An explosion-proof oil-immersed current transformer with buffer and no leakage.

Abstract

This invention relates to an explosion-proof oil-immersed current transformer with buffer and no external leakage, belonging to the technical field of current transformers. It includes: a porcelain bushing, an oil tank, a vacuum chamber, and a primary rupture disc. The oil tank is located outside the porcelain bushing and has a connecting hole on one side and a primary rupture hole on the other side. The connecting hole of the oil tank is fixed to the other open end of the porcelain bushing; a connecting ring is fixed to the other open end of the porcelain bushing; the vacuum chamber is fitted outside the oil tank and has a fixing hole on one side, which is fixed to the connecting ring; the primary rupture disc is fixed to the primary rupture hole. This invention, by fitting a sealed vacuum chamber outside the oil tank and fixing a primary rupture disc at the primary rupture hole of the oil tank, ensures that when an arcing fault occurs inside the porcelain bushing, the high-temperature, high-pressure oil-gas mixture breaks through the rupture disc and is directly released into the vacuum chamber, achieving complete leakage prevention of high-pressure oil and gas. This fundamentally avoids the risks of insulating oil splashing pollution, flammable gas explosion, and fire.

Description

Technical Field

[0001] This invention relates to the field of current transformer technology, and in particular to an explosion-proof oil-immersed current transformer with buffer and no leakage. Background Technology

[0002] Oil-immersed current transformers are filled with insulating oil. During long-term operation, internal arcing faults may occur due to insulation aging, overvoltage, or other reasons. At the moment of the fault, the arc energy causes the insulating oil to decompose rapidly and generate a large amount of high-temperature and high-pressure gas, which leads to a sharp increase in the internal pressure of the porcelain bushing. If the pressure cannot be released in time and in a controllable manner, it is very easy to cause the porcelain bushing to explode, resulting in equipment damage, insulating oil splashing, and flashover of surrounding equipment. In severe cases, it may even cause fire or personal injury.

[0003] To prevent porcelain bushing explosions, current technology typically involves installing explosion-proof diaphragms or single-stage rupture discs on the transformer's oil tank or expander. When the internal pressure exceeds a set threshold, the rupture disc breaks, directly releasing the high-temperature oil-gas mixture into the external environment. However, this direct pressure relief method has significant drawbacks: ① Once the rupture disc activates, the high-temperature, high-pressure mixture containing oil leaks out instantaneously, contaminating electrical equipment and the site. Furthermore, the flammable gas mixed with air poses a risk of deflagration, threatening substation safety; ② Single-stage pressure relief lacks a buffer design, and the impact force at the moment of release can still cause excessive stress on the root of the porcelain bushing, leading to breakage, thus limiting explosion-proof reliability; ③ After the rupture disc breaks, a large amount of internal insulating oil is lost, causing the equipment to lose its insulation capacity, necessitating immediate shutdown for maintenance, resulting in poor power supply continuity.

[0004] Therefore, how to provide an explosion-proof current transformer that can reliably prevent the porcelain bushing from exploding and ensure that the high-temperature and high-pressure oil and gas mixture does not leak out is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] This invention provides an explosion-proof oil-immersed current transformer with buffer and no leakage, which solves the technical problem that existing oil-immersed current transformers suffer from high-temperature oil and gas leakage due to direct pressure relief by the rupture disc and easy breakage of the porcelain sleeve by impact force when there is an internal arcing fault.

[0006] The technical solution of this invention to solve the above-mentioned technical problems is as follows: An explosion-proof oil-immersed current transformer with buffer and no leakage includes: a porcelain bushing, a terminal block, electronic components, an oil tank, a vacuum chamber, and a first-stage rupture disc. The terminal block is fixed to one open end of the porcelain bushing; the electronic components are inserted into the porcelain bushing and electrically connected to the terminal block; the oil tank is located outside the porcelain bushing and has a connecting hole on one side and a first-stage rupture hole on the other side. The connecting hole of the oil tank is fixed to the other open end of the porcelain bushing and defines an oil chamber filled with insulating oil between the porcelain bushing and the oil tank; a connecting ring is fixed to the outside of the other open end of the porcelain bushing; the vacuum chamber is sleeved outside the oil tank and has a fixing hole on one side. The fixing hole of the vacuum chamber is fixed to the connecting ring to define a closed vacuum chamber between the oil tank and the vacuum chamber; the first-stage rupture disc is fixed to the first-stage rupture hole so that after an arcing fault occurs inside the porcelain bushing, it is ruptured by the mixture of high-temperature and high-pressure insulating oil and high-temperature and high-pressure air generated, causing the mixture in the oil chamber to flow into the vacuum chamber.

