35kv low-voltage large-current transformer

Abstract

The present invention belongs to the technical field of transformer design and manufacturing, and specifically disclosed is a 35kV low-voltage large-current transformer. The transformer comprises an oil tank; a three-phase low-voltage coil arranged in the oil tank; a plurality of sleeves having the bottom fixed to a side wall of the oil tank and being perpendicular to the side wall of the oil tank; and connectors configured to connect a wire outgoing end of the low-voltage coil and the corresponding sleeves, wherein the low-voltage coil is formed by means of winding transposed conductors, and the transposed conductors, the connectors and the sleeves are electrically connected in sequence. In the present invention, the height of the transformer is greatly reduced, such that the dimensional requirement of the Fahrenheit-type package transformer is met, and the climbing operation of workers can be reduced, thereby not only improving the production efficiency, but also increasing the production safety. The cost is reduced, because the sleeves are designed on the side wall of the oil tank such that the size of the transformer is reduced to the maximum extent and less amount of steel, transformer oil and copper is used; therefore, materials can be effectively saved on while the product performance is guaranteed.

Description

A 35kV low voltage and high current transformer Technical Field

[0001] The invention belongs to the technical field of transformer design and manufacturing, and particularly relates to a 35kV low-voltage and high-current transformer. Background Art

[0002] In the current 35kV transformer manufacturing industry, the transformer's low-voltage bushing is generally located above the core, near the low-voltage coil outlet. The low-voltage coil is wound with copper foil, and the low-voltage copper busbar is welded to the copper foil as the first and last terminals, and connected to the lead copper busbar with bolts. The lead copper busbar is then connected to the bushing with the terminal lug.

[0003] However, due to the complex operating environments of transformers, the bushing height of small-capacity transformers is typically several tens of centimeters, making proper installation impossible in some complex environments, especially those with height restrictions. For example, with products like Chinese-style box-type transformers, the low-voltage side must be connected to a low-voltage cabinet, which places relatively high demands on the transformer's overall dimensions. For low-voltage, high-current products, eddy currents, stray currents, and other additional losses contribute significantly, requiring a significant distance between the device body and the box wall. Therefore, arbitrary changes to the bushing position are generally not possible.

[0004] In summary, the transformer space utilization in the prior art is unreasonable, which not only causes waste of materials, but also the excessive size of the transformer increases the cost of installation and transportation.

[0005] Summary of the Invention

[0006] The present invention provides a 35kV low-voltage high-current transformer, which is used to solve the problem of height of the current transformer during installation.

[0007] In order to solve the above technical problems, the technical solution of the present invention is as follows: a 35kV low-voltage high-current transformer is characterized by comprising: an oil tank, a three-phase low-voltage coil arranged in the oil tank, a plurality of bushings whose bottoms are fixed to the side wall of the oil tank and arranged perpendicular to the side wall of the oil tank, and a connector for connecting the outlet end of the low-voltage coil and the corresponding bushing;

[0008] The low-voltage coil is wound with a transposed conductor, and the transposed conductor, the connector and the sleeve are electrically connected in sequence.

[0009] In a preferred embodiment of the present invention, the connecting parts include a terminal, a copper busbar and a wiring piece, and the outlet end of the low-voltage coil, the terminal, the copper busbar and the wiring piece are electrically connected in sequence; there are 8 transposed conductors, which are wound in a 4-in-2 stack, and every two transposed conductors are electrically connected to one of the terminal.

[0010] In a preferred embodiment of the present invention, the three-phase low-voltage coil is an a-phase coil, a b-phase coil and a c-phase coil, and the multiple bushings are an a-phase bushing, a b-phase bushing, a c-phase bushing and a 0-phase bushing. The first outlet end of the a-phase coil is connected to the a-phase bushing, the first outlet end of the b-phase coil is connected to the b-phase bushing, the first outlet end of the c-phase coil is connected to the c-phase bushing, and the last outlet end of the a-phase coil, the last outlet end of the b-phase coil and the last outlet end of the c-phase coil are all connected to the 0-phase bushing.

