Three-dimensional wound core type double-body distribution transformer

Abstract

The utility model relates to a three-dimensional wound core type double-body distribution transformer which comprises two bodies rotationally and symmetrically arranged in an oil tank, the two bodies are the three-dimensional wound core type bodies and are the same in structure, and each body comprises three iron cores shaped like a Chinese character'hui '. A low-voltage terminal is arranged on one side of the upper end of the oil tank, and a high-voltage sleeve is arranged on the other side of the upper end of the oil tank. The low-voltage winding outlet head of the first transformer body and the low-voltage winding outlet head of the second transformer body are connected with the corresponding low-voltage terminals through the corresponding low-voltage lead copper bars respectively, and the high-voltage winding outlet head of the first transformer body and the high-voltage winding outlet head of the second transformer body are connected with the corresponding high-voltage bushings through the corresponding high-voltage lead cables respectively. The two transformer bodies are the three-dimensional wound core type transformer bodies and are rotationally and symmetrically arranged in the oil tank, the two transformer bodies can achieve different connection group labels, and the low-voltage side can carry loads with different sizes and do not affect each other.

Description

Technical Field

[0001] The utility model relates to the technical field of distribution transformers, and particularly relates to a three-dimensional wound-core type double-core distribution transformer. Background Art

[0002] The electrical loads of some enterprises are different from the single and stable loads of the power grid. For example, the electricity consumption in steel mills has the characteristic of diverse loads. Therefore, the types of load requirements that the transformer can withstand are also more. For example, some steel mills require that two low-voltage windings respectively carry two loads, and the connection group numbers and loads of the two low-voltage windings are different, and at the same time, they cannot affect each other. Although the traditional split transformer can realize that one transformer has two low-voltage windings, the sizes of the two loads must be the same, and the connection group numbers must also be the same, which cannot meet the special requirements of the steel mill load. For example, the patent with the authorization announcement number CN111613426B discloses a double-core double-split rectifier transformer and its manufacturing method. As described in the background art of this patent, the double-split transformer is generally designed in a structural form of one high-voltage winding and two low-voltage windings with equal voltage and equal capacity. And this patent sets a first transformer and a second transformer, but the high-voltage sides of the first transformer and the second transformer in this patent are connected in series, that is, the flowing current is the same, and then it is transmitted to the low voltage through the principle of electromagnetic induction. The purpose of this patent is to make the designed transformer safe and reliable, and at the same time have the advantages of small floor area and convenient debugging by setting winding constraint conditions and short-circuit reactance relationships, and it cannot meet the requirement that there is no mutual influence between the two low-voltage windings in the steel mill.

[0003] In addition, the double-core transformers in the prior art usually include a main transformer core and a voltage regulator core or a compensator core. For example, the patent with the authorization announcement number CN102315005B discloses a UHV generator step-up transformer with a double-core structure, which includes a main core and a voltage regulator core. The core of the voltage regulator core is a two-core column structure, and an exciting coil and a voltage regulating coil are sleeved on each core column. Another example is the patent with the authorization announcement number CN105655110B, which discloses a single-tank double-core autotransformer, which includes a main transformer core and a compensator core. The main transformer core has structures such as a third winding, a low-voltage regulating winding, a common winding, and a series winding. However, the two cores in the above transformers need to be related, so they also cannot meet the use requirements of the steel mill. Content of the Utility Model

[0004] The purpose of the utility model is to provide a three-dimensional wound core double-body distribution transformer, wherein both bodies adopt three-dimensional wound core bodies and are rotationally symmetrically arranged in an oil tank, and the two bodies can realize different connection group numbers (for example, Dd0, Dyn11), and the low-voltage side can carry loads of different sizes without affecting each other. In addition, the utility model can also ensure short-circuit performance and reduce losses and costs as much as possible.

