Transformer

Abstract

The invention discloses a transformer, which relates to the technical field of transformers and comprises an upper-section oil tank edge and a lower-section oil tank edge. The upper-section oil tank edge and the lower-section oil tank edge are connected through a grounding device, the grounding device comprises a grounding sleeve and a fastener, the grounding sleeve is arranged between the upper-section oil tank edge and the lower-section oil tank edge, and two sharp ends are oppositely arranged on the grounding sleeve, so that when the fastener and the grounding sleeve are locked, the two sharp ends are connected with the upper-section oil tank edge and the lower-section oil tank edge. And the two tips respectively pierce paint films on the edges of the upper-section oil tank and the lower-section oil tank. According to the transformer provided by the invention, under the action of fastening force between the fastener and the grounding sleeve and the action of gravity of the upper-section oil tank, the two tips on the grounding sleeve can respectively pierce paint films on the edges of the upper-section oil tank and the lower-section oil tank, so that the edges of the upper-section oil tank and the lower-section oil tank can be connected through the grounding device; the potential generated by the box edge due to excitation inrush current can be effectively absorbed, and the situation that the box edge discharges during impact closing is avoided.

Description

Technical Field

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

[0002] The impact closing test is an important experimental method for testing the performance of switchgear in power systems. When the transformer is handed over for acceptance, the impact closing test is one of the important items in the transformer acceptance process.

[0003] When the transformer is closed and powered on under no-load conditions, the voltage, current, and magnetic flux of the transformer transition from one steady state to another, and an excitation surge current is generated 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. When the circuit is closed, under the action of the excitation surge current, a large leakage magnetic flux is generated instantly, which will form a loop through the transformer casing. When the upper and lower oil tank edges are tightened, a small gap is formed between the paint 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, it will break through the small gap to discharge and generate sparks, resulting in low safety and reliability of the transformer during operation.

[0004] Therefore, how to absorb the potential generated at the box edge due to the excitation surge current and improve the safety and reliability of the transformer has become a technical problem that needs to be urgently solved by technical personnel in this field. Summary of the invention

[0005] In view of this, the purpose of the present application is to provide a transformer to absorb the potential generated at the edge of the box due to the excitation surge current, thereby improving the safety and reliability of the transformer.

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

[0007] A transformer comprises an upper oil tank edge and a lower oil tank edge, wherein:

[0008] The upper fuel tank edge and the lower fuel tank edge are connected by a grounding device, and the grounding device includes a grounding sleeve and a fastener. The grounding sleeve is arranged between the upper fuel tank edge and the lower fuel tank edge, and two pointed ends are arranged opposite to each other on the grounding sleeve, so that when the fastener is locked with the grounding sleeve, the two pointed ends respectively pierce the paint film of the upper fuel tank edge and the lower fuel tank edge.

[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 flange, the first tip is located on the outward flange 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 abutted against the outwardly turned 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 flange; 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, the upper oil tank edge is provided with a first mounting hole, the lower oil tank edge is provided with a second mounting hole adapted to the first mounting hole, the first end of the grounding sleeve abuts against the hole eave of the first mounting hole, and the 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 edge of the lower oil tank, the outer diameter of the grounding sleeve is smaller than the aperture of the second mounting hole of the edge of the lower oil tank, 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 shape of the outer eaves is circular, square or triangular; and / or,

[0018] The outline shape of the grounding pad 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-mentioned transformer, there are multiple grounding devices, and the edge of the upper oil tank and the edge of the lower oil tank 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] The transformer provided by the present application, through the action of the fastening force between the fastener and the grounding sleeve and the gravity of the upper oil tank, the two pointed ends on the grounding sleeve can respectively pierce the paint film on the edge of the upper oil tank and the edge of the lower oil tank, so that the edge of the upper oil tank and the edge of the lower oil tank can be connected through the grounding device, which can effectively absorb the potential generated at the edge of the box due to the excitation surge current, avoid the discharge of the box edge during impact closing, and improve 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 combined with each other arbitrarily, as long as the combined technical features are not contradictory. All feasible feature combinations are technical contents clearly recorded in this article. Any of the multiple sub-features contained in the same sentence can be applied independently, and does not have to be applied together with other sub-features. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are merely embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0025] Figure 1 A partial schematic diagram of a transformer provided in an embodiment of the present application;

[0026] Figure 2 A schematic diagram of the structure of a grounding device provided in an embodiment of the present application;

[0027] Figure 3 A front view of a ground sleeve provided in an embodiment of the present application;

[0028] Figure 4 A top view of a ground sleeve provided in an embodiment of the present application;

[0029] Figure 5 A front view of a grounding gasket provided in an embodiment of the present application;

[0030] Figure 6A bottom view of the grounding gasket provided in an embodiment of the present application.

