KR20180041220A - Transition joint - Google Patents

Abstract

The transition joint connects the oil fill cable to a solid dielectric cable and includes a connector, a glass fiber tube 210, a preformed joint body 108, 228, and a copper housing 106. The glass fiber tube 210 circumferentially encapsulates the end segments 102, 220 of the oil fill cable. The preformed joint body 108,228 circumferentially surrounds the first deflector 214, the second deflector 215 and the high voltage (HV) electrode 316. The pre- The copper housing 106 circumferentially surrounds the preformed joint body to form the outermost layer of the transition joints 100,200. Transitional joints with preformed joint bodies have a reduced size, while the time to connect the two types of cables using transition joints is reduced.

Description

Transition joint

The present invention relates to a transition joint that connects an oil-filled cable to a solid dielectric cable.

Oil-filled high-voltage power cables have been used since the 1920s and their performance was very satisfactory. Since the 1980s, solid dielectric power cables have been developed and gradually replaced oil-filled power cables. Different transition joints are used to connect the oil fill cable and the solid dielectric cable. It is not easy and efficient to utilize the transition joints currently available for connecting oil-filled cables and solid dielectric cables.

In view of the need to efficiently connect the two types of power cables, improvements in transition joints are desired.

In order to solve the above problems, the invention described in claims is provided.

Figure 1 shows a transition joint according to an exemplary embodiment.
Figure 2 shows a longitudinal view of a transition joint according to an exemplary embodiment.
3 shows a pre-molded joint body of a transition joint according to an exemplary embodiment.
4 shows a glass fiber tube of a transition joint according to an exemplary embodiment.

One exemplary embodiment is a transition joint that connects an oil fill cable to a solid dielectric cable. The transition joint comprises a connector, a glass fiber tube, a pre-molded joint body, and a copper housing. The connector secures the end segment of the oil fill cable and the end segment of the solid dielectric cable to form a transition joint core. The glass fiber tube is covered by a metal cap at the first end and is inserted over the end segment of the oil fill cable at the second end to enclose the end segment of the oil fill cable within the transition joint. The pre-molded joint body circumferentially circumscribes the first deflector at the first tapered end, circumferentially surrounds the second deflector at the tapered second end, and circumferentially surrounds the high voltage (HV) electrode in the middle section . The copper housing surrounds the preformed joint body circumferentially to form the outermost layer of the transition joint.

Other exemplary embodiments are described below.

Exemplary embodiments relate to an apparatus and method for connecting an oil filled cable to a solid dielectric cable having a transition joint, wherein the transition joint comprises a preformed joint body and a glass fiber tube. The glass fiber tube acts as an insulator to separate the oil filled cable from the preformed joint body and other parts of the transition joint.

Paper-insulated and oil-filled cables have been used as high-voltage power cables since the 1920s, and the performance of oil-filled cables has been very satisfactory. Users are faced with the difficulty of using oil-filled cables because of the complexity of the technology and the high technical requirements to bond the oil-filled cable, and oil leaks after long periods of work impose problems. In the case of an oil leak, it is necessary to continuously pump the oil to the ground to keep the oil fill cable operating. This causes pollution of the environment.

Since installing solid dielectric cables is user-friendly and simpler, solid dielectric cables are gradually replacing oil-filled cables since the 1980s. In this regard, manufacturing facilities for oil-filled cables are also being reduced. Oil-filled cables are now used for ultra-high voltage cables or submarine cables with voltage loads in excess of 220kV.

If the operating life of the power cables is in the range of 30 to 50 years or more, and the oil charging cable still works satisfactorily, it would be a waste of resources if the robust circuit using the oil charging cable would be stripped. Thus, a transition joint is developed to connect an existing oil-filled cable to a newly installed solid dielectric cable.

In general, a normal transition joint is designed based on the following.

1. Stop joint technique of oil-filled cable with two insulators facing back inside the container;

2. Use epoxy resin elements as transitions between the two types of cables. The pre-fabricated joint technique of solid dielectric cables requires a compression cone and a stress cone at one side and a paper stress cone at the oil-filled cable side.

3. A straight-through connection with O-rings is used to prevent the oil-filled oil-filled cable from penetrating the solid dielectric cable side and isolate them.

Conventional transition joints are bulky and it is complex and time-consuming to use transition joints that are common in connecting the two types of cables.

