A low-sensitivity explosion-proof flexible DC distribution network bus assembly

Abstract

The present invention relates to a low-sensitivity explosion-proof flexible DC distribution network bus assembly, which includes bus layer I, bus layer II, and bus layer III arranged in a stacked manner. Each bus layer includes a plate and insulating films provided on the upper and lower surfaces of the plate. The cross-sections of bus layer II and bus layer III are Z-shaped. The lower cross plates of bus layer III extend respectively towards its left and right ends. Bus layer I is arranged on the lower cross plate of bus layer II and is vertically corresponding to the lower cross plate of bus layer III. An installation gap is formed between the upward bending on the left side of bus layer I and the left side of the lower cross plate of bus layer III. Copper columns and connecting plates with press riveting nuts are respectively provided on bus layer I, bus layer II, and bus layer III. Installation holes are respectively provided on bus layer II and bus layer III. The structure of the present invention is compact, occupies a small space, has a high integration degree, is convenient for reducing the design space, and is convenient for installation and maintenance.

Description

Technical Field

[0001] The present invention belongs to the technical field of flexible DC distribution network busbars, and particularly relates to a low-inductance explosion-proof flexible DC distribution network busbar assembly. Background Art

[0002] Flexible DC is a new type of power transmission technology developed based on MMC technology. Flexible DC power transmission is an important equipment for constructing smart grids. Compared with traditional methods, flexible DC power transmission has strong technical advantages in aspects such as island power supply and capacity expansion and transformation of urban distribution networks, and is a strategic choice to change the development pattern of large power grids. And distribution network flexible DC is a kind of flexible DC, known as small flexible DC, which has the advantages of small floor area, convenient installation and commissioning, and can be plugged and used on site, and has begun to be widely used in distribution networks.

[0003] The power module is the core part of the distribution network converter and plays a key role in the normal operation of the entire distribution network. There are various important components distributed in the power module, such as capacitors, IGBTs, vacuum switches, thyristors, absorption capacitors, etc. The devices are connected by conductors to form a loop. The traditional method is to independently connect these devices with copper bars to form a loop to meet the normal operation of the module. This connection method will generate a large inductance, large partial discharge, high heat generation, and the overall connection wiring is chaotic. When encountering a design with limited space, the connection between conductors cannot be designed, the installation and maintenance are cumbersome, and it is easy to give a large impact to the power device IGBT, resulting in damage to the power device. When the IGBT explodes, the large impact will also cause other devices to be damaged, and the explosion products will also spread inside and outside the module and affect the surrounding modules. Summary of the Invention

[0004] The purpose of the present invention is to provide a low-inductance explosion-proof flexible DC distribution network busbar assembly to solve the problems of chaotic wiring and cumbersome installation and maintenance between the devices of the power module in the distribution network converter.

[0005] The low-inductance explosion-proof flexible DC distribution network busbar assembly of the present invention is realized as follows:

[0006] A low-inductance explosion-proof flexible DC distribution network busbar assembly includes a stacked busbar layer I, busbar layer II, and busbar layer III. Each busbar layer includes a plate and insulating films provided on the upper and lower surfaces of the plate. The cross-sections of the busbar layer II and busbar layer III are Z-shaped. The lower cross plate of the busbar layer III extends towards its left and right ends respectively. The busbar layer I is arranged on the lower cross plate of the busbar layer II and corresponds up and down to the lower cross plate of the busbar layer III. An installation gap is formed between the upward bending of the left side of the busbar layer I and the left side of the lower cross plate of the busbar layer III. Copper columns and connecting plates with rivet nuts are respectively arranged on the busbar layer I, busbar layer II, and busbar layer III. Installation holes are respectively arranged on the busbar layer II and busbar layer III.

[0007] Furthermore, insulating films are not provided on the surface layers of partial electrodes of the busbar layer I and the busbar layer III that form the installation gap.