[0005] The purpose of this utility model is achieved through the following technical solutions:

[0006] A three-dimensional wound core double-body distribution transformer comprises an oil tank and a first body and a second body rotationally symmetrically arranged in the oil tank, wherein the first body and the second body are both three-dimensional wound core bodies and have the same structure, the first body and the second body both comprise three U-shaped cores, and the adjacent side core columns of any two cores are wound with low-voltage windings, high-voltage windings and winding shields in sequence from the inside to the outside, a first low-voltage terminal and a second low-voltage terminal are arranged on one side of the upper end of the oil tank, and a first high-voltage bushing and a second high-voltage bushing are arranged on the other side, and each low-voltage winding outlet of the first body is connected to the corresponding first low-voltage terminal through a first low-voltage lead copper bar, each low-voltage winding outlet of the second body is connected to the corresponding second low-voltage terminal through a second low-voltage lead copper bar, each high-voltage winding outlet of the first body is connected to the corresponding first high-voltage bushing through a first high-voltage lead cable, and each high-voltage winding outlet of the second body is connected to the corresponding second high-voltage bushing through a second high-voltage lead cable.

[0007] The upper end of the oil tank is provided with a first low-pressure side mounting flange and a second low-pressure side mounting flange on one side, and a first high-pressure side mounting flange and a second high-pressure side mounting flange on the other side, and the first low-pressure terminal is provided on the first low-pressure side mounting flange, the second low-pressure terminal is provided on the second low-pressure side mounting flange, the first high-pressure bushing is provided on the first high-pressure side mounting flange, and the second high-pressure bushing is provided on the second high-pressure side mounting flange.

[0008] A tank cover is provided at the upper end of the oil tank, and a grounding riser with a grounding sleeve is provided on the upper side of the tank cover. Each winding shielding lead of the first body and each winding shielding lead of the second body are led out by the grounding sleeve.

[0009] The inner wall of the oil tank is provided with a shielding component.

[0010] The shielding assembly comprises an aluminum shield and a magnetic shield, wherein the aluminum shield is arranged on the inner wall of the oil tank, and the magnetic shield is arranged on the aluminum shield.

[0011] The middle position and both ends of the oil tank are provided with hanging plates.

[0012] On both side walls of the fuel tank, there are vertical reinforcing bars arranged along the height direction and horizontal reinforcing bars of the tank wall arranged along the horizontal direction, and the hanging plate is arranged on the corresponding vertical reinforcing bar.

[0013] A tank cover is provided at the upper end of the fuel tank, and a reinforcing bar of the tank cover is provided on the tank cover.

[0014] The advantages and positive effects of the present utility model are as follows:

[0015] 1. Both bodies of the present utility model adopt a three-dimensional wound core type body, and the two bodies are rotationally symmetrically arranged in the fuel tank. In this way, while ensuring that the insulation distance between the two bodies meets the requirements, the distance between the two bodies and the length of the fuel tank can be minimized as much as possible. At the same time, since the three phases of the three-dimensional wound core type body are completely symmetrical, the present utility model can adjust the phase sequence of the two bodies according to actual needs without electrical problems. In this way, it is convenient to lead the wires out from both sides of the upper end of the fuel tank. In addition, the low-voltage leads of the two bodies of the present utility model all adopt low-voltage lead copper busbar structures, and the high-voltage leads all adopt high-voltage lead cables. At the same time, the present utility model leaves enough space inside the upper end of the fuel tank to stagger and separate the low-voltage leads and high-voltage leads in height. In this way, it can not only ensure that the leads on the high-voltage side and the low-voltage side will not be chaotic, but also ensure that the leads of each winding are staggered in the height direction to ensure the insulation distance.

[0016] 2. The two bodies of the present utility model can achieve two different connection group labels, so as to meet the special requirements of users (such as steel mills). In addition, since there is no electrical connection between the two bodies, the two loads do not affect each other. And during operation, even if one winding is short-circuited, only one load is affected, and the other load can be normally powered. The loss, cost, and floor area of the product of the present utility model are also better than purchasing two transformers, having a market advantage.