The exemplary embodiment includes a simplified approach using a specially designed pre-molded joint body that covers both the oil fill cable and the solid dielectric cable. In one exemplary embodiment, the transition joint with the pre-molded joint body is reduced in size, and the time for connecting the two types of cables using the transition joint is reduced.

In an exemplary embodiment, the pre-molded joint body can control the electric field in the transition joint. In another exemplary embodiment, by using a pre-molded joint body, the main components of the transition joint can be tested in the factory and the routine routine of such testing is similar to testing for other XLPE cable joints . Thus, the reliability of the installation of the transition joint is much improved.

As an example, the length of the transition joint is significantly reduced. In one exemplary embodiment, the transition joint is approximately half the length of a typical transition joint. In one exemplary embodiment, the installation of the transition joint is simple and quick.

In an exemplary embodiment, the transition joint passes an internally-developed high voltage alternating current (HVAC) test for a requirement of 132 kV voltage level under a heat cycle and an impulse.

An exemplary embodiment includes a system for connecting an oil fill cable to a solid dielectric cable. The system includes a solid metal connector, a hollow insulator, an electric field controller, a silicone rubber joint body, and a copper sleeve. A solid metal connector secures the end portion of the oil-filled cable and the end portion of the solid electrical cable to form a core. The hollow insulator is connected to the solid metal connector at the first end and into the end portion of the oil fill cable at the second end and the hollow insulator concentrically surrounds the end portion of the oil fill cable in the system. The electric field controller concentrically surrounds the hollow insulator and the solid metal connector and controls the electric field within the system. The silicon rubber joint body surrounds the electric field controller with the same center. The copper sleeve surrounds the silicon rubber joint body with the same center.

In one exemplary embodiment, the electric field controller includes a first deflector, which is co-centered within the silicone rubber joint body. The first deflector is surrounded by the same center of the hollow insulator at the first end of the silicon rubber joint body.

In another exemplary embodiment, the electric field controller has a second deflector coaxially surrounded in the silicone rubber joint body. The second deflector concentrically surrounds the hollow insulator at the first end of the silicon rubber joint body.

In one exemplary embodiment, the electric field controller has a high voltage (HV) electrode that co-centers the core.

In an exemplary embodiment, the electric field controller coaxially surrounds the first end of the hollow insulator.

As an example, the hollow insulator is made of glass fiber.

In one exemplary embodiment, the system includes a T-shaped intermediate flange and a bottom flange. The T-shaped intermediate flange and bottom flange are disposed at the first end of the copper sleeve and abut against the second end of the hollow insulator to secure the copper sleeve to the hollow insulator.

In one exemplary embodiment, the hollow insulator is secured to the silicone rubber joint body with an epoxy resin at the second end of the hollow insulator.

Figure 1 shows a transition joint 100, which connects the oil filled cable 102 and the solid dielectric cable 104 according to the present embodiment. A portion of the transition joint 100 where the transition joint 100 is connected to the oil fill cable 102 is wrapped by the copper housing 106 as shown in the exemplary embodiment of FIG. Accordingly, some elements of the transition joint 100 included in connection with the oil fill cable are not shown in FIG. The copper housing 106 forms the outermost layer of the transition joint 100 and shields the transition joint 100 from insulation. In an exemplary embodiment, the copper housing 106 circumferentially surrounds the entire transition joint.

In one exemplary embodiment, the oil fill cable has a voltage load of at least 110 kV. For example, the oil-filled cable has a voltage load of 132 kV.

In one exemplary embodiment, the solid dielectric cable is made of cross-linked polyethylene (XPLE) and has a voltage load of at least 110 kV. For example, a solid dielectric cable has a voltage load of 132 kV .

The transition joint 100 comprises a preformed joint body 108 and a deflector 110 which is directly underneath the copper housing 106 and tapers at both ends, (110) is located in a segment of the solid dielectric cable (104) and surrounds the segment. The pre-molded joint body 108 is made of an elastomeric material having good tensile strength so that it can be supported within the transition joint 100 by the transition joint 100 without the use of support elements such as a compression unit .

As an example, the preformed joint body 108 is made of silicone rubber. In another example, the pre-molded joint body 108 is made of ethylene-propylene rubber (EPR).

In one exemplary embodiment, the transition joint 100 performs an internal development high voltage alternating current (HVAC) test for a 132 kV voltage level requirement under a heat cycle and an impulse It passes.

