A copper busbar module for rotor coils of large air-cooled generators

Abstract

The present invention provides a copper busbar module for rotor coils of large air-cooled generators, comprising: a long copper busbar and epoxy glass cloth sheets bonded to both sides of the copper busbar in the thickness direction. The copper busbar comprises multiple pieces stacked in the thickness direction. Ventilation holes are provided on the copper busbar that penetrate the copper busbar in the thickness direction, so that there are multiple ventilation holes that are evenly spaced along the extension direction of the copper busbar. Multiple through-holes are provided on the epoxy glass cloth sheets so that the ventilation holes on the copper busbar correspond one-to-one with the through-holes on the epoxy glass cloth sheets on both sides of the copper busbar and are interconnected. A cooling air duct can be formed on the copper busbar module that penetrates the copper busbar module in the thickness direction. When the copper busbar module rotates with the rotor coil, the airflow in the cooling air duct can be used to self-cool the copper busbar, thereby improving the thermal and electrical conductivity and ensuring power generation efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of generators, and in particular to a copper busbar module for rotor coils of large air-cooled generators. Background Art

[0002] A generator consists of a stator and a rotor. The stator's primary function is to generate a rotating magnetic field, while the rotor's primary function is to be cut by magnetic lines of force within the rotating field, thereby generating (outputting) current. The rotor consists of a rotor shaft, rotor coils, claw-shaped magnetic poles, and slip rings. The rotor coils are the core component of the rotor. For large, air-cooled generators of 30-50 MW, the rotor coils are made from copper busbar modules. Existing copper busbar modules are mostly stacked long copper bars, which only provide electrical and thermal conductivity and cannot cool themselves during rotation. As power generation increases, the temperature gradually increases, reducing the effectiveness of thermal and electrical conductivity, affecting power generation efficiency. Summary of the Invention

[0003] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a copper busbar module for large air-cooled generator rotor coils with a self-cooling function.

[0004] To achieve the above-mentioned object, the present invention provides a technical solution, which is a copper busbar module for rotor coils of large air-cooled generators, comprising:

[0005] A copper busbar, wherein the copper busbar is in the shape of a long strip and multiple pieces of the copper busbar are stacked along the thickness direction;

[0006] Epoxy glass cloth board, the epoxy glass cloth board is bonded to two side surfaces of the copper busbar in the thickness direction;

[0007] The copper busbar is provided with ventilation holes that penetrate the copper busbar along the thickness direction. There are multiple ventilation holes that are evenly spaced along the extension direction of the copper busbar. The epoxy glass cloth board is provided with multiple through holes. The ventilation holes on the copper busbar correspond one-to-one with the through holes on the epoxy glass cloth boards on both sides of the copper busbar and are interconnected, forming a cooling air duct that penetrates the copper busbar module along the thickness direction.

[0008] Preferably, the ventilation holes located on the same copper busbar are divided into two rows, and the ventilation holes in the two rows are symmetrically distributed along a center line in the width direction of the copper busbar.

[0009] Preferably, the ventilation hole is a waist-shaped hole, and the ventilation hole is provided with a chamfer at the hole edge on the surface of the copper busbar.

[0010] Preferably, the length of the epoxy glass cloth board is greater than the length of the copper busbar, and both ends of the epoxy glass cloth board extend out of the copper busbar by 80-120 mm.

[0011] Further preferably, the epoxy glass cloth board is a single-side rough epoxy glass cloth board, and an insulating adhesive layer for bonding the copper busbar is provided on the rough surface.

[0012] Further preferably, the insulating adhesive layer is composed of a phenolic nitrile adhesive coated on the rough surface of the epoxy glass cloth board.

[0013] Further preferably, the method for manufacturing the copper busbar module comprises the following steps:

[0014] S1. Punch ventilation holes on the copper busbar and chamfer the edges of the holes to remove burrs.

[0015] S2 first punch out the through holes in the epoxy glass cloth plate corresponding to the ventilation hole positions in step S1, and then apply phenolic nitrile adhesive on the rough surface of the epoxy glass cloth plate and treat it to a non-stick B-stage state at room temperature to form an insulating adhesive layer;

[0016] S3. Overlay the epoxy glass cloth sheet obtained in step S2 on both sides of the copper busbar obtained in step S1, along its thickness. When stacking, position the insulating adhesive layer toward the copper busbar and align the ventilation holes with the through-holes. Before stacking, apply nitrile adhesive to the insulating adhesive layer of the epoxy glass cloth sheet at evenly spaced intervals to achieve a preliminary bond and prevent misalignment between the copper busbar and the epoxy glass cloth sheet.

