Internal discharge fault test electrode device based on large power transformer entity and installation method

Abstract

The invention discloses an internal discharge fault test electrode device based on a large power transformer entity and an installation method. The internal discharge fault test electrode device comprises a grounding installation plate, a grounding copper strip connected with the grounding installation plate, a ground end pin electrode, a ground end disc electrode and a high-voltage pin electrode. According to the method, the internal structure of the large power transformer can be fully utilized to realize the high-voltage electrode tip, the ground electrode tip and the disc-shaped ground electrode, so that various discharge defects in the large power transformer are overcome. According to the electrode design, the interior of the large power transformer is not greatly changed, but the development of various discharge defects in the large power transformer can be researched.

Description

Technical Field

[0001] The present invention relates to the technical field of power transformer protection, and particularly relates to an internal discharge fault test electrode device and an installation method for a large power transformer entity. Background Art

[0002] At present, the research on internal discharge faults of transformers is mostly limited to research on scaled-down models. The main reasons are as follows: The physical large power transformers are huge in size and high in cost; the requirements for test sites are also very high; the maintenance costs such as oil filtration are high. For the development laws of most discharges, it is feasible to use scaled-down models. However, the internal discharges of large transformer entities cannot be fully reflected by scaled-down models alone in terms of the influence brought by size effects. Summary of the Invention

[0003] Object of the Invention: The present invention provides an internal discharge fault test electrode device and an installation method for a large power transformer entity, which can combine various discharge tests inside the transformer and provide a real test environment for internal discharge fault tests of large power transformers.

[0004] Technical Solution: An internal discharge fault test electrode device for a large power transformer entity proposed by the present invention includes a grounding mounting plate, a grounding copper strip, a ground electrode, and a bushing grading sphere; the lower end of the grounding mounting plate is fixed on the transformer vertical pole, one end of the grounding copper strip is fixedly connected to the grounding mounting plate, and the other end is connected to the oil tank wall; the ground electrode is fixed on the grounding mounting plate, and the ground electrode cooperates with the bushing grading sphere.

[0005] Preferably, the ground electrode is a ground-end needle electrode, one end of the ground-end needle electrode is a tip, and the other end is a threaded body, and the threaded body of the ground-end needle electrode is fixedly connected to the grounding mounting plate.

[0006] Preferably, the ground electrode is a ground-end disc electrode, one end of the ground-end disc electrode is a disc-shaped electrode, and the other end is a threaded body. The threaded body of the ground-end disc electrode is fixedly connected to the grounding mounting plate. A high-voltage needle electrode is provided on the bushing grading sphere. The high-voltage needle electrode includes an arc-shaped metal sheet and a needle electrode welded to the arc-shaped metal sheet, and the arc-shaped metal sheet of the high-voltage needle electrode is fixed on the bushing grading sphere.

[0007] Preferably, the grounding mounting plate is made of metal and is bent at 90°.

[0008] Preferably, the material of the ground-end needle electrode is selected from copper electrode, iron electrode, or tungsten electrode.

[0009] Preferably, the materials of the ground-end disc electrode and the high-voltage needle electrode are selected from copper electrode, iron electrode, or tungsten electrode.

[0010] Preferably, the inner diameter of the arc-shaped metal sheet is matched with the grading ball of the bushing.

[0011] Preferably, the grounding mounting plate is provided with a vertical pole fixing hole, a copper strip mounting hole and a threaded hole. The lower end of the grounding mounting plate is fixedly connected to the vertical pole of the transformer through the vertical pole fixing hole. The middle part of the side of the grounding mounting plate is connected to the grounding copper strip through the copper strip mounting hole. The upper end of the grounding mounting plate is respectively connected to the ground terminal needle electrode and the ground terminal disc electrode through the threaded holes.

[0012] Preferably, the ground terminal needle electrode and the ground terminal disc electrode are respectively matched with the threaded holes to adjust the discharge distance between the electrodes.

[0013] An installation method for an internal discharge fault test electrode device based on a large power transformer entity includes the following steps:

[0014] S1: The lower end of the grounding mounting plate is fixedly installed on the vertical pole of the transformer through the vertical pole fixing hole;

[0015] S2: Connect and fix the double-hole end of the grounding copper strip to the copper strip mounting hole of the grounding mounting plate, and bolt the other end of the grounding copper strip to the oil tank wall for fixing;

[0016] S3: Connect the ground electrode to the grounding mounting plate and conduct a discharge test; the ground electrode is the ground terminal needle electrode or the ground terminal disc electrode; when the ground electrode is the ground terminal needle electrode, the tip of the ground terminal needle electrode faces the grading ball of the bushing, and this is the discharge test of the ground electrode to high voltage at this time; when the ground electrode is the ground terminal disc electrode, a high voltage needle electrode is installed on the grading ball of the bushing. At this time, the disc-shaped electrode of the ground terminal disc electrode faces the needle electrode of the high voltage needle electrode on the grading ball of the bushing, and this is the discharge test of high voltage to the ground electrode at this time.

