A transformer

Abstract

The present application discloses a transformer, which relates to the technical field of transformers and includes an upper tank flange and a lower tank flange; the upper tank flange and the lower tank flange are connected through a grounding device, and the grounding device includes a grounding sleeve and a fastener. The grounding sleeve is arranged between the upper tank flange and the lower tank flange, and two tips are oppositely arranged on the grounding sleeve, so that when the fastener is locked with the grounding sleeve, the two tips respectively pierce the paint films of the upper tank flange and the lower tank flange. For the transformer provided by the present application, under the action of the fastening force between the fastener and the grounding sleeve and the gravity of the upper tank, the two tips on the grounding sleeve can respectively pierce the paint films of the upper tank flange and the lower tank flange, so that the upper tank flange and the lower tank flange can be connected through the grounding device, effectively eliminating the potential generated at the flange due to the magnetizing inrush current and avoiding the situation of flange discharge during the impact closing.

Description

Technical Field

[0001] This application relates to the technical field of transformers, and more specifically, to a transformer. Background Art

[0002] The switching-on test is an important experimental method for testing the performance of switchgear in a power system. When a transformer is undergoing handover acceptance, the switching-on test is one of the important items in the transformer acceptance process.

[0003] When a transformer is switched on and energized under no-load conditions, the voltage, current, and magnetic flux of the transformer transition from one steady state to another. An exciting inrush current is generated instantaneously at the moment of switching on. For a small-capacity transformer, it can reach a steady state within a few tenths of a second, while for a large-capacity transformer, it may take more than ten seconds to stabilize. Under the action of the exciting inrush current during switching on, a very large instantaneous leakage magnetic flux is generated, which forms a loop through the outer shell of the transformer. When the upper tank flange and the lower tank flange are tightened, small gaps are formed in the paint film or between the screws. At this time, when the potential difference generated by the leakage magnetic flux reaches the breakdown voltage value of the air gap, the small gap will be broken down and discharge will occur, generating sparks, resulting in relatively low safety and reliability of the transformer during operation.

[0004] Therefore, how to eliminate the potential generated at the tank flange due to the exciting inrush current and improve the safety and reliability of the transformer has become a technical problem that needs to be solved urgently by those skilled in the art. Summary of the Invention

[0005] In view of this, the purpose of this application is to provide a transformer to eliminate the potential generated at the tank flange due to the exciting inrush current and improve the safety and reliability of the transformer.

[0006] To achieve the above purpose, this application provides the following technical solutions:

[0007] A transformer includes an upper tank flange and a lower tank flange, wherein:

[0008] The upper tank flange and the lower tank flange are connected through a grounding device. The grounding device includes a grounding sleeve and a fastener. The grounding sleeve is arranged between the upper tank flange and the lower tank flange, and two tips are oppositely arranged on the grounding sleeve, so that when the fastener is locked with the grounding sleeve, the two tips respectively pierce the paint films of the upper tank flange and the lower tank flange.

[0009] Optionally, in the above-mentioned transformer, the tip includes a first tip and a second tip, the grounding sleeve has a first end and a second end arranged opposite to each other, the first end of the grounding sleeve is provided with an outward-flashed eaves, the first tip is located on the outward-flashed eaves and is arranged in the direction of the edge of the upper oil tank, the second end of the grounding sleeve is movably provided with a grounding gasket, the second tip is located on the grounding gasket and is arranged in the direction of the edge of the lower oil tank.

[0010] Optionally, in the above-mentioned transformer, a reset elastic member is sleeved on the outer side of the grounding sleeve, and the two ends of the reset elastic member are respectively in contact with the outward eaves and the grounding gasket, so that the first tip and the second tip can respectively pierce the paint film of the upper oil tank edge and the lower oil tank edge under the elastic force of the reset elastic member.

[0011] Optionally, in the above transformer, the first tip is arranged in a ring shape along the edge of the outer eaves; and / or,

[0012] The second tip is arranged in a ring shape along the edge of the grounding pad.

[0013] Optionally, in the above transformer, a first mounting hole is provided on the edge of the upper oil tank, a second mounting hole adapted to the first mounting hole is provided on the edge of the lower oil tank, a first end of the grounding sleeve abuts against a hole edge of the first mounting hole, and a second end of the grounding sleeve extends into the second mounting hole;

[0014] The fastener passes through the first mounting hole and the grounding sleeve in sequence from the side of the upper section oil tank box edge facing away from the lower section oil tank box edge, and is threadedly connected with the fastening nut located on the side of the lower section oil tank box edge facing away from the upper section oil tank box edge.

