An insulation protection structure for a high voltage built-in outlet of a large transformer

Abstract

The present invention relates to an insulation protection structure for a high-voltage built-in outlet of a large transformer, and belongs to the technical field of transformer manufacturing. The technical scheme is as follows: the high-voltage coil outlet protection structure is to set a high-voltage outlet protection angle ring (8) at the outlet of the high-voltage coil (9), the lower part of the high-voltage outlet protection angle ring (8) is a groove-shaped structure matching the outlet of the high-voltage coil (9), and the upper part of the high-voltage outlet protection angle ring (8) is a sleeve structure matching the high-voltage lead (10); the clamp web protection structure is to set a web protection angle ring (3) on the clamp web (1) near the outlet of the high-voltage coil (9), the lower part of the web protection angle ring (3) is an arc surface, the upper part of the web protection angle ring is a plane, and the lower part of the web protection angle ring is inserted into the body. The beneficial effect of the present invention is that a specially shaped molded insulating part is used to protect the high-voltage coil outlet and the surrounding clamp web, thereby improving the safety performance of the transformer.

Description

Technical Field

[0001] The invention relates to an insulation protection structure of a high-voltage built-in outlet of a large transformer, belonging to the technical field of transformer manufacturing. Background Art

[0002] The arrangement structure of large 220kV transformer coils is generally low, medium, high, and adjustable from the inside to the outside. For high-impedance products, built-in reactors must be set. In order to simplify the transformer structure and meet the impedance parameter requirements, the coil arrangement must be adjusted, so the high-voltage coil is often set at the innermost side and the low-voltage coil is set at the outermost side. When the high-voltage coil is set at the innermost side, the first end of the high-voltage coil needs to pass through the body pressure plate to exit the line, which will cause the creepage distance from the high-voltage outlet to the core clamp web to be tight, and partial discharge is prone to occur. Therefore, a series of measures must be studied to protect this structure and to correct the structural parts with poor electric field environment to meet the electrical distance and improve the electric field environment. Summary of the invention

[0003] The purpose of the present invention is to provide an insulation protection structure for a high-voltage built-in outlet of a large transformer, which uses a specially shaped molded insulating part to protect the high-voltage coil outlet and the surrounding clamp webs, thereby improving the safety performance of the transformer and solving the problems existing in the background technology.

[0004] The technical solution of the present invention is:

[0005] An insulation protection structure for a high-voltage built-in outlet of a large transformer, comprising a high-voltage coil outlet protection structure and a clamp web protection structure;

[0006] The high-voltage coil outlet protection structure is to set a high-voltage outlet protection angle ring at the outlet of the high-voltage coil, the lower part of the high-voltage outlet protection angle ring is a groove structure matching the outlet of the high-voltage coil, the upper part of the high-voltage outlet protection angle ring is a sleeve structure matching the high-voltage lead, the lower part of the high-voltage outlet protection angle ring is clamped on the outlet end of the high-voltage coil, and the upper part of the high-voltage outlet protection angle ring is sleeved on the high-voltage lead;

[0007] The clamp belly protection structure is to set a belly protection angle ring on the clamp belly near the high-voltage coil protrusion, the lower part of the belly protection angle ring is an arc surface, the upper part of the belly protection angle ring is a plane, the lower part of the belly protection angle ring is inserted into the body, and the upper part of the belly protection angle ring is fixed to the clamp belly by insulating bolts.

[0008] The center lines of the upper and lower parts of the high-voltage outlet protection angle ring are arranged at an angle less than 90 degrees, for example, 30 degrees or 45 degrees.

[0009] The plane of the upper part of the web protection angle ring is a rectangle, and bolt holes matching with the insulating bolts are arranged in the rectangle.

[0010] The surface of the clamp web opposite to the upper part of the web protection angle ring is coated with insulating paint.

[0011] The beneficial effects of the present invention are: using web protection angle rings and high-voltage lead protection angle rings to protect the high-voltage coil outlet and the surrounding clamp webs, greatly improving the creepage distance between the high-voltage lead and the web structural parts, avoiding local discharge, and improving the safety performance of the transformer. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of the structure of the present invention;

[0013] Figure 2 It is a schematic diagram of the web protection of the clamp;

[0014] Figure 3 for Figure 2 FF cross-section diagram;

[0015] Figure 4 This is a schematic diagram of the high-voltage line protection angle ring;

[0016] Figure 5 for Figure 4 BB cross-section diagram;

[0017] Figure 6 This is the front view of the web protection angle ring;

[0018] Figure 7 This is the left view of the web protection angle ring;

[0019] Figure 8 It is the top view of the web protection angle ring;

[0020] In the figure: the clamp web 1, insulating bolts 2, web protection angle ring 3, clamp limb plate 4, press-fit pad 5, device body pressure plate 6, device body end ring 7, high-voltage outlet protection angle ring 8, high-voltage coil 9, high-voltage lead 10, bolt hole 11. DETAILED DESCRIPTION

[0021] The present invention will be further described below by way of examples with reference to the accompanying drawings.

