Transformer lightning protection system and transformer

Abstract

The utility model relates to the technical field of power equipment protection, in particular to a transformer lightning protection system and a transformer, a lightning arrester is arranged at an outlet sleeve of the transformer or a reactor, and when lightning attack exists and lightning shock waves transmitted along a line exceed the protection level of the lightning arrester, the lightning arrester is arranged at the outlet sleeve of the transformer or the reactor. The lightning arrester arranged at the position of the outlet sleeve of the transformer or the electric reactor discharges firstly, lightning current is safely led into the ground, the amplitude of lightning voltage is limited below the lightning impulse level of protected equipment, and therefore the transformer or the electric reactor is effectively protected against lightning damage. As the lightning arrester is arranged at the outlet sleeve of the transformer or the electric reactor, the transformer can be protected to the maximum extent, lightning impacts are prevented from entering the transformer or the electric reactor, the propagation distance of lightning waves in a system can be shortened, attenuation and deformation of the lightning waves in the propagation process are reduced, and the protection effect of the lightning arrester is improved. The problem that an existing transformer lightning arrester cannot comprehensively protect a transformer is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of power equipment protection, in particular to a transformer lightning protection system and a transformer. Background Art

[0002] A transformer is a stationary electrical device widely used in industry, agriculture, transportation, and urban communities. Its main components include the core, windings, oil tank, cooling system, voltage regulator, protective devices, and lead bushings. The core and windings are the core components of the transformer and constitute the transformer body. The oil tank is filled with transformer oil, which provides insulation and heat dissipation. The cooling system dissipates heat generated during transformer operation. The voltage regulator adjusts the output voltage. Protective devices are used to promptly cut off power in the event of a transformer fault, protecting equipment and personnel. In power systems, transformers are used to step up or down voltage to meet the needs of various equipment and transmission lines. Transformers also provide electrical isolation and impedance matching, ensuring safe and stable operation of power systems. The transformer's principle of voltage transformation is as follows: when the transformer's primary coil is connected to an AC power source, an alternating magnetic flux is generated in the core. This alternating magnetic flux passes through both the primary and secondary coils, generating an induced electromotive force in the secondary coil. Because the primary and secondary coils have different numbers of turns, the magnitude of the induced electromotive force also differs, thus achieving voltage conversion.

[0003] There are many types of transformers. They are categorized by purpose, such as power transformers, distribution transformers, and special transformers; by structure, they include two-winding transformers, three-winding transformers, multi-winding transformers, and autotransformers; by cooling method, they include oil-immersed transformers and dry-type transformers; and by the number of power phases, they include single-phase transformers, three-phase transformers, and multi-phase transformers. As transformer technology continues to improve, regional power infrastructure is also developing. However, in areas with underdeveloped power systems, voltage instability and line failures are common. Therefore, lightning arresters are required at the transformer line ends to protect the transformer. Lightning arresters, sometimes also called overvoltage protectors or overvoltage limiters, are widely used overvoltage limiters. They are essentially overvoltage energy absorbers. They operate in parallel with the on-load tap changer. When the applied voltage exceeds a certain amplitude, the arrester activates first, dissipating a large amount of energy through its own circuit breaker, limiting the overvoltage and thus protecting the on-load tap changer. In the prior art, since the transformer outlet adopts a non-oil-air bushing outlet structure, it is difficult to arrange a lightning arrester at the line end, and it is impossible to arrange a lightning arrester at the transformer outlet.

[0004] For example, Chinese utility model application CN115579778A discloses a UHV substation and layout method for quickly replacing the standby phase of a main transformer. By placing an incoming lightning arrester on the incoming line frame of the main transformer and connecting it to the incoming line jumper, the transformer is protected from lightning by ensuring that no other equipment is blocking the main transformer's operating phase or standby phase. However, this arrangement only provides lightning protection for the incoming line frame of the main transformer and cannot protect the transformer's outlet. As the key connection point between the transformer and the external power grid, the outlet can cause serious consequences such as equipment damage and power outages if struck by lightning.

[0005] The Chinese utility model with the authorization publication number CN217847669U discloses a transformer-integrated lightning arrester mounting structure, which involves the application of an integrated arrangement of a transformer and a lightning arrester. The utility model includes a transformer body, and an upper support plate is fixedly installed on the top of the transformer body. The transformer-integrated lightning arrester mounting structure is connected to the lightning arrester body and the bushing through an upper slot steel frame installed on the transformer body box cover through a copper busbar, and then a bracket is installed on the upper oil tank of the transformer body. The lightning arrester body is grounded and integrated by leading the copper busbar from the lightning arrester body to the mounting bracket of the lower oil tank, which is convenient for observing and recording data during the installation of the main transformer, saving materials and space. Compared with the existing technology, the distance between the lightning arrester body and the bushing is shortened and the grounding is integrated, which enhances the lightning resistance and aesthetics of the transformer body, is easy to install, saves space, improves the reliability of the transformer operation, saves costs, and makes the operating performance of the transformer body more stable. However, this arrangement is complicated in line layout, and when lightning waves invade from a direction other than the direction where the lightning arrester is installed, it is impossible to intercept the lightning waves in that direction, so it is impossible to effectively protect the transformer. Utility Model Content

[0006] Aiming at the problem that the transformer lightning protection device in the prior art cannot fully protect the transformer, the utility model provides a transformer lightning protection system and a transformer.

