A self-off gap arrester for three-dimensional wound core transformer

Abstract

The present invention discloses a self-off type gap arrester for a three-dimensional wound core transformer, comprising an insulating cavity, an umbrella cover is arranged on the outside of the insulating cavity, a discharge cavity is arranged on the upper part of the insulating cavity, a sliding electrode is arranged on the upper part of the discharge cavity, and a fixed electrode is arranged on the lower part, and the initial position of the sliding electrode is in the middle of the discharge cavity; the upper part of the sliding electrode abuts against a wedge-shaped contact block, one end of the wedge-shaped contact block is a straight surface, and the other end is an inclined surface, the straight surface end of the wedge-shaped contact block contacts the power supply side, and the inclined surface end of the wedge-shaped contact block contacts the power consumption side; a sliding rod is arranged on the upper part of the wedge-shaped contact block, and the sliding rod passes through a compression spring and is inserted into a guide groove of a fixed block; the fixed block is arranged in an end cap; the lower part of the fixed electrode abuts against a resistor sheet, and the resistor sheet is multi-layered, and the lowest resistor sheet is connected to the lower electrode. The advantages of the present invention are: it ensures that when a lightning strike occurs, the power consumption side is automatically disconnected, while the power supply side is still normally grounded through the arrester.

Description

Technical Field

[0001] The invention relates to the technical field of electric power equipment, in particular to a lightning arrester. Background Art

[0002] In the use of three-dimensional wound core transformers, lightning arresters are widely used in power supply lines to prevent lightning overvoltage and operating overvoltage problems; Chinese patent application number 201910259664 .2 discloses "a variable series gap composite insulated metal oxide arrester, characterized in that: the arrester (1) comprises a hollow insulating tube (2), an umbrella group sleeve (3) coated on the outer wall of the hollow insulating tube (2), a first metal end plate (4) and a second metal end plate (5) respectively arranged at the upper and lower ends of the hollow insulating tube (2), an insulating container (6) axially arranged in the hollow insulating tube (2) from top to bottom, and at least two stacked zinc oxide resistors (8), the outer walls of the insulating container (6) and the zinc oxide resistor (8) both form a gap (9) with the inner wall of the hollow insulating tube (2), the upper end of the insulating container (6) is connected to the first metal end plate (4), and the lower end of the zinc oxide resistor (8) is arranged on the second metal end plate (5); the insulating container (6) is a retractable bellows, and a discharge gap structure is axially arranged in its inner cavity; the discharge gap The gap structure comprises a first discharge electrode (10) and a second discharge electrode (11) which are separated and arranged along the axial direction of the insulating container (6), a discharge gap (7) of the arrester is formed between the first discharge electrode (10) and the second discharge electrode (11), the first discharge electrode (10) is arranged at the upper end of the insulating container (6), the second discharge electrode (11) is arranged at the lower end of the insulating container (6), and the lower end of the second discharge electrode (11) is connected to the zinc oxide resistor (8) through a flexible copper braid (12). ", the patent prevents the operating voltage and the lightning overvoltage and operating overvoltage allowed by the electrical equipment from being applied to the zinc oxide resistor during normal operation by setting a discharge gap, avoids the electrical aging and thermal damage caused by the long-term electrification, improves the service life and performance reliability of the metal oxide arrester, and ensures the safe and stable operation of the power system to a certain extent. However, the patent has the following problems: when a large overvoltage occurs and the arrester is connected to the ground terminal, the power supply side and the power consumption side are still connected, which inevitably causes hidden dangers and damages the equipment on the power consumption side. Summary of the invention

[0003] In order to solve the above technical problems, the purpose of the present invention is to provide a lightning arrester which automatically disconnects the power supply side from the power supply side when the lightning arrester is connected to the grounding terminal. The specific technical solution is as follows:

[0004] A self-off gap lightning arrester for a three-dimensional wound iron core transformer comprises an insulating cavity, an umbrella cover is arranged on the outer side of the insulating cavity, a discharge cavity is arranged on the upper part of the insulating cavity, a sliding electrode is arranged on the upper part of the discharge cavity, and a fixed electrode is arranged on the lower part, and the initial position of the sliding electrode is in the middle of the discharge cavity; the upper part of the sliding electrode abuts against a wedge-shaped contact block, one end of the wedge-shaped contact block is a straight surface, and the other end is an inclined surface, the straight surface end of the wedge-shaped contact block contacts the power supply side, and the inclined surface end of the wedge-shaped contact block contacts the power consumption side; a sliding rod is arranged on the upper part of the wedge-shaped contact block, and the sliding rod passes through a compression spring and is inserted into a guide groove of a fixed block; the fixed block is arranged in an end cap; the lower part of the fixed electrode abuts against a resistor sheet, the resistor sheet is multi-layered, and the lowest resistor sheet is connected to a lower electrode.

