KR102463629B1 - Busbar and busduct having the same - Google Patents

Abstract

The present invention relates to a bus bar for supplying power for each phase comprising a multi-layer conductor, and to a bus bar capable of minimizing the amount of conductor used in consideration of the skin effect and proximity effect of the conductor when power is supplied, and a bus duct having the same will be.

Description

Bus bar and bus duct having same {BUSBAR AND BUSDUCT HAVING THE SAME}

The present invention relates to a bus bar and a bus duct having the same. More specifically, the present invention relates to a busbar for supplying power for each phase is configured to include a multi-layered conductor, and a busbar capable of minimizing the amount of conductor used in consideration of the skin effect and proximity effect of the conductor when power is supplied, and a busbar having the same It is about the bus duct.

In general, a cable has been widely used as a medium for transmitting electrical energy, but recently, a bus duct has been widely used as an alternative to the cable. The bus duct has a bus bar that performs the same role as the conductor core included in the cable, and has the advantage of passing a large amount of current.

In wiring in a high-rise building or a large-scale factory, wiring by a bus duct having a bus bar is gradually being adopted.

These bus ducts and cables have in common in that they have conductors and insulators, but cables are provided with oil immersion paper or a polymer material layer by layer around the conductors to protect or insulate the conductors, and the bus ducts are molded with an insulating material with a high heat resistance rating. Alternatively, in order to increase the insulation and heat dissipation effect, the busbars for each phase are spaced apart from each other and the busbars are accommodated in a metal duct.

These bus ducts are not only easy to install, extend, and relocate on complicated wiring paths, but also can be quickly restored because they are easy to handle in case of abnormalities or accidents on the power wiring of busbars, and they require increasingly large and diverse amounts of energy. In line with this trend, the use of safe and low energy loss bus ducts is rapidly increasing.

For example, bus ducts include factories, buildings, apartments, large discount marts, officetels, research complexes, department stores, golf courses, tunnels, semiconductor and LCD factories, chemicals, oil refining, steel manufacturing, high-rise buildings, ultra-high voltage substations, LNG receiving bases, new airports, and ports. It is applied to facilities in various fields such as

The bus bar provided inside the bus duct is usually provided inside a duct of a predetermined size and isolated from the outside because a large current flows. It is connected and constructed according to the facility and distribution design to be installed.

These bus ducts usually constitute three or more phases, and power for each phase may be supplied through a bus bar. Busbars for each phase may be accommodated in an insulated state spaced apart in a duct.

As a method of insulating the busbars of each phase within the bus duct, an air insulation method may be used by separating the bare conductor type busbars, or a method of molding the busbars of each phase with epoxy, etc. may be used, but the former method is based on the size of the duct The latter method can be used due to the problem of having to be large.

In addition, as the voltage of the power supplied through the bus duct increases, the distance between the phases should also be increased, so that the separation distance may be increased according to the voltage.

Furthermore, when the capacity of the power supplied through the bus duct increases, the method of increasing the size or cross-sectional area of one conductor is not preferable due to the effect of the skin effect, etc., so the conductors constituting the bus bar are mutually insulated A method of configuring as many as possible may be used.

Even in this case, the cross-sectional area of the busbars of each phase must be determined to satisfy the limiting calorific value of the busbar conductors required according to the magnitude of the voltage or current of the power supplied through the busduct. For example, according to the IEC60694 standard in relation to the MV class bus duct system, the maximum temperature rise on the busbar conductor surface constituting the bus duct using class A insulation is required to be 65K or less, and the insulator of each phase busbar The temperature of each conductor should be maintained below about 105°C in order not to be damaged by the heating of the conductor.

However, even when a plurality of conductors constituting the busbar are configured, the allowable power is not directly proportional to the increase in the total conductor cross-sectional area due to the proximity effect, etc. and a design that minimizes the amount of wasted conductors in consideration of the proximity effect is required.

The present invention provides a busbar and a bus duct having the same, in which a busbar for supplying power for each phase is configured to include a multi-layered conductor, and the use of conductors can be minimized in consideration of the skin effect and proximity effect of the conductor when power is supplied Make it a task you want to solve.

In order to solve the above problems, the present invention provides a plurality of busbars having a plurality of conductors and a molding part surrounding the conductors; and a duct in which the plurality of busbars are accommodated apart from each other, wherein three or more stages of conductors of the busbars are provided, and conductors excluding the outermost conductors are provided with a discontinuous portion in cross section. can

In this case, a conductor constituting the bus bar may have a flat cross-sectional shape in which a width is greater than a thickness, and may be disposed in parallel and spaced apart from each other in a molding unit constituting the bus bar.

In addition, the bus bar may have three stages of conductors, and the discontinuous portion may be formed by dividing a central conductor into two.

Here, the divided conductors may have the same width.

