WO2022221996A1

WO2022221996A1 - Bus-duct and associated manufacturing method

Info

Publication number: WO2022221996A1
Application number: PCT/CN2021/088164
Authority: WO
Inventors: Xiaosong Zhou
Original assignee: Abb Schweiz Ag
Priority date: 2021-04-19
Filing date: 2021-04-19
Publication date: 2022-10-27
Also published as: CN115152113A

Abstract

A bus-duct comprises a housing (101) comprising a plurality of walls (1011) and an internal chamber surrounded by the plurality of walls(1011); a plurality of insulation supports (102) arranged on at least one of the plurality of walls (1011); and at least one tubular busbar (103) arranged in the internal chamber via the plurality of insulation supports (102), each of the at least one tubular busbar (103) comprising a pair of connection ends (1031)each adapted to be electrically coupled to a respective one of the high-voltage devices. The current carrying capacity of the tubular busbar is higher than that of the conventional busbar with rectangular cross section in the case of the same cross-sectional area. With the tubular busbar, since there are no sharp corners and reduced eddy current effects, the distance between the busbars corresponding the phases is allowed to be smaller without reducing the insulation performance. In this way, the bus-duct can be made more compact to meet the needs of miniaturized high-voltage devices. An associated manufacturing method and a power transmission and distribution system are also provided.

Description

BUS-DUCT AND ASSOCIATED MANUFACTURING METHOD

FIELD

Embodiments of the present disclosure generally relate to a power transmission and distribution system, and more specifically, to a bus-duct used in a power transmission and distribution system.

BACKGROUND

In electric power distribution, a bus-duct (also called busway) is a sheet metal duct or also cast resin insulated duct containing either copper or aluminium busbars for the purpose of conducting a substantial current of electricity. Bus-ducts transport electricity and connect to electrical gear such as switchgear, panelboards and transformers. Bus-ducts are an excellent alternative to cable and conduit in commercial and industrial applications because they are not as complex to configure, less expensive to install and easier to replace, especially in applications where load locations are likely to change.

Bus ducts typically have thicker, cold-formed steel side rails and thinner sheet metal coverings. Busbars inside may be separated with distinct and even gaps between them, or “sandwiched” together. Typically, individual busbars are wrapped or coated with a non-conducting, covalent material, such as plastic or electrical tape. At the connection point, busbars flare out to enable connection to the next segment.

SUMMARY

Embodiments of the present disclosure provide a pressure relief component for a gearbox, an associated gearbox and a robot.

In a first aspect, a bus-duct for power transmission between high-voltage devices is provided. The bus-duct comprises a housing comprising a plurality of walls and an internal chamber surrounded by the plurality of walls; a plurality of insulation supports arranged on at least one of the plurality of walls; and at least one tubular busbar arranged in the internal chamber via the plurality of insulation supports, each of the at least one tubular busbar comprising a pair of connection ends each adapted to be electrically coupled to a respective one of the high-voltage devices.

The current carrying capacity of the tubular busbar is higher than that of the conventional busbar with rectangular cross section in the case of the same cross-sectional area. With the tubular busbar, since there are no sharp corners and reduced eddy current effects, the distance between the busbars corresponding the phases is allowed to be smaller without reducing the insulation performance. In this way, the bus-duct can be made more compact to meet the needs of miniaturized high-voltage devices.

In some embodiments, the pair of connection ends are radially pushed into flat plates to facilitate coupling of the high-voltage devices to the at least one tubular busbar. This can ensure the connection performance between the tubular busbar and high-voltage devices in a cost-efficient way.

In some embodiments, at least one tubular busbar comprises a plurality of sections each having a length less than or equal to a predetermined length. This arrangement can facilitate transportation and manufacturing of the tubular busbar.

In some embodiments, each of the plurality of sections comprises an intermediate connection end via which the plurality of sections are connected to form the at least one tubular busbar.

