Copper shield for partial discharge test of transformer and transformer structure

Abstract

The utility model discloses a copper shield and transformer structure for a transformer partial discharge test, which comprises a copper plate piece, the copper plate piece is integrally bent to form a cylindrical structure, and the cylindrical copper plate piece is provided with a first edge, a second edge, a third edge and a fourth edge. The first edge and the second edge are parallel to the axis of the cylindrical copper plate piece, the first edge and the second edge are not in contact, the third edge and the fourth edge are arc edges at the two ends of the cylindrical copper plate piece correspondingly, transition parts are arranged on the third edge and the fourth edge correspondingly, and the transition parts are arranged at the two ends of the cylindrical copper plate piece correspondingly. The copper plate piece and the transition part are wrapped with insulating layers. The shielding sleeve is sleeved between a low-voltage coil and a high-voltage coil of a transformer, so that shielding between the low-voltage coil and the high-voltage coil is realized, transmission of partial discharge interference signals on a low-voltage side to a high-voltage side is reduced, background partial discharge quantity is reduced, and test accuracy is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to transformer test technical field, concretely relates to a copper shield for transformer partial discharge test and transformer structure. BACKGROUND

[0002] The transformer needs to carry out partial discharge test to detect the transformer performance in the production process, when carrying out partial discharge test, the external equipment background interference signal will carry out test interference to the partial discharge signal, and the partial discharge interference signal of low voltage side will be transmitted to high voltage side, and will further influence test data.

[0003] In the prior art test process, the protection device is set up to protect the whole transformer to reduce the test interference of external equipment background interference signal to the partial discharge signal, but the partial discharge interference signal of low voltage side will still be transmitted to high voltage side, causing the influence of background partial discharge interference on the test.

[0004] In view of the above-mentioned defects, the utility model creator finally obtains the utility model after long time research and practice. UTILITY MODEL CONTENT

[0005] In order to solve the above technical defects, the utility model adopts the technical scheme to provide a copper shield for transformer partial discharge test, which comprises a copper plate piece, the copper plate piece is integrally bent to form a cylindrical structure, the cylindrical copper plate piece is provided with a first edge, a second edge, a third edge and a fourth edge, the first edge and the second edge are parallel to the axis of the cylindrical copper plate piece, and the first edge and the second edge are not in contact, the third edge and the fourth edge are respectively the arc edges of the two ends of the cylindrical copper plate piece, the third edge and the fourth edge are provided with a transition part, and the copper plate piece and the transition part are wrapped with an insulating layer.

[0006] Preferably, the transition part is provided as a cylindrical part extending along the third edge and the fourth edge, and the transition part is provided with a connecting seam, the third edge and the fourth edge are arranged in the corresponding connecting seam, and the connecting seam is welded and fixed with the third edge or the fourth edge on both sides.

[0007] Preferably, the first edge and the second edge are fixed in a lap joint manner, the insulating layer is arranged between the first edge and the second edge, the transition part is correspondingly provided with a lap joint section at the lap joint position of the first edge and the second edge, the cross section of the lap joint section is provided as a semicircular ring type, and the lap joint section is arranged on the inner wall and the outer wall of the cylindrical copper plate piece.

[0008] Preferably, a separation gap is arranged between the first edge and the second edge, the insulating layer comprises an inner ring layer and an outer ring layer, the inner ring layer and the outer ring layer are both arranged in a cylindrical barrel type structure, the inner ring layer covers the inner wall of the cylindrical copper plate member, and the outer ring layer covers the outer wall of the cylindrical copper plate member.

[0009] Preferably, a round corner is arranged at the end of the separation gap.

[0010] Preferably, the third edge and the fourth edge are arranged as arc edges, so as to form the transition part, and the radius of the arc edges is arranged as 0.5mm-1.2mm.

[0011] Preferably, the first edge and the second edge are fixed in a lap joint mode, and the insulating layer is arranged between the first edge and the second edge.

[0012] Preferably, a separation gap is arranged between the first edge and the second edge, the insulating layer comprises an inner ring layer and an outer ring layer, the inner ring layer and the outer ring layer are both arranged in a cylindrical barrel type structure, the inner ring layer covers the inner wall of the cylindrical copper plate member, and the outer ring layer covers the outer wall of the cylindrical copper plate member.

[0013] Preferably, a round corner is arranged at the connection position of the first edge, the second edge, the third edge and the fourth edge, and the first edge and the second edge are arranged as arc edges.