In addition, positions of both ends of the stacked conductors in the width direction may be arranged in a straight line.

In addition, the ratio of the discontinuous portion of the conductor provided with the discontinuous portion may be determined so as to be within a limiting calorific value of a conductor constituting the busbar when the busbar is energized.

In this case, the thickness of the conductor constituting the bus bar and the upper limit of the ratio of the discontinuous portion may be proportional to each other.

And, the thickness x (mm) of the three layers of conductors constituting the bus bar is in the range of 13 millimeters (mm) to 20 millimeters (mm), and the removal rate of the intermediate conductor is y (=8.2x-90) percent (%) can be the following

In addition, in order to solve the above problems, the present invention is a conductor made of a plate-shaped aluminum, aluminum alloy, copper or copper alloy material in which the length of N (N is an integer greater than or equal to 3) is longer than the width; and a molding part made of an epoxy material surrounding the plurality of conductors so as to be spaced apart in parallel, wherein at least one of the conductors except for the two conductors disposed at the outermost of the conductors is divided in the width direction. It is possible to provide a bus bar with

According to the bus duct according to the present invention, the bus bar for power supply for each phase is configured to include a multi-layer conductor, and when power is supplied, the use of conductor is minimized in consideration of the skin effect and proximity effect of the conductor to reduce the weight of the product, It can prevent wastage of resources.

1 shows a perspective view of a bus duct constituting an embodiment of the present invention.
Figure 2 shows an exploded perspective view showing a state in which the duct of the bus duct constituting an embodiment of the present invention is separated.
3 is a perspective view showing the configuration of a molding part, a molding support part, and a base frame of a bus duct constituting an embodiment of the present invention.
4 is a side view showing the configuration of the molding part, the molding support part, and the base frame of the bus duct constituting an embodiment of the present invention.
FIG. 5 shows a cross-sectional view of the bus duct shown in FIG. 1 .
6 shows a plan view of a bus duct system in a state in which a pair of bus ducts of the present invention are connected.
7 and 8 show the current density (current per unit area) of conductor loss analysis when 4,000 amperes (A) of a bus duct equipped with three busbars each having a thickness of 15 millimeters and a width of 200 millimeters is provided. density) distribution.
FIG. 9 is a graph showing the result of heat generation (heat loss) of the busbar according to the ratio of the discontinuity shown in FIG. 8 .
10 and 11 show the results of the current density distribution of the conductor loss analysis when 4,000 amperes (A) of a bus duct equipped with three busbars each having a thickness of 20 millimeters and a width of 200 millimeters is provided in three phases. show
FIG. 12 is a graph showing the result of heat generation (heat loss) of the busbar according to the ratio of the discontinuous portion of the intermediate conductor shown in FIG. 11 .
13 shows the relationship between the thickness of the conductor constituting the busbar and the maximum removable ratio of the intermediate conductor.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided so that the disclosed subject matter may be thorough and complete, and the spirit of the present invention may be sufficiently conveyed to those skilled in the art. Like reference numerals refer to like elements throughout.

1 is a perspective view of a unit bus duct 100 constituting an embodiment of the present invention, and FIG. 2 is an exploded perspective view showing a state in which the duct of the unit bus duct 100 constituting an embodiment of the present invention is separated. 3 is a perspective view showing the configuration of the molding part, the molding support part, and the base frame of the unit bus duct 100 constituting an embodiment of the present invention. 4 is a side view showing the configuration of the molding part, the molding support part, and the base frame of the unit bus duct 100 constituting an embodiment of the present invention, and FIG. 5 is a cross-sectional view of the bus duct shown in FIG. 6 shows a plan view of a bus duct system in a state in which a pair of bus ducts of the present invention are connected.

1 to 6 , a bus duct 100 constituting an embodiment of the present invention includes a plurality of bus bars 20 including a plurality of conductors 21 and a molding part 23 surrounding the conductors. ; and a duct (60) in which the plurality of bus bars (20) are spaced apart and accommodated, wherein the conductors constituting the bus bars of each phase of the bus bars (20) are composed of three or more stages, and the bus bars (20) ) of the plurality of conductors 21 constituting the conductor except for the outermost conductor may be provided with a discontinuous portion in cross-section.

In the case of a bus duct having a large power transmission capacity, if the conductor constituting the bus bar for each phase is composed of a single square conductor with a large cross-sectional area, the conductor width is too large, making it difficult to manufacture, increasing the molding cost, and reducing the durability to withstand short-circuit electromagnetic force This is inefficient, so the bus duct 100 according to the present invention can reduce the effect of the skin effect when dividing the conductors constituting the busbars of each phase into a plurality, so that the conductors constituting the busbars of each phase are divided into a plurality of sheets. make up

1 and 2, the bus duct 100 of the present invention may have a structure in which a plurality of bus bars 20 are arranged side by side, and a duct 60 surrounds the outside thereof.

