A cable joint structure for ring network cabinet

Abstract

The present invention proposes a cable joint structure for a ring network cabinet, wherein the cable joint is a plug-in joint, including a sleeve joint, and also including a conductive rod contact seat for assembling a cable terminal and a lightning arrester fixing seat for assembling a lightning arrester terminal; the cable joint is fixed to the gas box through a sleeve pressure plate, and the cable joint is fixedly connected to the gas box and the conductor inside the gas box by fasteners to form a combination; the combination is assembled on the upper part of the cable room; the sleeve joint is an epoxy-cast one-piece sleeve, which has a conductive rod and a grounding shielding grille, a top metal insert, and a bottom metal insert built in; the conductive rod is welded and connected to a high-voltage shielding ring and is installed with a sealing ring, and is fixed to the gas box through a pressure plate and a front plate of the gas box to ensure the sealing of the sleeve and the gas box; the present invention can solve the insulation problems caused by mechanical damage, insulation moisture, aging of the insulating medium, and poor manufacturing process under the existing interface insulation form.

Description

Technical Field

[0001] The invention relates to the technical field of power supply and distribution system and medium voltage switch equipment, in particular to a cable joint structure for a ring network cabinet. Background Art

[0002] The application of power cables in power systems has increased year by year. Since most power cables are buried underground and the working environment is relatively harsh, cable failures occur from time to time. According to statistics, cable joint failures account for 70% of cable failures, and their safe operation is very important. The European cable T-joints currently used on the market: use insulating materials such as silicone rubber and EPDM rubber, the lap joints use interface bonding, apply silicone grease to eliminate air gaps, and have high requirements for stress cones and T-head cone surfaces. Analysis of the causes of the problem can be roughly divided into the following categories: mechanical damage, insulation moisture, insulation medium aging, poor manufacturing process, etc., but analysis of the root causes of these problems found that they are all problems with interface insulation. Therefore, the development of a new type of non-interface insulation joint form can avoid the above problems. The idea of ​​this design scheme is to use air insulation instead of interface insulation. Summary of the invention

[0003] The present invention provides a cable joint structure for a ring network cabinet, which can solve the insulation problems caused by mechanical damage, insulation moisture, insulation medium aging and poor manufacturing process in the existing interface insulation form.

[0004] The present invention adopts the following technical solutions.

[0005] A cable joint structure for a ring network cabinet, the cable joint being a plug-in type joint, comprising a sleeve joint (3), a conductive rod contact seat for assembling a cable terminal, and a lightning arrester fixing seat (16) for assembling a lightning arrester terminal; the cable joint is fixed to an air box (2) via a sleeve pressure plate (7), and the cable joint is fixedly connected to the air box and a conductor (1) inside the air box via a fastener (6) to form a combination; the combination is assembled on the upper part of a cable chamber (5);

[0006] The bushing joint is an epoxy-cast one-piece bushing, which has a built-in conductive rod (10), a grounding shielding grille (11), a top metal insert (12), and a bottom metal insert (13); the conductive rod is welded to a high-voltage shielding ring and is equipped with a sealing ring, which is fixed to the gas box by pressing the pressure plate against the front plate of the gas box to ensure the sealing of the bushing and the gas box;

[0007] The surface of the integrated sleeve is sprayed with a metal layer to form a touchable surface full shielding structure and to form a reliable grounding.

[0008] The cable terminal includes a cold shrink sleeve, a stress cone, a contact seat and two spring contact fingers. During assembly, first insert the holding seal device, then assemble the stress cone, the contact seat and the spring contact fingers, and then install the conductive rod contact seat of the integrated sleeve.

[0009] The clamping and sealing device at the bottom of the integrated sleeve is provided with a flange structure, which is fastened to the integrated sleeve, and the clamping and sealing device contains a sealing ring for sealing the cable and the integrated sleeve.

[0010] The specific method of assembling the cable terminal of the cable connector is as follows:

[0011] A1. First, assemble the cable terminal, specifically: insert the cable (26) into the holding seal device (20), the metal fixing sleeve (18), the sealing ring (19), and then install the stress cone (17), the contact seat and the spring contact finger (14) to form a cable terminal;

[0012] A2. Install the cable terminal at the cable joint, specifically: insert the cable terminal into the cable joint, use fasteners to connect and assemble the cable joint with the metal fixing sleeve (18) and the cable sealing ring (22), and then screw the clamping sealing device (20) into the metal fixing sleeve (18) and press it tightly, thereby clamping the cable and completing the cable terminal assembly;

