WO2019046923A1

WO2019046923A1 - Method for obtaining a power conductor of closed tubular profile form and a busbar of closed tubular profile form

Info

Publication number: WO2019046923A1
Application number: PCT/BR2018/050329
Authority: WO
Inventors: Melquisedec Francisquini
Original assignee: Melquisedec Francisquini
Priority date: 2017-09-11
Filing date: 2018-09-10
Publication date: 2019-03-14
Also published as: BR102017019390A2; BR102017019390B1

Abstract

Method for obtaining a power conductor of closed tubular profile form and a busbar of closed tubular profile form, which relates to a conducting busbar suitable for high alternating currents, having a closed tubular profile, greater rigidity and obtained by means of a profiling method, and also the steps for manufacturing the conducting busbar for obtaining a closed tubular profile, in which the electrical conductivity of said busbar is higher than a solid extruded profile of the same format, thereby resulting in a saving in terms of material and a technical gain.

Description

"PROCESS OF OBTAINING ENERGY CONDUCTOR IN CLOSED TUBULAR PROFILE AND BUS IN TUBULAR CLOSED PROFILE"

APPLICATION FIELD

The present invention relates to a process for the manufacture of electric conductors by means of forming machines, which work from a coil of metal sheets and allow the obtaining of profiles of shapes without prejudice to the electrical resistivity or the resistance mechanics.

The present invention also relates to an electric conductor conductor for application in electric cabinets obtained by subjecting a coil to a forming machine, which results in a closed tubular profile which has the same electrical resistivity than commonly used extruded solid busses.

DESCRIPTION OF THE STATE OF THE TECHNIQUE

Electrical cabinets, or cabinets as they are also known, are important electrical devices and widely used in industry in general.

[004] Its basic function is to energize and / or control equipment, devices, areas or work cells in industrial plants, adapting to almost all areas of industry, automation and / or services. [005] Electrical cabinets are usually divided into compartments or drawers, which have a variety of assembled components, for various purposes.

In the vast majority of applications, electrical cabinets are connected to the primary grid of electrical energy through electric busses, which are constructed of copper or other electrically conductive material, these materials being of low electrical resistivity, which conduct the conduction of electricity between the primary network and the electrical cabinets, which will power the company's equipment.

In the electrical area, the calculation of the resistance (R) in Ω (ohm) of a material is performed by the equation: R = p. L / A, where p indicates the specific resistivity of each material, measured in Ω (ohm) meter; L indicates the length of the material, measured in meters; and A indicates the cross-sectional area of the material, measured in m ² (square meter).

[008] The material used as the main electric conductor in the electrical industry is copper (Cu), since its electrical resistivity (p) at 20 ° C equals 1, 72x10 ^"8 Qm (ohm meter). The material that best conducts electricity is silver (Ag) where its electrical resistivity is 1, 59x10 ^"8 Qm (ohm meter); however its commercial value is too high for large-scale use.

[009] Other materials with low electrical resistivity are gold (Au) - 2,44x10 ^"8 Q m (ohm meter) and aluminum (Al) - ^{2,92x10" 8} Q m (ohm meter). However, gold (Au) as well as a resistivity higher than copper (Cu) and silver (Ag), also has a high commercial value for large scale application, while aluminum (Al) also has a higher resistivity than copper (Cu) and silver ( Ag), has a low mechanical resistance, which considerably impacts its application ranges.

In this way, copper has become the most used material as the conductor of electricity in the industry, not only because of its low electrical resistivity (p) but also because its commercial value is lower than silver (Ag) and (Au) and does not compromise its large scale application, as well as its mechanical resistance to that of aluminum (Al), thus not compromising its application in sectors that require such properties.

[001 1] One of the ways copper is used as the conductor of electricity is in the manufacture of electric busses, which consist of solid copper bars, usually obtained by means of an extrusion process. These copper buses used in conducting electricity can receive high currents such as, 1200A, 3200A, 4000A, 5000A and 6300A.

However, electricity conductors subjected to alternating high currents, as well as copper busbars, are subject to variations in their effective electrical resistance, through a phenomenon known as a peculiar effect, which has been studied over the years, mainly by Lord Kelvin. The main characteristic of the film effect is the increase of the effective electrical resistance in a conductor, being directly proportional the intensity of the electric current applied in a conductor, the frequency of the system, the intensity of the magnetic field, the electrical conductivity and the dimensions of drivers.