And, the busbar 20 of each phase includes a plurality of flat conductors 21, and the molding part 23 is wrapped around the conductor 21 constituting the busbar 20 of each phase, The busbars 20 of each phase may be accommodated in the duct 60 while being spaced apart in parallel at regular intervals.

1 and 2, the duct 60 includes an upper panel 62 provided on the upper portion, a lower panel 64 provided on the lower portion, and a plurality of side panels 66 provided on the side surfaces. They can be combined to form a certain internal space.

The upper panel 62 , the lower panel 64 , and the side panel 66 may be coupled by various methods such as bolt fastening, riveting fastening, bonding or welding.

The duct 60 may include at least one vent hole 69 communicating with the outside air. 1 and 2, a plurality of vent holes 69 are formed in the side panel 66 constituting the duct 60, respectively. Here, the vent hole 69 formed in the side panel 66 may be configured in the form of a vent inclined downward to make it difficult for rainwater to penetrate in case of rain or the like.

By forming a vent hole 69 in the duct 60 , it is possible to prevent or alleviate dew condensation inside the duct 60 by allowing outside air to flow in and humid bet air to be discharged. In addition, by the method of forming the vent hole 69, condensation inside the duct is prevented and the heat generated from the conductor 21 can be expected to be released to the outside, so the stability and reliability of the product can be secured. have.

And, when describing the bus bar, as shown in FIGS. 1 to 3 , each of the bus bars 20 may have a structure in which the molding part 23 is individually wrapped. The molding part 23 may be formed by arranging the conductor 21 on a flask (not shown) and then hardening it by injecting an insulating resin for the mold. Here, the insulating resin for the mold may be, for example, epoxy.

The present invention may be configured by providing a plurality of conductors 21 on the busbar 20 of each phase in order to increase the carrying capacity. A method of providing a plurality of conductors in the molding unit 23 may be a method of forming the molding unit through epoxy molding or the like by fixing each conductor to a flask in a state in which the conductors are spaced apart in parallel to each other.

And, as shown in FIG. 1 and the like, the bus bar 20 constituting the bus duct according to the present invention is provided with conductors spaced apart in three stages, and the central conductor is divided into two. has the characteristics of being The reason why the central conductor is divided into two is to reduce the amount of conductor used for the same power transmission capacity, which is to minimize the use of metal conductors in consideration of the skin effect and proximity effect. A detailed description thereof is deferred.

In addition, the molding part 23 and the molding support part 40 to be described later may be integrally formed together by injecting an insulating resin for a mold into a flask.

The molding part 23 serves to protect and insulate the conductor 21 at the same time, thereby improving the stability of power supply and basically exhibiting waterproof and dustproof performance.

The molding part 23 and the molding support part 40 to be described later are integrally formed by injecting an insulating resin for a mold into a single flask, and epoxy may be applied as the insulating resin for the mold, for example.

The epoxy included in the molding part 23 may be composed of a mixture of a main agent and a curing agent that promotes curing, and a mixing ratio of the main agent and the curing agent may be 100:25 to 100:35.

If the mixing ratio of the curing agent is less than 100:25, there is a problem that it takes a long time to cure the molding part 23, and if it is greater than 100:35, the curing quality may be deteriorated. Therefore, the mixing ratio of the main agent and the curing agent is The molding part 23 is configured within the range of 100:25 to 100:35.

At this time, the dielectric breakdown voltage of the molding part 23 is set to be greater than 24 kV/mm to ensure safety. And, the tensile strength of the molding part 23 is formed in the range of 25N/mm2 to 35N/mm2, and it is generally preferable to configure about 30N/mm2.

When the molding part 23 is formed, various types of fillers other than the epoxy may be mixed and included. The filler may include at least one of coarse ground sand, fine ground sand, fine silica powder, chalk, or micro glass ball, and in general, all of the five types of fillers may be mixed together in an appropriate ratio to be added. have.

In this case, the epoxy and the filler must be input in a predetermined amount through automatic metering, so that the product quality can be kept constant.

On the other hand, the mixing ratio of the filler and the epoxy included in the molding part 23 is configured in the range of 70:30 to 80:20. When the mixing ratio of the filler is less than 70:30, there is a problem in that the specific gravity of the epoxy increases, thereby increasing the manufacturing cost. In addition, when the mixing ratio is greater than 80:20, there is a problem in that the curing quality is lowered and the mechanical strength and insulating performance of the molding part 23 are reduced. Therefore, the mixing ratio of the filler and the epoxy is preferably determined in the range of 70:30 to 80:20.

Among the fillers, a product having a PH value of 5.3 to 9.3 and a specific gravity of 0.78 to 1.78 is applied for coarse ground sand among the fillers, and the contained moisture should be maintained at 0.03% or less. And, in the case of the fine ground sand, a product having a PH value of 4.8 to 8.8, a specific gravity of 1.09 to 2.09 is applied, and the moisture contained therein must be maintained at 0.05% or less.