[0015] Optionally, in the above-mentioned transformer, the outer diameter of the grounding gasket is larger than the aperture of the second mounting hole of the lower oil tank edge, the outer diameter of the grounding sleeve is smaller than the aperture of the second mounting hole of the lower oil tank edge, and the inner diameter of the grounding sleeve is larger than the diameter of the fastener.

[0016] Optionally, in the above transformer, the depth of the second end of the grounding sleeve inserted into the second mounting hole of the edge of the lower oil tank is not greater than the depth of the second mounting hole of the edge of the lower oil tank.

[0017] Optionally, in the above transformer, the outline of the outer eaves is circular, square or triangular; and / or,

[0018] The outline shape of the grounding gasket is circular, square or triangular; and / or,

[0019] The resetting elastic member is a compression spring or a plurality of butterfly springs.

[0020] Optionally, in the above transformer, there are multiple grounding devices, and the upper tank flange and the lower tank flange are connected through each of the grounding devices.

[0021] Optionally, in the above transformer, the grounding device is made of hot-dip galvanized material or stainless steel material.

[0022] In the transformer provided by this application, under the action of the fastening force between the fastener and the grounding sleeve and the gravity of the upper tank, the two tips on the grounding sleeve can respectively pierce the paint films on the upper tank flange and the lower tank flange, so that the upper tank flange and the lower tank flange can be connected through the grounding device, effectively eliminating the potential generated on the flange due to inrush current, avoiding the situation of flange discharge during impact closing, and improving the safety and reliability of the transformer.

[0023] The technical features mentioned above, the technical features to be mentioned below, and the technical features shown separately in the drawings can be arbitrarily combined with each other, as long as the combined technical features are not contradictory. All feasible feature combinations are the technical contents clearly recorded in this article. Any one of the sub-features included in the same sentence can be independently applied without necessarily being applied together with other sub-features. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to the provided drawings.

[0025] Figure 1 It is a partial schematic diagram of the transformer provided by the embodiment of the present application;

[0026] Figure 2 It is a structural schematic diagram of the grounding device provided by the embodiment of the present application;

[0027] Figure 3 It is a front view of the grounding sleeve provided by the embodiment of the present application;

[0028] Figure 4 It is a top view of the grounding sleeve provided by the embodiment of the present application;

[0029] Figure 5 It is a front view of the grounding gasket provided by the embodiment of the present application;

[0030] Figure 6The bottom view of the grounding gasket provided by the embodiment of the present application.

[0031] Among them, 100 is the edge of the upper fuel tank section, and 101 is the first mounting hole;

[0032] 200 is the edge of the lower fuel tank section, and 201 is the second mounting hole;

[0033] 300 is the grounding device, 301 is the grounding sleeve, 3011 is the outward turned eaves, 302 is the fastener, 303 is the first tip, 304 is the second tip, 305 is the grounding gasket, 306 is the reset elastic member, and 307 is the fastening nut. Detailed implementation manners

[0034] The core of the present application is to provide a transformer to absorb the potential generated at the edge of the fuel tank due to inrush current and improve the safety and reliability of the transformer.

[0035] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0036] The impulse closing test is an important experimental method for testing the performance of switchgear in the power system. When a transformer is subject to handover acceptance, the impulse closing test is one of the important items in the transformer acceptance process.

[0037] When the transformer is switched on with no load, the voltage, current, and magnetic flux of the transformer transition from one steady state to another. An inrush current is generated instantaneously at the moment of closing. A small-capacity transformer can reach a steady state within a few tenths of a second, while a large-capacity transformer may take more than ten seconds to stabilize. Under the action of the inrush current during impulse closing, a large instantaneous leakage magnetic flux is generated and forms a loop through the outer shell of the transformer. When there are small gaps formed by the paint film between the edges of the upper fuel tank section and the lower fuel tank section during fastening or small gaps between the screws, and when the potential difference generated by the leakage magnetic flux reaches the breakdown voltage value of the air gap, the small gap will be broken down and discharge and generate sparks, resulting in low safety and reliability during the operation of the transformer.

[0038] In order to better ensure the safety and reliability of the power transformer during operation, generally, the paint on the fastening bolts and washers between the edges of the upper fuel tank section and the lower fuel tank section is removed, or a short-circuiting piece is added on the short-axis side between the edges of the upper fuel tank section and the lower fuel tank section to prevent discharge.