[0011] In a preferred embodiment of the present invention, the connector is an a-phase connector for connecting the a-phase coil to the a-phase bushing, a b-phase connector for connecting the b-phase coil to the b-phase bushing, a c-phase connector for connecting the c-phase coil to the c-phase bushing, and a 0-phase connector for connecting the terminal end of the a-phase coil, the terminal end of the b-phase coil, and the terminal end of the c-phase coil to the 0-phase bushing;

[0012] It also includes fixing parts for fixing the connecting parts, and the fixing parts include a phase a fixing part for fixing the phase a connecting part, a phase b fixing part for fixing the phase b connecting part, a phase c fixing part for fixing the phase c connecting part, and a phase 0 fixing part for fixing the phase 0 connecting part.

[0013] In a preferred embodiment of the present invention, the a-phase connector includes four a-phase terminals, an a-phase copper busbar, and an a-phase terminal block. The four a-phase terminals are arranged in a 2×2 array along the radial plane of the coil; the a-phase copper busbar is an integrally formed Z-shaped copper busbar, which includes a first section, a second section, and a bent section for connecting the first section and the second section; the end of the first section is located between the four a-phase terminals, two a-phase terminals are fixed to one side of the first section, and the other two a-phase terminals are fixed to the other side of the first section.

[0014] In a preferred embodiment of the present invention, the a-phase terminal block is L-shaped, and includes a first connecting section connected to the a-phase copper busbar and a second connecting section connected to the a-phase bushing.

[0015] In a preferred embodiment of the present invention, it further includes an upper clamping piece arranged on the upper part of the three-phase low-voltage coil and a lower clamping piece arranged on the lower part of the three-phase low-voltage coil; the a-phase fixing piece includes multiple a-phase base plates and multiple a-phase wire clamps; the a-phase base plate is a C-shaped plate, the open side of which is fixed to the upper clamping piece, and the other side is fixed to the a-phase wire clamp; one side of the a-phase wire clamp is fixed to the a-phase base plate, and the other side is fixed to the a-phase copper busbar.

[0016] In a preferred embodiment of the present invention, the b-phase fixing member includes a plurality of b-phase base plates and a plurality of b-phase conductor clamps, and the arrangement of the b-phase base plates and the b-phase conductor clamps is the same as that of the a-phase base plates and the a-phase conductor clamps;

[0017] The c-phase fixing member includes a plurality of c-phase bottom plates and a plurality of c-phase conductor clamps, and the arrangement of the c-phase bottom plates and the c-phase conductor clamps is the same as that of the a-phase bottom plates and the a-phase conductor clamps;

[0018] The material of the a-phase conductor clamp, the b-phase conductor clamp and the c-phase conductor clamp is laminated wood; the width of the a-phase conductor clamp is greater than the width of the b-phase conductor clamp and the c-phase conductor clamp.

[0019] In a preferred embodiment of the present invention, the b-phase connector includes a b-phase terminal, a b-phase copper busbar and a b-phase lug. The first outlet end of the b-phase coil, the b-phase terminal, the b-phase copper busbar, the b-phase lug and the b-phase bushing are electrically connected in sequence. The b-phase copper busbar is a straight copper busbar in a straight line, and the thickness of the b-phase copper busbar is less than that of the a-phase copper busbar.

[0020] In a preferred embodiment of the present invention, the 0-phase connector includes a 0-phase terminal, a 0-phase copper bar and a 0-phase wiring lug, the 0-phase copper bar includes a 0-phase straight copper bar and a 0-phase L-shaped copper bar, the 0-phase straight copper bar is electrically connected to the 0-phase terminal, and the thickness of the 0-phase straight copper bar is greater than the thickness of the b-phase copper bar.

[0021] In a preferred embodiment of the present invention, the 0-phase L-shaped copper busbar includes an integrally formed horizontal section and a vertical section, the horizontal section is welded to the vertical section, one end of the horizontal section is electrically connected to the 0-phase straight copper busbar, and the other end is connected to one end of the vertical section, and the other end of the vertical section is connected to the 0-phase wiring lug.