[0017] S4. The copper bars obtained in step S3 and bonded with epoxy glass cloth on both sides are stacked sequentially along the thickness direction. When stacked, the ventilation holes of adjacent copper bars are aligned;

[0018] S5 step S4 stacked copper into the insulating mold baking, baking temperature of 150-160 ℃, baking time of 1.5-2.5h, baking, in the thickness direction of the copper bar pressure of 6-8MPa;

[0019] S6. After the baking and pressing, the copper busbar is naturally cooled. When the temperature of the copper busbar is lower than 100°C, the pressure is released and the busbar is removed. After trimming and removing the excess glue, the copper busbar module is obtained.

[0020] Further preferably, the copper busbar in step S1 is made of silver-containing oxygen-free copper, and its cross-section is a rectangle with rounded corners.

[0021] Further preferably, the ventilation holes in step S1 are divided into two rows, and the two rows of ventilation holes are symmetrically distributed along the center line in the width direction of the copper busbar.

[0022] Further preferably, in step S2, the length of the epoxy glass cloth board is longer than the length of the copper busbar in step S1, and in step S3, both ends of the epoxy glass cloth board extend equidistantly beyond both ends of the copper busbar.

[0023] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0024] The present invention provides a copper busbar module for rotor coils of large air-cooled generators, comprising: a long copper busbar and epoxy glass cloth sheets bonded to both sides of the copper busbar in the thickness direction. The copper busbar comprises multiple pieces stacked in the thickness direction. Ventilation holes are provided on the copper busbar that penetrate the copper busbar in the thickness direction, so that there are multiple ventilation holes that are evenly spaced along the extension direction of the copper busbar. Multiple through-holes are provided on the epoxy glass cloth sheets so that the ventilation holes on the copper busbar correspond one-to-one with the through-holes on the epoxy glass cloth sheets on both sides of the copper busbar and are interconnected. A cooling air duct can be formed on the copper busbar module that penetrates the copper busbar module in the thickness direction. When the copper busbar module rotates with the rotor coil, the airflow in the cooling air duct can be used to self-cool the copper busbar, thereby improving the thermal and electrical conductivity and ensuring power generation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic front view of a preferred embodiment of the present invention.

[0026] Figure 2 yes Figure 1 Enlarged cross-sectional view in the AA direction.

[0027] Figure 3 yes Figure 2 A partial enlarged schematic diagram of point B in the middle.

[0028] Among them: 10. Copper busbar; 11. Ventilation hole; 12. Flat chamfer; 13. Round chamfer; 20. Epoxy glass cloth board; 21. Through hole; 22. Insulation adhesive layer; 30. Cooling air duct. DETAILED DESCRIPTION

[0029] The preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more precise definition of the protection scope of the present invention.

[0030] The thickness direction described in the present invention refers to Figure 2 The up and down directions in .

[0031] like Figures 1 to 3As shown, the copper bar module for the rotor coil of a large air-cooled generator provided by the present invention includes a copper bar 10 and an epoxy glass cloth plate 20. The material of the copper bar 10 is silver-containing oxygen-free copper, wherein the sum of the Cu content and the Ag content is greater than or equal to 99.95%, the Ag content is 0.070%-0.085%, and the oxygen content is less than or equal to 0.0015%; the copper bar 10 is in the shape of a long strip, with a length range of 2000-4500 mm, a thickness range of 4.50-6.00 mm, and a width range of 25-35 mm. In this embodiment, the copper bar 10 has a length of 3000 mm, a thickness of 5 mm, and a width of 30 mm; the cross-sectional shape of the copper bar 10 is a rectangle with rounded chamfers 13 at the four corners, and the radius of the rounded chamfers 13 is 1.2 mm; the state of the copper bar 10 is hard, with a tensile strength of 242-296 MPa, an elongation greater than or equal to 25%, and a hardness of 65-9 5HB, relative electrical conductivity greater than or equal to 98.3% IACS, average grain size at the center of the cross section less than or equal to 0.075 mm, no cracks on the surface when bent 90° laterally on a round rod with a diameter of no more than 76 mm, and no cracks on the surface when bent 90° in the plane on a round rod with a diameter of no more than 10 mm, and a surface roughness of no more than 3.2 μm. Multiple copper busbars 10 are stacked in the thickness direction, and epoxy glass cloth sheets 20 are bonded to both sides of the copper busbar 10 in the thickness direction. Specifically, the copper busbar 10 is provided with ventilation holes 11 extending through the copper busbar 10 in the thickness direction. Multiple ventilation holes 11 are arranged equidistantly along the extension direction of the copper busbar 10. The epoxy glass cloth sheets 20 are provided with multiple through-holes 21. The ventilation holes 11 on the copper busbar 10 correspond one-to-one with the through-holes 21 on the epoxy glass cloth sheets 20 on both sides of the copper busbar 10 and are interconnected, forming a cooling air duct 30 extending through the copper busbar module in the thickness direction.

