High-voltage and high-current laminated busbar and preparation method therefor

Abstract

The present invention belongs to the technical field of electrical equipment. Provided are a high-voltage and high-current laminated busbar and a preparation method therefor. The preparation method comprises the following steps: using glass fabric tape to wind both a positive busbar and a negative busbar to form an insulated positive busbar and an insulated negative busbar, using the glass fabric tape to jointly wind the insulated positive busbar, a metal isolation plate and the insulated negative busbar to form a laminated busbar sample, and heating and curing the laminated busbar sample to obtain a high-voltage and high-current laminated busbar. The laminated busbar prepared in the present invention has low self-impedance and requires minimal installation space, and is applicable to high-power electrical equipment with a current exceeding 30 kA and a total voltage exceeding 20 kV.

Description

A high-voltage and high-current laminated busbar and its preparation method Technical Field

[0001] The present invention relates to the technical field of power equipment, and in particular to a high-voltage and high-current laminated busbar and a preparation method thereof. Background Art

[0002] A busbar is a product made of highly conductive copper or aluminum materials used to transmit, aggregate, and distribute electrical energy. It serves as the main conductor for power transmission within a power plant or substation, delivering power from generators, transformers, or rectifiers to individual users or other substations. Currently, the high-current, high-power busbars used in my country's nuclear power plants primarily utilize split busbars. However, due to their large footprint and high stray impedance, they cannot meet growing demand.

[0003] Traditionally used laminated busbars have voltages of less than a few thousand volts and currents of less than a few thousand amperes, and are primarily used in low-voltage, low-current applications such as frequency converters, serving as specialized internal components. High-current, high-voltage busbars, on the other hand, require enclosed or insulated bushings. However, these types of busbars have high inherent impedance, require extensive installation space, and carry relatively low current (a few thousand amperes), making them unable to meet growing demand.

[0004] Currently, the maximum DC transmission and distribution current of a single power supply system must meet 30kA and 10kV, respectively. Therefore, how to provide a new high-voltage, high-current laminated busbar has become an urgent problem for those skilled in the art.

[0005] Summary of the Invention

[0006] In view of this, the present invention provides a high-voltage and high-current laminated busbar and a preparation method thereof, the purpose of which is to solve the technical problem that traditional laminated busbars cannot be directly applied to high-power electrical equipment.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] The present invention provides a high-voltage and high-current laminated busbar, comprising an insulated positive busbar, a metal isolation plate and an insulated negative busbar;

[0009] The metal isolation plate is located between the insulated positive busbar and the insulated negative busbar. The insulated positive busbar includes an insulating layer and a positive busbar, and the insulated negative busbar includes an insulating layer and a negative busbar. The thickness of the insulating layer is independently 1 to 10 mm.

[0010] Furthermore, the cross-sectional area of ​​the positive busbar and the negative busbar is independently 10000-15000 mm 2 .

[0011] Furthermore, the center of the positive busbar and the negative busbar both contain water holes, and the area of ​​the water holes is independently 300-400mm. 2 .

[0012] Furthermore, the positive busbar, the negative busbar and the metal isolation plate are independently made of any one of aluminum, copper, aluminum alloy and copper alloy.

[0013] Furthermore, the insulating layer is a glass cloth tape.

[0014] The present invention provides a method for preparing the above-mentioned high-voltage and high-current laminated busbar, comprising the following steps:

[0015] The positive busbar and the negative busbar are respectively wrapped with glass cloth tape to form an insulated positive busbar and an insulated negative busbar, the insulated positive busbar, the metal isolation plate and the insulated negative busbar are wrapped with glass cloth tape to form a laminated busbar sample, and the laminated busbar sample is heated and cured to obtain a high-voltage and high-current laminated busbar;

[0016] The thickness of the winding is 1 to 10 mm;

[0017] The temperature of the heat curing treatment is 160-180° C., and the time of the heat curing treatment is 20-30 hours.

[0018] Furthermore, epoxy adhesive is firstly coated on the positive busbar and the negative busbar, and then glass cloth tapes are wrapped around them; the glass cloth tapes used are all soaked in the epoxy adhesive.

[0019] Furthermore, the epoxy adhesive includes epoxy resin and / or curing agent anhydride.

[0020] Furthermore, after the heating and curing treatment is completed, the laminated busbar sample is subjected to a cooling treatment and a surface passivation treatment in sequence.

[0021] Furthermore, the cooling rate of the cooling treatment is ≤2°C / min.