[0017] 3. After the present utility model adopts two three-dimensional wound core type bodies arranged in a rotationally symmetric manner, due to the complete symmetry of the magnetic circuit of the transformer core, the harmonics in the core are reduced, and at the same time, the weight of the core and the no-load loss can also be reduced. And the grounding winding shield arranged on the body can also effectively shield the harmonics. In addition, the present utility model adds a shielding component at the position of the inner wall of the fuel tank close to the two bodies to reduce the stray loss. Therefore, the present utility model can ensure the short-circuit performance and reduce the loss and cost as much as possible. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is the top view of the present utility model,

[0019] Figure 2 is Figure 1 the view from direction A in

[0020] Figure 3 isFigure 1 Schematic diagram of the structure of the first body

[0021] Figure 4 is Figure 1 Schematic diagram of the wiring principle of the first body in

[0022] Figure 5 is Figure 1 Schematic diagram of the wiring principle of the second body in

[0023] Figure 6 is Figure 1 Schematic diagram of the lead-out of the winding shield on two bodies in

[0024] Figure 7 is Figure 1 Schematic diagram of the arrangement of the shielding components on the inner wall of the fuel tank in

[0025] Figure 8 is Figure 1 Top view of the appearance of the fuel tank in

[0026] Among them, 1 is the first body, 101 is the iron core, 102 is the low-voltage winding, 103 is the high-voltage winding, 104 is the winding shield, 105 is the upper clamping piece, 106 is the lower clamping piece, 2 is the second body, 3 is the fuel tank, 301 is the second high-voltage side mounting flange, 302 is the second low-voltage side mounting flange, 303 is the first high-voltage side mounting flange, 304 is the first low-voltage side mounting flange, 305 is the magnetic shield, 306 is the aluminum shield, 307 is the vertical reinforcing iron, 308 is the horizontal reinforcing iron of the tank wall, 309 is the lifting plate, 310 is the reinforcing iron of the tank cover, 4 is the second low-voltage lead copper bar, 5 is the second high-voltage lead cable, 6 is the first low-voltage lead copper bar, 7 is the first high-voltage lead cable, 8 is the first high-voltage bushing, 9 is the second high-voltage bushing, 10 is the first low-voltage terminal, and 11 is the second low-voltage terminal. Specific implementation mode

[0027] The present utility model will be further described in detail below with reference to the accompanying drawings.

[0028] As Figures 1 to 8 shown, the present utility model includes a fuel tank 3 and a first body 1 and a second body 2 rotatably symmetrically arranged in the fuel tank 3. Among them, as Figure 3 shown, both the first body 1 and the second body 2 are three-dimensional wound core type bodies and have the same structure. Both the first body 1 and the second body 2 include three U-shaped iron cores 101, and the adjacent side cores of any two iron cores 101 are successively wound with a low-voltage winding 102, a high-voltage winding 103, and a winding shield 104 from the inside to the outside. In this embodiment, the winding shield 104 is a copper shield. The three iron cores 101 are clamped and fixed by an upper clamping piece 105 on the upper side and a lower clamping piece 106 on the lower side. And as Figures 1 to 2As shown in the figure, on one side of the upper end of the fuel tank 3, there are a first low-voltage terminal 10 and a second low-voltage terminal 11, and on the other side, there are a first high-voltage bushing 8 and a second high-voltage bushing 9. As Figure 1 and Figure 4 shown, the leads of each low-voltage winding of the first body 1 are connected to the corresponding first low-voltage terminal 10 through the first low-voltage lead copper busbar 6, the leads of each low-voltage winding of the second body 2 are connected to the corresponding second low-voltage terminal 11 through the second low-voltage lead copper busbar 4, the leads of each high-voltage winding of the first body 1 are connected to the corresponding first high-voltage bushing 8 through the first high-voltage lead cable 7, and the leads of each high-voltage winding of the second body 2 are connected to the corresponding second high-voltage bushing 9 through the second high-voltage lead cable 5.

[0029] The utility model adopts two three-dimensional wound core type bodies to form a double-body structure and is placed in the fuel tank 3. The advantages of this structure are

[0030] 1. The two bodies can be rotationally symmetrically arranged in the fuel tank. In this way, while ensuring that the insulation distance between the two bodies meets the requirements, the distance between the two bodies and the length of the fuel tank 3 can be minimized as much as possible, thereby reducing the usage of steel plates, transformer oil, etc., making the equipment structure compact and reducing the production cost at the same time.

