CN101479814B - Integrated outdoor termination for high voltage cable - Google Patents

Abstract

An integrated outdoor termination reduces the effects of environmental and electrical stresses by integrating a first portion, a second portion, and a plurality of sheds into a single piece of insulation. The first part comprises an integrated first connector for connecting the outdoor termination to a high voltage cable. The second portion acts as a stress cone and is connected to a second terminal, which is intended to be connected to ground. The first portion has a substantially cylindrical shape and the stress cone has a substantially conical shape. The first section transitions into the second section without any abrupt change in cross-sectional area, thereby avoiding an increase in electric field. The integrated outdoor termination may be prefabricated using materials such as silicone. The sheds extend substantially perpendicular to the longitudinal axis of the insulator and may be evenly distributed along the longitudinal axis of the insulator, by evenly distributing the sheds, the risk of flashovers is avoided.

Description

Integrated outdoor lugs for high voltage cables

Background technique

In many cases, power is transmitted through cables located outdoors. To reduce power loss caused by resistance in the cables, power is often transmitted at voltages in excess of 50KV. In order to terminate the cables, there must be a connection between the cable conductors and the ground. Connect a transition that must be able to withstand the voltage drop between the cable conductors and ground, these transitions are commonly referred to as "terminations". Due to the high voltage of the cable, and the fact that the cable and the terminal head are located outdoors, the terminal head is subject to electrical and environmental stresses, including water, dust, snow, wind and temperature fluctuations, the electrical stress is generally caused by the terminal head itself, and These include high electric field strengths, leakage currents ("leakage"), and flashovers.

Outdoor terminations generally include a partial assembly structure in which multiple components are assembled to form the termination. Figure 2 shows an example of an outdoor terminal head for high-voltage cables with a partially assembled structure. The outdoor terminal head 200 includes three parts, namely two insulating assemblies 202, 204 and a stress cone 208. The first insulating assembly 202 A first terminal 212 for connecting the terminal head 200 to a high voltage cable (not shown), through which the high voltage cable enters the terminal head 200 is included. The portion of the cable received by the first insulation assembly 202 is stripped back to the insulation and connected to the first terminal 212 via a connector. The stress cone 208 includes a second terminal 214 for connecting the ground cable to a ground (not shown). The second terminal 214 includes an inlet housing and a clip through which the ground cable enters the terminal head 200. The clamp connects the ground cable Connect to the second terminal 214 .

Both insulation assemblies 202, 204 include a plurality of sheds 206 that reduce the accumulation of dust and/or water on the terminal heads, which reduces the occurrence of leaks and flashovers. The two insulation assemblies 202 , 204 are connected together, and the second insulation assembly 204 is connected to the stress cone 208 . Outdoor terminal head 200 may be prefabricated and assembled prior to use.

To improve the mechanical and electrical properties of the terminal, the insulator can be manufactured from silicone, which provides dust and water resistance and reduces flashover and arcing in the terminal. In addition, silicone can expand the range of temperatures and other environmental factors that the termination can withstand.

Even with the advantages offered by silicone, terminations with partial fit structures are still subject to electrical and environmental stress. For example, the highest electric field strength for the terminal head 200 occurs at the junction between the insulation assembly 204 and the stress cone 208, and because there is no shed at this location, dust and water can accumulate, causing flashover, especially when rain is involved or in a humid environment. Furthermore, the lack of sheds also results in current leakage at the junctions between the insulation assembly 204 and the stress cone 208 and at the junctions between the insulation assemblies 202 , 204 .

Contents of the invention

An integrated outdoor termination is disclosed that reduces the effects of environmental and electrical stresses by integrating a first portion, a second portion, and a plurality of sheds into a single-piece insulator. The first part, the second part and the shed may be molded together as a single piece such that the insulator does not include a section seam. The first part includes an integrated first connector for connecting the outdoor terminal to a high-voltage cable, and the second part is connected to a second terminal for connecting to ground, so The second terminal is used to connect to the ground, and the second part acts as a stress cone. said first part has a substantially cylindrical shape, said stress cone has a substantially conical shape, said first part transitions into said second part without any abrupt change in cross-sectional area, thereby avoiding the influence of the electric field Increase. The integrated outdoor terminal head may be prefabricated using a material such as silicone.

The sheds extend generally perpendicular to the longitudinal axis of the insulator and may be evenly distributed along the longitudinal axis of the insulator. By evenly distributing the sheds, the risk of flashover is avoided.

In summary, the present invention provides a one-piece terminal head for high voltage cables, comprising:

a first part including an integrated first terminal, wherein the first terminal is configured to receive the high voltage cable through an aperture; and

A second part, wherein the terminal head includes a plurality of sheds, and the first part, the second part and the sheds are molded together as a single piece.