[0022] It can be seen from the above technical solution that compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] 1. The preparation method of the present invention can be cured and formed in one step, reducing the risk of interface handling and bonding defects in multiple curing processes;

[0024] 2. The high-voltage and high-current laminated busbar prepared by the present invention has a large conductor current carrying capacity;

[0025] 3. The high-voltage and high-current laminated busbar prepared by the present invention can save installation space. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] FIG1 is a cross-section of a high-voltage, high-current laminated busbar prepared according to the present invention;

[0027] FIG2 is an elbow of a high-voltage, high-current laminated busbar prepared by the present invention;

[0028] FIG3 shows the terminal end of the high-voltage and high-current laminated busbar prepared by the present invention. DETAILED DESCRIPTION

[0029] The present invention provides a high-voltage and high-current laminated busbar, comprising an insulated positive busbar, a metal isolation plate and an insulated negative busbar;

[0030] The metal isolation plate is located between the insulated positive busbar and the insulated negative busbar. The insulated positive busbar includes an insulating layer and a positive busbar, and the insulated negative busbar includes an insulating layer and a negative busbar. The thickness of the insulating layer is independently 1 to 10 mm, preferably 2 to 8 mm, and further preferably 4 to 6 mm.

[0031] In the present invention, as shown in the cross-section of the high-voltage and high-current laminated busbar in FIG1 , the high-voltage and high-current laminated busbar is symmetrical with the metal isolation plate in order to make the electric field between the positive busbar and the negative busbar uniform; the metal isolation plate can realize electrical isolation between the positive busbar and the negative busbar.

[0032] In the present invention, the cross-sectional area of ​​the positive busbar and the negative busbar is independently 10000-15000 mm 2 , preferably 11000~14000mm 2 , more preferably 12000~13000mm 2 .

[0033] In the present invention, the center of the positive busbar and the negative busbar both contain water holes, and the area of ​​the water holes is independently 300-400mm. 2 , preferably 320~380mm 2 , more preferably 340 to 360 mm 2 The shape of the water hole is preferably a circular hole, and the diameter of the circular hole is preferably 15 to 25 mm, and more preferably 18 to 22 mm.

[0034] In the present invention, the positive busbar and the negative busbar are prepared by a hot core bending process, which is recorded in the "Fundamentals of Mold Design, 2nd Edition" by Chen Jianhe and Wu Yunfei. The hot core bending process can enable the positive busbar and the negative busbar to be bent in the width and length directions (bending radius ≥2.5D, preferably ≥3.5D, and further preferably ≥4.0D), as shown in Figure 2, which facilitates the subsequent rapid connection between the positive busbar and the negative busbar and between the positive busbar, the negative busbar and the equipment, while ensuring that the bending process prevents the waterway from being easily damaged or cracked.

[0035] In the present invention, the material of the positive busbar, the negative busbar and the metal isolation plate is independently any one of aluminum, copper, aluminum alloy and copper alloy, preferably copper or aluminum, more preferably aluminum.

[0036] In the present invention, the insulating layer is a glass cloth tape.

[0037] The present invention provides a method for preparing the above-mentioned high-voltage and high-current laminated busbar, comprising the following steps:

[0038] The positive busbar and the negative busbar are respectively wrapped with glass cloth tape to form an insulated positive busbar and an insulated negative busbar, the insulated positive busbar, the metal isolation plate and the insulated negative busbar are wrapped with glass cloth tape to form a laminated busbar sample, and the laminated busbar sample is heated and cured to obtain a high-voltage and high-current laminated busbar;

[0039] The thickness of the wrapped layer is 1 to 10 mm, preferably 2 to 8 mm, and more preferably 4 to 6 mm;

[0040] The temperature of the heat curing treatment is 160-180° C., preferably 165-175° C., and more preferably 170° C.; the time of the heat curing treatment is 20-30 hours, preferably 22-28 hours, and more preferably 24-26 hours.

[0041] In the present invention, epoxy adhesive is first coated on the positive busbar and the negative busbar, and then glass cloth tape is wrapped around them; the glass cloth tapes used are all soaked with epoxy adhesive. The reason is that after wrapping, the positive and negative busbars have rounded corners, which will produce grooves at the splicing points, and the epoxy adhesive can fill the grooves and make them smooth.