[0031] 2. For the two bodies arranged in the above-mentioned rotationally symmetric manner, the high- and low-voltage leads will be rotationally mirrored accordingly. If the high- and low-voltage leads are directly led out from the body, it is easy to cause chaos in the outgoing lines. To facilitate the lead-out of the leads, the phase sequence needs to be adjusted in combination with the bushing arrangement at the beginning of the design of the utility model. Figure 1 In the figure, the different phase sequences of the two bodies are the adjustments made for considering the lead-out of the leads. If the phase sequence design is unreasonable, it is very difficult to lead out the leads. Since the three phases of the three-dimensional wound core type body are completely symmetric, the utility model can adjust the phase sequences of the two bodies according to actual needs without electrical problems, so that the leads can be conveniently led out from both sides of the upper end of the fuel tank uniformly.

[0032] 3. As Figure 1 shown, for the utility model, there will be a lead crossing phenomenon for both the low-voltage leads and the high-voltage leads of the two bodies. However, after the utility model adopts the three-dimensional wound core type body, enough space can be left inside the upper end of the fuel tank 3 to stagger and separate the low-voltage leads and the high-voltage leads in height to ensure the insulation distance, and at the same time ensure that the leads on the high-voltage side and the low-voltage side will not be chaotic and there will be no influence between the two bodies. Among them, the low-voltage leads of the two bodies of the utility model all adopt the low-voltage lead copper busbar structure. In this way, as Figure 2As shown, the low-voltage lead copper bars can be staggered in height to ensure the insulation distance. The low-voltage lead copper bars are well-known in the art. For example, reference can be made to the patent CN211237938U. In the present utility model, the high-voltage leads of both body parts adopt high-voltage lead cables, which are relatively thin in diameter. On the one hand, this is convenient for distinguishing from the low-voltage lead copper bars with a certain width. On the other hand, it is also convenient for passing the leads between the copper bars. The high-voltage lead cables can be staggered from other leads and insulated by means such as support by brackets in height to ensure the insulation distance.

[0033] IV. As Figures 4 to 5 shown, the two body parts of the present utility model can achieve two different connection group labels, so as to meet the special requirements of users (such as steel mills). In this embodiment, the first body part 1 is as Figure 4 shown, its connection group label is Dd0, with an 8 MVA load, and the second body part 2 is as Figure 5 shown, its connection group label is Dyn11, with a 4 MVA load. As Figure 1 shown, since there is no electrical connection between the two body parts, the two loads do not affect each other. And during operation, even if a short circuit occurs in one winding, only one load is affected, and the other load can be normally powered. In addition, the losses, costs, and floor areas of the products of the present utility model are also better than purchasing two transformers, having a market advantage.

[0034] Therefore, in summary, the present utility model is not simply a simple superposition of two three-dimensional wound core body parts, but fully considers the special requirements of users (the steel mill requires that the two low-voltage windings respectively drive two loads, and the two low-voltage windings have different connection group labels and different loads, and at the same time require that they do not affect each other), and combines the characteristics of the three-dimensional wound core body parts to form a double-body part product.

[0035] As Figure 1 shown, in this embodiment, one side of the upper end of the fuel tank 3 is provided with a first low-voltage side mounting flange 304 and a second low-voltage side mounting flange 302, and the other side is provided with a first high-voltage side mounting flange 303 and a second high-voltage side mounting flange 301. And all the first low-voltage terminals 10 are arranged on the first low-voltage side mounting flange 304, all the second low-voltage terminals 11 are arranged on the second low-voltage side mounting flange 302, all the first high-voltage bushings 8 are arranged on the first high-voltage side mounting flange 303, and all the second high-voltage bushings 9 are arranged on the second high-voltage side mounting flange 301.

[0036] The upper end of the fuel tank 3 is provided with a tank cover, and a grounding riser with a grounding bushing is provided on the upper side of the tank cover. And as Figure 3 shown, winding shields 104 are provided on the outer sides of the high-voltage windings of both the first body part 1 and the second body part 2. And asFigure 6 As shown, the leads of the six winding shields 104 of the two body cores are all led out by the grounding bushing. Since the low-voltage side of the transformer is connected to the rectifier, the present invention also needs to avoid the influence of the harmonics in the rectifier on the high-voltage side. After the present invention adopts two three-dimensional wound core type body cores arranged in rotational symmetry, since the magnetic circuit of the transformer core is completely symmetrical, this reduces the harmonics in the core, and at the same time can reduce the core weight and no-load loss, and the above-mentioned grounded winding shield 104 can also effectively shield the harmonics.