In some embodiments, the intermediate connection end is radially pushed into a flat plate to facilitate a connection between the plurality of sections. This can ensure the connection performance between the plurality of sections of the tubular busbar in a cost-efficient way.

In some embodiments, the bus-duct further comprises at least one insulation cover arranged to at least surround the pair of connection ends and the intermediate connection end. In this way, the insulation performance of the bus-duct can be significantly improved.

In some embodiments, each of the plurality of insulation supports comprises a protrusion extending along an axial direction of the insulation support and adapted to pass radially through a respective through hole of the at least one tubular busbar to support the at least one tubular busbar. In this way, the tubular busbar may be firmly supported by the insulation supports.

In some embodiments, an outer diameter and a wall thickness of the at least one tubular busbar are configured at least according to a magnitude of a rated current carried by the at least one tubular busbar.

In some embodiments, the bus-duct further comprises at least one pressure relief component arranged on at least one of the plurality of walls and adapted to be at least partially broken to release a pressure within the internal chamber in response to the pressure within the internal chamber reaching or exceeding a predetermined threshold. This arrangement can further improve the safe performance of the bus-duct.

In some embodiments, the bus-duct further comprises at least one access window formed on at least one of the plurality of walls and adjacent to at least one of the pair of connection ends. This arrangement can facilitate the maintenance and assembly of the bus-duct.

In some embodiments, inner surfaces and/or outer surfaces of the housing is painted for better heat dissipation performance.

In a second aspect of the present disclosure, a method of manufacturing a bus-duct is provided. The method comprises providing a housing comprising a plurality of walls and an internal chamber surrounded by the plurality of walls; arranging a plurality of insulation supports on at least one of the plurality of walls; and arranging at least one tubular busbar in the internal chamber via the plurality of insulation supports, each of the at least one tubular busbar comprising a pair of connection ends each adapted to be electrically coupled to a respective high-voltage device.

In a third aspect of the present disclosure, a power transmission and distribution system comprising at least one bus-duct as mentioned in the above first aspect is provided.

It is to be understood that the Summary is not intended to identify key or essential features of embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become easily comprehensible through the description below.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objectives, features and advantages of the present disclosure will become more apparent through more detailed depiction of example embodiments of the present disclosure in conjunction with the accompanying drawings, wherein in the example embodiments of the present disclosure, same reference numerals usually represent the same components.

FIG. 1 shows a perspective view of a bus-duct according to embodiments of the present disclosure;

FIG. 2 shows a front view of a bus-duct according to embodiments of the present disclosure;

FIG. 3 shows a perspective view of a busbar used in the bus-duct according to embodiments of the present disclosure;

FIG. 4 shows a front view of a busbar used in the bus-duct according to embodiments of the present disclosure; and

FIG. 5 shows a flowchart illustrating a method of manufacturing a bus-duct according to example embodiments of the present disclosure.

Throughout the drawings, the same or similar reference symbols are used to indicate the same or similar elements.

DETAILED DESCRIPTION

The present disclosure will now be discussed with reference to several example embodiments. It is to be understood these embodiments are discussed only for the purpose of enabling those skilled persons in the art to better understand and thus implement the present disclosure, rather than suggesting any limitations on the scope of the subject matter.

As used herein, the term “comprises” and its variants are to be read as open terms that mean “comprises, but is not limited to. ” The term “based on” is to be read as “based at least in part on. ” The term “one embodiment” and “an embodiment” are to be read as “at least one embodiment. ” The term “another embodiment” is to be read as “at least one other embodiment. ” The terms “first, ” “second, ” and the like may refer to different or same objects. Other definitions, explicit and implicit, may be comprised below. A definition of a term is consistent throughout the description unless the context clearly indicates otherwise.

A bus-duct is typically defined as a prefabricated electrical distribution system consisting of busbars in a protective enclosure. A Bus-duct typically comprises busbars, an insulating and/or support material, and a housing. A major advantage of bus-duct is the ease in which bus-duct sections are connected together. Electrical power can be supplied to any area of a building by connecting standard lengths of bus-duct. It typically takes fewer man-hours to install or change a bus-duct system than cable and conduit assemblies.