[0008] Furthermore, the copper columns include a pair of IGBT connection copper columns I installed on the busbar layer I, an IGBT connection copper column II installed on the lower cross plate of the busbar layer II, and an IGBT connection copper column III installed on the lower cross plate of the busbar layer III, and the IGBT connection copper column I, the IGBT connection copper column II, and the IGBT connection copper column III are arranged side by side.

[0009] Furthermore, the connecting plate includes an incoming and outgoing line connecting plate provided at the right end of the lower cross plates of the busbar layer I and the busbar layer III.

[0010] Furthermore, the connecting plate includes a device connecting plate provided on the upper cross plates of the busbar layer II and the busbar layer III and facing the side of the lower cross plate.

[0011] Furthermore, the connecting plate includes a vacuum switch connecting plate provided on the right side of the busbar layer I and facing the direction of the upper cross plate of the busbar layer I, and the installation holes include a pair of vacuum switch installation holes provided on the upper cross plate of the busbar layer III.

[0012] Furthermore, the installation holes include a capacitor installation hole I provided on the upper cross plate of the busbar layer II and a capacitor installation hole II provided on the upper cross plate of the busbar layer III, and the capacitor installation hole I and the capacitor installation hole II are provided in pairs;

[0013] The capacitor installation hole I is a stamping convex hull facing the direction of the busbar layer III.

[0014] Furthermore, an insulating plate is provided between the right side of the busbar layer I and the right side of the lower cross plate of the busbar layer III.

[0015] Furthermore, through holes are provided at the corresponding positions of each copper column and the installation holes on the other two busbar layers, and insulating gaskets are coated on the through holes.

[0016] The electrode plate is a copper plate with a thickness of 0.5 - 4 mm.

[0017] After adopting the above technical solutions, the beneficial effects of the present invention are as follows:

[0018] (1) The structure of the present invention is compact, occupies a small space, has a high integration degree, and is convenient for reducing the design space;

[0019] (2) The present invention can replace the copper busbars to connect each device, reduce the chaos of the wiring between devices, is convenient for installation and maintenance, and provides an efficient power distribution system;

[0020] (3) The present invention can completely cover the IGBT and thyristor during the installation process, prevent the impact caused by explosion, play a role in explosion-proof and vibration absorption, and avoid affecting other devices inside and outside the module. Description of the Drawings

[0021] The present invention will be further described below in conjunction with the drawings and embodiments.

[0022] Figure 1 is the structural diagram of the low-inductance explosion-proof flexible DC distribution network bus assembly according to the preferred embodiment of the present invention;

[0023] Figure 2 is the exploded view of the low-inductance explosion-proof flexible DC distribution network bus assembly according to the preferred embodiment of the present invention;

[0024] Figure 3 is the exploded view of the low-inductance explosion-proof flexible DC distribution network bus assembly without the installation of the insulating film according to the preferred embodiment of the present invention;

[0025] Figure 4 is the top view of the low-inductance explosion-proof flexible DC distribution network bus assembly according to the preferred embodiment of the present invention;

[0026] Figure 5 is Figure 4 the sectional view taken along the A-A direction in

[0027] Figure 6 is Figure 5 the enlarged view of part B in

[0028] Figure 7 is the device installation diagram of the low-inductance explosion-proof flexible DC distribution network bus assembly according to the preferred embodiment of the present invention;

[0029] In the figure: bus layer Ⅰ 1, bus layer Ⅱ 2, bus layer Ⅲ 3, electrode plate 4, insulating film 5, lower cross plate 6, installation gap 7, press riveting nut 8, double-sided adhesive or adhesive 9, thyristor 10, opening 11, IGBT 12, IGBT connection copper column Ⅰ 13, IGBT connection copper column Ⅱ 14, IGBT connection copper column Ⅲ 15, incoming and outgoing line connection plate 16, upper cross plate 17, device connection plate 18, vacuum switch 19, vacuum switch connection plate 20, vacuum switch installation hole 21, capacitor 22, capacitor installation hole Ⅰ 23, capacitor installation hole Ⅱ 24, insulating plate 25, insulating gasket 26. Detailed Embodiments

[0030] To make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments.