[0031] Wherein, 100 is the upper fuel tank edge, and 101 is the first mounting hole;

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

[0033] 300 is a grounding device, 301 is a grounding sleeve, 3011 is an outer flange, 302 is a fastener, 303 is a first tip, 304 is a second tip, 305 is a grounding gasket, 306 is a reset elastic member, and 307 is a fastening nut. DETAILED DESCRIPTION

[0034] The core of the present application is to provide a transformer to absorb the potential generated at the edge of the box due to the excitation surge current, thereby improving the safety and reliability of the transformer.

[0035] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0036] The impact closing test is an important experimental method for testing the performance of switchgear in power systems. When the transformer is handed over for acceptance, the impact closing test is one of the important items in the transformer acceptance process.

[0037] When the transformer is closed and powered on under no-load conditions, the voltage, current, and magnetic flux of the transformer transition from one steady state to another, and an excitation surge current is generated 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. When the circuit is closed, under the action of the excitation surge current, a large leakage magnetic flux is generated instantly, which will form a loop through the transformer casing. When the upper and lower oil tank edges are tightened, a small gap is formed between the paint 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, it will break through the small gap to discharge and generate sparks, resulting in low safety and reliability of the transformer during operation.

[0038] In order to better ensure the safe and reliable operation of the power transformer, the fastening bolts, washers, etc. on the edge of the upper and lower oil tanks are generally stripped of paint, or short-circuit plates are added on the short axis side of the upper and lower oil tanks to prevent discharge.

[0039] However, when depainting the fastening bolts, washers, etc., problems such as incomplete depainting and residual paint film often exist. At the same time, after depainting, fasteners such as bolts and washers will rust during long-term operation. When adding short-axis sides of the upper and lower oil tank edges, the short-axis sides may be far away from the center of the transformer body and cannot effectively absorb the electric potential generated by leakage magnetic field. At the same time, it is also impossible to guarantee that the transformer will not be corroded due to environmental factors during operation, and the material cost of adding short-axis links is high.

[0040] For this reason, Figure 1 As shown, an embodiment of the present application discloses a transformer, comprising an upper oil tank edge 100 and a lower oil tank edge 200, and the upper oil tank edge 100 and the lower oil tank edge 200 are connected by a grounding device 300, thereby effectively absorbing the potential generated by the tank edge due to the excitation surge current, avoiding the discharge of the tank edge during impact closing, and improving the safety and reliability of the transformer.

[0041] The following will be combined Figures 1 to 6 The transformer disclosed in the embodiment of the present application is specifically explained and illustrated.

[0042] Among them, Figure 1 and Figure 2 As shown, the grounding device 300 includes a grounding sleeve 301 and a fastener 302. The grounding sleeve 301 is arranged between the edge of the upper oil tank 100 and the edge of the lower oil tank 200, and two tips are arranged opposite to each other on the grounding sleeve 301. When the fastener 302 such as a bolt is used to lock the grounding sleeve 301, the two tips can pierce the paint film of the edge of the upper oil tank 100 and the edge of the lower oil tank 200 respectively under the action of the fastening force and the gravity of the upper oil tank, so that the edge of the upper oil tank 100 and the edge of the lower oil tank 200 can be connected through the grounding device 300, and the potential generated by the box edge due to the excitation surge current can be effectively absorbed, thereby avoiding the discharge of the box edge during impact closing, and improving the safety and reliability of the transformer.

[0043] In some embodiments, Figures 1 to 6As shown, for ease of understanding, the two tips provided on the ground sleeve 301 are defined as a first tip 303 and a second tip 304 respectively, and the first tip 303 and the second tip 304 are arranged opposite to each other, that is, the sharp corner of the first tip 303 and the sharp corner of the second tip 304 are arranged opposite to each other. At the same time, the grounding sleeve 301 has a first end and a second end that are relatively arranged, and the first end of the grounding sleeve 301 is provided with an outward flange 3011, the first tip 303 is located on the edge of the outward flange 3011 and is arranged in the direction of the upper oil tank edge 100, and the second end of the grounding sleeve 301 can be movably sleeved with a grounding gasket 305, and the second tip 304 is located on the edge of the grounding gasket 305 and is arranged in the direction of the lower oil tank edge 200, so that when the fastener 302 is locked with the grounding sleeve 301, the two tips can pierce the paint film of the upper oil tank edge 100 and the lower oil tank edge 200 respectively under the action of the fastening force and the gravity of the upper oil tank, so that the upper oil tank edge 100 and the lower oil tank edge 200 can be connected through the grounding device 300, and then the potential generated by the tank edge due to the excitation surge current can be effectively absorbed, avoiding the discharge of the tank edge during impact closing, thereby improving the safety and reliability of the transformer. It should be noted that the contour shapes of the outer flange 3011 and the grounding gasket 305 can be circular, square, triangular, etc., which is not limited herein.