Figure 2 illustrates a transition joint 200 that connects an oil fill cable 202 to a solid dielectric cable 204 in accordance with an exemplary embodiment. The transition joint 200 is tapered at both ends and has a cylindrical shape. The transition joint 200 includes a connector 206, a glass fiber tube 210, a high voltage (HV) electrode 212, a first deflector 214, a second deflector 215, and a preformed joint body 216). The copper housing 218 serves as the outermost layer of the transition joint 200.

In one exemplary embodiment, the end segment 220 of the oil fill cable has a head section 220a and a tail section 220B. In another exemplary embodiment, the end segment of the solid dielectric cable 222 has a head section 222A and a tail section 222B.

The oil fill cable 202 is mechanically and electrically connected to the solid dielectric cable (not shown) by securing the end section of the oil fill cable 220 and the end section of the solid dielectric cable 222 to form a transition joint core. 204, respectively.

In one exemplary embodiment, the oil fill cable connector 230 is fixedly connected to the connector 206 by connecting the end segment 220 of the oil fill cable to the connector 206 . An indenting support tube 232 is embedded in the oil filled cable conductor 230 to maintain the oil path within the oil fill cable 202. In one exemplary embodiment, the indwelling support tube 232 is made of stainless steel.

The glass fiber tube 210 is capped at the first end 252 with a connector 206. The glass fiber tube 210 is inserted onto the end segment 220 of the oil fill cable at the second end 254 and encircles the end segment 220 of the oil fill cable circumferentially. In one exemplary embodiment, the glass fiber tube 210 is secured to the preformed joint body 216 at the second end 254 with an epoxy resin. The glass fiber tube 210 separates the oil fill cable 220 from the transition joint 200 and prevents the oil inside the oil fill cable 202 from leaking out and leaking into the transition joint 200. In one exemplary embodiment, the glass fiber tube 210 acts as the oil septum of the pre-molded joint body 210 so that the pre-molded joint body 216 can leak from the oil fill cable 202 It prevents contact with any oil. As an example, the glass fiber tube 210 has a cylindrical shape.

In one exemplary embodiment, the oil fill cable 202 is filled with a paper roll 260 and is further surrounded by paper stress cones 262 at the top of the paper roll 260. The paper stress cone 262 provides additional insulation to the oil fill cable 202.

The HV electrode 212 is made of a semiconductor material and surrounds the transition joint core circumferentially. The first end of the glass fiber tube 252 is surrounded by the HV electrode 212. The HV electrode 212 controls the electric field in the transition joint 200 so that the transition joint 200 functions properly at all voltage loads and the transition joint 200 can withstand the long operating life.

The first deflector 214 is located at the first end of the preformed joint body 226 made of semiconductor material. The first deflector 215 has a tapered head section that closely surrounds the glass fiber tube 210 and opens outward toward the center of the transition joint 200 to provide a uniform distribution of the electric field To be guaranteed.

The second deflector 215 is made of a semiconductor material and is located at the second end of the preformed joint body 228. The second deflector 215 has a tapered head section that closely surrounds the end segment of the solid dielectric cable 222 and is open outward toward the center of the transition joint 200 to ensure a uniform distribution of the electric field .

The pre-molded joint body 216 is made of an elastic material with good tensile strength and tapers at both ends. The pre-molded joint body 216 includes a first deflector 214 at a tapered first end 226 and a second deflector 215 at a second tapered end 228, All. The HV electrode 212 is entirely embedded and surrounded in the middle section of the preformed joint body 216.

As an example, the preformed joint body 216 is made of silicone rubber. In another example, preformed body 216 is made of ethylene propylene rubber (EPR).

The copper housing 218 circumferentially surrounds the entire transition joint to form the outermost layer of the transition joint 200 and provide mechanical protection to the transition joint 200. In one exemplary embodiment, the inner surface of the copper housing 218 is entirely covered with a cable sheath insulator 266.

In one exemplary embodiment, the transition joint 200 has a cable gland 264, which is connected to the first end of the copper housing 250 and is connected to the tail section of the end segment of the oil fill cable 220B in the circumferential direction. The cable gland 264 seals the end segment 220 of the oil fill cable and prevents moisture from entering the end segment 220 of the oil fill cable. In another exemplary embodiment, the cable gland 264 has two cylindrical nipples 244A-244B disposed on each side of the cable gland 264.