[0031] Accordingly, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0032] As Figure 1-7 shown, a low-inductance explosion-proof flexible DC distribution network bus assembly includes a stacked bus layer I 1, a bus layer II 2, and a bus layer III 3. Each bus layer includes a plate 4 and insulating films 5 disposed on the upper and lower surfaces of the plate 4. The cross-section of the bus layer II 2 and the bus layer III 3 is Z-shaped. The lower cross plates of the bus layer III 3 extend towards its left and right ends respectively. The bus layer I 1 is disposed on the lower cross plate 6 of the bus layer II 2 and corresponds to the lower cross plate 6 of the bus layer III 3 up and down. An installation gap 7 is formed between the left side of the bus layer I 1 that bends upwards and the left side of the lower cross plate 6 of the bus layer III 3. Copper columns and connecting plates with rivet nuts 8 are respectively disposed on the bus layer I 1, the bus layer II 2, and the bus layer III 3. Installation holes are respectively disposed on the bus layer II 2 and the bus layer III 3.

[0033] The plate 4 and the insulating film 5 of each bus layer are formed by hot pressing, and adjacent bus layers are bonded together by double-sided tape or an adhesive 9.

[0034] The insulating film 5 uses a PET insulating film. The insulating film 5 seals the plate 4. The edge-sealing width of the plate 4 with a thickness of 1 - 15 mm is greater than 6 mm. The edge-sealing width of the plate 4 with a thickness of 2 - 3 mm is greater than 9 mm. The edge-sealing width of other plates 4 is greater than 10 mm. The edge-sealing width is the distance from the edge of the plate 4 to the edge of the insulating film 5.

[0035] The installation gap 7 is provided for installing a thyristor 10. In order to facilitate the connection of the thyristor 10 to the bus assembly, the surface layers of the partial plates 4 of the bus layer I 1 and the bus layer III 3 that form the installation gap 7 are not provided with insulating films 5.

[0036] Specifically, there are openings 11 on the plates 4 on the upper and lower sides of the installation gap 7. The thyristor 10 is disposed in the installation gap 7 by means of press fitting to fix the thyristor 10. This installation method of the thyristor 10 can completely cover it, thereby increasing the safety performance of the entire power module.

[0037] In the entire power module, two IGBT12s are provided and are connected in reverse series. They are placed below the lower cross plate 6 of the busbar layer III 3. In order to connect them to the busbar assembly, the copper posts include a pair of IGBT connection copper posts I 13 installed on the busbar layer I 1, an IGBT connection copper post II 14 installed on the lower cross plate 6 of the busbar layer II 2, and an IGBT connection copper post III 15 installed on the lower cross plate 6 of the busbar layer III 3. The IGBT connection copper posts I 13, the IGBT connection copper post II 14, and the IGBT connection copper post III 15 are arranged in parallel.

[0038] Specifically, the two IGBT connection copper posts I 13 are used to connect the emitter of the first IGBT12 and the collector of the other IGBT12. The IGBT connection copper post II 14 is used to connect the collector of the first IGBT12, and the IGBT connection copper post III 15 is used to connect the emitter of the other IGBT12.

[0039] Preferably, the copper posts can be installed on the electrode plates 4 of their respective busbar layers by means of pop riveting, press riveting or welding.

[0040] When the copper posts are connected by pop riveting, their material can be selected as red copper TMY2. When the copper posts are connected by press riveting or welding, their material can be selected as brass H59.

[0041] Preferably, the surface of the copper posts is provided with a tin plating layer with a thickness of 5 - 10 μm, which can prevent the oxidation of the copper posts and play a protective role for the copper posts.

[0042] To facilitate the incoming and outgoing lines of the busbar assembly, the connecting plate includes an incoming and outgoing line connecting plate 16 provided at the right end of the lower cross plate 6 of the busbar layer I 1 and the busbar layer III 3.

[0043] Specifically, the incoming and outgoing line connecting plate 16 located at the end of the busbar layer I 1 is vertically arranged, and the incoming and outgoing line connecting plate 16 located at the end of the busbar layer III 3 is vertically arranged downward. One of them connects the outgoing line copper bar, and the other connects the incoming line copper bar.