[0042] In the present invention, the glass cloth tape is wrapped around the positive and negative busbars at a 45° angle and pressed halfway. When the tape is wrapped around the ends of each layer, as shown in FIG3 , a small end phenomenon will occur. To compensate for this, a glass cloth tape with half the width is pre-wound around the ends to ensure a smooth surface after each layer is wrapped. The ends are also nickel-plated using the method described in the "Electroplating Nickel Process Specification" to reduce the contact resistance of the positive (negative) busbar and prevent surface oxidation of the positive (negative) busbar.

[0043] In the present invention, the epoxy adhesive comprises epoxy resin and / or curing agent anhydride, and the curing agent anhydride is preferably one or more of phthalic anhydride, tetrahydrophthalic anhydride and hexahydrophthalic anhydride, and more preferably phthalic anhydride.

[0044] In the present invention, before the heat curing treatment, the laminated busbar sample is pressurized and compacted using a mold.

[0045] In the present invention, after the heating and curing treatment is completed, the laminated busbar sample is subjected to a cooling treatment and a surface passivation treatment in sequence.

[0046] In the present invention, the cooling rate of the cooling treatment is ≤2°C / min, preferably ≤1.8°C / min, and more preferably ≤1.5°C / min;

[0047] The specific steps of the surface passivation treatment are: the first step is surface polishing; the second step is surface cleaning; the third step is protective treatment of both ends of the conductor; and the fourth step is protective treatment of the insulation surface. The purpose of the surface passivation treatment is to ensure that the surface of the high-voltage and high-current laminated busbar is smooth and beautiful.

[0048] The technical solutions provided by the present invention are described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0049] Example 1

[0050] The positive and negative (aluminum) busbars with a cross-section of 200×60mm are prepared using the hot core bending process. A circular water hole with a diameter of 20mm is opened in the center of the cross-section of the positive and negative busbars. The burrs on the surface of the positive and negative busbars are removed and their surfaces are cleaned. A layer of epoxy adhesive (phthalic anhydride) is rolled on the positive and negative busbars. Then, a glass cloth tape soaked in epoxy adhesive (phthalic anhydride) is used to wrap the positive and negative busbars to form insulated positive and negative busbars. Since the positive and negative busbars have rounded corners, grooves will be generated at the splicing. The epoxy adhesive (phthalic anhydride) can fill the grooves and make them smooth. The insulation layer of the insulated positive and negative busbars is 5mm. Then, a glass cloth tape soaked in epoxy adhesive (phthalic anhydride) is used to insulate the positive busbar, aluminum partition and insulation. The negative busbar is wound together to form a laminated busbar sample. When the thickness of the winding reaches 5mm, the laminated busbar sample is placed in a mold, and the pressure template is pressed on all sides. The clip is clamped on the pressure plate and slowly rotated to gradually pressurize and compact. Then the compacted laminated busbar sample is placed in a curing furnace, and the laminated busbar sample is slowly rotated for heating and curing. After curing at 180℃ for 22h, it is cooled to room temperature. The surface of the laminated busbar sample is then passivated to ensure the smoothness and beauty of the product surface. Finally, the end of the high-voltage and high-current laminated busbar is nickel-plated to obtain a high-voltage and high-current laminated busbar.

[0051] Example 2

[0052] The positive and negative (aluminum) busbars with a cross-section of 200×50mm are prepared using the hot core bending process. A circular water hole with a diameter of 15mm is opened in the center of the cross-section of the positive and negative busbars. The burrs on the surface of the positive and negative busbars are removed and their surfaces are cleaned. A layer of epoxy resin adhesive is then rolled on the positive and negative busbars. Then, glass cloth tape soaked in epoxy resin adhesive is used to wrap the positive and negative busbars to form insulated positive and negative busbars. Since the positive and negative busbars have rounded corners, grooves will be generated at the joints. Epoxy resin adhesive can fill the grooves to make them smooth. The insulation layer of the insulated positive and negative busbars is 3mm. Then, glass cloth tape soaked in epoxy resin adhesive is used to wrap the insulated positive busbar, aluminum partition and insulated negative busbar together to form a stack. For busbar samples, when the thickness of the winding reaches 8mm, the laminated busbar sample is placed in the mold, the pressure template is pressed on all sides, the clip is clamped on the pressure plate and slowly rotated to gradually pressurize and compact. Then the compacted laminated busbar sample is placed in a curing furnace, and the laminated busbar sample is slowly rotated for heating and curing. After curing at 170°C for 25 hours, it is cooled to room temperature. The surface of the laminated busbar sample is then passivated to ensure the smoothness and beauty of the product surface. Finally, the end of the high-voltage and high-current laminated busbar is nickel-plated to obtain a high-voltage and high-current laminated busbar.