[0044] In order to make the two tips pierce the paint film of the upper fuel tank edge 100 and the lower fuel tank edge 200 more efficiently, so as to achieve the connection between the upper fuel tank edge 100 and the lower fuel tank edge 200 through the grounding device 300, in some embodiments, as Figure 1 and Figure 2 As shown, a reset elastic member 306 is sleeved on the outer side of the grounding sleeve 301, and the two ends of the reset elastic member 306 can respectively abut against the outer flange 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 more quickly pierce the paint film of the upper and lower oil tank edges 100 and 200 under the elastic force of the reset elastic member 306, the tightening force and the gravity of the upper oil tank, effectively absorbing the potential generated by the tank edge due to the excitation inrush current, avoiding the discharge of the tank edge during impact closing, and improving the safety and reliability of the transformer. It should be noted that the reset elastic member 306 can adopt a compression spring. When the distance between the edge of the upper oil tank 100 and the edge of the lower oil tank 200 is small, the reset elastic member 306 can adopt multiple butterfly springs, which can be selected specifically according to the distance between the edge of the upper oil tank 100 and the edge of the lower oil tank 200.

[0045] In order to ensure the stability of the connection between the upper fuel tank edge 100 and the lower fuel tank edge 200 through the grounding device 300, in some embodiments, as Figure 4 and Figure 6 As shown, the first tip 303 can be arranged in a ring shape and distributed continuously along the edge of the outer flange 3011, and the second tip 304 can be arranged in a ring shape and distributed continuously along the edge of the grounding pad 305, so as to ensure the stability and reliability of the connection between the upper fuel tank edge 100 and the lower fuel tank edge 200 through the grounding device 300. Of course, the first tip 303 can also be distributed at intervals on the outer flange 3011, or the second tip 304 can be distributed at intervals on the grounding pad 305, which is not limited herein.

[0046] When installing the grounding device 300, Figure 1 As shown, the upper section oil tank edge 100 is provided with a first mounting hole 101, and the lower section oil tank edge 200 is provided with a second mounting hole 201 adapted to the first mounting hole 101, and the first end of the grounding sleeve 301 is abutted against the hole eaves 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 passed through the first mounting hole 101 and the grounding sleeve 301 in sequence from the side of the upper section oil tank edge 100 away from the lower section oil tank edge 200, and passes through the second mounting hole 201 of the lower section oil tank edge 200, and is threadedly connected through the fastening nut 307 located on the side of the lower section oil tank edge 200 away from the upper section oil tank edge 100. While fastening with the fastener 302, the reset elastic member 306 is compressed. At this time, the first tip 303 and the second tip 304 can pierce the paint film of the upper oil tank edge 100 and the lower oil tank edge 200 more quickly under the action of the elastic force of the reset elastic member 306, the tightening force and the gravity of the upper oil tank, effectively absorbing the potential generated at the tank edge due to the excitation surge current, avoiding discharge of the tank edge 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 section oil tank edge 200 to ensure that the grounding gasket 305 is located above the lower section oil tank edge 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 section oil tank edge 200 to ensure that the grounding sleeve 301 can be inserted into the second mounting hole 201 of the lower section oil tank edge 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 section oil tank edge 200 is not greater than the depth of the second mounting hole 201 of the lower section oil tank edge 200 to ensure that the fastener 302 is connected with the fastening nut 307.

[0048] At the same time, if Figure 3 and Figure 4As shown, when the contour of the outer flange 3011 of the grounding sleeve 301 is circular, the outer diameter of the outer flange 3011 needs to be larger than the aperture of the first mounting hole 101 of the upper section oil tank edge 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 section oil tank edge 200 to ensure that the grounding sleeve 301 is installed in the second mounting hole 201 without displacement.