[0039] However, when degreasing fastening bolts, washers, etc., there are often problems such as incomplete degreasing and residual paint film. At the same time, after degreasing, fasteners such as bolts and washers will rust during long-term operation. When adding a shorting piece on the short-axis side of the upper tank rim and the lower tank rim, there may be a situation where the short-axis side is far from the center of the transformer core, so it cannot effectively absorb the potential generated by leakage magnetic flux. At the same time, it is also impossible to ensure that problems such as rusting occur during the operation of the transformer due to environmental factors, and the material cost of adding a shorting piece is relatively high.

[0040] Therefore, as Figure 1 shown, an embodiment of the present application discloses a transformer, which includes an upper tank rim 100 and a lower tank rim 200, and the upper tank rim 100 and the lower tank rim 200 are connected through a grounding device 300, so as to effectively absorb the potential generated by the tank rim due to inrush current, avoid the situation of the tank rim discharging during switching on with voltage, and improve the safety and reliability of the transformer.

[0041] Next, the transformer disclosed in the embodiments of the present application will be specifically explained and described in conjunction with Figures 1 to 6 this.

[0042] Among them, as Figure 1 and Figure 2 shown, the grounding device 300 includes a grounding sleeve 301 and a fastener 302. The grounding sleeve 301 is arranged between the upper tank rim 100 and the lower tank rim 200, and two tips are oppositely arranged on the grounding sleeve 301. When using a fastener 302 such as a bolt to lock with the grounding sleeve 301, the two tips can respectively pierce the paint films of the upper tank rim 100 and the lower tank rim 200 under the action of the fastening force and the gravity of the upper tank, so as to realize the connection between the upper tank rim 100 and the lower tank rim 200 through the grounding device 300. Furthermore, the potential generated by the tank rim due to inrush current can be effectively absorbed, the situation of the tank rim discharging during switching on with voltage can be avoided, and the safety and reliability of the transformer are improved.

[0043] In some embodiments, as Figures 1 to 6As shown, for the convenience of understanding, the two tips provided on the grounding sleeve 301 are respectively defined as the first tip 303 and the second tip 304, and the first tip 303 and the second tip 304 are arranged oppositely, that is, the sharp corners of the first tip 303 and the second tip 304 are arranged away from each other. At the same time, the grounding sleeve 301 has a first end and a second end arranged oppositely, and the first end of the grounding sleeve 301 is provided with an outward-turning eaves 3011. The first tip 303 is located on the edge of the outward-turning eaves 3011 and is arranged towards the edge 100 of the upper-section fuel tank. The second end of the grounding sleeve 301 is movably sleeved with a grounding gasket 305. The second tip 304 is located on the edge of the grounding gasket 305 and is arranged towards the edge 200 of the lower-section fuel tank. So that when the fastener 302 is locked with the grounding sleeve 301, the two tips can respectively pierce the paint films on the edge 100 of the upper-section fuel tank and the edge 200 of the lower-section fuel tank under the action of the fastening force and the gravity of the upper-section fuel tank, thereby realizing the connection between the edge 100 of the upper-section fuel tank and the edge 200 of the lower-section fuel tank through the grounding device 300. Furthermore, the potential generated at the edge due to the magnetizing inrush current can be effectively dissipated, avoiding the situation of edge discharge during the impact closing, and improving the safety and reliability of the transformer. It should be noted that the contour shapes of the outward-turning eaves 3011 and the grounding gasket 305 can be circular, square, triangular, etc., which are not limited herein.

[0044] In order to enable the two tips to pierce the paint films on the edge 100 of the upper-section fuel tank and the edge 200 of the lower-section fuel tank more efficiently, so as to realize the connection between the edge 100 of the upper-section fuel tank and the edge 200 of the lower-section fuel tank through the grounding device 300, in some embodiments, as Figure 1 and Figure 2 shown, a reset elastic member 306 is sleeved on the outer side of the grounding sleeve 301, and both ends of the reset elastic member 306 can respectively abut against the outward-turning eaves 3011 and the grounding gasket 305. When the fastener 302 is locked with the grounding sleeve 301, the reset elastic member 306 is compressed. At this time, the first tip 303 and the second tip 304 can pierce the paint films on the edge 100 of the upper-section fuel tank and the edge 200 of the lower-section fuel tank more quickly under the action of the elastic force of the reset elastic member 306, the fastening force, and the gravity of the upper-section fuel tank, effectively dissipating the potential generated at the edge due to the magnetizing inrush current, avoiding the situation of edge discharge during the impact closing, and improving the safety and reliability of the transformer. It should be noted that the reset elastic member 306 can be a compression spring. When the distance between the edge 100 of the upper-section fuel tank and the edge 200 of the lower-section fuel tank is relatively small, the reset elastic member 306 can be a plurality of disc springs, which can be specifically selected according to the distance between the edge 100 of the upper-section fuel tank and the edge 200 of the lower-section fuel tank.