[0014] Preferably, a transformer structure for transformer partial discharge test comprises a low-voltage coil, a high-voltage coil and a copper shield for transformer partial discharge test, the copper shield for transformer partial discharge test is sleeved between the low-voltage coil and the high-voltage coil, the end of a grounding lead is fixedly connected to the inner wall of the cylindrical copper plate member, the grounding lead is led out from the copper shield for transformer partial discharge test, and the grounding lead is wrapped with an insulating tape outside.

[0015] Compared with the prior art, the utility model has the beneficial effects that by sleeving the utility model between the low-voltage coil and the high-voltage coil of the transformer, shielding between the low-voltage coil and the high-voltage coil is realized, so that the transmission of partial discharge interference signals from the low-voltage side to the high-voltage side is reduced, the background partial discharge amount is reduced, and the accuracy of the test is improved. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 It is a front view of the copper shield for transformer partial discharge test in embodiment two.

[0017] Figure 2 It is a structure top view of the copper shield for transformer partial discharge test in embodiment two.

[0018] Figure 3 The lap joint structure view of the copper shielding for transformer partial discharge test embodiment two;

[0019] Figure 4 The front view cross-sectional view of the copper shielding for transformer partial discharge test embodiment three;

[0020] Figure 5 The structure top view of the copper shielding for transformer partial discharge test embodiment three;

[0021] Figure 6 The gap structure view of the copper shielding for transformer partial discharge test embodiment three;

[0022] Figure 7 The front view cross-sectional view of the copper shielding for transformer partial discharge test embodiment four;

[0023] Figure 8 The structure top view of the copper shielding for transformer partial discharge test embodiment four;

[0024] Figure 9 The lap joint structure view of the copper shielding for transformer partial discharge test embodiment four;

[0025] Figure 10 The front view cross-sectional view of the copper shielding for transformer partial discharge test embodiment five;

[0026] Figure 11 The structure top view of the copper shielding for transformer partial discharge test embodiment five;

[0027] Figure 12 The gap structure view of the copper shielding for transformer partial discharge test embodiment five;

[0028] Figure 13 The structure schematic view of the transformer structure for transformer partial discharge test;

[0029] Figure 14 The setting structure schematic view of the grounding lead.

[0030] The figure number indicates:

[0031] 1-copper plate; 2-transition part; 3-insulating layer; 4-lap joint section; 5-separation gap; 6-low voltage coil; 7-high voltage coil; 8-grounding lead; 9-insulating belt. DETAILED DESCRIPTION

[0032] The above and other technical features and advantages of the present application will be more apparent from the following description with reference to the attached drawings.

[0033] Embodiment One

[0034] The utility model discloses a copper shield for transformer partial discharge test includes copper sheet piece 1, copper sheet piece 1 whole bending forms the cylinder type structure, and the first edge and the second edge of cylinder type copper sheet piece 1 are parallel with the axis of cylinder type copper sheet piece 1, and the first edge and the second edge do not contact, and the third edge and the fourth edge are the circular arc edge of two ends on cylinder type copper sheet piece 1 respectively, and the transition part 2 is set up on the third edge and the fourth edge, and the copper sheet piece 1 and the transition part 2 outside are all wrapped with insulating layer 3.

[0035] The field intensity is most concentrated on the upper and lower ends of the copper sheet piece 1, the transition part 2 is arranged to avoid the occurrence of a sharp end on the upper and lower ends of the copper sheet piece 1, and the first edge and the second edge do not contact to ensure that the copper sheet piece 1 as a whole is not conductive to avoid the formation of a circulating current.

[0036] By sleeving the utility model between the low-voltage coil and the high-voltage coil of the transformer, shielding between the low-voltage coil and the high-voltage coil is realized, thereby reducing the transmission of partial discharge interference signals from the low-voltage side to the high-voltage side, reducing the background partial discharge amount, and improving the accuracy of the test.

[0037] Embodiment Two

[0038] As shown in Figures 1 to 3 , the copper shield for transformer partial discharge test is a front view cross-sectional view of the embodiment; Figure 1 , the copper shield for transformer partial discharge test is a structure top view of the embodiment; Figure 2 , the copper shield for transformer partial discharge test is a lap joint structure view of the embodiment. Figure 3

[0039] In the embodiment, the transition part 2 is arranged as a cylindrical piece extending along the third edge and the fourth edge, and the transition part 2 is provided with a connecting seam, the third edge and the fourth edge are arranged in the corresponding connecting seam, and the connecting seam on both sides is welded and fixed with the third edge or the fourth edge, thereby ensuring that the circular arc of the third edge and the fourth edge has no sharp end.