There are many types of bus-duct such as a non-segregated bus-duct, a sandwich-style bus-duct, a track bus-duct, an air-insulated bus-duct or the like. High-current bus-ducts with copper or aluminum rectangular busbars are often used in switching stations and power substations due to their ease of assembly and operation. Due to electromagnetic coupling, currents in rectangular busbars induce eddy currents in the metal conductive shield. Hence, there is a complex electromagnetic coupling between rectangular busbars and the enclosure of the bus-duct system. In the case of a parallel conductor system, the uneven distribution of current density in these conductors is caused by the skin effect as well as the proximity effect, which affect their self and mutual impedances. Both the skin effect and proximity effect will generally cause the resistance of the busbars to increase and the inductance to decrease.

To avoid the above mentioned effects as much as possible, the distance between the rectangular busbars is usually set large enough. One of the problems brought about by this is that as the required carrying current increases, the size of the bus-duct must be correspondingly increased to meet various performance requirements. This has caused some bus-ducts to fail to meet the needs of miniaturized switchgear, for example, due to incompatibility caused size reasons.

In order to at least partially address the above and other potential problems, embodiments of the present disclosure provide a bus-duct 100 for power transmission between high-voltage devices. The high-voltage device herein refers to equipment with a rated voltage above 1000V. In some embodiments, the high-voltage devices may comprise switchgears and/or transformer equipment or the like. Now some example embodiments will be described with reference to FIGs. 1-4.

FIGs. 1 and 2 respectively show a perspective view and a front view of a bus-duct 100 according to embodiments of the present disclosure. As shown in FIG. 2, the bus-duct 100 according to embodiments of the present disclosure generally comprises a housing 101, a plurality of insulation supports 102 and at least one tubular busbar 103. The number of tubular busbars 103 may correspond to the number of phases in the circuit. For example, for three-phase electricity, there may be three tubular busbars 103. The housing 101 comprises a plurality of walls 1011 made from metal plates and an internal chamber surrounded by the walls 1011.

The metal plates that make up the walls 1011 of the housing 101 may comprise aluminum-zinc plates, aluminum plates, aluminum alloy plates, Q235 steel plates, or stainless steel plates. The use of an aluminum plate or aluminum-zinc plate as the wall 1011 of the housing 101 can make the housing 101 have better heat dissipation performance and anti-eddy current performance. In some embodiments, the housing 101 can be airtight to hermetically contain the protective gas within the internal chamber. In some alternative embodiments, the housing 101 may be sealed only for reasons such as insulation.

In some embodiments, inner surfaces and/or outer surfaces of the housing 101 may be surface-treated to obtain better heat dissipation performance and corrosion resistance. Surface treatment may comprise, but is not limited to, painting, electro-galvanizing, hot-dip galvanizing, etc. For example, in some embodiments, the inner surfaces and/or outer surfaces of the housing 101 may be painted for better heat dissipation performance.

The housing 101 may have any suitable shape that adapts positions of the high-voltage devices such as switchgears and/or transformer equipment or the like to be coupled via the bus-duct 100. For example, as shown in FIGs. 1 and 2, in some embodiments, the housing 101 may have a bending shape and comprise two vertical sections and a horizontal section arranged between the vertical sections. The vertical sections may be arranged on the high-voltage devices to allow the tubular busbar 103 to be coupled to terminals of the high-voltage devices. Embodiments of the present disclosure will be discussed mainly by taking the shape of the housing 101 as shown in FIGs. 1 and 2 as an example in the following. It is to be understood that other shapes of the housing 101 are possible according to factors such as where positions of the high-voltage devices are located, and will not be discussed further in the following.