[0022] In a preferred embodiment of the present invention, the horizontal section is a Z-shaped copper bar, one end of which is connected between the end outlet terminal of the a-phase coil and the end outlet terminal of the b-phase coil, and the other end is connected to the vertical section.

[0023] In a preferred embodiment of the present invention, the 0-phase fixing member includes a plurality of 0-phase base plates, a plurality of 0-phase conductor clamps, a wooden pole, and a plurality of special-shaped wooden pieces;

[0024] The 0-phase base plate and the 0-phase conductor clamp are arranged in the same manner as the a-phase base plate and the a-phase conductor clamp;

[0025] One end of the wooden pole is fixedly connected to the upper clamp, and the other end is fixedly connected to the lower clamp. A straight support plate is provided between the end of the wooden pole and the upper clamp or the lower clamp, and the support plate is bolted to the wooden pole.

[0026] The vertical section is connected to the wooden pole through special-shaped wooden pieces; the special-shaped wooden pieces are arranged at 1 / 3 and 2 / 3 of the wooden pole.

[0027] In a preferred embodiment of the present invention, a copper bar groove is provided at one end of the special-shaped wooden piece, and two through holes are provided on one side of the copper bar groove. The other end of the special-shaped wooden piece is provided with a wooden pole groove, and bolt holes are provided at both ends of the wooden pole groove. The special-shaped wooden piece is connected to the wooden pole by bolts.

[0028] The technical solution provided by the present invention has the following advantages compared with the prior art:

[0029] The transformer height of this invention is significantly reduced, meeting the dimensional requirements of the Fahrenheit box transformer. It also reduces the need for workers to climb high, improving both production efficiency and safety. Costs are also reduced by designing the bushings into the side walls of the oil tank, minimizing the transformer size and reducing the use of steel, transformer oil, and copper. This effectively saves materials while ensuring product performance. A fully rational layout ensures the insulation performance of the transformer's low-voltage leads while also making the lead layout more aesthetically pleasing and compact, balancing practicality and aesthetics. Compared to conventional lead structures, the three-phase copper busbars in this structure are shorter, making installation more convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, without paying any creative work, they can also obtain drawings of other embodiments based on these drawings.

[0031] FIG1 is an overall schematic diagram of a 35 kV low-voltage, high-current transformer according to an embodiment of the present invention;

[0032] 2 is a schematic diagram showing the connection principle of a three-phase low-voltage coil of a 35kV low-voltage high-current transformer according to an embodiment of the present invention;

[0033] 3 is a schematic diagram showing the connection of the first outgoing line terminals of a three-phase low-voltage coil of a 35kV low-voltage, high-current transformer according to one embodiment of the present invention;

[0034] FIG4 is a schematic diagram of a phase a copper busbar of a 35 kV low-voltage, high-current transformer according to an embodiment of the present invention;

[0035] 5 is a schematic diagram of a phase a fixing member of a 35kV low-voltage high-current transformer according to an embodiment of the present invention;

[0036] 6 is a schematic diagram of the wiring of the terminal outgoing line of a three-phase low-voltage coil of a 35kV low-voltage high-current transformer according to one embodiment of the present invention;

[0037] FIG7 is a schematic diagram of a special-shaped wooden piece of a 35 kV low-voltage high-current transformer according to an embodiment of the present invention.