[0005] A parallel groove clamp is arranged at the upper end of the insulating cavity, and both the power consumption side and the power supply side are connected to the wire through the parallel groove clamp. The power consumption side is connected to a three-dimensional wound iron core transformer.

[0006] The resistor is a zinc oxide resistor.

[0007] The inclination angle of the inclined surface is 45 degrees.

[0008] The end cap and the parallel groove wire clamp are both arranged in the protective cover.

[0009] The advantages of the present invention are: due to the provision of a sliding electrode, when an overvoltage occurs, the gas in the discharge chamber is heated by the arc and expands rapidly, pushing the sliding electrode to move upward, and the sliding electrode is a straight surface with the power supply side and an inclined surface with the power consumption side. Therefore, when the sliding electrode moves upward, it always maintains contact with the power supply side and is disconnected from the power consumption side; the purpose of maintaining contact with the power supply side is to guide the current to the lightning arrester and ground it at the lower electrode; in this way, it is ensured that when a lightning strike occurs, the power consumption side is automatically disconnected, while the power supply side is still normally grounded through the lightning arrester. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a structural schematic diagram of the present invention;

[0011] Figure 2 This is a partial enlarged schematic diagram of the discharge chamber. DETAILED DESCRIPTION

[0012] The present invention is described in detail below in conjunction with the accompanying drawings. As shown in the figure, the present invention includes an insulating cavity 1, an umbrella cover 2 is arranged on the outside of the insulating cavity 1, a discharge cavity 3 is arranged on the upper part of the interior of the insulating cavity 1, a sliding electrode 4 is arranged on the upper part of the discharge cavity 3, and a fixed electrode 5 is arranged on the lower part. The initial position of the sliding electrode 4 is in the middle of the discharge cavity 3; the upper part of the sliding electrode abuts against a wedge-shaped contact block 6, one end of the wedge-shaped contact block is a straight surface, and the other end is an inclined surface, the straight surface end of the wedge-shaped contact block contacts with the power supply side 11, and the inclined surface end of the wedge-shaped contact block contacts with the power consumption side 12; a sliding rod 17 is arranged on the upper part of the wedge-shaped contact block, and the sliding rod 17 passes through the compression spring 9 and is inserted into the guide groove 8 of the fixed block 7; the fixed block 7 is arranged in the end cap 10; the lower part of the fixed electrode 5 abuts against a resistor 16, and the resistor 16 is multi-layered, and the lowest resistor is connected to the lower electrode 15.

[0013] A parallel groove clamp is provided at the upper end of the insulating cavity 13, and both the power consumption side and the power supply side are connected to the wire through the parallel groove clamp.

[0014] The resistor 16 is a zinc oxide resistor.

[0015] The inclination angle a of the inclined surface is 45 degrees.

[0016] The end cap and the parallel groove clamp are both arranged in the protective cover 14 .

Claims

1. A self-power-off gap arrester for a three-dimensional wound core transformer, characterized in that: The invention comprises an insulating cavity, an umbrella cover is arranged on the outer side of the insulating cavity, a discharge cavity is arranged on the upper part of the insulating cavity, a sliding electrode is arranged on the upper part of the discharge cavity, and a fixed electrode is arranged on the lower part, and the initial position of the sliding electrode is in the middle part of the discharge cavity; in order to ensure that the power-consuming side is automatically disconnected when a lightning strike occurs, while the power-supplying side is still normally grounded through the arrester, the upper part of the sliding electrode abuts against a wedge-shaped contact block, one end of the wedge-shaped contact block is a straight surface, and the other end is an inclined surface, the straight surface end of the wedge-shaped contact block contacts the power-supplying side, and the inclined surface end of the wedge-shaped contact block contacts the power-consuming side; a sliding rod is arranged on the upper part of the wedge-shaped contact block, and the sliding rod passes through a compression spring and is inserted into a guide groove of a fixed block; the fixed block is arranged in an end cap; the lower part of the fixed electrode abuts against a resistor sheet, the resistor sheet is multi-layered, and the lowest resistor sheet is connected to the lower electrode; the power-consuming side is connected to a three-dimensional wound iron core transformer; a parallel groove wire clamp is arranged on the upper end of the insulating cavity, and both the power-consuming side and the power-supplying side are connected to the wire through the parallel groove wire clamp; the resistor sheet is a zinc oxide resistor sheet.

2. The self-power-off gap arrester for the three-dimensional wound core transformer according to claim 1 is characterized in that: The inclination angle of the inclined surface is 45 degrees.

3. The self-power-off gap arrester for the three-dimensional wound core transformer according to claim 1 is characterized in that: The end cap and the parallel groove wire clamp are both arranged in the protective cover.

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