[0044] To facilitate connection with other devices in the grid-connected converter, the connecting plate includes a device connecting plate 18 provided on the upper cross plate 17 of the busbar layer II 2 and the busbar layer III 3 and facing the side of the lower cross plate 6.

[0045] Specifically, device connecting plates 18 are provided on both the left and right sides of the busbar layer II 2 and the busbar layer III 3. The device connecting plate 18 on the left side of the busbar layer II 2 is used to connect the square resistor, the SMC board, and the power supply board. The device connecting plate 18 on the left side of the busbar layer III 3 is used to connect the power supply board and the square resistor, and the device connecting plate 18 on the left side is used to connect the ground wire of the power supply card board.

[0046] To facilitate the connection of the vacuum switch 19 in the power module, the connecting plate includes a vacuum switch connecting plate 20 disposed on the right side of the busbar layer I 1 and facing the upper cross plate 17 of the busbar layer I 1. The mounting holes include a pair of vacuum switch mounting holes 21 disposed on the upper cross plate 17 of the busbar layer III 3.

[0047] Specifically, the vacuum switch 19 is mounted below the upper cross plate 17 of the busbar layer III 3. Its top connection end is connected to the vacuum switch connection hole 21, while the side connection end is connected to the rivet nut 8 on the vacuum switch connecting plate 20.

[0048] Preferably, the connecting plates are all exposed and no insulating film is provided on their surfaces to facilitate the connection of the connection ends of each device.

[0049] To facilitate the connection of the capacitor 22, the mounting holes include a capacitor mounting hole I 23 disposed on the upper cross plate 17 of the busbar layer II 2 and a capacitor mounting hole II 24 disposed on the upper cross plate 17 of the busbar layer III 3, and the capacitor mounting hole I 23 and the capacitor mounting hole II 24 are arranged in pairs;

[0050] Specifically, the capacitors 22 are arranged side by side below the upper cross plate 17 of the busbar layer III 3. One of the connection ends is connected to the capacitor mounting hole I 23, and the other connection end is connected to the capacitor mounting hole II 24.

[0051] Since there is a height difference between the upper and lower busbar layers connecting the two poles of the capacitor 22, the capacitor mounting hole I 23 is a stamping convex hull facing the busbar layer III direction.

[0052] The problem of the height difference between the two busbar layers can be solved by the setting of the stamping convex hull.

[0053] Alternatively, copper posts can be used to replace the stamping convex hull, which can also solve the problem of height difference.

[0054] Since the lower cross plate 9 of the busbar layer II 5 does not extend between the right side of the busbar layer I 4 and the right side of the lower cross plate 6 of the busbar layer III 3, in order to compensate for the drop between the two, an insulating plate 25 is provided between the right side of the busbar layer I 1 and the right side of the lower cross plate 6 of the busbar layer III 3.

[0055] Specifically, the insulating plate 25 is bonded to the insulating films 5 above and below it with double-sided tape or adhesive 9.

[0056] Preferably, the insulating plate 25 is made of EPGC202 and GP03 materials to increase the reliability of insulation.

[0057] The copper posts and the mounting holes are both connected to the electrode plate 4 of the busbar layer to which they are connected. To facilitate the connection between the connection ends of each device and the busbar assembly, each copper post and mounting hole penetrates through each layer of the busbar layer at that location. To prevent the connection ends of the devices, the copper posts, or the mounting holes from conducting with the electrode plates of other busbar layers, it is necessary to insulate the positions where no devices are connected. Specifically, in this embodiment, through holes are provided at the corresponding positions of each copper post and mounting hole in the other two busbar layers, and insulating gaskets 26 are coated on the through holes.

[0058] Specifically, a through hole is provided on the lower cross plate 6 of the busbar layer III 3 corresponding to the IGBT connection copper post I 13. An insulating gasket 26 is provided in the through hole. Both the upper and lower surfaces of the insulating gasket 26 are covered by an insulating film 5. The insulating film 5 thermally presses the insulating gasket 26 into the through hole of the electrode plate 4 by hot pressing.