[0022] See attached Figures 1 to 8 , an insulation protection structure for a high-voltage built-in outlet of a large transformer, comprising a high-voltage coil outlet protection structure and a clamp web protection structure;

[0023] The high-voltage coil outlet protection structure is to set a high-voltage outlet protection angle ring 8 at the outlet of the high-voltage coil 9, the lower part of the high-voltage outlet protection angle ring 8 is a groove structure matching the outlet of the high-voltage coil 9, the upper part of the high-voltage outlet protection angle ring 8 is a sleeve structure matching the high-voltage lead 10, the lower part of the high-voltage outlet protection angle ring 8 is clamped on the outlet end of the high-voltage coil 9, and the upper part of the high-voltage outlet protection angle ring 8 is sleeved on the high-voltage lead 10;

[0024] The clamp belly protection structure is a belly protection angle ring 3 arranged on the clamp belly 1 near the high-voltage coil 9, the lower part of the belly protection angle ring 3 is an arc surface, the upper part of the belly protection angle ring 3 is a plane, the lower part of the belly protection angle ring 3 is inserted into the interior of the device body, and the upper part of the belly protection angle ring 3 is fixed to the clamp belly 1 by an insulating bolt 2.

[0025] In this embodiment, refer to the attached Figure 1 , 4 5. The lower part of the high-voltage line protection angle ring 8 is a groove structure, which is used to clamp on the upper end of the high-voltage coil 9 to ensure that the angle ring will not fall off. The upper part of the high-voltage line protection angle ring 8 is a sleeve structure, and the high-voltage lead 10 is placed inside the sleeve, which can greatly improve the creepage distance of the high-voltage lead to the web structure.

[0026] Refer to the attached Figure 6 , 7 8. The lower part of the web protection angle ring 3 is an arc-shaped structure, which is inserted into the body. On the one hand, it is convenient to fix the angle ring, and on the other hand, it can also increase the creepage distance; the upper part of the web protection angle ring 3 is a flat plate structure, on which four Φ14 circular holes are opened, and the corresponding position of the clamp web 1 is opened with M12 threaded holes, as shown in the attached Figure 2 As shown, it is fixed with bakelite nuts and insulating screws, which can also increase the creepage distance of the high-voltage lead to the web.

[0027] Refer to the attached Figure 2 , 3 The lower edge of the clamp web 1 is rounded off at an angle α to make the electrode smoother, which can make the electric field distribution more uniform. Figure 2 The A area and D surface of the web 1 of the middle clamp are respectively coated with 20 μm thick insulating paint to increase the allowable value of the field strength there.

Claims

1. An insulation protection structure for a high voltage built-in outlet of a large transformer, characterized in that: It includes a high-voltage coil head protection structure and a clamp web protection structure; The high-voltage coil outlet protection structure comprises a high-voltage outlet protection angle ring (8) provided at the outlet of the high-voltage coil (9), the lower part of the high-voltage outlet protection angle ring (8) being a groove-shaped structure matching the outlet of the high-voltage coil (9), the upper part of the high-voltage outlet protection angle ring (8) being a sleeve structure matching the high-voltage lead (10), the lower part of the high-voltage outlet protection angle ring (8) being clamped on the outlet end of the high-voltage coil (9), and the upper part of the high-voltage outlet protection angle ring (8) being sleeved on the high-voltage lead (10); The clamp web protection structure comprises a web protection angle ring (3) provided on the clamp web (1) near the protruding end of the high-voltage coil (9), the lower part of the web protection angle ring (3) being an arc-shaped surface, the upper part of the web protection angle ring (3) being a plane, the lower part of the web protection angle ring (3) being inserted into the body, and the upper part of the web protection angle ring (3) being fixed to the clamp web (1) by means of insulating bolts (2); The center lines of the upper and lower parts of the high-voltage outlet protection angle ring (8) are provided with an angle, which is less than 90 degrees; and the surface of the clamp web (1) opposite to the upper part of the web protection angle ring (3) is coated with insulating paint.

2. The insulation protection structure of a large transformer high voltage built-in outlet according to claim 1 is characterized in that: The upper plane of the web protection angle ring (3) is rectangular, and a bolt hole (11) matching the insulating bolt (2) is provided in the rectangle.

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