When the filler includes fine silica powder, a product having a PH value of 5 to 8 and a specific gravity of 1.6 to 3.6 of the fine silica powder is applied. In this case, the Mohs hardness of the fine silica powder should be maintained at 7 or more, the contained moisture should be maintained at 0.1% or less, and the average particle size is preferably 10 μm to 15 μm.

When the filler includes chalk, a product with a pH value of 6.8 to 10.8 of the chalk is applied. At this time, the Mohs' Hardness of the chalk should be maintained at 7 or more, the moisture contained in it should be maintained at 0.35% or less, and the average particle size is preferably 9 μm to 13 μm. And the whiteness of the chalk, that is, a product with a whiteness of 90% to 94% is applied. The chalk can be replaced with microdol.

When the filler includes a micro glass ball, the specific gravity of the micro glass ball is applied to a product in the range of 1.5 to 3.5. Here, the whiteness of the micro glass ball should be maintained at 90% to 94%, and the moisture contained therein is 0.1% or less.

Filler: Epoxy (76:24)

topic

0.17700
hardener

0.06300
coarse ground sand

0.23800
fine ground sand

0.25000
find silica powder

0.14000
chalk or microdol

0.04200
micro glass ball

0.09000
total

1.0000

Table 1 shows examples of actual application mixing ratios of the main components of the aforementioned molding unit 23 . Of course, the ratio of the filler to the epoxy is not limited to the above 76:24, for example, 75:25 may be applied. That is, as described above, it is possible to carry out the deformation within the range of 70:30 to 80:20.

Meanwhile, in addition to the above-described epoxy and filler, a pigment may be mixed and applied to the molding unit 23 to match the surrounding color when the power distribution is installed.

In this way, the bus duct 100 is manufactured as a unit with a maximum length of 3.5 m including the bus bar 20 and the duct 60, and then connected to and installed through a connection part (not shown) to be used as a power distribution facility. can be implemented.

In the bus duct according to the present invention shown in FIGS. 1 to 3, the bus bar is composed of R, S, and T three phases, but is not limited thereto. Specifically, the configuration of the bus bar 20 may be variously configured according to the installation target of the bus duct 100 , the installation environment, the power capacity to be supplied, and the like.

A plurality of bus bars 20 capable of supplying power are provided inside the bus duct 100, and the conductor 21 constituting the bus bar 20 is made of a metal material such as copper, copper alloy, aluminum or aluminum alloy. can be done When the conductor of the conductor 21 is copper or a copper alloy, a material having a conductivity of 99% or more may be used, and in the case of aluminum or an aluminum alloy, a conductivity of 61% or more may be used.

In the case of copper, its own rigidity is excellent and conductivity is good, but it has the disadvantage of being more expensive than aluminum.

In general, an air-insulated bus duct is composed of a bus bar in which a heat-shrinkable tube is covered with a bare conductor, and the bus bar is sufficiently spaced from the inside of the duct 60 to use air as a main insulating material.

In particular, in the case of a bus duct composed of a busbar in the form of a bare conductor covered with a heat shrinkable tube, in case of an accident such as a short circuit, the conductor is deformed in response to the problem of conductor deformation due to fault current or conductor deformation due to the expansion and contraction of the conductor. In order to prevent this, the conductor itself must be rigid, so copper or copper alloy conductors are mainly used. However, since the bus bar constituting the bus duct 100 of the present invention is provided with the molding part 23 on the outside of the conductor, the deformation of the conductor due to the short-circuit fault current can be prevented or alleviated, and the molding part 23 The rigidity of the conductor constituting the conductor 21 is reinforced by the rigidity reinforcement effect by its own rigidity, so that the above-described problem can be minimized. Therefore, as the conductor of the unit bus duct 100 of the present invention, an inexpensive aluminum or aluminum alloy conductor may be sufficiently used.

Of course, the busbar conductor of the bus duct of the present invention combining the advantages of the air insulation method and the molding method may be made of aluminum or an aluminum alloy material, but of course, it may be made of a copper material having good rigidity and electrical conductivity, In this case, the required cross-sectional area of the conductor can be further reduced.

In general, 3.3 kV to 24 kV is classified as MV (medium voltage) class, that is, high pressure, and those below it are classified as LV (low voltage) class, that is, low voltage. And in the case of high voltage, it is necessary to make the distance between the phases, that is, the gap between the conductors 21, larger than that of the low voltage to sufficiently maintain the insulation distance.

Therefore, the bus duct 100 of the present invention has a structure that surrounds the outside of each conductor 21 with a molding part 23 integrally formed by a mold, and as shown in FIGS. 1 to 3 , three molding parts (23) are arranged in a state spaced apart from each other by a predetermined interval.