The insulation supports 102 are arranged on at least one of the walls 1011 of the housing 101 and each protrudes away from the respective wall 1011 within the internal space to support the tubular busbar 103. In some embodiments, the insulation supports 102 may be made of epoxy resin. It is to be understood other suitable material such as glass, ceramic or silicone rubber to be made into the insulation support 102 are also possible.

In comparison with conventional solutions, the busbar used in the bus-duct 100 according to embodiments of the present disclosure is tubular. Due to the skin effect which is the tendency of an alternating electric current (AC) to become distributed within a conductor such that the current density is largest near the surface of the conductor and decreases exponentially with increasing depth in the conductor, the current carrying capacity of the tubular busbar 103 is higher than that of the conventional busbar with rectangular cross section in the case of the same cross-sectional area.

Furthermore, since there are no sharp corners and reduced eddy current effects, the use of a tubular busbar 103 allows the distance between the busbars corresponding to the phases to be smaller without reducing the insulation performance. In this way, the bus-duct 100 can be made more compact to meet the needs of miniaturized high-voltage devices.

In some embodiments, the outer diameter and the wall 1011 thickness of the tubular busbar 103 may be configured at least according to a magnitude of a rated current carried by the tubular busbar 103. For example, as the rated current carried increases, the outer diameter and wall 1011 thickness also increase. The tubular busbar 103 may be made of materials with excellent electrical conductivity, such as copper or aluminum.

The tubular busbar 103 may be bent or manufactured in a shape in line with the shape of the housing 101. For example, in the cases where the housing 101 comprises the vertical sections and the horizontal section as shown in FIGs. 1 and 2, the tubular busbar 103 may be bent to also comprise two vertical sections and a horizontal section, which can facilitate arrangement of the tubular busbar 103 within the internal chamber and further facilitate the coupling of the tubular busbar 103 to the high-voltage devices.

In some embodiments, due to the good insulation properties, the surface of the tubular busbar 103 may not be insulated, thereby further reducing the cost of the bus-duct 100. Furthermore, to further improve the insulation performance, at least a portion of the surface of the tubular busbar 103 may also be insulated for example by being painted or wrapped with heat shrinkable tubing.

To facilitate the coupling of the tubular busbar 103 to the high-voltage devices, in some embodiments, tubular busbar 103 may comprise a pair of connection ends 1031 to be electrically coupled to the high-voltage devices. In some embodiments, the connection ends 1031 may be formed by pushing into flat plates, as shown in FIGs. 3 and 4. In this way, the connection end 1031 of the tubular busbar 103 can be electrically coupled to a respective terminal of the electrical device easily while ensuring the connection performance.

In some embodiments, for ease of transportation and manufacturing, the tubular busbar 103 may be divided into a plurality of sections having a length less than or equal to a predetermined length. The predetermined length may be, for example, the maximum length of the tubular busbar 103 that can be transported using conventional transportation means. The plurality of sections of the tubular busbar 103 may be assembled into a required shape or length on site.

In some embodiments, to facilitate the coupling between the plurality of sections of the tubular busbar 103, each of the plurality of sections of the tubular busbar 103 may comprise an intermediate connection end 1032, as shown in FIGs. 3 and 4. The plurality of sections of the tubular busbar 103 can be connected via the intermediate connection ends 1032 to form the tubular busbar 103. In some embodiments, the intermediate connection end 1032 may also be formed by being radially pushed into a flat plate to facilitate the connection between the plurality of sections of the tubular busbar 103.

The formation means of the connection ends 1031 and the intermediate connection ends 1032 can ensure the connection performance between the tubular busbar 103 and high-voltage devices and between the plurality of sections of the tubular busbar 103. It is to be understood that the above mentioned formation means are merely illustrative, without suggesting any limitation as to the scope of the present disclosure. Any other suitable means are also possible. For example, in some alternative embodiments, the connection ends 1031 and the intermediate connection ends 1032 may also be formed by welding a conductor to ends of the respective sections of the tubular busbar 103.