[0032] The advantage of this arrangement is that when the copper busbar module rotates with the rotor coil, the airflow in the cooling duct can be used to self-cool the copper busbar, thereby improving the thermal and electrical conductivity and ensuring power generation efficiency. At the same time, the material and state of the copper busbar can also ensure that the copper busbar will not deform at high speeds and can operate for a long time.

[0033] In this embodiment, the ventilation hole 11 is a waist-shaped hole. The extension direction of the ventilation hole 11 is parallel to the extension direction of the copper busbar 10. The narrow side size of the ventilation hole 11 is 3.0 mm, and the wide side size is 45 mm. The two ends of the narrow side of the ventilation hole 11 are semicircular arc-shaped, making the ventilation hole 11 waist-shaped. The ventilation hole 11 is provided with a flat chamfer 12 at the hole edge on the surface of the copper busbar 10.

[0034] To enhance the cooling effect, in this embodiment, the ventilation holes 11 located on the same copper busbar 10 are divided into two rows. The two rows of ventilation holes 11 are symmetrically distributed along the center line of the width direction of the copper busbar 10. The spacing between the two rows of ventilation holes 11 is 6.0 mm, and the spacing between adjacent ventilation holes 11 in the same row of ventilation holes 11 is 100 mm. The ventilation holes 11 are processed and formed by mold stamping. After stamping, the burrs at the edges of the ventilation holes 11 on the surface of the copper busbar 10 are removed by manual grinding, and flat chamfers 12 are formed.

[0035] The epoxy glass cloth board 20 has a thickness of 0.4 mm and a length greater than that of the copper busbar 10. Specifically, the epoxy glass cloth board 20 is 200 mm longer than the copper busbar 10, and both ends of the epoxy glass cloth board 20 extend 100 mm beyond the copper busbar. The epoxy glass cloth board 20 is a single-sided roughened epoxy glass cloth board, and an insulating adhesive layer 22 for bonding the copper busbar 10 is provided on the rough surface. The insulating adhesive layer 22 is composed of a phenolic nitrile adhesive coated on the rough surface of the epoxy glass cloth board 20.

[0036] The present invention also provides a method for manufacturing the copper busbar module, which comprises the following steps:

[0037] S1. Stamping out the ventilation holes 11 on the copper bus 10, and chamfering the edges of the ventilation holes 11 to remove burrs;

[0038] S2. First, punch out a through hole 21 on the epoxy glass cloth plate 20 corresponding to the position of the ventilation hole 11 in step S1, and then apply a phenolic nitrile adhesive to the rough surface of the epoxy glass cloth plate 20 and treat it to a non-stick B-stage state at room temperature to form an insulating adhesive layer 22;

[0039] S3. Overlay the epoxy glass cloth sheet 20 obtained in step S2 on both sides of the copper busbar 10 obtained in step S1 in the thickness direction. When stacking, align the insulating adhesive layer 22 with the copper busbar 10 and align the ventilation holes 11 with the through holes 21. Before stacking, apply nitrile adhesive to the insulating adhesive layer 22 of the epoxy glass cloth sheet 20 at evenly spaced intervals to achieve preliminary bonding and prevent misalignment between the copper busbar 10 and the epoxy glass cloth sheet 20.

[0040] S4. The copper bars 10 obtained in step S3 and bonded with epoxy glass cloth sheets 20 are stacked sequentially along the thickness direction. When stacked, the ventilation holes 11 of adjacent copper bars 10 are aligned;

[0041] S5. The copper busbar 10 stacked in step S4 is placed in an insulating mold and baked and pressed at a temperature of 150-160°C for 1.5-2.5 hours. During baking, a pressure of 6-8MPa is applied in the thickness direction of the copper busbar 10.