At least one molding support part 40 integrally formed when the molding part 23 is formed and supporting the molding part 23 may be provided under the molding part 23 . The molding support part 40 may have a shape in which a portion of the molding part 23 extends downward by a predetermined length.

The molding support part 40 is integrally formed when the molding part 23 is formed in order to fix the busbar of each phase to the lower panel, and at least one molding support part supporting the molding part is attached to one molding part 23. A plurality may be provided spaced apart.

As shown in FIG. 4 , four molding support parts 40 of the bus bar of the bus duct 100 of the present invention are formed in one molding part 23 along the longitudinal direction, but the present invention is not limited thereto. The number of the molding support parts 40 can be increased or decreased according to the length of the molding part 23 or the installation environment.

The molding support part 40 may be integrally formed with the molding part 23 . The shape of the molding support part 40 may also be applied to the flask for injecting the molding part 23 so that not only the molding part 23 but also the molding support part 40 can be formed together. Therefore, when the conductor 21 is placed in the flask and the insulating resin for the mold is put in, the molding part 23 and the molding support part 40 are cured together and formed integrally.

A plurality of base frames 50 for mounting the molding support part 40 to the lower panel side while crossing the plurality of molding parts 23 may be provided under the molding support part 40 .

The base frame 50 includes a vertical main bar 52 extending across the plurality of molding parts 23 , and bending and extending from an upper end of the main bar 52 in the horizontal direction, and the molding support part It may include an upper bent plate 54 fastened to the 40, and a lower bent plate 56 bent from a lower portion of the main bar 52 to extend in the horizontal direction and fastened to the lower panel 64. have.

The base frame 50 may be disposed in a number corresponding to the number of the molding support parts 40 formed on one molding part 23 to support the molding support parts 40 .

In the present embodiment, the base frame 50 is configured such that the main bar 52, the upper bent plate 54, and the lower bent plate 56 form a 'C' shape, but is not limited thereto, and the molding support part ( 40) and the lower panel 64 can be changed into various shapes to support the molding support 40. For example, the base frame 50 may have a shape such as 'E' to support the base frame 50 .

In addition, as shown in FIGS. 3 and 4 , in the plurality of base frames 50 , the upper bent plate 54 and the lower bent plate 56 extend in different directions based on the central part of the molding part 23 . can be arranged as much as possible.

That is, referring to FIG. 4 , the two left base frames 50 are arranged such that the upper bent plate 54 and the lower bent plate 56 extend toward the left, and the two right base frames 50 are is arranged such that the upper bent plate 54 and the lower bent plate 56 extend toward the right.

The base frames 50 may be alternately disposed so that the adjacent base frames 50 extend in different directions.

6 shows a connection part 200 to which a pair of bus ducts constituting the bus duct system according to the present invention are connected. The method of interconnecting the bus ducts of the present invention uses a general method of connecting the bus ducts of the air insulation method, but a method of molding the connection part with epoxy or the like may also be used.

In the embodiment shown in FIG. 6 , when the two bus ducts 100a and 100b are connected, the length of the side panel 66 is longer than that of the upper panel 62 or the lower panel 64, specifically When the position of the end of the bus bar and the position of the end of the side panel coincide, the bus bar of each bus duct (100a, 100b) and the end of the side panel are in a state of abutting the three steps constituting the bus bar of each phase. In a state in which the four connecting conductors 25 for connecting the conductors are stacked and arranged, they are fastened through the fastening member b to constitute the connecting portion 200 . In this case, the side panels 66a and 66b may also be connected by being fastened with a fastening member such as a bolt.

And, since the length of the side panel 66 is longer than that of the upper panel 62 or the lower panel 64, the side panels 66a and 66b are also connected by being fastened with fastening members such as bolts, In a state in which the busbars 21a and 21b of each phase are also connected via the connecting conductor 25, the upper and lower regions of the connecting part 200 are in an open state, so the open area is separated by a separate cover member (c). By shielding, the bus duct connection can be completed.

The bus duct connection method shown in FIG. 6 is only one example, and various methods other than the method using the connection conductor 25 may be used as a method of connecting each phase bus bar or panel.

And, since the connecting conductor 25 is added to the side of the conductor in the state where the conductor of the conductor 21 is faced in the connecting portion 200, the cross-sectional area of the conductor is eventually increased in the connecting portion, so that the amount of heat generated can be reduced. Even if the molding part is not formed on the conductor in (200), heat generation may not be much of a problem compared to the region in which the molding part is provided.

In addition, the region to which the conductors are connected through the connection conductor 25 may be configured to be wrapped using a separate boot (insulation material) or a cap member for the purpose of protecting the conductor.

7 and 8 show the current density (current per unit area) of conductor loss analysis when 4,000 amperes (A) of a bus duct equipped with three busbars each having a thickness of 15 millimeters and a width of 200 millimeters is provided. density) distribution.