[0017] Beneficial effects: The method of the present invention simplifies the structural design by arranging electrodes inside the large power transformer without welding electrodes on the oil tank or clamping parts. Moreover, through the cooperation of the electrode threads and the grounding mounting plate, the adjustment of the discharge gap can be realized, simulating various internal discharges in the real environment, and further improving the accuracy of the research on the internal discharge law of the large power transformer. Description of the Drawings

[0018] Figure 1 It is the overall structure diagram of the device during the discharge test of the ground electrode to high voltage of the present invention;

[0019] Figure 2 It is the overall structure diagram of the device during the discharge test of high voltage to the ground electrode of the present invention;

[0020] Figure 3 It is the structural schematic diagram of the grounding mounting plate of the present invention;

[0021] Figure 4Schematic diagram of the grounding copper strip structure of the present invention;

[0022] Figure 5 Schematic diagram of the ground-end needle electrode structure of the present invention;

[0023] Figure 6 Schematic diagram of the ground-end disc electrode structure of the present invention;

[0024] Figure 7 Schematic diagram of the high-voltage needle electrode structure of the present invention. Detailed implementation manners

[0025] The following further describes the present invention in detail with reference to the Figures 1 - 7 accompanying drawings and embodiments.

[0026] Embodiment 1

[0027] As Figure 1 shown, an internal discharge fault test electrode device for a large power transformer entity includes a grounding mounting plate 1, a grounding copper strip 2, a ground electrode, and a bushing grading ball 8; the grounding mounting plate 1 is bent at 90°, the lower end of the grounding mounting plate 1 is fixed on the transformer vertical pole 6, one end of the grounding copper strip 2 is fixedly connected to the grounding mounting plate 1, and the other end is connected to the oil tank wall 7; the ground electrode is fixed on the grounding mounting plate 1, the ground electrode is a ground-end needle electrode 3, one end of the ground-end needle electrode 3 is a tip, and the other end is a threaded body. The threaded body of the ground-end needle electrode 3 is fixedly connected to the grounding mounting plate 1, and the tip of the ground-end needle electrode 3 cooperates with the bushing grading ball 8 for a discharge test.

[0028] As Figure 3 shown, the grounding mounting plate 1 is made of a metal material and can be bent from a steel plate or a copper plate. A vertical pole fixing hole 11, a copper strip mounting hole 12, and a threaded hole 13 are provided thereon. The lower end of the grounding mounting plate 1 is fixedly connected to the transformer vertical pole 6 through the vertical pole fixing hole 11, the middle part of the side of the grounding mounting plate 1 is connected to the grounding copper strip 2 through the copper strip mounting hole 12, and the upper end of the grounding mounting plate 1 is connected to the ground-end needle electrode 3 through the threaded hole 13.

[0029] As Figure 4 shown, both ends of the grounding copper strip 2 are perforated. One end has double holes for connection to the grounding mounting plate 1; the other end has a hole for connection to the oil tank wall 7.

[0030] As Figure 5 shown, the ground-end needle electrode 3 is made of a metal material, preferably a tungsten electrode. If it is not easy to implement, a copper electrode or an iron electrode can also be used. One end of the ground-end needle electrode 3 is a tip with taper requirements and tip curvature requirements, and the rest is an external thread. The ground-end needle electrode 3 can adjust the discharge distance between electrodes through the thread.

[0031] The installation method of the internal discharge fault test electrode device for large power transformer entities provided in this embodiment includes the following steps:

[0032] Step 1: Align the installation holes at the lower end of the grounding mounting plate 1 with the fixing holes at the upper end of the transformer vertical pole 6, and install the grounding mounting plate on the vertical pole. The bent part of the grounding mounting plate contacts two surfaces of the transformer vertical pole 6, which can effectively fix the grounding mounting plate 1;

[0033] Step 2: Connect and fix the double-hole end of the grounding copper strip 2 to the grounding mounting plate 1, and connect and fix the other end of the grounding copper strip 2 to the bolt on the oil tank wall 7, so as to make the grounding mounting plate 2 at ground potential;

[0034] Step 3: Connect the threaded body of the ground end needle electrode 3 to the threaded hole 13 of the grounding mounting plate 1, and make the tip of the ground end needle electrode 3 face the bushing grading ball 8. The ground end needle electrode 3 controls the distance between the ground end needle electrode 3 and the bushing grading ball 8 through the thread. At this time, it is the ground electrode to high-voltage discharge test.