[0040] The first edge and the second edge are fixed in a lap joint manner, and the insulating layer 3 is arranged between the first edge and the second edge to ensure that the first edge and the second edge do not contact.

[0041] ​The transition part 2 is correspondingly provided with an overlapping section 4 at the overlapping position of the first edge and the second edge, the cross section of the overlapping section 4 is provided as a semi-circular ring type, and the overlapping section 4 is provided on the inner wall and the outer wall of the cylindrical copper plate 1, so as to avoid the influence of the setting of the transition part 2 on the overlapping position, and also ensure that the third edge and the fourth edge are not provided with sharp ends at the overlapping position.

[0042] Embodiment three

[0043] As Figures 4 to 6 shown, Figure 4 the front view of the copper shield for the transformer partial discharge test is shown in the embodiment; Figure 5 the structure top view of the copper shield for the transformer partial discharge test is shown in the embodiment; Figure 6 the gap structure view of the copper shield for the transformer partial discharge test is shown in the embodiment.

[0044] In the embodiment, the structure of the transition part 2 is consistent with that of embodiment two, and a cylindrical part extending along the third edge and the fourth edge is adopted.

[0045] Different from embodiment two, the embodiment is provided with a separation gap 5 between the first edge and the second edge, the insulation layer 3 includes an inner ring layer and an outer ring layer, both of which are provided as cylindrical structures, the inner ring layer is covered on the inner wall of the cylindrical copper plate 1, and the outer ring layer is covered on the outer wall of the cylindrical copper plate 1, so as to cover the separation gap 5 as a whole, thereby ensuring that the first edge and the second edge are not in contact while the copper plate 1 is wrapped in the insulation layer 3 as a whole to ensure the insulation effect.

[0046] The transition part 2 is provided with a round corner at the end of the separation gap 5, and the radius of the round corner is generally 0.5 mm, so as to avoid the presence of a sharp end on the transition part 2.

[0047] Embodiment four

[0048] As Figures 7 to 9 shown, Figure 7 the front view of the copper shield for the transformer partial discharge test is shown in the embodiment; Figure 8 the structure top view of the copper shield for the transformer partial discharge test is shown in the embodiment; Figure 9 the overlapping structure view of the copper shield for the transformer partial discharge test is shown in the embodiment.

[0049] In the embodiment, the third edge and the fourth edge are provided as circular arc edges, so as to form the transition part 2, and the radius of the circular arc edge is set to 0.5 mm-1.2 mm, so as to ensure that the third edge and the fourth edge do not have sharp ends.

[0050] The first edge and the second edge are fixed by overlapping, and the insulating layer 3 is provided between the first edge and the second edge to ensure that the first edge and the second edge do not contact each other.

[0051] In this embodiment, since the first edge and the second edge are closed by overlapping, the thickness at the overlap increases. In order to ensure the overall wall thickness, the thickness of the copper plate 1 is set to be small. Therefore, the radius of the arc edge is set based on the thickness of the copper plate 1.

[0052] Example 5

[0053] like Figures 10 to 12 As shown, Figure 10 This is a front cross-sectional view of the copper shield used for transformer partial discharge testing in this embodiment; Figure 11 This is a top view of the copper shield used for transformer partial discharge testing in this embodiment. Figure 12 This is a view of the gap structure of the copper shield used for transformer partial discharge testing in this embodiment.

[0054] In this embodiment, the third edge and the fourth edge are set as arc edges to form the transition portion 2. The radius of the arc edge is set to 0.5mm to 1.2mm to ensure that the third edge and the fourth edge do not have sharp points.

[0055] In this embodiment, a separation gap 5 is provided between the first edge and the second edge. The insulating layer 3 includes an inner ring layer and an outer ring layer. Both the inner ring layer and the outer ring layer are configured as cylindrical structures. The inner ring layer covers the inner wall of the cylindrical copper plate 1, and the outer ring layer covers the outer wall of the cylindrical copper plate 1, thereby completely covering the separation gap 5. This ensures that the first edge and the second edge do not contact each other, while the copper plate 1 is completely wrapped in the insulating layer 3 to ensure the insulation effect. The separation gap 5 is filled with pulp for insulation and to strengthen the structural strength.

[0056] The first and second edges are connected to the third and fourth edges with rounded corners, and the first and second edges are set as arc edges to avoid sharp points at the separation gap 5. The rounded corner radius is generally set to 1mm.