For one of the plurality of sections of the tubular busbar 103 arranged adjacent to the respective high-voltage device, the connection end 1031 and the intermediate connection end 1032 thereof may be interchanged. For example, for the cases where the tubular busbar 103 comprises two sections, the connection end 1031 and the intermediate connection end 1032 of each section may be interchanged when the shape of the final formed tubular busbar 103 allows. For the cases where the tubular busbar 103 comprises more than two sections, the connection end 1031 and the intermediate connection of end section adjacent to the high-voltage device may be interchanged. Correspondingly, two ends of the intermediate section (s) arranged between the end sections are both intermediate connection ends 1032.

To improve the insulation performance, in some embodiments, the bus-duct 100 may further comprise at least one insulation cover 104 arranged to at least surround the connection ends 1031 and the intermediate connection end 1032, as shown in FIGs. 1 and 2. For example, the insulation cover 104 may be a cage surrounding the connection ends 1031 and the intermediate connection end 1032 and their adjacent areas. In addition, the insulation cover 104 may also surround the areas where the electric field distribution is poor. For example, the insulation cover 104 may also be arranged at positions where the tubular busbar 103 is supported by the insulation supports 102.

The tubular busbar 103 may be supported by the insulation supports 102 in any suitable way. For example, in some embodiments, each of the insulation supports 102 may comprise a protrusion 1021 extending along an axial direction thereof and can pass radially through a respective through hole 1033 of the tubular busbar 103. After the protrusion 1021 passing radially through the through hole 1033, a fastener may be coupled to the protrusion 1021 to fix and support the tubular busbar 103 in position.

It is to be understood that the above embodiments where the insulation support 102 comprises a protrusion 1021 passing through the tubular busbar 103 are merely illustrative, without suggesting any limitation as to the scope of the present disclosure. Any other supporting means are also possible. For example, in some alternative embodiments, the insulation support 102 may also comprise a tube to sleeve the tubular busbar 103.

To further improve the safety performance, the bus-duct 100 may further comprise at least one pressure relief component 105 arranged on at least one wall 1011 of the housing 101. For example, the pressure relief component 105 may be arranged on a top wall of the housing 101, as shown in FIGs. 1 and 2. The pressure relief component 105 can be at least partially broken to release a pressure within the internal chamber when the pressure within the internal chamber reaches or exceeds a predetermined threshold. Furthermore, the pressure relief component 105 can also improve the heat dissipation performance of the bus-duct 100.

When e.g., a short-circuit fault occurs in conductors of the bus-duct 100, the generated arc may cause the internal chamber to have high temperature and high pressure. If the high pressure is not released, it may cause the destruction of the entire bus-duct 100 and damage to nearby devices. With the pressure relief component 105, if the pressure within the internal chamber reaches or exceeds a predetermined threshold, which means that there are faults within the internal chamber, at least a portion of the pressure relief component 105 may be broken to make the internal chamber open to the ambient environment thereby to release the high pressure within the internal chamber. In this way, the safe performance of the bus-duct 100 is further improved.

In some embodiments, the bus-duct 100 may further comprise at least one access window 106 formed on at least one wall 1011 of the housing 101. For example, the access window 106 may be arranged adjacent to the connection ends 1031 to allow operators to access the connection ends 1031 or the intermediate connection ends 1032 and maintain them. The access window 106 may be closed during the normal operation of the bus-duct 100.

According to other aspects of the present disclosure, a method 300 of manufacturing a bus-duct 100 is provided. FIG. 5 shows a flowchart illustrating a method of manufacturing a bus-duct 100 according to embodiments of the present disclosure. As shown in FIG. 5, in block 310, a housing 101 comprising a plurality of walls 1011 and an internal chamber surrounded by the plurality of walls 1011 is provided. The plurality of walls 1011 may be welded, riveted, etc. to form the housing 101.