Specifically, FIG. 7 is a comparative example in which a discontinuous portion is not provided in conductors constituting each busbar, and FIG. 8 illustrates an embodiment in which a discontinuous portion is included in an intermediate conductor constituting each busbar.

The bus duct according to the present invention includes three or more phase busbars, each phase busbar is provided with a plurality of conductors 21, and the conductors except for the outermost conductor are provided with a discontinuous portion 21c in cross section. do. When the conductors constituting the busbar of each phase are composed of three or more stages, the conductors other than the outermost conductor, for example, the second conductor 21b disposed in the center among the first to third conductors 21a of the three stages. This is because the central portion in the width direction does not significantly contribute to energization due to the proximity effect, and thus, the amount of use of the conductor can be minimized by forming the discontinuous portion 21c in the conductor within a range in which the molding portion is not deteriorated or damaged by heat. A method of determining the size or ratio of the discontinuous portion 21c will be described in detail later.

That is, the bus bar according to the present invention includes a plate-shaped conductor made of aluminum, aluminum alloy, copper, or copper alloy in which the length of N (N is an integer greater than or equal to 3) is longer than the width; and a molding part made of an epoxy material that surrounds the plurality of conductors so as to be spaced apart in parallel, wherein at least one of the conductors except for the two conductors disposed at the outermost of the conductors is divided in the width direction, so that the amount of conductor used can be minimized. Therefore, even when each busbar is composed of three or more phase conductors, the amount of conductor used can be minimized by forming a discontinuity in the conductor except for the outermost conductor.

As a specific example, like the embodiment of the description with reference to FIGS. 1 to 6 , each of the bus bars shown in FIG. 8 is provided with conductors spaced apart in three stages, and the central conductor may be divided into two. .

In addition, as for the first to third conductors constituting the first to third busbars, respectively, the second conductor 21b excluding the first and third conductors, which are the outermost conductors, are shown in FIGS. 7 to 11 . The discontinuous portion 21c may be provided at the center of the second conductor 21b by dividing into two as described above.

In addition, the divided second conductors 21b have the same width, but the positions of both ends of the first to third conductors in the width direction are positioned to improve fastening properties by the fastening members shown in FIGS. 8 to 11. It is preferably configured to be arranged in a straight line.

According to the result shown in FIG. 7, even when the busbar uses three stages of flat conductors 21 instead of one conductor, the current density is high near the end or both sides in the width direction, but the current density increases toward the center in the thickness direction or the width direction. It can be seen that the density is low.

In addition, when the bus bar is configured by arranging three stages of flat conductors 21 at equal intervals in parallel instead of one conductor, it can be confirmed that the overall current density is not relatively high in the second conductor 21b arranged in the center. can That is, it can be confirmed that the current density is not higher than that of the outermost conductor due to the proximity effect, and in particular, the blue color becomes deeper toward the center of the width direction of the second conductor 21b, and thus the current density is the lowest. .

In conclusion, in the busbar composed of three parallel conductors, the part with the smallest role in energization has a small central area in the thickness direction or width direction rather than the thickness direction end (both sides) or width direction end due to the skin effect. , because of the proximity effect, it can be confirmed that the conductor arranged in the middle is the smallest among the conductors composed of three stages. In conclusion, if a part of a specific conductor is removed to minimize the amount of conductor constituting the busbar, it is not the outermost conductor but the center. It can be inferred that the method of removing the central region in the width direction of the conductor, furthermore, the central conductor can obtain the greatest effect.

In the comparative example shown in FIG. 7, the thickness of the conductors is 15 millimeters (mm), and when the thickness of the conductor of the busbar is experimentally reduced to a size smaller than about 13 millimeters (mm), which is smaller than that of the above test example, a current of about 4000A It was confirmed that it is not preferable because the limit heating value of the conductor can be easily reached when energized.

In summary, if the thickness of the conductors constituting the busbar is greater than or equal to a certain size, it can be assumed that there is no significant problem in terms of conduction ability even if the central area in the width direction of the central conductor rather than the outermost conductor among the conductors constituting the busbar is removed. have.

The test result of the embodiment shown in FIG. 8 is 4000 amps in a bus duct with three phases, each of which is made of aluminum and has three layers of conductors each having a thickness of 15 millimeters (mm) and a width of 200 millimeters (mm). (A) A current density analysis result when the discontinuous portion 21c of the second conductor 21b constituting the first to third busbars is about 40% (39%) during energization.

Among the results of the current density analysis, the blue section of the conductor when the conductor is energized shows the lowest current density, and the higher the current density goes toward yellow.

As described above, it was confirmed that there was no significant change in the overall conduction capability of the busbar even when a part of the center conductor of the busbar having three conductors was removed.