[0014] Practically, the skin effect on solid cylindrical conductors causes the alternating current to flow almost entirely through the periphery of the conductor, and there is practically no conduction of electricity in the interior. In solid rectangular conductors, the skin effect causes the current to be driven by the perimeter of the conductor, restricted to a penetration profile.

Based on this condition, in cases where the electric current conducted is in the range of 3200 A, the copper busbars in electrical cabinets, predominantly used by the market, consist of a configuration of three bars of 100x10mm, per phase, resulting in a cross section of 3000 mm ² per phase.

In this way, buses for conducting high currents in electrical cabinets use a high amount of copper because they are massive and depending on the film effect.

Another solution proposed in an attempt to reduce the amount of copper required to manufacture high-current busbars is the use of four bars in the size of 50x10 mm per phase for the same 3200 A, resulting in an area of section transversal of 2000 mm ² per phase. However, even though it is a massive rectangular bar, the use of copper is still high.

BRIEF DESCRIPTION OF THE INVENTION

The present invention has the object of presenting an electrically conductive bus capable of conducting high alternating electric currents in low and medium voltage electrical cabinets without the need to have a massive configuration.

Another object of the present invention is to describe a method of manufacturing such electrical conductors, these being obtained from copper plates or other electrically conductive material.

The present invention also allows drilling holes in the conductor in the same manufacturing process, thereby reducing the manufacturing steps.

The present invention, finally, is arranged to present the steps for the manufacture of said conductors by means of profiling process.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter of this invention will be fully clear in its technical aspects from the detailed description which will be made on the basis of the following figures, in which:

Figure 1 shows the perspective view of the busbar;

Figure 2 shows the side view of the bus conductor;

Figure 3 shows the front view of the busbar;

Figure 4 shows the top view of the busbar; Figure 5 shows the perspective view of a solid conductor bus assembly; Figure 5.1 shows the perspective view of a set of two solid conductor buses, in the same insulator model; Figure 6 shows the perspective view of a busbar assembly; and Figure 7 shows the steps of the profiling process for obtaining the driver bus.

DETAILED DESCRIPTION OF THE INVENTION

According to the objects presented by way of the brief description, the present patent application has a conductor bus (1), which consists of an electric conductor obtained through a profiling process with a closed tubular profile shape.

Said conductor bus 1 is designed to conduct high alternating electric currents between 1000 A and 6300 A, ie highly subject to the skin effect present in conductors in these characteristics. However, the conductor bus 1, unlike the other conductors of high alternating currents, is not solid, as shown in figure 5, having a closed tubular profile shape, so that its perimeter is larger than the drivers commonly employed in industry.

For this purpose, unlike traditional conductors, which are extruded and solid, the conductor bush (1) is obtained through the profiling process from a sheet coil, preferably of copper, and may also be constructed of other material of low resistivity.

In this way, the driver bus (1), unlike the traditional conductors that choose to increase their cross section to minimize the film effect and guarantee a low electrical resistance, opts for a construction based on walls and a hollow center, thus increasing the perimeter conduction of the electric current without the need to increase the amount of conductive material, resulting in material savings, since the current conduction area is not damaged, maintaining the same relation: (px I ) / THE.

To this end, the driver bus 1 has a parallelepipedal shape containing two sides 2a and 2b, joined by an upper wall 3 and a lower wall 4, wherein the lower wall 4 has a (4a), in its central portion, substantially rectangular towards the center of the conductor bush (1) and the upper wall (3) has a side step (3a) and a closure flap (3b) opposing each other, so that the closing flap contains a triple joint of facing material.

The driver bus 1 also has a series of bores in its side walls 2a and 2b along its length, equidistant from each other and coincident in each of the side walls 2a and 2b. Such drills are intended to cooperate in the installation of the conductor bus (1) in the electrical cabinet and to provide a better cooling thereto, since the air can flow through these holes helping in the dissipation of the heat generated by the conduction of the electric current.

The conductor bush (1) also has holes in its upper wall (3) and lower wall (4), throughout its length, equidistant from each other and coincident in both the top wall (3) and the bottom wall (4).

Due to its shape, the driver bus (1) in addition to the decrease of the amount of material engaged in the construction, compared to the extruded profiles, since the hollow shape of the driver bus (1) allows the elimination of the material would be used in its central portion, if it presented a massive format, it also presents the possibility, together with the profiling steps, to drill the profile in the same process, without the need for a specific process to do so. Since the walls of the profile do not have supports it would not be possible to obtain the holes in a process other than profiling.