[0013] A3. The cable is protected and sealed by a clamping sealing device, specifically: the clamping sealing device comprises a clamping sealing device rubber sealing ring (23), a gripping plastic sleeve (24), and a clamping metal sleeve (25), the clamping metal sleeve having a threaded structure, and the lower part of the clamping metal sleeve has a conical surface fit with the gripping plastic sleeve (24); the gripping plastic sleeve at the lower part of the clamping metal sleeve is contracted by assembling the threaded structure of the clamping metal sleeve upward, thereby clamping the cable; during the clamping process, the clamping sealing device rubber sealing ring (23) is attached to the outer wall of the cable to play a protective and sealing role, thereby preventing the cable from being damaged by force;

[0014] A4. After the cables are installed, the cable fixing clamp (4) is used to fix the cables at the bottom of the cable cabinet. The bushing joint forms a fixed support point at the top of the cable chamber (5) through the support plate (8) at the top plate of the cable chamber. The rear of the integrated bushing is fixed to the ring main cabinet body through a bracket to prevent the integrated bushing from being subjected to excessive force.

[0015] The air chamber of the cable room is a normal pressure sealed air insulation structure of the cable connector; the integrated sleeve and cable terminal and lightning arrester terminal of the cable connector are sealed inside the air cavity of the air chamber, so that their use is not affected by the external environment. A high-voltage shielding ring is provided around the contact seat of the integrated sleeve. The high-voltage shielding ring makes the electric field in the air cavity uniform to achieve normal pressure sealed air insulation.

[0016] The air chamber of the cable chamber includes a metal shell; the metal shell is provided with an air vent; the air vent is provided with an exhalation valve capable of filtering moisture and impurities; the exhalation valve ensures pressure balance inside and outside the air chamber through air exchange.

[0017] The method of assembling the arrester terminal of the cable connector is as follows:

[0018] B1. Assemble the arrester terminal, specifically: press-fit the contact seat at one end of the arrester, install the spring contact finger, and fix it at the arrester fixing seat (16) using M10 bolts, flat washers, spring washers, and grounding wires to form the arrester terminal;

[0019] B2. Install the arrester terminal at the cable joint. Specifically, insert the arrester terminal into the cable joint, rivet it with fasteners, and seal it with an arrester sealing ring (21) at the connection between the arrester fixing base and the cable joint.

[0020] The advantages of the present invention are:

[0021] 1. A cable connector structure for connecting a ring main unit to a cable is provided. The device has a simple structure, uses a plug-in connector instead of a copper terminal assembly structure, and has a simple assembly process.

[0022] 2. Use normal pressure sealed air insulation instead of interface insulation to effectively avoid interface air gap problems and eliminate silicone grease failure problems.

[0023] 3. The surface sprayed metal layer realizes full shielding of accessible surface, uniform electric field and reliable performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments:

[0025] Figure 1 It is a schematic diagram of the installation structure of the present invention;

[0026] Figure 2 It is a partial enlarged schematic diagram of the installation structure of the present invention;

[0027] Figure 3 is a three-dimensional schematic diagram of the connection between the cable connector and the gas box of the present invention;

[0028] Figure 4 It is a cross-sectional schematic diagram of the cable connector of the present invention when assembled;

[0029] Figure 5a is a top view schematic diagram of the cable connector of the present invention;

[0030] Figure 5b is a cross-sectional schematic diagram of a cable connector of the present invention;

[0031] Figure 6a is a schematic diagram of the sealing structure of the cable connector of the present invention;

[0032] Figure 6b is a cross-sectional schematic diagram of a holding seal device;

[0033] In the figure: 1-conductor; 2-gas box; 3-casing joint; 4-cable fixing clamp; 5-cable chamber; 6-fastener; 7-pressing plate; 8-supporting plate; 9-fastener;

[0034] 10-conductive rod; 11-grounding shielding grille; 12-top metal insert; 13-bottom metal insert; 14-spring contact finger; 15-lightning arrester; 16-lightning arrester fixing seat; 17-stress cone; 18-metal fixing sleeve; 19-sealing ring;

[0035] 20-holding sealing device; 21-lightning arrester sealing ring; 22-cable sealing ring; 23-holding sealing device rubber sealing ring; 24-holding plastic sleeve; 25-holding metal sleeve; 26-cable. DETAILED DESCRIPTION

[0036] As shown in the figure, a new type of cable joint structure for ring main unit, the cable joint is a plug-in joint, including a sleeve joint 3, a conductive rod contact seat for assembling a cable terminal and a lightning arrester fixing seat 16 for assembling a lightning arrester terminal; the cable joint is fixed to the gas box 2 through the sleeve pressure plate 7, and the cable joint is fixedly connected to the gas box and the conductor 1 inside the gas box by a fastener 6 to form a combination; the combination is assembled on the upper part of the cable chamber 5;

[0037] The bushing joint is an epoxy-cast one-piece bushing, which has a built-in conductive rod 10 and a grounded shielding grille 11, a top metal insert 12, and a bottom metal insert 13; the conductive rod is welded to a high-voltage shielding ring and is installed with a sealing ring, which is fixed to the gas box by pressing the pressure plate with the front plate of the gas box to ensure the sealing of the bushing and the gas box;

[0038] The surface of the integrated sleeve is sprayed with a metal layer to form a touchable surface full shielding structure and to form a reliable grounding.