[0042] S6. After the baking and pressing, the copper busbar 10 is naturally cooled. When the temperature is lower than 100°C, the pressure is released and the copper busbar 10 is removed. The epoxy glass cloth sheet 20 is tightly adhered to the copper busbar 10 through the insulating adhesive layer 22. After trimming and removing the excess adhesive, the copper busbar module is obtained.

[0043] The advantage of this setting is that it can solve problems such as uneven manual glue brushing, unstable inter-turn insulation pasting quality, and easy glue overflow.

[0044] Preferably, the copper busbar 10 in step S1 is made of silver-containing oxygen-free copper, and its cross-section is a rectangle with rounded corners 13 .

[0045] Preferably, the ventilation holes 11 in step S1 are divided into two rows, and the two rows of ventilation holes 11 are symmetrically distributed along the center line of the copper busbar 10 in the width direction.

[0046] Further preferably, in step S2 , the length of the epoxy glass cloth board 20 is longer than the length of the copper busbar 10 in step S1 , and in step S3 , both ends of the epoxy glass cloth board 20 extend equidistantly beyond both ends of the copper busbar 10 .

[0047] The above embodiments are only for illustrating the technical concept and features of the present invention. Their purpose is to enable people familiar with this technology to understand the contents of the present invention and implement them accordingly. They are not intended to limit the scope of protection of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for manufacturing a copper busbar module for rotor coils of large air-cooled generators. The copper busbar module comprises a long copper busbar and epoxy glass cloth sheets bonded to both sides of the copper busbar in the thickness direction. The copper busbar comprises multiple pieces stacked in the thickness direction. The copper busbar is provided with ventilation holes extending through the busbar in the thickness direction. The ventilation holes are arranged in a plurality of equal intervals along the extension direction of the copper busbar. The epoxy glass cloth sheets are provided with multiple through-holes. The ventilation holes on the copper busbar correspond one-to-one with the through-holes on the epoxy glass cloth sheets on both sides of the copper busbar and are interconnected, forming a cooling air duct extending through the copper busbar module in the thickness direction. It is characterized in that The production method comprises the following steps: S1. Punch ventilation holes in the copper busbar and chamfer the edges of the holes to remove burrs. The copper busbar is made of silver-containing oxygen-free copper and has a rectangular cross-section with rounded corners. The ventilation holes are arranged in two rows, symmetrically along the centerline of the width of the busbar. S2 first punch out the through holes in the epoxy glass cloth plate corresponding to the ventilation hole positions in step S1, and then apply phenolic nitrile adhesive on the rough surface of the epoxy glass cloth plate and treat it to a non-stick B-stage state at room temperature to form an insulating adhesive layer; S3. Overlay the epoxy glass cloth sheet obtained in step S2 on both sides of the copper busbar obtained in step S1, along its thickness. When stacking, position the insulating adhesive layer toward the copper busbar and align the ventilation holes with the through-holes. Before stacking, apply nitrile adhesive to the insulating adhesive layer of the epoxy glass cloth sheet at evenly spaced intervals to achieve a preliminary bond and prevent misalignment between the copper busbar and the epoxy glass cloth sheet. S4. The copper bars obtained in step S3 and bonded with epoxy glass cloth on both sides are stacked sequentially along the thickness direction. When stacked, the ventilation holes of adjacent copper bars are aligned; S5 step S4 stacked copper into the insulating mold baking, baking temperature of 150-160 ℃, baking time of 1.5-2.5h, baking, in the thickness direction of the copper bar pressure of 6-8MPa; S6. After the baking and pressing, the copper busbar is naturally cooled. When the temperature of the copper busbar is lower than 100°C, the pressure is released and the busbar is removed. After trimming and removing the excess glue, the copper busbar module is obtained.

2. The production method according to claim 1, characterized in that: The ventilation hole is a waist-shaped hole, and a chamfer is provided at the hole edge of the surface of the copper busbar.

3. The production method according to claim 1, characterized in that: The epoxy glass cloth board is a single-side rough epoxy glass cloth board.

4. The production method according to claim 1, wherein: In step S2, the length of the epoxy glass cloth board is longer than the length of the copper busbar in step S1. In step S3, both ends of the epoxy glass cloth board extend out of both ends of the copper busbar at equal distances.

5. The production method according to claim 3, characterized in that: Both ends of the epoxy glass cloth plate extend out of the copper busbar by 80-120 mm.

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