[0035] Embodiment 2

[0036] As Figure 2 shown, an internal discharge fault test electrode device for large power transformer entities includes a grounding mounting plate 1, a grounding copper strip 2, a ground electrode, and a bushing grading ball 8; the grounding mounting plate 1 is bent at 90°, the lower end of the grounding mounting plate 1 is fixed on the transformer vertical pole 6, one end of the grounding copper strip 2 is fixedly connected to the grounding mounting plate 1, and the other end is connected to the oil tank wall 7; the ground electrode is fixed on the grounding mounting plate 1, the ground electrode is a ground end disc electrode 4, one end of the ground end disc electrode 4 is a disc-shaped electrode, and the other end is a threaded body. The threaded body of the ground end disc electrode 4 is fixedly connected to the grounding mounting plate 1; a high-voltage needle electrode 5 is provided on the bushing grading ball 8. The high-voltage needle electrode 5 includes an arc-shaped metal sheet 51 and a needle electrode 52 welded to the arc-shaped metal sheet 51. The arc-shaped metal sheet 51 of the high-voltage needle electrode 5 is fixed on the bushing grading ball 8.

[0037] As Figure 3 shown, the grounding mounting plate 1 is made of metal material, which can be bent from a steel plate or a copper plate. A vertical pole fixing hole 11, a copper strip mounting hole 12, and a threaded hole 13 are opened on it. The lower end of the grounding mounting plate 1 is fixedly connected to the transformer vertical pole 6 through the vertical pole fixing hole 11. The middle part of the side of the grounding mounting plate 1 is connected to the grounding copper strip 2 through the copper strip mounting hole 12. The upper end of the grounding mounting plate 1 is connected to the ground end disc electrode 4 through the threaded hole 13.

[0038] As Figure 4 shown, both ends of the grounding copper strip 2 are opened with holes. One end has double holes for connecting to the grounding mounting plate 1; the other end has a hole for connecting to an equipotential point such as a clamp or a tank wall.

[0039] AsFigure 6 As shown, the ground terminal plate electrode 4 is made of a metal material, preferably a tungsten electrode. If it is not easy to implement, a copper electrode or an iron electrode can also be used. One end of the ground terminal plate electrode is a disc-shaped electrode, and the rest is an external thread. The ground terminal plate electrode 4 can adjust the discharge distance between the electrodes through the thread.

[0040] Such as Figure 7 As shown, the high-voltage needle electrode 5 is made of a metal material, preferably a tungsten electrode. If it is not easy to implement, a copper electrode or an iron electrode can also be used. The high-voltage needle electrode consists of a needle electrode 52 with taper and curvature requirements welded to an arc-shaped metal sheet 51. The inner diameter of the arc-shaped metal sheet 51 is matched with the grading ball of the high-voltage bushing.

[0041] The installation method of the internal discharge fault test electrode device based on the large power transformer entity provided in this embodiment includes the following steps:

[0042] Step 1: Align the installation holes at the lower end of the grounding installation plate 1 with the fixing holes at the upper end of the transformer vertical pole 6, and install the grounding installation plate on the vertical pole. The bent part of the grounding installation plate contacts two surfaces of the transformer vertical pole 6, which can effectively fix the grounding installation plate 1;

[0043] Step 2: Connect and fix the double-hole end of the grounding copper strip 2 to the grounding installation plate 1, and connect and fix the other end of the grounding copper strip 2 to the bolt on the oil tank wall 7, so as to make the grounding installation plate 2 at ground potential;

[0044] Step 3: Press the arc-shaped metal sheet 51 of the high-voltage needle electrode 5 tightly against the grading ball 8 of the bushing, and make the needle electrode 52 of the high-voltage needle electrode 5 face the grounding installation plate 1; Connect the threaded body of the ground terminal plate electrode 4 to the threaded hole 13 of the grounding installation plate 1, and make the disc-shaped electrode of the ground terminal plate electrode 4 face the grading ball 8 of the bushing. The ground terminal plate electrode 4 adjusts the distance between the ground terminal plate electrode 4 and the grading ball 8 of the bushing through the thread. At this time, it is a high-voltage-to-ground electrode discharge test.