[0045] In order to ensure the stability of the connection between the edge 100 of the upper-section fuel tank and the edge 200 of the lower-section fuel tank through the grounding device 300, in some embodiments, asFigure 4 and Figure 6 As shown in Figure 6 , the first tip 303 can be annularly arranged and continuously distributed along the edge of the everted eaves 3011, and at the same time, the second tip 304 can be annularly arranged and continuously distributed along the edge of the grounding gasket 305, so as to ensure the stability and reliability of the connection between the upper tank rim 100 and the lower tank rim 200 through the grounding device 300. Of course, the first tip 303 can also be spaced apart on the everted eaves 3011, or the second tip 304 can be spaced apart on the grounding gasket 305, which is not limited herein.

[0046] When installing the grounding device 300, as Figure 1 shown, the upper tank rim 100 is provided with a first mounting hole 101, and at the same time, the lower tank rim 200 is provided with a second mounting hole 201 adapted to the first mounting hole 101. The first end of the grounding sleeve 301 is abutted against the hole edge of the first mounting hole 101, and the second end of the grounding sleeve 301 extends into the second mounting hole 201. At this time, the fastener 302 is sequentially passed through the first mounting hole 101 and the grounding sleeve 301 from the side of the upper tank rim 100 facing away from the lower tank rim 200, and passes through the second mounting hole 201 of the lower tank rim 200, and is threadedly fitted and connected by a fastening nut 307 located on the side of the lower tank rim 200 facing away from the upper tank rim 100. While the fastener 302 is being tightened, the reset elastic member 306 is compressed. At this time, under the action of the elastic force of the reset elastic member 306, the fastening force, and the gravity of the upper tank, the first tip 303 and the second tip 304 can more quickly pierce the paint film of the upper tank rim 100 and the lower tank rim 200, effectively eliminating the potential generated by the inrush current on the tank rim, avoiding the situation of tank rim discharge during impact closing, and improving the safety and reliability of the transformer.

[0047] It should be noted that for the convenience of installation, the outer diameter of the grounding gasket 305 needs to be larger than the aperture of the second mounting hole 201 of the lower tank rim 200 to ensure that the grounding gasket 305 is located above the lower tank rim 200. At the same time, the outer diameter of the grounding sleeve 301 needs to be slightly smaller than the aperture of the second mounting hole 201 of the lower tank rim 200 to ensure that the grounding sleeve 301 can be inserted into the second mounting hole 201 of the lower tank rim 200, and the inner diameter of the grounding sleeve 301 is larger than the diameter of the fastener 302. The insertion depth of the second end of the grounding sleeve 301 into the second mounting hole 201 of the lower tank rim 200 is not greater than the depth of the second mounting hole 201 of the lower tank rim 200 to ensure the mating connection between the fastener 302 and the fastening nut 307.

[0048] At the same time, as Figure 3 and Figure 4As shown in the figure, when the contour of the outer turned edge 3011 of the grounding sleeve 301 is circular, the outer diameter of the outer turned edge 3011 needs to be greater than the aperture of the first mounting hole 101 of the upper fuel tank rim 100 to limit the upward displacement of the grounding device 300. And the second end of the grounding sleeve 301 is inserted into the second mounting hole 201 of the lower fuel tank rim 200 to ensure that the grounding sleeve 301 does not displace when installed in the second mounting hole 201.

[0049] In addition, as Figure 5 and Figure 6 shown in the figure, when the contour of the grounding gasket 305 is circular, the outer diameter of the grounding gasket 305 needs to be greater than the aperture of the second mounting hole 201 of the lower fuel tank rim 200, and the inner diameter of the grounding gasket 305 is slightly greater than the outer diameter of the grounding sleeve 301 to limit the downward displacement of the grounding device 300.

[0050] Of course, there can also be multiple grounding devices 300, and each grounding device 300 can be installed at multiple second mounting holes 201 of the lower fuel tank rim 200 to prevent the situation that the potential generated by leakage magnetic flux cannot be effectively absorbed due to being far from the center of the transformer core. The specific number of installations can be determined according to the transformer capacity, voltage, and the size of the fuel tank structure.

[0051] In the above embodiments, the grounding device 300 can be made of hot-dip galvanized material or stainless steel material to prevent rusting and other phenomena during the long-term operation of the transformer.