[0039] The cable terminal includes a cold shrink sleeve, a stress cone, a contact seat and two spring contact fingers. During assembly, first insert the holding seal device, then assemble the stress cone, the contact seat and the spring contact fingers, and then install the conductive rod contact seat of the integrated sleeve.

[0040] The clamping and sealing device at the bottom of the integrated casing is provided with a flange structure, which is fastened to the integrated casing, and the clamping and sealing device contains a sealing ring for sealing the cable and the integrated casing.

[0041] The specific method of assembling the cable terminal of the cable connector is as follows:

[0042] A1. First assemble the cable terminal, specifically: insert the cable 26 into the holding seal device 20, the metal fixing sleeve 18, the sealing ring 19, and then install the stress cone 17, the contact seat and the spring contact finger 14 to form a cable terminal;

[0043] A2. Install the cable terminal at the cable joint, specifically: insert the cable terminal into the cable joint, use fasteners to connect and assemble the cable joint with the metal fixing sleeve 18 and the cable sealing ring 22, and then screw the holding sealing device 20 into the metal fixing sleeve 18 and press it tightly, so as to hold the cable tightly and complete the cable terminal assembly;

[0044] A3. The cable is protected and sealed by a holding and sealing device. Specifically, the holding and sealing device comprises a holding and sealing device rubber sealing ring 23, a gripping plastic sleeve 24 and a gripping metal sleeve 25. The gripping metal sleeve has a threaded structure, and the lower part of the gripping metal sleeve is a conical surface. The gripping plastic sleeve at the lower part of the gripping metal sleeve is contracted by assembling the threaded structure of the gripping metal sleeve upward to hold the cable. During the gripping process, the rubber sealing ring 23 of the gripping sealing device is attached to the outer wall of the cable to protect and seal the cable, thereby preventing the cable from being damaged by force.

[0045] A4. After the cable is installed, the cable fixing clamp 4 is used to fix the cable at the bottom of the cable cabinet, and the sleeve joint forms a fixed support point on the top of the cable room 5 at the top plate of the cable room through the support plate 8; the rear of the integrated sleeve is fixed to the ring network cabinet body through the bracket to prevent the integrated sleeve from being subjected to excessive force.

[0046] The air chamber of the cable room is a normal pressure sealed air insulation structure of the cable connector; the integrated sleeve and cable terminal and lightning arrester terminal of the cable connector are sealed inside the air cavity of the air chamber, so that their use is not affected by the external environment. A high-voltage shielding ring is provided around the contact seat of the integrated sleeve. The high-voltage shielding ring makes the electric field in the air cavity uniform to achieve normal pressure sealed air insulation.

[0047] The air chamber of the cable chamber includes a metal shell; the metal shell is provided with an air vent; the air vent is provided with an exhalation valve capable of filtering moisture and impurities; the exhalation valve ensures pressure balance inside and outside the air chamber through air exchange.

[0048] The method of assembling the arrester terminal of the cable connector is as follows:

[0049] B1. Assemble the arrester terminal, specifically: press-fit the contact seat at one end of the arrester 15, install the spring contact finger, and fix the arrester fixing seat 16 with M10 bolts, flat washers, spring washers, and grounding wires to form the arrester terminal;

[0050] B2. Install the arrester terminal at the cable joint, specifically: insert the arrester terminal into the cable joint, rivet it with fasteners, and use the arrester sealing ring 21 to seal the connection between the arrester fixing seat and the cable joint.

[0051] Example:

[0052] In this example, a new type of air-insulated cable joint sleeve structure for a ring main unit is provided, wherein the sleeve structure is an integrated sleeve including a grounding shielding mesh, a conductive rod, an insert, a cable air chamber, and a lightning arrester air chamber; the conductive rod is an integrated conductive rod in the shape of the letter F, and one of its two horizontal branches is provided at the end with a first contact seat for connecting the cable in the cable air chamber, and the other end is provided with a second contact seat for connecting the lightning arrester in the lightning arrester air chamber; the first contact seat and the second contact seat are both provided with high-voltage shielding rings, which are respectively used to make the electric field in the cable air chamber and the lightning arrester air chamber uniform, so that the cable air chamber and the lightning arrester air chamber form air insulation structures at the first contact seat and the second contact seat.

[0053] In this example, the cable air chamber and the lightning arrester air chamber also form a normal pressure sealed air insulation structure for the cable joint. The cable terminal and lightning arrester terminal installed in this product are sealed inside the air chamber to prevent their use from being affected by the external environment. A high-voltage shielding ring is provided around the integrated sleeve contact seat to make the electric field inside the air chamber uniform to achieve normal pressure sealed air insulation.