However, when the size of the discontinuous portion increases, the cross-sectional area of the entire conductor constituting one busbar is reduced, and thus deterioration or damage of the molding part due to heat generation may occur. It is necessary to examine the relationship between the (limit) calorific value of

FIG. 9 is a graph showing the result of heat generation (heat loss) of the busbar according to the ratio of the discontinuity shown in FIG. 8 .

The green horizontal dotted line shown in the graph of FIG. 9 shows the upper limit of the limiting calorific value of the conductor at which deterioration or damage of the molding part does not occur.

As shown in FIG. 9, until the discontinuity 21c of FIG. 8 reaches about 40%, there is no problem of deterioration or ignition of the molding part due to heat generated due to a decrease in the conductor area, but a discontinuity of 40% or more does not occur. It was confirmed that the limit heating value of the conductor causing deterioration or damage to the molding part was exceeded.

That is, the thickness of the conductor 21 of the bus bar is 15 millimeters (mm) and the width is 200 millimeters (mm), and the second conductor 21b of the bus bar of each phase having three levels of conductors is divided into 2 Even when the discontinuous portion 21c is formed between the divided conductors 21b by about 40%, it can be confirmed that there is no problem in the conduction ability of the conductor and heat generation of the busbar due to the reduction in the area of the conductor. This means that the conductor 21 of the busbar can be reduced by about 14%.

Further, as the thickness of the conductor constituting the busbar increases, the size of the discontinuous portion will be described with reference to the comparative examples and examples shown in FIGS. 10 and 11 .

The test results shown in FIGS. 10 and 11 show that when a bus duct equipped with three phases of busbars each of which is 20 millimeters (mm) thick and 200 millimeters (mm) wide is equipped with three levels of conductors, 4000 amps (A) are energized. The comparative example of FIG. 10 in which the discontinuous portion 21c does not exist and the bus duct embodiment according to the present invention in which the discontinuous portion 21c of the second conductor 21b constituting the first to third busbars is 78%. This is the current density analysis result.

Likewise, in the comparison shown in FIGS. 10 and 11 , it can be confirmed that there is no significant change in the overall conduction capability of the busbar even when a part of the center conductor of the busbar having three conductors is removed, as in the comparative example described above. could

The embodiment shown in FIG. 11 is a case in which the thickness of the conductor is thicker than the embodiment shown in FIG. 8. Even when the discontinuous portion 21c occupies about 80% of the second conductor 21b, the bus bar is energized. It was confirmed that there is no major problem, and in this case, it means that the cross-sectional area of the conductor 21 of the busbar of one phase can be reduced by about 26%.

Also in the embodiment shown in FIG. 11, when the size of the discontinuous portion increases even when the thickness of the conductor is increased, the cross-sectional area of the entire conductor constituting one busbar is reduced, resulting in deterioration or damage to the molding portion due to heat generation. Therefore, it is necessary to examine the relationship between the (limit) calorific value of the conductor according to the removal rate of the intermediate conductor constituting the busbar.

FIG. 12 is a graph showing the result of heat generation (heat loss) of the busbar according to the ratio of the discontinuous portion of the intermediate conductor shown in FIG. 11 .

The green horizontal dotted line shown in the graph of FIG. 12 indicates the limiting calorific value of the conductor without deterioration or damage to the molding part when 4000 amps (A) are energized in a busbar equipped with three conductors each having a thickness of 20 millimeters and a width of 200 millimeters. shows the upper limit of

As shown in FIG. 12 , it can be confirmed that there is no problem of deterioration or ignition of the molding part due to heat due to a decrease in the conductor area until the discontinuous part 21c of FIG. 11 reaches about 80%.

The reason why the maximum ratio of the discontinuous portion 21c differs by about 40% and 80% in the results shown in Fig. 9 and the results shown in Fig. 12 is presumed to be the influence of the thickness of the conductor constituting the sub-sub bar of each embodiment. .

That is, when the thickness of the conductor constituting the busbar is large, it is determined that the ratio of the discontinuous portion 21c that can be removed is proportional to the ratio. The total conductor cross-sectional area of the busbar shown in FIG. 11 in which the thickness of the conductor is 20 millimeters (mm) and 80% of the discontinuity 21c is formed, the thickness of the conductor is 15 millimeters (mm), and the discontinuity 21c is 40% It is presumed that this is because it is wider than the total conductor cross-sectional area of the formed busbar shown in FIG. 8 .

For reference, in the embodiment shown in FIG. 11 , when the discontinuous portion 21c is formed to have a size of 80% or more, fastening at the connection portion may be problematic.

In the end, we came to the conclusion that the consumption of the conductor can be reduced by forming a discontinuity in the intermediate conductor constituting the busbar. Roughly, the thickness of the conductor and the removable ratio are expected to be proportional, but specifically, the thickness of the conductor and the maximum removable ratio A review of the relationship is required.