[0052] As can be seen from the above embodiments, the transformer provided by the present application can effectively absorb the potential generated at the fuel tank rim due to inrush current during impulse closing, avoiding the situation of fuel tank rim discharge during impulse closing. At the same time, it can simplify the transformer process treatment steps, avoid problems such as rusting and corrosion caused by environmental factors. Compared with the method of adding short-circuiting pieces, it reduces the material cost. At the same time, it can be made into a standardized structural form according to the size of the fastener 302, enabling large-scale mass production, further reducing the production and manufacturing cost while reducing the material cost.

[0053] The terms "first" and "second" etc. in the description, claims, and the above drawings of the present application are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may include steps or units not listed.

[0054] The foregoing description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A transformer, characterized in that, It includes the upper tank rim (100) and the lower tank rim (200), where: The upper tank rim (100) and the lower tank rim (200) are connected by a grounding device (300). The grounding device (300) includes a grounding sleeve (301) and a fastener (302). The grounding sleeve (301) is arranged between the upper tank rim (100) and the lower tank rim (200), and two tips are oppositely arranged on the grounding sleeve (301), so that when the fastener (302) is locked with the grounding sleeve (301), the two tips respectively pierce the paint films of the upper tank rim (100) and the lower tank rim (200); The tips include a first tip (303) and a second tip (304). The grounding sleeve (301) has a first end and a second end arranged oppositely. An outward flange (3011) is arranged at the first end of the grounding sleeve (301). The first tip (303) is located on the outward flange (3011) and is arranged in the direction towards the upper tank rim (100). A grounding gasket (305) is movably sleeved on the second end of the grounding sleeve (301). The second tip (304) is located on the grounding gasket (305) and is arranged in the direction towards the lower tank rim (200); A reset elastic member (306) is sleeved on the outer side of the grounding sleeve (301). Two ends of the reset elastic member (306) respectively abut against the outward flange (3011) and the grounding gasket (305), so that the first tip (303) and the second tip (304) respectively pierce the paint films of the upper tank rim (100) and the lower tank rim (200) under the elastic force of the reset elastic member (306); When the fastener (302) is locked with the grounding sleeve (301), the reset elastic member (306) is compressed, and the first tip (303) and the second tip (304) pierce the paint films of the upper tank rim (100) and the lower tank rim (200) under the elastic force of the reset elastic member (306), the fastening force of the fastener (302), and the gravity of the upper tank, so as to eliminate the potential generated at the tank rim due to the magnetizing inrush current; The upper tank rim (100) is provided with a first mounting hole (101), and the lower tank rim (200) is provided with a second mounting hole (201) adapted to the first mounting hole (101). The first end of the grounding sleeve (301) abuts against the hole rim of the first mounting hole (101), and the second end of the grounding sleeve (301) extends into the second mounting hole (201); The fastener (302) passes through the first mounting hole (101) and the grounding sleeve (301) in sequence from the side of the upper fuel tank rim (100) facing away from the lower fuel tank rim (200), and is threadedly connected to the fastening nut (307) located on the side of the lower fuel tank rim (200) facing away from the upper fuel tank rim (100); The outer diameter of the grounding gasket (305) is larger than the aperture of the second mounting hole (201) of the lower fuel tank rim (200), the outer diameter of the grounding sleeve (301) is smaller than the aperture of the second mounting hole (201) of the lower fuel tank rim (200), and the inner diameter of the grounding sleeve (301) is larger than the diameter of the fastener (302); The depth of the second end of the grounding sleeve (301) inserted into the second mounting hole (201) of the lower fuel tank rim (200) is not greater than the depth of the second mounting hole (201) of the lower fuel tank rim (200).

2. The transformer according to claim 1, characterized in that, The first tip (303) is annularly arranged along the edge of the outer flanging (3011); and / or, The second tip (304) is annularly arranged along the edge of the grounding gasket (305).

3. The transformer according to claim 1, characterized in that, The contour shape of the outer flanging (3011) is circular, square or triangular; and / or, The contour shape of the grounding gasket (305) is circular, square or triangular; and / or, The restoring elastic member (306) is a compression spring or a plurality of disc springs.

4. The transformer according to claim 1, characterized in that, There are multiple grounding devices (300), and the upper fuel tank rim (100) and the lower fuel tank rim (200) are connected by each grounding device (300).

5. The transformer according to any one of claims 1 to 4, characterized in that, The grounding device (300) is made of hot-dip galvanized material or stainless steel material.

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