[0038] In the figure: 1- oil tank; 201- phase a coil; 202- phase b coil; 203- phase c coil; 301- upper clamp; 302- lower clamp; 401- phase a bushing; 402- phase b bushing; 403- phase c bushing; 404- phase 0 bushing; 501- phase a terminal; 502- phase b terminal; 503- phase c terminal; 504- phase 0 lug; 601- phase a copper busbar; 6011- first section; 6012- bent section; 6013- second section; 602- phase b copper busbar; 603- phase c copper busbar; 604 1-0 phase straight copper busbar; 6042-0 phase L-shaped copper busbar; 701-a phase lug; 702-b phase lug; 703-c phase lug; 704-0 phase lug; 8011-a phase base plate; 8012-a phase conductor clamp; 8021-b phase base plate; 8022-b phase conductor clamp; 8031-c phase base plate; 8032-c phase conductor clamp; 8041-0 phase base plate; 8042-0 phase conductor clamp; 901-support plate; 902-special-shaped wooden piece; 9021-bolt hole; 9022-through hole; 903-wooden pole. DETAILED DESCRIPTION

[0039] For ease of understanding, the 35kV low-voltage, high-current transformer is described below in conjunction with embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0040] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations and positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0041] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention.

[0042] To facilitate understanding of the present invention, the present invention will be described more fully below with reference to the accompanying drawings. The accompanying drawings illustrate preferred embodiments of the present invention. However, the present invention may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the present disclosure.

[0043] As shown in Figure 1, the present invention discloses a 35kV low-voltage, high-current transformer, which includes: a transformer oil tank 1, a three-phase low-voltage coil arranged in the oil tank 1, an upper clamp 301 arranged on the upper part of the three-phase low-voltage coil, a lower clamp 302 arranged on the lower part of the three-phase low-voltage coil, a plurality of bushings whose bottoms are fixed to the side wall of the oil tank 1 and are arranged perpendicular to the side wall of the oil tank 1, and a connector for connecting the outlet end of the low-voltage coil and the corresponding bushing.

[0044] Specifically, the three-phase low-voltage coils are a-phase coil 201, b-phase coil 202, and c-phase coil 203. Each coil includes a first terminal and a last terminal, with the first terminal leading out from the top of the coil and the last terminal leading out from the bottom. The multiple bushings are a-phase bushing 401, b-phase bushing 402, c-phase bushing 403, and 0-phase bushing 404. Referring to FIG. 2 , the three low-voltage coils in the present invention are connected in a star configuration. That is, in conjunction with FIG. 1 and FIG. 2 , a-phase bushing 401, b-phase bushing 402, c-phase bushing 403, and 0-phase bushing 404 are compactly arranged near one side of c-phase coil 203. The first outgoing wire end of the a-phase coil 201 is connected to the a-phase bushing 401, the first outgoing wire end of the b-phase coil 202 is connected to the b-phase bushing 402, the first outgoing wire end of the c-phase coil 203 is connected to the c-phase bushing 403, and the last outgoing wire end of the a-phase coil 201, the last outgoing wire end of the b-phase coil 202 and the last outgoing wire end of the c-phase coil 203 are all connected to the 0-phase bushing 404.

[0045] Specifically, the connecting parts include an a-phase connecting part for connecting the a-phase coil 201 with the a-phase bushing 401, a b-phase connecting part for connecting the b-phase coil 202 with the b-phase bushing 402, a c-phase connecting part for connecting the c-phase coil 203 with the c-phase bushing 403, and a 0-phase connecting part for connecting the end outlet terminal of the a-phase coil 201, the end outlet terminal of the b-phase coil 202 and the end outlet terminal of the c-phase coil 203 to the 0-phase bushing 404.

[0046] In order to make the outgoing line structure more stable, one embodiment of the present invention further includes a fixing part for fixing the connecting part. Specifically, the fixing part includes an a-phase fixing part for fixing the a-phase connecting part, a b-phase fixing part for fixing the b-phase connecting part, a c-phase fixing part for fixing the c-phase connecting part, and a 0-phase fixing part for fixing the 0-phase connecting part.

[0047] Since the present invention disposes the multiple bushings originally disposed on the top of the fuel tank 1 on the side wall of the fuel tank 1, and since the eddy current loss of the low-voltage foil winding is too large and the skin effect at the end is obvious, in one embodiment of the present invention, the a-phase coil 201, the b-phase coil 202, and the c-phase coil 203 are all spiral structures, and are wound in two layers using transposed conductors 4. That is, there are a total of 8 transposed conductors, wherein every two transposed conductors are electrically connected to one terminal.

