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EP-4523302-B1 - BENT UNIT AND GAS-INSULATED TRANSMISSION LINE

EP4523302B1EP 4523302 B1EP4523302 B1EP 4523302B1EP-4523302-B1

Inventors

  • HUANG, WEI
  • NONG, Jieshen
  • CHEN, Tiansong
  • Meng, GuoZhu
  • PENG, Pei

Dates

Publication Date
20260506
Application Date
20230224

Claims (12)

  1. A bent unit (100) for a gas-insulated transmission line, comprising: a bent housing (102) comprising a cylindrical first housing section (108) and a cylindrical second housing section (110), the first housing section (108) and the second housing section (110) being connected with each other at an angle (α); a tubular bent conductor (104) arranged in the bent housing (102); wherein the bent conductor (104) comprises a straight conductor section (122) and a bent conductor section (124) which are formed separately and connected with each other; the straight conductor section (122) extends along the first housing section (108); and the bent conductor section (124) extends along the first housing section (108) and the second housing section (110), and is bent to have the angle (α); characterized in that an insulator (106) is arranged in the bent housing (102) to support the bent conductor (104).
  2. The bent unit (100) for a gas-insulated transmission line according to claim 1, wherein the bent unit (100) further comprises a shield (146) arranged inside the bent housing (102) and sleeved outside the bent conductor (104); and a junction where the straight conductor section (122) is connected with the bent conductor section (124) is covered by the shield (146).
  3. The bent unit (100) for a gas-insulated transmission line according to claim 2, wherein the insulator (106) is arranged to support the bent conductor (104) near the junction where the straight conductor section (122) is connected with the bent conductor section (124).
  4. The bent unit (100) for a gas-insulated transmission line according to claim 3, wherein the insulator (106) is in the form of a three-post insulator; the insulator (106) comprises an insulator body (142), and a metal bushing (144) embedded in the center of the insulator body (142) and extending through the insulator body (142); the straight conductor section (122) is directed through the metal bushing (144) and connected to the metal bushing (144) at an end portion of the metal bushing (144); and a junction where the straight conductor section (122) is connected with the end portion of the metal bushing (144) is covered by the shield (146).
  5. The bent unit (100) for a gas-insulated transmission line according to any one of claims 1 to 4, wherein the straight conductor section (122) comprises a first connecting end plate (128); the bent conductor section (124) comprises a second connecting end plate (132); and the first connecting end plate (128) and the second connecting end plate (132) are connected with each other via a threaded fastener (138).
  6. The bent unit (100) for a gas-insulated transmission line according to any one of claims 1 to 4, wherein the first housing section (108) and the second housing section (110) are provided with a first inclined end face (112) and a second inclined end face (114), respectively, and the first inclined end face (112) and the second inclined end face (114) are welded to each other.
  7. The bent unit (100) for a gas-insulated transmission line according to any one of claims 1 to 4, wherein the bent conductor (104) comprises one straight conductor section (122) and one bent conductor section (124), and the bent conductor (104) extends along the substantially entire length of the bent housing (102).
  8. The bent unit (100) for a gas-insulated transmission line according to any one of claims 1 to 4, wherein the length of the bent conductor (104) ranges from 1 m to 18 m.
  9. The bent unit (100) for a gas-insulated transmission line according to any one of claims 1 to 4, wherein the angle (α) ranges from 160° to 179°.
  10. A gas-insulated transmission line, comprising at least one bent unit (100) for a gas-insulated transmission line according to any one of claims 1 to 9.
  11. The gas-insulated transmission line according to claim 10, wherein the gas-insulated transmission line comprises a corner unit (200) and an electrical contact (300), and the corner unit (200) comprises a conductor (204); wherein a bent conductor (104) of the bent unit (100) is electrically connected with the conductor (204) of the corner unit (200) via the electrical contact (300).
  12. The gas-insulated transmission line according to claim 11, wherein the electrical contact (300) comprises a first connecting shoulder (302) and a second connecting shoulder (304) at both ends thereof, respectively; wherein the first connecting shoulder (302) is connected with the bent conductor (104) of the bent unit (100) via a threaded fastener, and the second connecting shoulder (304) is connected with the conductor (204) of the corner unit (200) by welding.