[0007] The beneficial effects of this invention are as follows: By installing a sealed vacuum chamber outside the oil tank and fixing a primary rupture disc at the primary rupture hole of the oil tank, when an arcing fault occurs inside the porcelain bushing, the high-temperature and high-pressure oil-gas mixture breaks through the rupture disc and is directly released into the vacuum chamber, achieving complete non-leakage of high-pressure oil and gas, fundamentally avoiding the risks of insulating oil splashing pollution, combustible gas explosion, and fire; at the same time, since the oil and gas are trapped in the vacuum chamber, the insulating oil will not leak out to the external environment in large quantities, and the equipment can still maintain a certain level of insulation capacity, buying time for short-term load transfer or planned shutdown after a fault, thus improving the continuity of power supply.

[0008] Based on the above technical solution, the present invention can be further improved as follows.

[0009] Furthermore, it also includes a secondary rupture disc, and a secondary rupture hole is provided on one side of the vacuum chamber; the secondary rupture disc is fixed on the secondary rupture hole so that after a continuous arcing failure occurs in the ceramic sleeve, it is punctured by the high temperature and high pressure mixture, causing the mixture in the vacuum chamber to flow out.

[0010] The further beneficial effects of adopting the above are as follows: the secondary rupture disc, installed on the side wall of the vacuum chamber and with a burst pressure significantly higher than that of the primary rupture disc, can accurately penetrate under extreme pressure, providing a second-stage controllable pressure relief channel for the vacuum chamber. This completely avoids the vacuum chamber from bursting or the welds from overpressure, effectively protecting the structural integrity of the porcelain bushing and the entire equipment. Compared with the single-stage explosion-proof structure, the introduction of the secondary rupture disc allows the system to maintain completely leak-free operation under "normal arcing faults" (because the secondary rupture disc will not activate), while under "extreme continuous arcing faults," it acts as a final safety barrier for directional pressure relief. The direction of pressure relief is controllable, ensuring both zero leakage and zero pollution performance in daily explosion protection and maximizing the safety of equipment, personnel, and surrounding substations under rare severe faults.

[0011] Furthermore, it also includes an oil-resistant foamed rubber layer, which is adhered to the inner wall of the oil tank.

[0012] The further beneficial effect of the above-mentioned method is that by adhering an oil-resistant foamed rubber layer to the inner wall of the oil tank, this rubber layer occupies a certain volume inside the oil tank under normal operating conditions, thereby effectively reducing the space available for the free expansion of insulating oil and gas inside the oil tank. When an arcing fault occurs inside the porcelain bushing, after a high-temperature and high-pressure oil-gas mixture is generated, the effective volume inside the oil tank is already squeezed by the rubber layer, significantly reducing the space for gas and oil expansion caused by the fault. This greatly reduces the peak pressure and pressure rise rate inside the oil chamber, delaying or even preventing the porcelain bushing from bearing excessive impact pressure. Please check if this is correct.

[0013] Furthermore, it also includes an expander, which is located outside the ceramic sleeve and fixed to the terminal block.

[0014] Furthermore, it also includes a support frame, which is located outside the oil tank and inside the vacuum chamber, with its opposite sides fixed to the oil tank and the vacuum chamber, respectively.

[0015] The further beneficial effect of adopting the above is that using a support frame to connect the oil tank and the vacuum box can enhance the connection strength between the oil tank and the vacuum box. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the internal structure of an explosion-proof oil-immersed current transformer with buffer and no leakage according to the present invention. Figure 2 This is a schematic diagram of the internal structure of the vacuum box and oil tank in an explosion-proof oil-immersed current transformer with buffer and no leakage according to the present invention.