[0048] As shown in Figures 1 and 3 , the A-phase connector includes four A-phase terminals 501, an A-phase copper busbar 601, and an A-phase lug 701. Specifically, at the head end of the A-phase coil 201, every two sub-conductors are connected to an A-phase terminal 501. The four A-phase terminals 501 are arranged in a 2×2 array along the radial plane of the coil. The A-phase copper busbar 601 is an integrally formed Z-shaped busbar. Specifically, as shown in Figures 3 and 4 , it includes a first section 6011, a second section 6013, and a bent section 6012 connecting the first and second sections 6011 and 6013. One end of the first section 6011 is connected to the bent section 6012, and the other end is located between the four a-phase terminals 501. Specifically, because the four a-phase terminals 501 are arranged in a 2×2 array, the end of the first section 6011 is located between the four a-phase terminals 501. Two a-phase terminals 501 are fixed to one side of the first section 6011, and the other two a-phase terminals 501 are fixed to the other side of the first section 6011. One end of the second section 6013 is connected to the bent section 6012, and the other end is connected to the a-phase lug 701. The a-phase lug 701 is L-shaped and includes a first connecting section connected to the a-phase copper busbar 601 and a second connecting section connected to the a-phase bushing 401.

[0049] As shown in Figures 3 and 5 , the a-phase fixing components include multiple a-phase base plates 8011 and multiple a-phase conductor clamps 8012. The a-phase base plates 8011 are C-shaped, with their open sides secured to the upper clamp 301 and their other sides secured to the a-phase conductor clamps 8012. One side of the a-phase conductor clamps 8012 is secured to the a-phase base plate 8011, and the other side is secured to the a-phase copper busbar 601. It should be noted that at least one of the a-phase conductor clamps 8012 is secured to the junction between the a-phase terminal 501 and the a-phase copper busbar 601 to enhance the connection strength there. Furthermore, the a-phase conductor clamps 8012 are made of laminated wood.

[0050] Referring to Figure 3 , the b-phase connector includes a b-phase terminal 502, a b-phase copper busbar 602, and a b-phase lug 702. The first outlet terminal of the b-phase coil 202, the b-phase terminal 502, the b-phase copper busbar 602, the b-phase lug 702, and the b-phase bushing 402 are electrically connected in sequence. The b-phase copper busbar 602 is a straight, inline copper busbar and is thinner than the a-phase copper busbar 601. The remaining components are configured in the same manner as the a-phase connector.

[0051] The b-phase fixing parts include multiple b-phase base plates 8021 and multiple b-phase wire clamps 8022. The setting method of the b-phase base plates 8021 and the b-phase wire clamps 8022 is the same as that of the a-phase base plates 8011 and the a-phase wire clamps 8012. The width of the a-phase wire clamps 8012 is greater than that of the b-phase wire clamps 8022.

[0052] Continuing with Figure 3 , the C-phase connector includes the C-phase terminal 503, the C-phase copper busbar 603, and the C-phase lug 703. The first outlet terminal of the C-phase coil 203, the C-phase terminal 503, the C-phase copper busbar 603, the C-phase lug 703, and the C-phase bushing 403 are electrically connected in sequence. The C-phase copper busbar 603 is a straight, inline copper busbar, and is thinner than the A-phase copper busbar 601. The remaining components are configured in the same manner as the A-phase connector.

[0053] The C-phase fixing parts include multiple C-phase base plates 8031 ​​and multiple C-phase wire clamps 8032. The arrangement of the C-phase base plates 8031 ​​and the C-phase wire clamps 8032 is the same as that of the A-phase base plates 8011 and the A-phase wire clamps 8012. The width of the A-phase wire clamps 8012 is greater than that of the C-phase wire clamps 8032.