The present invention also provides a method for manufacturing a terminal head for a high voltage cable, the method comprising:

molding a one-piece insulator formed of a first portion serving as a stress cone configured to connect to ground, a second portion and a plurality of sheds generally perpendicular to the first portion extending along the longitudinal axis of the second portion, and the plurality of sheds are evenly spaced along the longitudinal axis of the first portion and the second portion;

molding the first portion to include an integrated first terminal, wherein the first terminal is configured to receive the high voltage cable through an aperture; and

The second portion is molded to connect with a second terminal for connection to ground, wherein the second terminal is configured to receive a ground cable through the aperture.

Description of drawings

A better understanding of the invention may be obtained by reference to the following drawings and descriptions, the parts of which are not to scale and emphasis but placed to illustrate the principles of the invention. In the figures, unless otherwise indicated, the same reference numerals refer to the same parts, components, components or steps.

Figure 1 is an isometric view of an outdoor terminal head;

Figure 2 is an exploded isometric view of an outdoor terminal head according to the prior art;

Figure 3 is a front plan view of an outdoor terminal head; and

Fig. 4 is a cross-sectional view of the outdoor terminal head in Fig. 3 .

Detailed ways

Integrated terminations for high voltage cables (each "integrated outdoor termination") are provided, which are suitable for outdoor use. The integrated outdoor termination comprises a single piece which substantially eliminates seams and discontinuities between the different individual components, thus the outdoor termination reduces the effects of environmental as well as electrical stress. An example of an integrated outdoor terminal head 100 is shown in FIG. 1 . The integrated outdoor terminal head 100 generally includes a first portion 116 and a second portion 114 acting as a stress cone. The outdoor terminal head 100 may also include a plurality of sheds 112 extending approximately perpendicular to the outer surface 120 of the insulator 110 . The first portion 116, the stress cone 114 and the shed 112 are fully integrated to form a one-piece insulator 110.

The integrated outdoor terminal 100 may also include a first terminal 102 which may be integral with the first portion 116 and enable the integrated outdoor terminal 100 to be connected to a high voltage cable (not shown). The first terminal 102 may include an unshielded corrugated connector (not shown). In order to connect the high voltage cable to the terminal head 100, the insulation on the high voltage cable can be stripped back, and the corrugated connector is crimped onto the cable. However, the first terminal 102 may include other types of connectors. The outdoor terminal head 100 may also include a second terminal 104. The second terminal 104 (only a portion is shown) may be integrated with a stress cone 114 that connects the integrated outdoor terminal head 100 to a ground (not shown). .

The first portion 116 may include a substantially cylindrical shape and the stress cone 114 may include a substantially conical shape. Where the insulator 110 transitions from the first portion 116 into the stress cone 114 , the stress cone 114 includes a cross-sectional diameter approximately equal to that of the first portion and increasing in the direction of the second terminal 104 . Thus, a sudden change in diameter between the first portion 116 and the second portion 114, which could lead to an increased electric field, may be avoided. Furthermore, the cross-sectional diameter of the stress cone 114 may reach its maximum at a point between the first portion 116 and the second terminal 104 and then may decrease in the direction of the second terminal 104 . However, the cross-sectional diameter of the stress cone 114 is generally greater than the cross-sectional diameter of the first portion 116 at any location.

The insulator 110 generally includes a shed 112 positioned along and integral with the outer surface 120 of the insulator, and thus, the first portion 116 and the stress cone 114 generally include a plurality of sheds 112 that can be positioned along the outer surface 120 of the insulator. The longitudinal axis 126 of the insulator 110 is evenly distributed. By evenly distributing the sheds 112 , especially those in the area with the greatest electric field strength 122 , risks of flashovers such as those caused by rain and accumulation of dust are avoided.

In order to build a one-piece integrated outdoor terminal head 100, the first part 116, the second part 114, and the shed 112 are molded together to form a single piece, so that the insulator 110 is within the first part 116 or with the first part 116. Sectional joints are generally not included between stress cones 114 . The integrated outdoor terminal head 100 may be prefabricated using a material such as silicone.

Figures 3 and 4 show an example of an integrated outdoor terminal head. As shown in FIG. 4 , the integrated outdoor terminal head 300 includes a longitudinal axis 378 and can be generally symmetrical along the longitudinal axis 378 . The terminal head includes a first portion 316 , a second portion 314 , and a plurality of sheds 312 that are integrally joined to each other to form a one-piece insulator 310 . The insulator 310 is integrally joined with the first terminal 302 and the second terminal 304 to form the integrated outdoor terminal head 300 as a single piece. Furthermore, first terminal 302, first portion 316, second portion 314, and second terminal 304 are integrally formed such that the transition between their outer surfaces is substantially smooth with no generally coaxial seams or discontinuities. Thus, since the outdoor terminal head 300 comprises a single substantially smooth piece, leakage due to seams and/or discontinuities is avoided.

The sheds are integral with the outer surface 320 of the insulator 310 such that they can be distributed along the outer surface 320 and generally perpendicular to the longitudinal axis 378 of the terminal head 300, the sheds 312 can be evenly distributed. Because the terminal head 300 comprises a single piece, the shed 312 can be positioned along the second portion 314 that acts as a stress cone and along the transition between the first portion 316 and the second portion 314 and, therefore, can experience the highest electric field These areas of strength reduce leaks and flashovers.