In block 320, the insulation supports 102 may be arranged on at least one wall 1011 of the housing 101. In some embodiments, this step may be performed before the housing 101 is formed by welding or riveting the plurality of walls 1011. After the housing 101 is at least partially formed and the insulation supports 102 are arranged in position, in block 330, the at least one tubular busbar 103 may be arranged in the internal chamber via the insulation supports 102. In this way, a bus-duct 100 with compact size and excellent insulation performance can be manufactured.

According to other aspects of the present disclosure, a power transmission and distribution system comprising at least one bus-duct 100 as mentioned above is provided. The bus-duct 100 as mentioned above allows the power transmission and distribution system to have a compact size and excellent insulation performance.

It should be appreciated that the above detailed embodiments of the present disclosure are only for exemplifying or explaining principles of the present disclosure and do not limit the present disclosure. Therefore, any modifications, equivalent alternatives and improvements, etc. without departing from the spirit and scope of the present disclosure shall be comprised in the scope of protection of the present disclosure. Meanwhile, appended claims of the present disclosure aim to cover all the variations and modifications falling under the scope and boundary of the claims or equivalents of the scope and boundary.

Claims

A bus-duct for power transmission between high-voltage devices, comprising:

a housing (101) comprising a plurality of walls (1011) and an internal chamber surrounded by the plurality of walls (1011) ;

a plurality of insulation supports (102) arranged on at least one of the plurality of walls (1011) ; and

at least one tubular busbar (103) arranged in the internal chamber via the plurality of insulation supports (102) , each of the at least one tubular busbar (103) comprising a pair of connection ends (1031) each adapted to be electrically coupled to a respective one of the high-voltage devices.
The bus-duct of claim 1, wherein the pair of connection ends (1031) are radially pushed into flat plates to facilitate coupling of the high-voltage devices to the at least one tubular busbar (103) .
The bus-duct of claim 1, wherein at least one tubular busbar (103) comprises a plurality of sections each having a length less than or equal to a predetermined length.
The bus-duct of claim 3, wherein each of the plurality of sections comprises:

an intermediate connection end (1032) via which the plurality of sections are connected to form the at least one tubular busbar (103) .
The bus-duct of claim 4, wherein the intermediate connection end (1032) is radially pushed into a flat plate to facilitate a connection between the plurality of sections.
The bus-duct of claim 4, further comprising:

at least one insulation cover (104) arranged to at least surround the pair of connection ends (1031) and the intermediate connection end (1032) .
The bus-duct of claim 1, wherein each of the plurality of insulation supports (102) comprises:

a protrusion (1021) extending along an axial direction of the insulation support (102) and adapted to pass radially through a respective through hole (1033) of the at least one tubular busbar (103) to support the at least one tubular busbar (103) .
The bus-duct of claim 1, wherein an outer diameter and a wall thickness of the at least one tubular busbar (103) are configured at least according to a magnitude of a rated current carried by the at least one tubular busbar (103) .
The bus-duct of claim 1, further comprising:

at least one pressure relief component (105) arranged on at least one of the plurality of walls (1011) and adapted to be at least partially broken to release a pressure within the internal chamber in response to the pressure within the internal chamber reaching or exceeding a predetermined threshold.
The bus-duct of claim 1, further comprising:

at least one access window (106) formed on at least one of the plurality of walls (1011) and adjacent to at least one of the pair of connection ends (1031) .
The bus-duct of claim 1, wherein inner surfaces and/or outer surfaces of the housing (101) is painted for better heat dissipation performance.
A method of manufacturing a bus-duct, comprising:

providing a housing (101) comprising a plurality of walls (1011) and an internal chamber surrounded by the plurality of walls (1011) ;

arranging a plurality of insulation supports (102) on at least one of the plurality of walls (1011) ; and

arranging at least one tubular busbar (103) in the internal chamber via the plurality of insulation supports (102) , each of the at least one tubular busbar (103) comprising a pair of connection ends (1031) each adapted to be electrically coupled to a respective high-voltage device.
A power transmission and distribution system comprising at least one bus-duct of any of claims 1-11.