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

[0050] Of course, there may be multiple grounding devices 300, and each grounding device 300 may be installed at multiple second mounting holes 201 along the lower oil tank 200 to prevent the situation where the grounding device 300 is too far away from the center of the transformer body and cannot effectively absorb the electric potential generated by magnetic leakage. The specific number of installations may be determined based on the transformer capacity, voltage and oil tank structure size.

[0051] In the above embodiment, the grounding device 300 may be made of hot-dip galvanized material or stainless steel material to prevent rust and the like from occurring during long-term operation of the transformer.

[0052] It can be seen from the above embodiments that the transformer provided by the present application can effectively absorb the potential generated by the box edge due to the excitation inrush current during the impact closing, and avoid the discharge of the box edge during the impact closing. At the same time, the transformer process steps can be simplified to avoid rust and corrosion caused by environmental factors. Compared with the method of adding a short-circuit piece, the material cost is reduced. At the same time, a standardized structure can be made according to the size of the fastener 302, and large-scale batch production can be carried out, which reduces the material cost and further reduces the production cost.

[0053] The terms "first" and "second" and the like in the specification and claims of this application and the above drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. 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 that are not listed.

[0054] The above 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 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. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A transformer, characterized in that: It comprises an upper fuel tank edge (100) and a lower fuel tank edge (200), wherein: The upper fuel tank edge (100) and the lower fuel tank edge (200) are connected via a grounding device (300), wherein the grounding device (300) comprises a grounding sleeve (301) and a fastener (302), wherein the grounding sleeve (301) is arranged between the upper fuel tank edge (100) and the lower fuel tank edge (200), and two pointed ends are arranged opposite to each other on the grounding sleeve (301), so that when the fastener (302) and the grounding sleeve (301) are locked, the two pointed ends pierce the paint film of the upper fuel tank edge (100) and the lower fuel tank edge (200) respectively.

2. The transformer according to claim 1, characterized in that: The tip comprises a first tip (303) and a second tip (304); the grounding sleeve (301) has a first end and a second end that are arranged opposite to each other; the first end of the grounding sleeve (301) is provided with an outwardly turned eave (3011); the first tip (303) is located on the outwardly turned eave (3011) and is arranged in a direction along (100) of the upper section oil 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 grounding gasket (305) and is arranged in a direction along (200) of the lower section oil tank.

3. The transformer according to claim 2, characterized in that: A reset elastic member (306) is sleeved on the outer side of the grounding sleeve (301), and two ends of the reset elastic member (306) are respectively in contact with the outer flange (3011) and the grounding gasket (305), so that the first tip (303) and the second tip (304) can respectively pierce the paint film of the upper section oil tank edge (100) and the lower section oil tank edge (200) under the elastic force of the reset elastic member (306).

4. The transformer according to claim 2, characterized in that: The first tip (303) is arranged in a ring shape along the edge of the outer flange (3011); and / or, The second tip (304) is arranged in a ring shape along the edge of the grounding gasket (305).

5. The transformer according to claim 2, characterized in that: The upper section oil tank edge (100) is provided with a first mounting hole (101), the lower section oil tank edge (200) is provided with a second mounting hole (201) adapted to the first mounting hole (101), a first end of the grounding sleeve (301) abuts against a hole edge of the first mounting hole (101), and a 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 section oil tank edge (100) facing away from the lower section oil tank edge (200), and is threadedly connected with a fastening nut (307) located on the side of the lower section oil tank edge (200) facing away from the upper section oil tank edge (100).

6. The transformer according to claim 5, characterized in that: The outer diameter of the grounding gasket (305) is larger than the aperture of the second mounting hole (201) of the lower fuel tank edge (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 edge (200), and the inner diameter of the grounding sleeve (301) is larger than the diameter of the fastener (302).

7. The transformer according to claim 5, characterized in that: The depth of the second end of the grounding sleeve (301) inserted into the second mounting hole (201) of the lower fuel tank edge (200) is no greater than the depth of the second mounting hole (201) of the lower fuel tank edge (200).

8. The transformer according to claim 3, characterized in that: The outline shape of the outer eaves (3011) is circular, square or triangular; and / or, The outline shape of the grounding gasket (305) is circular, square or triangular; and / or, The resetting elastic member (306) is a compression spring or a plurality of butterfly springs.

9. The transformer according to claim 1, characterized in that: There are a plurality of grounding devices (300), and the upper section fuel tank edge (100) and the lower section fuel tank edge (200) are connected via each of the grounding devices (300).

10. The transformer according to any one of claims 1 to 9, characterized in that: The grounding device (300) is made of hot-dip galvanized material or stainless steel material.

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