[0059] Similarly, through holes are also provided on the lower cross plate 6 of the busbar layer I 1 and the busbar layer III 3 corresponding to the IGBT connection copper post II 14. The insulating gasket 26 of this through hole is also arranged in the above-mentioned manner.

[0060] In addition, a through hole is provided on the upper cross plate 17 of the busbar layer III 3 corresponding to the capacitor mounting hole I 23, and an insulating gasket 26 is also provided. The capacitor mounting hole II 24 and the vacuum switch mounting hole 21 are both arranged in the same way.

[0061] Preferably, the insulating gasket 26 is made of EPGC202 and GP03 materials, which can increase its insulation reliability. And the thickness D of the insulating gasket 26 = the thickness d of the electrode plate - 0.01 mm. The outer diameter of the insulating gasket 26 is closely matched with the aperture of the through hole, and the gap is 0.1 mm, so as to prevent the insulating gasket from loosening.

[0062] To increase the heat dissipation effect and reduce the inductance, the electrode plate 4 is a copper plate with a thickness of 0.5 - 4 mm.

[0063] Specifically, the electrode plate 4 is machined from TMY2 copper material. It has a large width and a thin thickness, which is beneficial to heat dissipation.

[0064] Preferably, a tin plating layer with a thickness of 5 - 10 μm is provided on the surface of the electrode plate 4, which can prevent the oxidation of the electrode plate and play a protective role for the electrode plate.

[0065] When processing the busbar assembly, first, each layer of the busbar will be processed to determine the positions of the mounting holes, copper posts, and through holes on each busbar layer. The insulating gasket 26 is fixed in the through hole by hot pressing the insulating film 5. Specifically, the hot pressing temperature is 135 - 160 °C, the pressure is 7 - 14 bar, and the hot pressing time is 15 - 45 min. Then, copper post press riveting, flaring riveting, or welding is carried out, and press riveting nuts 8 are set on the connecting plate. Finally, each layer of the busbar is adhesively laminated.

[0066] The busbar assembly provided by the present invention can integrate devices such as thyristors 10, IGBTs 12, vacuum switches 19, and capacitors 22, reducing the chaos of connecting adjacent devices through copper bars. It has a high degree of integration, facilitating later maintenance and repair. Moreover, when installed, the thyristors 10 and IGBTs 12 are fully covered, with good explosion-proof and shock absorption performance, and strong safety and environmental adaptability.