The insulator 310, the first terminal 302, and the second terminal 304 include holes 360 for receiving high voltage cables and ground cables. The first terminal 302 may include corrugated connectors that are crimped to the high voltage cables. The second terminal 304 includes a connector 370 that can receive a ground cable with its insulation exposed and a ground hole 374 that can receive a ground cable with its conductor exposed, and a ground hole 374 that secures the ground cable to the second terminal 304 .

3 includes exemplary dimensions in millimeters of an integrated outdoor terminal head 300 suitable for 138KV applications, however, the integrated outdoor terminal head 300 may be scaled up for higher voltage levels, such as 220KV and 500KV, or scaled down for Applications at lower voltages such as 69KV. The total length of the integrated outdoor terminal 300, including the first connector 302 and the second connector 304, is about 1400 mm. The diameter of the first terminal is about 86mm, and the distance from the end of the second connector 304 (only a part is shown) to the first shed on the stress cone 314 is about 141mm, and the widest part of the stress cone 314 , including umbrella skirt 312, is 332mm. The shed 312 of the terminal head 300 is at an angle of 8 degrees to the horizontal, which is substantially perpendicular to the longitudinal axis 326 of the terminal head 300, and the end 311 of the shed 312 is substantially concave relative to the second connector 304 such that the end 311 Pointing towards the second connection head 304, the end portion 311 has a radius of approximately 2.5 mm. The shed 312 includes a substantially concave portion 321 having a radius approximately 12 mm long, which provides a transition from the shed 312 to the outer surface 320 of the insulator 310 . Additionally, the sheds 312 extend 45 mm or 70 mm from the outer surface 320 of the insulator 310 and are approximately equally spaced about 48 mm to about 52 mm along the outer surface 320 of the insulator 310 .

While various embodiments of the invention have been described, it will be apparent to those skilled in the art that many more embodiments and implementations are possible within the scope of the invention, and thus, the invention is not to be limited , except in view of the appended claims and their equivalents.

Claims (12)

1. single-piece terminals that are used for high-tension cable comprise:

First, described first comprises integrated the first terminal, wherein said the first terminal is configured to admit and directly contact described high-tension cable by the hole; And

Second portion, wherein said terminals comprise a plurality of full skirts, and described first, described second portion and described full skirt are molded together and become single-piece.

2. the single-piece terminals for high-tension cable according to claim 1 also comprise the second terminal that is formed in the described second portion, and wherein, described the second terminal construction is for admitting earth cable by described hole.

3. single-piece terminals for high-tension cable according to claim 1, wherein, described a plurality of full skirts and described first and described second portion integral body form the part of molded single-piece insulator.

4. single-piece terminals for high-tension cable according to claim 3, wherein, the longitudinal axis ground that described a plurality of full skirt is approximately perpendicular to described first and described second portion extends, and described a plurality of full skirt roughly separates equably along the described longitudinal axis of described first and described second portion.

5. single-piece terminals for high-tension cable according to claim 1, wherein, described first has the shape of substantial cylindrical, and described second portion has the shape with the conical shaped of smaller end and larger end, and an end of wherein said first and the described smaller end of described second portion integrally form, and the described smaller end of described second portion forms gradually transition towards the described larger end of described second portion on sectional area.

6. single-piece terminals for high-tension cable according to claim 1, wherein molded single-piece insulator is formed by silicones.

7. single-piece terminals for high-tension cable according to claim 1, wherein, described terminals can support to carry at least high-tension cable of the voltage of 69kV.

8. method that is used for making for the terminals of high-tension cable, described method comprises:

The molded single-piece insulator that is formed by first, second portion and a plurality of full skirt, described second portion is used as the stress cone that is configured to grounding connection, the longitudinal axis ground that described a plurality of full skirt is approximately perpendicular to described first and described second portion extends, and described a plurality of full skirt separates equably along the described longitudinal axis of described first and described second portion;

Molded described first is to include integrated the first terminal, and wherein said the first terminal is configured to admit and directly contact described high-tension cable by the hole; And

Molded described second portion to be linking to each other with the second terminal that is used for being connected ground connection, and wherein said the second terminal construction is for by described hole admittance earth cable.

9. the method that is used for making for the terminals of high-tension cable according to claim 8, wherein, described first has the shape of substantial cylindrical, and described second portion has the shape with the conical shaped of smaller end and larger end, and an end of wherein said first and the described smaller end of described second portion integrally form, and the described smaller end of described second portion forms gradually transition towards the described larger end of described second portion on sectional area.

10. the method that is used for making for the terminals of high-tension cable according to claim 8, wherein said single-piece insulator is formed by silicones.

11. the method that is used for making for the terminals of high-tension cable according to claim 8, wherein, described terminals are made before installation.

12. the method that is used for making for the terminals of high-tension cable according to claim 8, wherein, described terminals can support to carry at least high-tension cable of the voltage of 69kV.

Images