[0017] The attached diagram lists the components represented by each number as follows: 1. Porcelain sleeve; 2. Terminal block; 3. Electronic components; 4. Oil tank; 5. Vacuum chamber; 51. Secondary rupture hole; 6. Primary rupture disc; 7. Secondary rupture disc; 8. Expander; 9. Support frame. Detailed Implementation

[0018] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0019] like Figure 1 As shown, an explosion-proof oil-immersed current transformer with buffer and no leakage includes: a porcelain bushing 1, a terminal block 2, electronic components 3, an oil tank 4, a vacuum box 5, and a first-stage rupture disc 6. The terminal block 2 is fixed to one open end of the porcelain bushing 1; the electronic components 3 are installed inside the porcelain bushing 1 and are electrically connected to the terminal block 2. The oil tank 4 is located outside the porcelain sleeve 1 and has a connecting hole on one side and a first-stage rupture hole on the other side. The connecting hole of the oil tank 4 is fixed to the other open end of the porcelain sleeve 1 and defines an oil chamber filled with insulating oil between the porcelain sleeve 1 and the oil tank 4. A connecting ring is fixed to the other open end of the porcelain sleeve 1. The vacuum box 5 is sleeved outside the oil tank 4 and has a fixing hole on one side. The fixing hole of the vacuum box 5 is fixed to the connecting ring to define a closed vacuum chamber between the oil tank 4 and the vacuum box 5. The first-stage rupture disc 6 is fixed to the first-stage rupture hole so that after an arcing failure occurs inside the porcelain sleeve 1, it is punctured by the mixture of high-temperature and high-pressure insulating oil and high-temperature and high-pressure air generated, causing the mixture in the oil chamber to flow into the vacuum chamber.

[0020] like Figure 2 As shown, in some specific embodiments, a secondary rupture disc 7 may also be included, and a secondary rupture hole 51 is provided on one side of the vacuum chamber 5; the secondary rupture disc 7 is fixed on the secondary rupture hole 51 so that after a continuous arcing failure occurs in the ceramic sleeve 1, it is punctured by the high temperature and high pressure mixture, causing the mixture in the vacuum chamber to flow out.

[0021] In some specific embodiments, an oil-resistant foamed rubber layer may also be included, which is adhered to the inner wall of the oil tank 4.

[0022] In some specific embodiments, an expander 8 may also be included, which is located outside the ceramic sleeve 1 and fixed on the terminal block 2.

[0023] In some specific embodiments, a support frame 9 may also be included, which is located outside the oil tank 4 and inside the vacuum box 5, with its opposite sides fixed to the oil tank 4 and the vacuum box 5, respectively.

[0024] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A buffered, leak-proof, explosion-proof oil-immersed current transformer, comprising: The porcelain sleeve (1), the terminal block (2), and the electronic component (3) are provided, wherein the terminal block (2) is fixed to one open end of the porcelain sleeve (1); the electronic component (3) is inserted into the porcelain sleeve (1) and electrically connected to the terminal block (2); characterized in that it further comprises: Oil tank (4), the oil tank (4) is located outside the porcelain sleeve (1) and has a connecting hole on one side and a first-stage burst hole on the other side. The connecting hole of the oil tank (4) is fixed to the other opening end of the porcelain sleeve (1) and defines an oil chamber filled with insulating oil between the porcelain sleeve (1) and the oil tank (4). Vacuum box (5), with a connecting ring fixed to the other open end of the ceramic sleeve (1); the vacuum box (5) is sleeved outside the oil tank (4) and has a fixing hole on one side. The fixing hole of the vacuum box (5) is fixed on the connecting ring to define a closed vacuum chamber between the oil tank (4) and the vacuum box (5). A primary rupture disc (6) is fixed on the primary rupture hole so that after an arcing failure occurs in the porcelain sleeve (1), it is punctured by the mixture of high-temperature and high-pressure insulating oil and high-temperature and high-pressure air generated, causing the mixture in the oil chamber to flow into the vacuum chamber.

2. The explosion-proof oil-immersed current transformer with buffer and no leakage as described in claim 1, characterized in that, It also includes a secondary rupture disc (7), and a secondary rupture hole (51) is provided on one side of the vacuum chamber (5); the secondary rupture disc (7) is fixed on the secondary rupture hole (51) so that after a continuous arcing failure occurs in the ceramic sleeve (1), it is punctured by the high temperature and high pressure mixture, causing the mixture in the vacuum chamber to flow out.

3. The explosion-proof oil-immersed current transformer with buffer and no leakage as described in claim 1, characterized in that, It also includes an oil-resistant foamed rubber layer, which is adhered to the inner wall of the oil tank (4).

4. The explosion-proof oil-immersed current transformer with buffer and no leakage as described in claim 1, characterized in that, It also includes an expander (8), which is located outside the ceramic sleeve (1) and fixed on the terminal block (2).

5. The explosion-proof oil-immersed current transformer with buffer and no leakage as described in claim 1, characterized in that, It also includes a support frame (9), which is located outside the oil tank (4) and inside the vacuum box (5), with its opposite sides fixed to the oil tank (4) and the vacuum box (5) respectively.

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