[0054] Specifically, the lead copper busbar for phase A uses two 8mm thick copper busbars that are overlapped and bent. Since the eddy current loss of two copper busbars is smaller than that of a single copper busbar, the cost can be reduced. Since the phase A copper busbar 601 is longer than the phase B copper busbar 602 and has a greater resistance, the resistance can be balanced by thickening the phase A copper busbar 601.

[0055] 1 and 6 , the 0-phase connector includes 0-phase terminals 504, a 0-phase copper busbar, and a 0-phase lug 704. In one embodiment of the present invention, there are twelve 0-phase terminals 504. The terminal end of the a-phase coil 201 is connected to four 0-phase terminals 504 arranged in a 2×2 pattern, the terminal end of the b-phase coil 202 is connected to four 0-phase terminals 504 arranged in a 2×2 pattern, and the terminal end of the c-phase coil 203 is connected to four 0-phase terminals 504 arranged in a 2×2 pattern. The 0-phase copper busbar includes a 0-phase straight copper busbar 6041 and a 0-phase L-shaped copper busbar 6042. The 0-phase straight copper busbar 6041 is connected to all 0-phase terminals 504 and is thicker than the b-phase copper busbar 602. Specifically, the 0-phase L-shaped copper busbar 6042 comprises an integrally formed horizontal section and a vertical section, which are welded to each other. One end of the horizontal section is electrically connected to the 0-phase straight copper busbar 6041, and the other end is connected to one end of the vertical section. The other end of the vertical section is connected to the 0-phase terminal lug 704. In one embodiment of the present invention, the horizontal section is a Z-shaped copper busbar. One end of the horizontal section is connected between the terminal ends of the a-phase coil 201 and the terminal ends of the b-phase coil 202, and the other end is connected to the vertical section to achieve resistance balance.

[0056] The 0-phase fixings include multiple 0-phase base plates 8041, multiple 0-phase conductor clamps 8042, wooden poles 903, and multiple special-shaped wooden pieces 902. The 0-phase base plates 8041 and 0-phase conductor clamps 8042 are configured in the same manner as the a-phase base plates 8011 and a-phase conductor clamps 8012. One end of the wooden pole 903 is fixedly connected to the upper clamp 301, and the other end is fixedly connected to the lower clamp 302. A straight-line support plate 901 is installed between the end of the wooden pole 903 and either the upper clamp 301 or the lower clamp 302. The support plate 901, wooden pole 903, and the horizontal section of the 0-phase L-shaped copper busbar 6042 are perpendicular to each other, and the support plate 901 is bolted to the wooden pole 903. The vertical section of the 0-phase L-shaped copper busbar 6042 is connected to the wooden pole 903 via a specially shaped wooden piece 902. Specifically, as shown in Figures 1 and 7 , one end of the specially shaped wooden piece 902 is provided with a copper busbar slot. Two through-holes 9022 are provided on one side of the slot for passing binding straps through to secure the vertical section of the 0-phase L-shaped copper busbar 6042 to the specially shaped wooden piece 902. The other end of the specially shaped wooden piece 902 is provided with a wooden pole slot, with bolt holes 9021 at each end. The specially shaped wooden piece 902 is connected to the wooden pole 903 via bolts. To reduce the length of the bolt holes, in one embodiment of the present invention, the specially shaped wooden piece 902 is appropriately cut to narrow one end. In one embodiment of the present invention, the specially shaped wooden pieces 902 are provided at the 1 / 3 and 2 / 3 positions of the wooden pole 903.

[0057] The height of the transformer in the present invention is greatly reduced, meeting the size requirements of the Fahrenheit box transformer, while also reducing the need for workers to climb high, thereby improving both production efficiency and safety. Costs are also reduced by designing the bushing onto the side wall of the oil tank 1, minimizing the size of the transformer and reducing the amount of steel, transformer oil, and copper used. While ensuring product performance, this effectively saves materials and reduces production costs. The fully reasonable layout ensures the insulation performance of the transformer's low-voltage leads and makes the lead arrangement more beautiful and compact, balancing practicality and aesthetics. It can adapt to different working conditions and allows the transformer to be installed normally when space height is limited. Compared with conventional lead structures, the length of the three-phase copper busbar in this structure is reduced, making installation more convenient.