[0037] In addition, since the present invention has a double-body-core structure, the leakage magnetic flux of the body cores will be greater as a whole. To reduce the stray losses caused by the leakage magnetic flux, as Figure 7 shown, the present invention adds a shielding assembly near the positions of the two body cores on the inner wall of the fuel tank 3 to reduce the stray losses. In this embodiment, the shielding assembly includes an aluminum shield 306 and a magnetic shield 305. The aluminum shield 306 is a thin aluminum plate, and small holes are opened at regular intervals thereon for plug welding. The aluminum shield 306 is formed by welding to the fuel tank 3 wall around the aluminum plate and at all plug welding holes. The magnetic shield 305 is arranged on the aluminum shield 306. The magnetic shield 305 can use low-grade non-oriented silicon steel. According to Ampere's circuital law, the magnetic shield 305 may not be placed at positions with small leakage magnetic flux far from the body core. In addition, the fuel tank 3 can also use a non-magnetic steel tank wall according to needs.

[0038] As Figure 8 shown, since the two body cores adopted by the present invention are both three-dimensional wound core type body cores, although their rotational symmetry placement can reduce the distance between the two body cores and the length of the fuel tank 3, it will also cause the problem of uneven stress during the lifting process, and the middle position of the fuel tank 3 is prone to deformation. Although thickening the steel plate can ensure the strength of the fuel tank 3, it will increase the cost, the lifting weight will also increase, and there may be a phenomenon that the lifting weight of the crane is insufficient when producing large-capacity products, and the thicker steel plate will also increase the eddy current loss. In addition to the lifting plates 309 at both ends of the fuel tank 3, the present invention also adds lifting plates 309 on both sides of the middle position of the fuel tank 3 respectively, so that each side of the fuel tank 3 has three-point stress, and the lifting stress of the fuel tank 3 is more uniform. At the same time, the present invention is provided with vertical reinforcing irons 307 arranged along the height direction and horizontal wall reinforcing irons 308 arranged along the horizontal direction on the two side walls of the fuel tank 3 to improve the wall strength. Each of the lifting plates 309 is respectively arranged on the corresponding vertical reinforcing iron 307. At the same time, the present invention also sets a cover reinforcing iron 310 on the cover of the fuel tank 3 at the upper end to improve the strength.

[0039] The working principle of the present invention is:

[0040] The utility model adopts two three-dimensional wound-core type cores to form a double-core structure. The two cores are rotationally symmetrically arranged in the oil tank. In this way, while ensuring that the insulation distance between the two cores meets the requirements, the distance between the two cores and the length of the oil tank 3 can be minimized as much as possible. At the same time, since the three phases of the three-dimensional wound-core type core are completely symmetrical, the utility model can adjust the phase sequence of the two cores according to actual needs without electrical problems. In this way, the leads can be conveniently led out from both sides of the upper end of the oil tank. The low-voltage leads of the two cores of the utility model both adopt low-voltage lead copper busbar structures, and the high-voltage leads both adopt high-voltage lead cables. At the same time, the utility model leaves enough space inside the upper end of the oil tank 3 to stagger and separate the low-voltage leads and high-voltage leads in height. In this way, it can not only ensure that the leads on the high-voltage side and the low-voltage side will not be confused, but also ensure that the leads of each winding are staggered in the height direction to ensure the insulation distance, thus avoiding the mutual influence between the leads and further avoiding the mutual influence between the two cores.

[0041] As Figures 4 to 5 shown, the two cores of the utility model can achieve two different connection group labels. The first core 1 is as Figure 4 shown, its connection group label is Dd0, with a load of 8 MVA. The second core 2 is as Figure 5 shown, its connection group label is Dyn11, with a load of 4 MVA. And as Figure 1 shown, since there is no electrical connection between the two cores, the two loads do not affect each other. Similarly, during operation, even if one winding is short-circuited, only one load is affected, and the other load can be normally powered. The loss, cost, and floor area of the product of the utility model are also superior to purchasing two transformers, having a market advantage.