[0054] The air chamber of the cable air chamber and the arrester air chamber includes a metal shell; the metal shell is provided with an air vent; the air vent is provided with an exhalation valve that can filter moisture and impurities; the exhalation valve ensures pressure balance inside and outside the air chamber through air exchange.

Claims

1. A cable joint structure for a ring main unit, characterized in that: The cable connector is a plug-in connector, comprising a sleeve connector (3), a conductive rod contact seat for assembling a cable terminal, and a lightning arrester fixing seat (16) for assembling a lightning arrester terminal; the cable connector is fixed to the gas box (2) via a sleeve pressure plate (7), and the cable connector is fixedly connected to the gas box and the conductor (1) inside the gas box via a fastener (6) to form a combination; the combination is assembled on the upper part of the cable chamber (5); The bushing joint is an epoxy-cast one-piece bushing, which has a built-in conductive rod (10), a grounding shielding grille (11), a top metal insert (12), and a bottom metal insert (13); the conductive rod is welded to a high-voltage shielding ring and is equipped with a sealing ring, which is fixed to the gas box by pressing the pressure plate against the front plate of the gas box to ensure the sealing of the bushing and the gas box; The surface of the integrated sleeve is sprayed with a metal layer to form a touchable surface full shielding structure and to form a reliable grounding; The cable terminal includes a cold shrink sleeve, a stress cone, a contact seat and two spring contact fingers. During assembly, first insert the holding seal device, then assemble the stress cone, the contact seat and the spring contact fingers, and then install the conductive rod contact seat of the integrated sleeve. The clamping sealing device at the bottom of the integrated casing is provided with a flange structure, which is fastened to the integrated casing, and the clamping sealing device contains a sealing ring for sealing the cable and the integrated casing; The specific method of assembling the cable terminal of the cable connector is as follows: A1. First, assemble the cable terminal, specifically: insert the cable (26) into the holding seal device (20), the metal fixing sleeve (18), the sealing ring (19), and then install the stress cone (17), the contact seat and the spring contact finger (14) to form a cable terminal; A2. Install the cable terminal at the cable joint, specifically: insert the cable terminal into the cable joint, use fasteners to connect and assemble the cable joint with the metal fixing sleeve (18) and the cable sealing ring (22), and then screw the clamping sealing device (20) into the metal fixing sleeve (18) and press it tightly, thereby clamping the cable and completing the cable terminal assembly; A3. The cable is protected and sealed by a clamping sealing device, specifically: the clamping sealing device comprises a clamping sealing device rubber sealing ring (23), a gripping plastic sleeve (24), and a clamping metal sleeve (25), the clamping metal sleeve having a threaded structure, and the lower part of the clamping metal sleeve has a conical surface fit with the gripping plastic sleeve (24); the gripping plastic sleeve at the lower part of the clamping metal sleeve is contracted by assembling the threaded structure of the clamping metal sleeve upward, thereby clamping the cable; during the clamping process, the clamping sealing device rubber sealing ring (23) is attached to the outer wall of the cable to play a protective and sealing role, thereby preventing the cable from being damaged by force; A4. After the cables are installed, the cable fixing clamp is used to fix the cables at the bottom of the cable cabinet. The bushing joint forms a fixed support point at the top of the cable chamber (5) through the support plate (8) at the top plate of the cable chamber. The rear of the integrated bushing is fixed to the ring main cabinet body through a bracket to prevent the integrated bushing from being subjected to excessive force. The air chamber of the cable room is a normal pressure sealed air insulation structure of the cable connector; the integrated sleeve and cable terminal and lightning arrester terminal of the cable connector are sealed inside the air cavity of the air chamber, so that their use is not affected by the external environment. A high-voltage shielding ring is provided around the contact seat of the integrated sleeve. The high-voltage shielding ring makes the electric field in the air cavity uniform to achieve normal pressure sealed air insulation.

2. A cable joint structure for a ring main unit according to claim 1, characterized in that: The air chamber of the cable chamber includes a metal shell; the metal shell is provided with an air vent; the air vent is provided with an exhalation valve capable of filtering moisture and impurities; the exhalation valve ensures pressure balance inside and outside the air chamber through air exchange.

3. The cable joint structure for a ring main unit according to claim 1, characterized in that: The method of assembling the arrester terminal of the cable connector is as follows: B1. Assemble the arrester terminal, specifically: press-fit the contact seat at one end of the arrester, install the spring contact finger, and fix it at the arrester fixing seat (16) using M10 bolts, flat washers, spring washers, and grounding wires to form the arrester terminal; B2. Install the arrester terminal at the cable joint. Specifically, insert the arrester terminal into the cable joint, rivet it with fasteners, and seal it with an arrester sealing ring (21) at the connection between the arrester fixing base and the cable joint.

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