[0057] Compared with Embodiment 4, this embodiment adopts a non-lapping structure. Under the requirement of overall wall thickness, the thickness of the copper plate 1 can be set higher, which is beneficial to ensure the overall structural strength of the copper shield and the effective setting of the copper shield.

[0058] Example 6

[0059] As Figure 13 and Figure 14 shown, Figure 13 is the structure diagram of the transformer structure for transformer partial discharge test; Figure 14 is the setting structure diagram of the ground lead.

[0060] The utility model discloses a transformer structure for transformer partial discharge test, including low voltage coil 6, high voltage coil 7 and the copper shield for transformer partial discharge test, the copper shield for transformer partial discharge test is set between low voltage coil 6 and high voltage coil 7, the end of the ground lead is fixedly connected on the inner wall of the cylindrical copper plate piece 1, the ground lead 8 is led out by the copper shield for transformer partial discharge test, and the ground lead 8 is wrapped with insulating tape 9 outside.

[0061] By setting copper shield between low voltage coil 6 and high voltage coil 7, the transmission of partial discharge interference signal of low voltage side to high voltage side is reduced, to reduce the background partial discharge amount, improve the accuracy of test.

[0062] The above only is the preferred embodiment of the utility model, is only illustrative to the utility model, but is not restrictive. The professional technical personnel understands, can make many changes, modification, even equivalent to it within the spirit and scope defined in the utility model claim, but all will fall into the protection scope of the utility model.

Claims

1. A copper shield for use in a partial discharge test of a transformer, characterized in that, The copper plate member is integrally bent to form a cylindrical structure, the cylindrical copper plate member is provided with a first edge, a second edge, a third edge and a fourth edge, the first edge and the second edge are parallel to the axis of the cylindrical copper plate member, and the first edge and the second edge do not contact, the third edge and the fourth edge are circular arc edges at the two ends of the cylindrical copper plate member respectively, and the third edge and the fourth edge are provided with a transition portion.

2. The copper shield for transformer partial discharge testing of claim 1, wherein, The transition portion is provided as a cylindrical member extending along the third edge and the fourth edge, and the transition portion is provided with a connecting seam, the third edge and the fourth edge are arranged in the corresponding connecting seam, and the connecting seam is welded and fixed with the third edge or the fourth edge on both sides.

3. The copper shield for transformer partial discharge testing of claim 1, wherein, The first edge and the second edge are fixed in a lap joint manner, the first edge and the second edge are provided with the insulating layer, the transition portion is correspondingly provided with a lap joint section at the lap joint position of the first edge and the second edge, the cross section of the lap joint section is provided as a semi-circular ring, and the lap joint section is arranged on the inner wall and the outer wall of the cylindrical copper plate member.

4. The copper shield for transformer partial discharge testing of claim 2, wherein, The first edge and the second edge are provided with a separation gap, the insulating layer comprises an inner ring layer and an outer ring layer, the inner ring layer and the outer ring layer are both provided as a cylindrical structure, the inner ring layer covers the inner wall of the cylindrical copper plate member, and the outer ring layer covers the outer wall of the cylindrical copper plate member.

5. The copper shield for transformer partial discharge testing of claim 4, wherein, The transition portion is provided with a fillet at the end of the separation gap.

6. The copper shield for transformer partial discharge testing of claim 1, wherein, The third edge and the fourth edge are provided as circular arc edges to form the transition portion, and the radius of the circular arc edge is 0.5mm-1.2mm.

7. The copper shield for transformer partial discharge testing of claim 6, wherein, The first edge and the second edge are fixed in a lap joint manner, and the first edge and the second edge are provided with the insulating layer.

8. The copper shield for transformer partial discharge testing of claim 6, wherein, The first edge and the second edge are provided with a separation gap, the insulating layer comprises an inner ring layer and an outer ring layer, the inner ring layer and the outer ring layer are both provided as a cylindrical structure, the inner ring layer covers the inner wall of the cylindrical copper plate member, and the outer ring layer covers the outer wall of the cylindrical copper plate member.

9. The copper shield for transformer partial discharge testing of claim 8, wherein, The first edge, the second edge, the third edge and the fourth edge are connected in a round corner transition manner, and the first edge and the second edge are provided as circular arc edges.

10. A transformer structure for a partial discharge test of a transformer, characterized by The copper shield for transformer partial discharge test is arranged between the low-voltage coil and the high-voltage coil, the end of the grounding lead is fixedly connected to the inner wall of the cylindrical copper plate member, the grounding lead is led out from the copper shield for transformer partial discharge test, and the grounding lead is wrapped with an insulating tape.

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