[0067] Inspired by the ideal embodiments of the present invention described above, through the above description, relevant staff can completely make various changes and modifications without departing from the technical idea of this invention. The technical scope of this invention is not limited to the content in the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A low-sensitivity explosion-proof flexible DC distribution network busbar assembly, characterized in that, It includes a busbar layer Ⅰ(1), a busbar layer Ⅱ(2) and a busbar layer Ⅲ(3) which are arranged in a stacked manner. Each busbar layer includes a plate electrode (4) and insulating films (5) provided on the upper and lower surfaces of the plate electrode (4). The cross-sections of the busbar layer Ⅱ(2) and the busbar layer Ⅲ(3) are Z-shaped. The lower cross plates (6) of the busbar layer Ⅲ(3) extend towards its left and right ends respectively. The busbar layer Ⅰ(1) is arranged on the lower cross plate (6) of the busbar layer Ⅱ(2) and corresponds to the lower cross plate (6) of the busbar layer Ⅲ(3) up and down. An installation gap (7) is formed between the left side of the busbar layer Ⅰ(1) bent upwards and the left side of the lower cross plate (6) of the busbar layer Ⅲ(3). Copper columns and connecting plates with riveted nuts (8) are respectively arranged on the busbar layer Ⅰ(1), the busbar layer Ⅱ(2) and the busbar layer Ⅲ(3). Installation holes are respectively arranged on the busbar layer Ⅱ(2) and the busbar layer Ⅲ(3). Openings (11) are provided on the plate electrodes (4) on the upper and lower sides of the installation gap (7). The thyristor (10) is arranged in the installation gap (7) by means of press fitting to fix the thyristor (10). Two IGBTs (12) are provided and are connected in reverse series and placed below the lower cross plate (6) of the busbar layer Ⅲ(3). The connecting plate includes device connecting plates (18) arranged on the upper cross plates (17) of the busbar layer Ⅱ(2) and the busbar layer Ⅲ(3) and facing the side edges of the lower cross plate (6) of the busbar layer Ⅱ(2) and the lower cross plate (6) of the busbar layer Ⅲ(3). Device connecting plates (18) are arranged on the left and right sides of the busbar layer Ⅱ(2) and the busbar layer Ⅲ(3). The device connecting plate (18) on the left side of the busbar layer Ⅱ(2) is used to connect a square resistor, an SMC board and a power supply board. The device connecting plate (18) on the left side of the busbar layer Ⅲ(3) is used to connect a power supply board and a square resistor. The device connecting plate (18) on the right side is used to connect the ground wire of the power supply card board. The connecting plate includes a vacuum switch connecting plate (20) arranged on the right side of the busbar layer Ⅰ(1) and facing the upper cross plates (17) of the busbar layer Ⅱ(2) and the busbar layer Ⅲ(3). The installation hole includes a pair of vacuum switch installation holes (21) arranged on the upper cross plate (17) of the busbar layer Ⅲ(3). The vacuum switch (19) is installed below the upper cross plate (17) of the busbar layer Ⅲ(3). The top connection end thereof is connected to the vacuum switch connection hole (21), and the side connection end is connected to the riveted nut (8) on the vacuum switch connecting plate (20). The mounting holes include capacitor mounting holes I (23) provided on the upper cross plate (17) of the busbar layer II (2) and capacitor mounting holes II (24) provided on the upper cross plate (17) of the busbar layer III (3), and the capacitor mounting holes I (23) and capacitor mounting holes II (24) are arranged in pairs; capacitors (22) are arranged side by side below the upper cross plate (17) of the busbar layer III (3), with one connection end connected to the capacitor mounting hole I (23) and the other connection end connected to the capacitor mounting hole II (24).

2. The low-sensitivity explosion-proof flexible DC distribution network bus assembly according to claim 1, wherein Insulating films (5) are not provided on the surfaces of the partial plates (4) of the busbar layer I (1) and the busbar layer III (3) that form the mounting gap (7).

3. The low-sensitivity explosion-proof flexible DC distribution network bus assembly according to claim 1, wherein, The copper posts include a pair of IGBT connection copper posts I (13) mounted on the busbar layer I (1), IGBT connection copper posts II (14) mounted on the lower cross plate (6) of the busbar layer II (2), and IGBT connection copper posts III (15) mounted on the lower cross plate (6) of the busbar layer III (3), and the IGBT connection copper posts I (13), IGBT connection copper posts II (14) and IGBT connection copper posts III (15) are arranged side by side.

4. The low-sensitivity explosion-proof flexible DC distribution network bus assembly according to claim 1, characterized in that, The connecting plate includes an incoming and outgoing line connecting plate (16) provided at the right end of the lower cross plates (6) of the busbar layer I (1) and the busbar layer III (3).

5. The low-sensitivity explosion-proof flexible DC distribution network bus assembly according to claim 1, wherein, The capacitor mounting hole I (23) is a stamping convex hull facing the direction of the busbar layer III (3).

6. The low-sensitivity explosion-proof flexible DC distribution network busbar assembly according to claim 1, wherein, An insulating plate (25) is provided between the right side of the busbar layer I (1) and the right side of the lower cross plate (6) of the busbar layer III (3).

7. The low-sensitivity explosion-proof flexible DC distribution network bus assembly according to claim 1, wherein, Through holes are provided at the corresponding positions of the copper posts and mounting holes of each busbar layer on the other two busbar layers, and insulating gaskets (26) are covered on the through holes.

8. The low-sensitivity explosion-proof flexible DC distribution network bus assembly according to claim 1, wherein, The plate (4) is a copper plate with a thickness of 0.5 - 4 mm.

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