In order to obtain the conductor bus (1) the process of manufacturing the same part of sheets obtained from a coil of conductive material, preferably copper, and another conductive material of low resistivity can be applied, which undergoes a previous drilling process , providing both the bores of the side walls (2a and 2b) and the bores of the upper walls (3) and the lower wall (4).

In a step subsequent to the drilling, the sheet of conductive material of the entry into the roll, being subjected to rollers that progressively begin the folding step of the sheet, three joint folds being made, one on its left outer side being one in the middle and one on the right outer side, so that the folds of the right central and lateral conform to plate a substantially square recess so that the walls of the recess are spaced at angles of 90 ^Q and the left outer end also have this angle in relation to the rest of the plate.

In a later step, still in the forming, the sheet of conductive material starts a process of bending the right outer recess, so that it progressively obtains an angle of 90 ^Q in relation to the central recess.

In a later step, still in the forming, the sheet of conductive material starts a process of folding the portions immediately to the left and right of the central recess so that the right recess faces the portion of the plate immediately opposite the left end.

Finally, in a last step, still in the section, the left end is progressively folded over the flap of the right recess, resulting in the closing flap (3b), with three facing walls and in a closed tubular profile .

The main advantages of the busbar (1) lie in the saving of material resulting from the use of a closed tubular profile in relation to a solid format, according to figure 5, without prejudice to the electrical resistance of the busbar (1), once that the perimeter on said busbar 1 is larger than on a bus of the same shape, but massive.

Another advantage of the conductor bus 1 and due to the material economy is in achieving a much lighter and more rigid tubular profile compared to a solid and solid profile, resulting in a decrease in the weight of the electrical cabinet in which it will be applied.

Finally, another advantage deriving from the conductor bus 1 is the possibility of carrying out the drilling process of the sheet, together with the profiling process of the same, different from the perforations made in solid extruded profiles, which are obtained in a later stage. It is to be understood that the present disclosure does not limit application to the details described herein and that the invention is capable of other embodiments and to be practiced or performed in a variety of ways within the scope of the claims. Although specific terms have been used, such terms should be interpreted in a generic and descriptive sense, and not for purposes of limitation.

Claims

A method of obtaining a power driver in a tubular closed profile, characterized in that it has the following steps: a step of drilling the sheet of conductive material obtained from a coil of conductive material; one profiling step in forming machine where the conductive material forming sheet passes through rollers progressively in a left end ^Q 90 relative to plate a central recess and a right outer recess walls at spaced both with ^Q 90; a roller-fold step of the right outer recess; a roller-folding step of the left and right portions of the central recess; and a left-hand fold over the side wall of the right outer recess, forming the closing flap (3b).

2. "PROCESS FOR OBTAINING ENERGY FROM LEAD IN TUBULAR PROFILE CLOSED" according to claim 1, characterized in that the step of bending the right external recess is carried out so that the right outer recess 90 meet the ^Q central recess.

3. A method according to claim 1, characterized in that the step of bending the left and right portions of the central recess results in the facing of the flap of the right external recess facing the portion of the plate immediately opposite the left end.

4. A method according to claim 1, characterized in that the left-hand folded over the lateral wall of the right external recess results in a closing flap (3b), with three facing walls and in a closed tubular profile.

5. "TUBULAR CLOSED PROFILE BUS", intended for conducting high alternating currents, applied to electrical and similar panels, characterized in that the conductive bus (1) has a closed tubular profile, obtained by profiling, where the busbar (1) has a substantially parallelepipedal shape containing two sides (2a and 2b) joined by an upper wall (3) and a lower wall (4), wherein the lower wall (4) has a recess (4a) in its (1) and the upper wall (3) has a side step (3a) and a closure flap (3b), opposite each other, in such a way that the closing flap contains a central portion, substantially rectangular towards the center of the conductor rail a triple joint of face material.

A "tubular closed profile" according to claim 5, characterized in that the tubular busbar (1) has a series of bores in its lateral walls (2a and 2b) extending parallel to each other and coincident on each of the side walls (2a and 2b)

7. "TUBULAR CLOSED PROFILE BUS" according to claim 5, characterized in that the tubular busbar (1) comprises (3) and lower wall (4) along their length, equidistant from each other and coincident in both the top wall (3) and the bottom wall (4).