[0058] Finally, it should be noted that the above embodiments are intended only to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art will appreciate that the technical solutions described in the above embodiments may be modified or some or all of the technical features thereof may be replaced with equivalents, and that such modifications or replacements do not deviate from the essence of the corresponding technical solutions within the scope of the various embodiments of the present invention.

Claims

1. A 35kV low-voltage large-current transformer, characterized in that, it includes: an oil tank, three-phase low-voltage coils arranged in the oil tank, a plurality of bushings fixedly arranged at the bottom of the side wall of the oil tank and perpendicular to the side wall of the oil tank, and a connecting member for connecting the outgoing line ends of the low-voltage coils and the corresponding bushings; the low-voltage coils are wound with transposed conductors, and the transposed conductors, the connecting member and the bushings are electrically connected in sequence.

2. The 35kV low-voltage large-current transformer according to claim 1, characterized in that: the connecting member includes a terminal, a copper busbar and a connection piece, the outgoing line end of the low-voltage coil, the terminal, the copper busbar and the connection piece are electrically connected in sequence; there are 8 transposed conductors, which are wound in a 4-parallel 2-layer manner, and every two transposed conductors are electrically connected to one terminal.

3. The 35kV low-voltage large-current transformer according to claim 1, characterized in that: the three-phase low-voltage coils are an a-phase coil, a b-phase coil and a c-phase coil, the plurality of bushings are an a-phase bushing, a b-phase bushing, a c-phase bushing and a 0-phase bushing, the first outgoing line end of the a-phase coil is connected to the a-phase bushing, the first outgoing line end of the b-phase coil is connected to the b-phase bushing, the first outgoing line end of the c-phase coil is connected to the c-phase bushing, and the last outgoing line ends of the a-phase coil, the b-phase coil and the c-phase coil are all connected to the 0-phase bushing.

4. The 35kV low-voltage large-current transformer according to claim 3, characterized in that: the connecting member is an a-phase connecting member for connecting the a-phase coil and the a-phase bushing, a b-phase connecting member for connecting the b-phase coil and the b-phase bushing, a c-phase connecting member for connecting the c-phase coil and the c-phase bushing, and a 0-phase connecting member for connecting the last outgoing line ends of the a-phase coil, the b-phase coil and the c-phase coil to the 0-phase bushing; it further includes a fixing member for fixing the connecting member, and the fixing member includes an a-phase fixing member for fixing the a-phase connecting member, a b-phase fixing member for fixing the b-phase connecting member, a c-phase fixing member for fixing the c-phase connecting member and a 0-phase fixing member for fixing the 0-phase connecting member.

5. The 35kV low-voltage large-current transformer according to claim 4, characterized in that: the a-phase connecting member includes four a-phase terminals, an a-phase copper busbar and an a-phase connection piece, and the 4 a-phase terminals are arranged in a 2×2 array in the plane where the radial direction of the coil is located; the a-phase copper busbar is a z-shaped copper busbar formed integrally, which includes a first section, a second section and a bending section for connecting the first section and the second section; the end of the first section is located between the 4 a-phase terminals, and two a-phase terminals are fixed on one side of the first section, and the other two a-phase terminals are fixed on the other side of the first section.

6. The 35kV low-voltage large-current transformer according to claim 5, characterized in that: the a-phase connection piece is L-shaped, which includes a first connection section connected to the a-phase copper busbar and a second connection section connected to the a-phase bushing.

7. A 35 kV low-voltage high-current transformer according to claim 6, characterized in that: it further includes an upper clamping member disposed above the three-phase low-voltage coil and a lower clamping member disposed below the three-phase low-voltage coil; the a-phase fixing member includes a plurality of a-phase bottom plates and a plurality of a-phase wire clamps; the a-phase bottom plate is a C-shaped plate, the opening side of which is fixed to the upper clamping member, and the other side is fixed to the a-phase wire clamp. One side of the a-phase wire clamp is fixed to the a-phase bottom plate, and the other side is fixed to the a-phase copper busbar.