As an example, the transition joint has a cable gland, which is connected to the second end of the copper housing and circumferentially surrounds the tail section of the end segment of the solid dielectric cable. The cable glands seal the end segments of the solid dielectric cable and prevent moisture from entering the end segments of the solid dielectric cable. In one exemplary embodiment, the cable gland has two nipples disposed on each side of the cable gland.

In one exemplary embodiment, a first lead sheath 236 is provided at the first end of the transition joint 238 with a tail section 220B of the end segment of the oil fill cable, The first leading shell 236 completely surrounds the cable gland 264 and the end segment 220 of the oil fill cable. Thus, the transition joint 200 is stably sealed to the end segment 220 of the oil fill cable at the first end of the transition joint 238.

In one exemplary embodiment, the T-shaped intermediate flange 246 and the bottom flange 248 are disposed at the first end 250 of the copper housing and abut against the second end of the glass fiber tube 254, The housing 218 and the glass fiber tube 210 are fixed. For example, intermediate flange 246 is made of H62 copper, and bottom flange 248 is made of copper.

In an exemplary embodiment, a second lead sheath 240 connects the second end of the copper housing 268 to the tail section 222B of the end segment of the solid dielectric cable at the second end 242 of the transition joint, The second leading shell 240 completely envelops the end segments of the solid dielectric cable 222 and the copper housing 218. [ Thus, the transition joint 200 is stably sealed to the end segment of the solid dielectric cable 222 at the second end 242 of the transition joint.

In one exemplary embodiment, a copper braid 256 connects the second end 268 of the copper housing at the second end 242 of the transition joint to the tail section 222B of the end segment of the solid dielectric cable By connection, the transition joint 200 is stably sealed to the end segment of the solid dielectric cable 222 at the second end 242 of the transition joint. The copper strap 256 prevents moisture from entering the solid dielectric cable 204.

In one exemplary embodiment, an insulation ring 258 is installed on the transition joint 200 at the second tapered end 228 of the pre-molded transition joint to form an oil fill cable 202 and a solid dielectric cable 0.0 > 204 < / RTI > As one example, the insulating ring 258 is made of an epoxy material.

In one exemplary embodiment, the layer of copper strap and taping 270 is circumferentially mounted on the intermediate section of the preformed joint body 216.

3 shows a pre-molded joint body 300 of a transition joint according to an exemplary embodiment. The oil fill cable and the solid dielectric cable are omitted in this exemplary embodiment so that they can be easily seen.

The preformed joint body 300 includes a first tapered end 302 and a second tapered end 304 and a cylindrical intermediate body 302 interposed between the first tapered end 302 and the second tapered end 304. The cylindrical tapered end 304, (306).

A first deflector 308 made of a semiconductor material is positioned at the first tapered end 302. In one embodiment, the first deflector 308 includes a tapered head section 310 that closely surrounds the glass fiber tube 312 and a tail section 314 that extends outwardly from the head section 310. In one embodiment, ). With this detailed configuration, the first deflector 308 ensures a uniform distribution of the electric field at the first end 302 of the preformed joint body. For example, the head section 310 circumferentially surrounds the first end 324 of the glass fiber tube.

In one example, the glass fiber tube 312 is cylindrical.

A high voltage (HV) electrode 316 is embedded within the intermediate body 306 and encircles the end of the glass fiber tube 312 circumferentially. For example, the HV electrode 316 circumferentially surrounds the second end of the glass fiber tube 326.

A second deflector 318 made of a semiconductor material is positioned at the second tapered end 304. In one embodiment, the second deflector 318 has a tapered head section 320 and a tail section 322 that extends outwardly from the head section 310.

4 illustrates a glass fiber tube 400 of a transition joint according to an exemplary embodiment. The oil fill cable is omitted in this exemplary embodiment so that it can be easily seen.

The glass fiber tube 400 is cylindrical in shape and has a first end 402 connected to the connector 404 and a second end 406 connected to the T flange 408. The T-shaped flange 408 and the connector 404 securely fasten the glass fiber tube 400 in the transition joint. For example, the glass fiber tube 400 is a hollow insulator.

In an exemplary embodiment, the glass fiber tube 400 is inserted onto the end segment of the oil fill cable (not shown) at the second end 406.