[0053] Example 3

[0054] The positive and negative (aluminum) busbars with a cross-section of 200×70mm are prepared using the hot core bending process. A square water hole with a side length of 18mm is opened in the center of the cross-section of the positive and negative busbars. The burrs on the surface of the positive and negative busbars are removed and their surfaces are cleaned. A layer of epoxy resin adhesive is rolled on the positive and negative busbars. Then, glass cloth tape soaked in epoxy resin adhesive is used to wrap the positive and negative busbars to form insulated positive and negative busbars. Since the positive and negative busbars have rounded corners, grooves will be generated at the joints. Epoxy resin adhesive can fill the grooves to make them smooth. The insulation layer of the insulated positive and negative busbars is 8mm. Then, glass cloth tape soaked in epoxy resin adhesive is used to wrap the insulated positive busbar, aluminum partition and insulated negative busbar together to form a stack. For busbar samples, when the thickness of the winding reaches 6mm, the laminated busbar sample is placed in the mold, the pressure template is pressed on all sides, the clip is clamped on the pressure plate and slowly rotated to gradually pressurize and compact. Then the compacted laminated busbar sample is placed in a curing furnace, and the laminated busbar sample is slowly rotated for heating and curing. After curing at 160°C for 28 hours, it is cooled to room temperature. The surface of the laminated busbar sample is then passivated to ensure the smoothness and beauty of the product surface. Finally, the end of the high-voltage and high-current laminated busbar is nickel-plated to obtain a high-voltage and high-current laminated busbar.

[0055] Various properties of the high-voltage and high-current laminated busbars prepared in Examples 1 to 3 were tested. The test items and test results are shown in Table 1.

[0056] Table 1 Performance test results

[0057] As can be seen from Table 1, the high-voltage and high-current laminated busbar prepared by the present invention has good physical properties, and the steady-state current exceeds 30 kV, and can be directly applied to high-power electrical equipment.

[0058] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A high voltage and high current laminated busbar, characterized in that: Includes insulated positive busbar, metal isolation plate and insulated negative busbar; The metal isolation plate is located between the insulated positive busbar and the insulated negative busbar. The insulated positive busbar includes an insulating layer and a positive busbar, and the insulated negative busbar includes an insulating layer and a negative busbar. The thickness of the insulating layer is independently 1 to 10 mm.

2. The high-voltage and high-current laminated busbar according to claim 1, characterized in that: The cross-sectional area of the positive busbar and the negative busbar is independently 10000~15000mm 2 .

3. The high-voltage and high-current laminated busbar according to claim 2, characterized in that: The center of the positive busbar and the negative busbar both contain water holes, and the area of the water holes is independently 300-400mm. 2 .

4. The high-voltage and high-current laminated busbar according to claim 2 or 3, characterized in that: The positive busbar, the negative busbar and the metal isolation plate are independently made of any one of aluminum, copper, aluminum alloy and copper alloy.

5. The high-voltage and high-current laminated busbar according to claim 4, characterized in that: The insulating layer is a glass cloth tape.

6. The method for preparing the high-voltage and high-current laminated busbar according to any one of claims 1 to 5, characterized in that: The following steps are involved: Use glass cloth tape to wrap the positive busbar and negative busbar to form an insulated positive busbar and an insulated negative busbar respectively, and use glass cloth tape to wrap the insulated positive busbar, metal isolation plate and insulated negative busbar to form a laminated busbar sample. The high-voltage and high-current laminated busbar is obtained by heating and curing the laminated busbar sample; The thickness of the winding is 1 to 10 mm; The temperature of the heat curing treatment is 160-180° C., and the time of the heat curing treatment is 20-30 hours.

7. The preparation method according to claim 6, characterized in that Epoxy adhesive is first applied to the positive busbar and the negative busbar, and then glass cloth tapes are wrapped around them; the glass cloth tapes used are all soaked in the epoxy adhesive.

8. The preparation method according to claim 7, characterized in that The epoxy adhesive includes epoxy resin and / or curing agent anhydride.

9. The preparation method according to claim 7 or 8, characterized in that After the heating and curing treatment is completed, the laminated busbar sample is subjected to a cooling treatment and a surface passivation treatment in sequence.

10. The preparation method according to claim 9, characterized in that The cooling rate of the cooling treatment is ≤2°C / min.

Images