the flange. The outermost capacitor plates are connected to the measuring terminals through the end screen leads; at least one conductive metal sheet is arranged on the inner side of the innermost capacitor plates of the dry capacitor core, and an equipotential device is arranged between the conductive metal sheet and the conductive tube, and the two ends of the equipotential device are respectively connected to the conductive metal sheet and the conductive tube.

[0007] Preferably, a wiring board is installed on the outer side of each of the end covers.

[0008] Preferably, a plurality of notches are formed on the conductive tube, and the insulating support is disposed in the corresponding notches.

[0009] Preferably, the equipotential device is connected to the conductive tube via a fastener.

[0010] Preferably, a grounding shielding cylinder is sleeved outside the dry capacitor core located outside both ends of the flange, and the grounding shielding cylinder is respectively installed on the ports of the flange at the corresponding ends.

[0011] Preferably, both ends of the conductive tube are sleeved with pressure equalizing covers, and the pressure equalizing covers are respectively installed on the inner sides of the end caps at the corresponding ends.

[0012] The beneficial effects of the utility model are:

[0013] By arranging insulating supports and setting up an equipotential device between the dry capacitor core and the conductive tube, it is ensured that the innermost capacitor plate of the dry capacitor core is at the same potential as the high-voltage side, and at the same time, it is ensured that the conductive tube and the dry capacitor core are evenly separated to avoid the occurrence of false connection. At the same time, it is convenient for the conductive tube to dissipate heat and prevent thermal aging of the insulating material of the dry capacitor core. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 A schematic diagram of the structure of the DC wall bushing provided by the utility model;

[0015] Figure 2 for Figure 1 Enlarged view of point A in the middle.

[0016] The main reference numerals in the figure have the following meanings:

[0017] 1. Dry capacitor core, 2. Insulating gas, 3. Conductive tube, 4. Flange, 5. End screen lead, 6. Measuring terminal, 7. Insulating support, 8. Zero screen, 9. Conductive metal sheet, 10. Equipotential device, 11. Fasteners, 12. End cover, 13. Terminal block, 14. Voltage grading cover, 15. Grounding shield tube, 16. Hollow composite insulator. DETAILED DESCRIPTION

[0018] The utility model is specifically introduced below in conjunction with the accompanying drawings and embodiments.

[0019] This embodiment is a single-conductor DC wall bushing. Figure 1As shown, it includes a flange 4 and two hollow composite insulators 16 symmetrically installed at both ends of the flange 4, and the ends of the two hollow composite insulators 16 away from each other are both installed with end covers 12, and the outer sides of the end covers 12 are both installed with terminal blocks 13; a conductive tube 3 is coaxially arranged in the flange 4 and the two hollow composite insulators 16, and the two ends of the conductive tube 3 are abutted against the inner side surfaces of the end covers 12 at the corresponding ends, and voltage equalizing covers 14 are sleeved on the outer sides of the two ends of the conductive tube 3, and the voltage equalizing covers 14 are respectively installed on the inner sides of the end covers 12 at the corresponding ends.

[0020] The DC wall bushing also includes a dry capacitor core 1 sleeved outside the conductive tube 3, a plurality of slots are formed on the conductive tube 3, and an insulating support 7 is arranged in each slot. The dry capacitor core 1 is supported by the plurality of insulating supports 7 to ensure uniform spacing between the conductive tube 3 and the dry capacitor core 1.

[0021] like Figure 1 As shown, a protrusion is formed outside the core of the dry capacitor core 1, the right end of the protrusion abuts against the inner side of the right port of the flange 4, the outer peripheral body of the left end of the protrusion fits against the inner wall of the left port of the flange 4, and a mounting plate is provided on the outer sleeve of the left end core body of the dry capacitor core 1, the mounting plate abuts against the left end of the protrusion and is fixedly connected to the left port of the flange 4. That is, the dry capacitor core 1 is inserted through the flange 4 and fixed on the flange 4. A mutually interpenetrating space is formed between the flange 4, the two hollow composite insulators 16 and the two end covers 12 (through holes can be provided at the ports of the flange 4), and the interpenetrating space is filled with insulating gas 2, and the dry capacitor core 1 and the insulating gas 2 together constitute the main insulation of the DC wall bushing. A grounding shielding tube 15 is provided outside the dry capacitor core 1 located outside the two ends of the flange 4, and the grounding shielding tube 15 is respectively installed on the ports of the flange 4 at the corresponding ends.

[0022] The dry capacitor core 1 has multiple layers of capacitor plates, and a measuring terminal 6 is installed on the flange 4. The outermost capacitor plates are connected to the measuring terminal 6 through the end screen lead 5 for the bushing electrical performance and insulation performance test. Figure 2 As shown, at least one conductive metal sheet 9 is arranged on the inner side of the innermost capacitor plate (zero screen 8) of the dry capacitor core 1, and the conductive metal sheet 9 can be made of copper or other materials; an equipotential device 10 is arranged between the conductive metal sheet 9 and the conductive tube 3, and the equipotential device 10 can also be a thin copper sheet, a lead wire, etc.; one end of the equipotential device 10 is connected to the conductive metal sheet 9, and the other end is connected to the conductive tube 3 through a fastener 11, thereby achieving the equipotential between the innermost capacitor plate (zero screen 8) of the dry capacitor core 1 and the high voltage side.

[0023] The above is only a preferred implementation of the utility model patent. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the utility model patent. These improvements and modifications should also be regarded as the protection scope of the utility model patent.

Claims

1. A single-conduit current-carrying DC wall bushing, characterized in that: It includes a flange and two hollow composite insulators symmetrically installed at both ends of the flange, and end covers are installed at the ends of the two hollow composite insulators that are away from each other; a conductive tube is coaxially arranged in the flange and the two hollow composite insulators, and the two ends of the conductive tube are abutted against the inner side surfaces of the end covers at the corresponding ends; it also includes a dry capacitor core sleeved outside the conductive tube, and a plurality of insulating supports for supporting the dry capacitor core are arranged on the conductive tube; the dry capacitor core is inserted through the flange and fixed on the flange, and the space formed by the flange, the hollow composite insulator and the end cover is filled with insulating gas; The dry capacitor core has multiple layers of capacitor plates, and measuring terminals are installed on the flange. The outermost capacitor plates are connected to the measuring terminals through the end screen leads; at least one conductive metal sheet is arranged on the inner side of the innermost capacitor plates of the dry capacitor core, and an equipotential device is arranged between the conductive metal sheet and the conductive tube, and the two ends of the equipotential device are respectively connected to the conductive metal sheet and the conductive tube.

2. A single-conductor current-carrying DC wall bushing according to claim 1, characterized in that: The outer sides of the end covers are all equipped with wiring boards.

3. A single-conductor current-carrying DC wall bushing according to claim 1, characterized in that: A plurality of notches are formed on the conductive tube, and the insulating support is arranged in the corresponding notches.

4. A single-conductor current-carrying DC wall bushing according to claim 1, characterized in that: The equipotential device is connected to the conductive tube via a fastener.

5. A single-conductor current-carrying DC wall bushing according to claim 1, characterized in that: A grounding shielding cylinder is sleeved outside the dry capacitor cores located outside the two ends of the flange, and the grounding shielding cylinders are respectively installed on the ports of the flanges at the corresponding ends.

6. A single-conductor current-carrying DC wall bushing according to claim 1, characterized in that: Both ends of the conductive tube are sleeved with pressure equalizing covers, and the pressure equalizing covers are respectively installed on the inner sides of the end caps of the corresponding ends.

Images