13 shows the relationship between the thickness of the conductor constituting the busbar and the maximum removable ratio of the intermediate conductor.

in more detail. 13 shows the cut ratio y percent (%), which is the maximum removable ratio of the intermediate conductor according to the thickness of the conductor x millimeters (mm), when the busbar for each phase is composed of a three-layer conductor.

That is, the blue graph of FIG. 13 shows that a busbar of one phase consists of a three-layer conductor, and as the thickness of the conductor increases (changes from 13 millimeters (mm) to 20 millimeters (mm) by 1 millimeter), conductors at each thickness Show the relationship of the removal rate (cutting rate) of a possible conductor at the limiting calorific value of .

As shown in the blue graph of FIG. 13, the thickness (x, millimeters) of the conductor constituting the busbar and the maximum removable ratio of the intermediate conductor, that is, the cut ratio (%), have an approximately proportional relationship as inferred. In the case of fitting it as a linear function, it was confirmed that y = 8.2x-90 in consideration of the safety factor, etc., and the thickness of the conductor in the range of 13 millimeters (mm) to 20 millimeters (mm) was x millimeters (mm), it was confirmed that deterioration or damage to the molding part constituting the busbar may not occur even if the maximum ratio of the discontinuous part of the intermediate conductor, not the outermost conductor, is set to y percent (%).

Therefore, when the thickness of the conductor is x millimeters (mm) in the range of 13 millimeters (mm) to 20 millimeters (mm), y (=8.2x-90) percent (%) of the intermediate conductor of the three-tiered busbar It can be confirmed that the amount of conductors constituting the busbar of one phase can be minimized by removing the following.

As such, in the case of configuring a multi-phase bus duct having a large power transmission capacity, if the conductor constituting the bus bar for each phase is composed of one conductor with a large cross-sectional area, waste of the conductor may occur due to the skin effect or proximity effect, etc. , when the conductors constituting the busbars of each phase are divided into a plurality of pieces, the effect of the skin effect can be minimized. In the conductor, for example, the second conductor disposed in the center among the first to third conductors of three stages, the central portion in the width direction does not significantly contribute to current flow due to the proximity effect. When the thickness of the conductor is x millimeters (mm) in the range of 13 millimeters (mm) to 20 millimeters (mm), the intermediate conductors of the three-tiered busbars must be y = 8.2x-90 percent (%) or less. It can be seen that the amount of conductor used can be minimized by forming a discontinuity in the

Although the present specification has been described with reference to preferred embodiments of the present invention, those skilled in the art can variously modify and change the present invention without departing from the spirit and scope of the present invention as set forth in the claims described below. will be able to carry out Therefore, if the modified implementation basically includes the elements of the claims of the present invention, all of them should be considered to be included in the technical scope of the present invention.

100: bus duct
20: bus bar
21 : conductor
21c: discontinuity

Claims (9)

a plurality of busbars having a plurality of conductors and a molding part surrounding the conductors; and,
Including; a duct in which the plurality of busbars are spaced apart and accommodated;
Conductors of the bus bar are provided with three or more stages, and conductors other than the outermost conductor are provided with discontinuous portions in cross-section,
The bus duct, characterized in that it has a flat cross-sectional shape in which the width of the conductor constituting the bus bar is greater than the thickness, and is disposed parallel and spaced apart in the molding part constituting the bus bar. delete According to claim 1,
The bus bar is provided with three stages of conductors, and the discontinuous portion is a bus duct, characterized in that the central conductor is divided into two. 4. The method of claim 3,
Bus duct, characterized in that the divided conductor is configured to have the same width. 5. The method of claim 4,
A bus duct, characterized in that the positions of both ends of the laminated conductor in the width direction are arranged in a straight line. 4. The method of claim 3,
Bus duct, characterized in that the ratio of the discontinuous portion of the conductor provided with the discontinuous portion is determined to be within a limiting calorific value of a conductor constituting the busbar when the busbar is energized. 7. The method of claim 6,
A bus duct, characterized in that the thickness of the conductor constituting the bus bar and the upper limit of the ratio of the discontinuous portion are proportional to each other. 4. The method of claim 3,
The thickness x (mm) of the three layers of conductors constituting the busbar is in the range of 13 millimeters (mm) to 20 millimeters (mm), and the removal rate of the intermediate conductor is y (=8.2x-90) percent (%) or less. Bus duct, characterized in that it becomes. N pieces (N is an integer greater than or equal to 3) a plate-shaped conductor made of aluminum, aluminum alloy, copper or copper alloy with a length longer than the width; and
Including; and a molding part made of an epoxy material surrounding the plurality of conductors to be spaced apart in parallel.
At least one of the conductors except for the two conductors disposed at the outermost of the conductors is divided in the width direction, and the width of the conductor has a flat cross-sectional shape greater than the thickness, and the conductor is parallel to the molding part, Bus duct, characterized in that spaced apart.

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