[0042] The utility model fully considers the special requirements of users (the steel mill requires that the two low-voltage windings respectively drive two loads, and the connection group labels and loads of the two low-voltage windings are different and cannot affect each other). At the same time, combined with the characteristics that the three phases of the three-dimensional wound-core type core are completely symmetrical, etc., the double-core product of the utility model is formed.

Claims

1. A three-dimensional wound core type double-core distribution transformer, characterized in that: It includes an oil tank (3), a first body (1) and a second body (2) which are rotationally symmetrically arranged in the oil tank (3). The first body (1) and the second body (2) are both three-dimensional wound core type bodies and have the same structure. The first body (1) and the second body (2) both include three U-shaped cores (101). For any two adjacent side cores of the cores (101), a low-voltage winding (102), a high-voltage winding (103) and a winding shield (104) are wound around them in sequence from inside to outside. On one side of the upper end of the oil tank (3), there are a first low-voltage terminal (10) and a second low-voltage terminal (11), and on the other side, there are a first high-voltage bushing (8) and a second high-voltage bushing (9). The leads of each low-voltage winding of the first body (1) are connected to the corresponding first low-voltage terminal (10) through a first low-voltage lead copper bar (6). The leads of each low-voltage winding of the second body (2) are connected to the corresponding second low-voltage terminal (11) through a second low-voltage lead copper bar (4). The leads of each high-voltage winding of the first body (1) are connected to the corresponding first high-voltage bushing (8) through a first high-voltage lead cable (7). The leads of each high-voltage winding of the second body (2) are connected to the corresponding second high-voltage bushing (9) through a second high-voltage lead cable (5).

2. The three-dimensional wound-core type double-core distribution transformer according to claim 1, wherein: On one side of the upper end of the oil tank (3), there are a first low-voltage side mounting flange (304) and a second low-voltage side mounting flange (302), and on the other side, there are a first high-voltage side mounting flange (303) and a second high-voltage side mounting flange (301). The first low-voltage terminal (10) is arranged on the first low-voltage side mounting flange (304), the second low-voltage terminal (11) is arranged on the second low-voltage side mounting flange (302), the first high-voltage bushing (8) is arranged on the first high-voltage side mounting flange (303), and the second high-voltage bushing (9) is arranged on the second high-voltage side mounting flange (301).

3. The three-dimensional wound-core type double-core distribution transformer according to claim 1, characterized in that: The upper end of the oil tank (3) is provided with a tank cover, and on the upper side of the tank cover, there is an earthing riser with an earthing bushing. The leads of each winding shield of the first body (1) and the leads of each winding shield of the second body (2) are led out through the earthing bushing.

4. The three-dimensional wound-core type double-core distribution transformer according to claim 1, characterized in that: A shielding component is arranged on the inner wall of the oil tank (3).

5. The three-dimensional wound-core type double-core distribution transformer according to claim 4, characterized in that: The shielding component includes an aluminum shield (306) and a magnetic shield (305). The aluminum shield (306) is arranged on the inner wall of the oil tank (3), and the magnetic shield (305) is arranged on the aluminum shield (306).

6. The three-dimensional wound-core type double-core distribution transformer according to claim 1, wherein: Lifting plates (309) are arranged at the middle position and both ends of the oil tank (3).

7. The three-dimensional wound-core type double-core distribution transformer according to claim 6, characterized in that: Vertical reinforcing irons (307) arranged along the height direction and horizontal wall reinforcing irons (308) arranged along the horizontal direction are arranged on the two side walls of the oil tank (3), and the lifting plates (309) are arranged on the corresponding vertical reinforcing irons (307).

8. The three-dimensional wound-core type double-core distribution transformer according to claim 1 or 6, characterized in that: The upper end of the oil tank (3) is provided with a tank cover, and a tank cover reinforcing iron (310) is arranged on the tank cover.

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