Description

RELATED FIELD The present disclosure generally relates to the technical field of high-voltage transmission, and more specifically to the technical field of gas-insulated transmission lines. BACKGROUND Gas insulated transmission lines (GIL) are generally installed in underground tunnels or vertical shafts, and have the advantages of excellent current-carrying capacity, small land occupation and easy maintenance. At present, GIL have been more and more widely used to replace overhead lines to realize power transmission. Due to the diversity of installation environment and line layout of GIL, there are normally many turnings in GIL engineering layout for changing the direction of GIL busbar/conductor. FIG. 1 shows an elbow unit for GIL, wherein the elbow unit is used to connect with two adjacent straight units to change the direction of GIL busbar/conductor so as to further change the transmission direction. The elbow unit includes an elbow housing 1 (most of which is represented by dash double-dot lines) and an elbow conductor 2 arranged in the elbow housing 1. The elbow housing 1 is substantially spherical, and two ends thereof are connected with the housings of adjacent straight units via flanges 3. The elbow housing 1 is integrally formed by casting and therefore has long lead-time. Further, it is required to develop different molds for different turning angles, resulting in high manufacturing costs. The elbow conductor 2 includes two conductor parts 4 with complex shape, and the two conductor parts 4 are connected with each other to form the elbow conductor 2. The elbow conductor 2 has a complex structure and high cost. It should be noted that this background technology section provides background information related to the content of the present disclosure, which may not necessarily constitute the prior art. CN 207398381 U describes a pipeline bus corner modular construction. JP S60 162408 A describes a bending unit used for a bent portion of a gas insulated equipment. CN 106785944 A describes a rigid gas-insulated power transmission line of a three-phase integrated body. DE 295 18 804 U1 describes a high-voltage tubular gas conductor. US 4 711 973 A describes transmission lines having an inner conductor concentrically within an outer sheath with a gaseous insulation medium. SUMMARY An object of the present disclosure is to address the above issues and to provide an improved bent unit and an improved gas-insulated transmission line. The object of the invention is solved by the features of the independent claim. Therefore, a bent unit for a gas-insulated transmission line is provided according to a first aspect of the present disclosure. The bent unit includes: a bent housing including a cylindrical first housing section and a cylindrical second housing section, the first housing section and the second housing section being connected with each other at an angle α; a tubular bent conductor arranged in the bent housing; and an insulator arranged in the bent housing to support the bent conductor. The bent conductor includes a straight conductor section and a bent conductor section which are formed separately and connected with each other. The straight conductor section extends along the first housing section. The bent conductor section extends along the first housing section and the second housing section and is bent to have the angle α. For the bent housing of the bent unit according to the present disclosure, the transmission direction can be easily changed by adjusting the connection angle of the first housing section and the second housing section and by adjusting the bending angle of the bent conductor section of the bent conductor, thus realizing a desired layout of the gas-insulated transmission line. Moreover, the bent unit has a simple structure and is easy to manufacture. According to the above technical concept, the first aspect of the present disclosure may further include one or more of the following alternative forms. In some alternative forms, the bent unit further includes a shield arranged inside the bent housing and sleeved outside the bent conductor, and a junction where the straight conductor section is connected with the bent conductor section is covered by the shield. In some alternative forms, the insulator is arranged to support the bent conductor near the junction where the straight conductor section is connected with the bent conductor section. In some alternative forms, the insulator is in the form of a three-post insulator, wherein the insulator includes an insulator body, and a metal bushing embedded in the center of the insulator body and extending through the insulator body; the straight conductor section is directed through the metal bushing and connected to the metal bushing at an end portion of the metal bushing; and a junction where the straight conductor section is connected with the end portion of the metal bushing is covered by the shield. In some alternative forms, the