Claims

1. An internal discharge fault test electrode device for a large power transformer entity, characterized in that, It includes a grounding mounting plate (1), a grounding copper strip (2), a ground electrode, and a bushing grading ball (8); the lower end of the grounding mounting plate (1) is fixed on the transformer pole (6), one end of the grounding copper strip (2) is fixedly connected to the grounding mounting plate (1), and the other end is connected to the tank wall (7); the ground electrode is fixed on the grounding mounting plate (1), and the ground electrode cooperates with the bushing grading ball (8).

2. The internal discharge fault test electrode device for large power transformer entities according to claim 1, characterized in that, The ground electrode is a ground end needle electrode (3), one end of the ground end needle electrode (3) is a tip, and the other end is a threaded body, and the threaded body of the ground end needle electrode (3) is fixedly connected to the grounding mounting plate (1).

3. The internal discharge fault test electrode device for large power transformer entities according to claim 1, characterized in that, The ground electrode is a ground end disk electrode (4), one end of the ground end disk electrode (4) is a disk-shaped electrode, and the other end is a threaded body. The threaded body of the ground end disk electrode (4) is fixedly connected to the grounding mounting plate (1). A high-voltage needle electrode (5) is provided on the bushing grading ball (8). The high-voltage needle electrode (5) includes an arc-shaped metal sheet (51) and a needle electrode (52) welded to the arc-shaped metal sheet. The arc-shaped metal sheet (51) of the high-voltage needle electrode (5) is fixed on the bushing grading ball (8).

4. The internal discharge fault test electrode device for large power transformer entities according to claim 1, wherein The material of the grounding mounting plate (1) is metal, and the grounding mounting plate (1) is bent at 90°.

5. The internal discharge fault test electrode device for large power transformer entities according to claim 2, characterized in that, The material of the ground end needle electrode (3) is selected from a copper electrode, an iron electrode, or a tungsten electrode.

6. The internal discharge fault test electrode device for large power transformer entities according to claim 3, characterized in that The materials of the ground end disk electrode (4) and the high-voltage needle electrode (5) are selected from a copper electrode, an iron electrode, or a tungsten electrode.

7. The internal discharge fault test electrode device for large power transformer entities according to claim 3, characterized in that, The inner diameter of the arc-shaped metal sheet (51) is matched with the bushing grading ball (8).

8. The internal discharge fault test electrode device for large power transformer entities according to claim 3, characterized in that, The grounding mounting plate (1) is provided with a pole fixing hole (11), a copper strip mounting hole (12), and a threaded hole (13). The lower end of the grounding mounting plate (1) is fixedly connected to the transformer pole (6) through the pole fixing hole (11). The middle part of the side of the grounding mounting plate (1) is connected to the grounding copper strip (2) through the copper strip mounting hole (12). The upper end of the grounding mounting plate (1) is connected to the ground end needle electrode (3) and the ground end disk electrode (4) respectively through the threaded hole (13).

9. The internal discharge fault test electrode device for large power transformer entities according to claim 1, characterized in that, The ground end needle electrode (3) and the ground end disk electrode (4) are respectively matched with the threaded hole (13) to adjust the discharge distance between the electrodes.

10. An installation method of an internal discharge fault test electrode device for a large power transformer entity according to any one of claims 1-9, characterized in that, It includes the following steps: S1: The lower end of the grounding mounting plate (1) is fixedly installed on the transformer pole (6) through the pole fixing hole (11). S2: Connect and fix the double-hole end of the grounding copper strip (2) to the copper strip mounting hole (12) of the grounding mounting plate, and bolt-connect and fix the other end of the grounding copper strip (2) to the tank wall (7). S3: Connect the ground electrode to the grounding mounting plate (1) for a discharge test; the ground electrode is the ground terminal needle electrode (3) or the ground terminal disc electrode (4); when the ground electrode is the ground terminal needle electrode (3), the tip of the ground terminal needle electrode (3) faces the bushing grading ball (8), and this is the ground electrode's discharge test against high voltage; when the ground electrode is the ground terminal disc electrode (4), a high voltage needle electrode (5) is installed on the bushing grading ball (8), and at this time, the disc-shaped electrode of the ground terminal disc electrode (4) faces the needle electrode (52) of the high voltage needle electrode (5) on the bushing grading ball (8), and this is the high voltage's discharge test against the ground electrode.

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