8. A 35 kV low-voltage high-current transformer according to claim 4, characterized in that: the b-phase fixing member includes a plurality of b-phase bottom plates and a plurality of b-phase wire clamps, and the b-phase bottom plate and the b-phase wire clamp are arranged in the same manner as the a-phase bottom plate and the a-phase wire clamp; the c-phase fixing member includes a plurality of c-phase bottom plates and a plurality of c-phase wire clamps, and the c-phase bottom plate and the c-phase wire clamp are arranged in the same manner as the a-phase bottom plate and the a-phase wire clamp; the a-phase wire clamp, the b-phase wire clamp, and the c-phase wire clamp are made of laminated wood; the width of the a-phase wire clamp is greater than the widths of the b-phase wire clamp and the c-phase wire clamp.

9. A 35 kV low-voltage high-current transformer according to claim 8, characterized in that: the b-phase connecting member includes a b-phase terminal, a b-phase copper busbar, and a b-phase connection piece. The head outgoing terminal of the b-phase coil, the b-phase terminal, the b-phase copper busbar, the b-phase connection piece, and the b-phase bushing are electrically connected in sequence. The b-phase copper busbar is a straight copper busbar in a straight line, and the thickness of the b-phase copper busbar is less than the thickness of the a-phase copper busbar.

10. A 35 kV low-voltage high-current transformer according to claim 7, characterized in that: the 0-phase connecting member includes a 0-phase terminal, a 0-phase copper busbar, and a 0-phase connection piece. The 0-phase copper busbar includes a 0-phase straight copper busbar and a 0-phase L-shaped copper busbar. The 0-phase straight copper busbar is electrically connected to the 0-phase terminal, and the thickness of the 0-phase straight copper busbar is greater than the thickness of the b-phase copper busbar.

11. A 35 kV low-voltage high-current transformer according to claim 10, characterized in that: the 0-phase L-shaped copper busbar includes a horizontally formed section and a vertically formed section integrally formed. The horizontally formed section is welded to the vertically formed section. One end of the horizontally formed section is electrically connected to the 0-phase straight copper busbar, the other end is connected to one end of the vertically formed section, and the other end of the vertically formed section is connected to the 0-phase connection piece.

12. A 35 kV low-voltage high-current transformer according to claim 11, characterized in that: the horizontally formed section is a zigzag copper busbar. One end of the horizontally formed section is connected between the tail outgoing terminal of the a-phase coil and the tail outgoing terminal of the b-phase coil, and the other end is connected to the vertically formed section.

13. A 35 kV low-voltage high-current transformer according to claim 12, characterized in that: the 0-phase fixing member includes a plurality of 0-phase bottom plates, a plurality of 0-phase wire clamps, a wooden rod, and a plurality of special-shaped wooden members; the 0-phase bottom plate and the 0-phase wire clamp are arranged in the same manner as the a-phase bottom plate and the a-phase wire clamp; One end of the wooden rod is fixedly connected to the upper clamping member, and the other end is fixedly connected to the lower clamping member. A flat plate is provided between the end of the wooden rod and the upper clamping member or the lower clamping member, and the flat plate is bolted to the wooden rod; The vertical section is connected to the wooden rod through a special-shaped wooden member; the above-mentioned special-shaped wooden members are provided at the 1 / 3 and 2 / 3 positions of the wooden rod.

14. A 35 kV low-voltage high-current transformer according to claim 13, characterized in that: One end of the special-shaped wooden member is provided with a copper busbar groove, and two through holes are provided on one side of the copper busbar groove. The other end of the special-shaped wooden member is provided with a wooden rod groove, and bolt holes are provided at both ends of the wooden rod groove. The special-shaped wooden member is connected to the wooden rod by bolts.

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