As used herein, a "transition joint" is a cable joint that connects cables of different types or made of different materials. Examples of cables include, but are not limited to, oil filled cables, cables with fluid or gas insulation materials, solid dielectric cables, and cross-linked polyethylene (XPLE) cables.

As used herein, the term "oil" includes all types of fluids or viscous materials used in cable constructions.

As used herein, the term "tube" includes, but is not limited to, an object having a circular cross-section, including any hollow section and elongated member.

In order to control the electric field in the transition joint, the edges of the insulating ring, the preformed joint body, the high voltage (HV) electrode and the deflector and / or the surface may preferably be rounded.

100. Transitional joint 102. Oil charging cable
104. Solid dielectric cable 106. Copper housing
108. Joint body 110. Deflector

Claims (17)

A transition joint for connecting an oil-filled cable to a solid dielectric cable,
A connector for securing an end segment of the oil fill cable and an end segment of the solid dielectric cable to form a transition joint core;
A glass fiber tube, capped by a connector at a first end and inserted onto an end segment of an oil fill cable at a second end, the glass fiber tube circumferentially surrounding an end segment of the oil fill cable within the transition joint, Glass fiber tubes;
A circumferentially surrounding first deflector at a tapered first end, circumferentially surrounding the second deflector at a tapered second end, circumferentially surrounding a high voltage (HV) electrode in the middle section, A pre-molded joint body; And
And a copper housing surrounding the joint body preformed to form the outermost layer of the transition joint on the circumference. The method according to claim 1,
The preformed joint body is made of an elastic material. The method according to claim 1,
The first deflector having a tapered head section circumferentially surrounding the glass fiber tube at the first end of the preformed joint body. The method according to claim 1,
The second deflector having a tapered head section circumferentially surrounding an end segment of the solid dielectric cable at a second end of the preformed joint body. The method according to claim 1,
Wherein the HV electrode surrounds the transition joint core circumferentially. The method according to claim 1,
The HV electrode circumferentially surrounds the first end of the glass fiber tube. The method according to claim 1,
Wherein the glass fiber tube is secured to the joint body pre-molded with epoxy resin at the second end of the glass fiber tube. The method according to claim 1,
A T-shaped intermediate flange disposed at a first end of the copper housing and abutting against a second end of the glass fiber tube; And
A bottom flange disposed at a first end of the copper housing and abutting against a second end of the glass fiber tube,
T-shaped intermediate flange and bottom flange are transition joints that fix the glass fiber tube and copper housing. The method according to claim 1,
Glass fiber tubes are hollow, transition joints. A system for connecting an oil fill cable to a solid dielectric cable,
A solid metal connector securing an end portion of the oil fill cable and an end portion of the solid dielectric cable to form a core;
A hollow insulator connected to the solid metal connector at a first end and inserted over an end portion of the oil fill cable at a second end and coaxially surrounding an end portion of the oil fill cable in the system;
An electric field controller for concentrically surrounding the hollow insulator and the solid metal connector and for controlling the electric field in the system;
A silicone rubber joint body surrounding the electric center controller with the same center; And
And a copper sleeve surrounding the silicon rubber joint body with the same center. 11. The method of claim 10,
Wherein the electric field controller comprises a first deflector wherein the first deflector is coaxially enclosed within the silicone rubber joint body and surrounds the hollow insulation at the first end of the silicone rubber joint body. 11. The method of claim 10,
The electric field controller has a second deflector which is coaxially enclosed within the silicone rubber joint body and surrounds a portion of the end segment of the solid dielectric cable at the second end of the silicone rubber joint body, system. 11. The method of claim 10,
Wherein the electric field controller has a high voltage (HV) electrode surrounding the core at the same center. 11. The method of claim 10,
Wherein the electric field controller surrounds the first end of the hollow insulator with the same center. 11. The method of claim 10,
Wherein the hollow insulator is made of glass fiber. 11. The method of claim 10,
Wherein the hollow insulator is secured to the silicone rubber joint body with an epoxy resin at a second end of the hollow insulator. 11. The method of claim 10,
A T-shaped intermediate flange disposed at a first end of the copper sleeve and abutting against a second end of the hollow insulator; And
Further comprising: a bottom flange disposed at a first end of the copper sleeve and abutting against a second end of the hollow insulator,
T-shaped intermediate flange and bottom flange fix the hollow insulator and copper sleeve.

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