[0007] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0008] The utility model provides a transformer lightning protection system, comprising a lightning arrester, which is sequentially connected to a transformer or reactor outlet bushing and a cable plug-in connector.

[0009] Optionally, a first transition bushing is provided between the arrester and the transformer or reactor outlet bushing.

[0010] Optionally, a voltage grading ball is provided between the first transition bushing and the transformer or reactor outlet bushing.

[0011] Optionally, a second transition sleeve is arranged between the first transition sleeve and the lightning arrester.

[0012] Optionally, a sealed chamber is arranged outside the second transition sleeve.

[0013] Optionally, the sealed chamber is filled with SF6 gas.

[0014] Optionally, a riser is arranged outside the transformer or reactor outlet sleeve and the cable plug head.

[0015] Optionally, the riser is filled with oil or SF6 gas.

[0016] Optionally, a valve is arranged at the bottom of the riser.

[0017] The utility model also provides a transformer, including transformer lightning protection system of above.

[0018] Compared with the prior art, the utility model has the following beneficial effects:

[0019] The utility model provides a transformer lightning protection system, including lightning arrester, lightning arrester is connected transformer or reactor outlet sleeve and cable plug head in proper order.When there is thunder and lightning attack, when the thunder and lightning shock wave along the line is more than lightning arrester protection level, the lightning arrester arranged at transformer or reactor outlet sleeve will first discharge, and the thunder and lightning current is safely introduced into the earth, and the thunder and lightning voltage amplitude is limited below the thunder and lightning impact level of the protected equipment, thereby effectively protecting transformer or reactor from thunder and lightning damage. Since the lightning arrester is arranged at the transformer or reactor outlet sleeve, the transformer can be protected to the maximum, the thunder and lightning shock to the inside of transformer or reactor can be prevented, the propagation distance of thunder and lightning wave in the system can be shortened, the attenuation and deformation of thunder and lightning wave in the propagation process can be reduced, thereby improving the protection effect of the lightning arreester. In addition, the transformer lightning protection system has simple structure, low maintenance cost, and better stability and reliability of the system.

[0020] The lightning arrester and the transformer or reactor outlet sleeve are provided with a first transition sleeve, the first transition sleeve serves as a connecting bridge between the lightning arrester and the transformer or reactor outlet sleeve, which can not only increase the electrical insulation between the lightning arrester and the transformer or reactor outlet sleeve, but also effectively prevent equipment damage and failure caused by electrical breakdown, and the first transition sleeve can absorb and disperse part of the thunder and lightning energy, thereby reducing the burden of the lightning arrester, prolonging the service life of the lightning arrester, and improving the lightning protection performance of the entire system.

[0021] The first transition bushing and the transformer or reactor outlet bushing are provided with a voltage equalizing ball, which can disperse the electric field, stabilize the electric field distribution inside the transformer or reactor, and reduce the degree of electric field concentration, thereby avoiding the generation of partial discharge and arc due to electric field concentration in a high-voltage environment, and reducing the risk of partial discharge and arc.

[0022] The second transition bushing is provided between the first transition bushing and the lightning arrester. The second transition bushing can further improve the lightning resistance level of the lightning arrester, absorb and disperse part of the lightning energy, and reduce the burden on the lightning arrester, thereby prolonging the service life of the lightning arrester. At the same time, it can also optimize the electric field distribution and reduce the impact and damage of lightning on the equipment. The second transition bushing allows the lightning arrester to maintain a certain distance from the first transition bushing, facilitating the installation and maintenance of the equipment. At the same time, the second transition bushing can also serve as a bridge connecting the two, ensuring the reliability and stability of the electrical connection. This design not only improves the flexibility and adaptability of the equipment, but also provides convenience for the upgrading and reconstruction of the power system.

[0023] The second transition bushing is provided with a sealed chamber outside. The sealed chamber provides an additional electrical insulation layer for the second transition bushing, which helps to reduce the risk of electrical breakdown and ensure the stable operation of the power system. It also provides a good electromagnetic shielding layer, reducing the interference of external electromagnetic fields on the second transition bushing and its internal electrical components, and ensuring the stability of electrical performance.

[0024] The sealed chamber is filled with SF6 gas, which also has good arc extinguishing performance. During the arc discharge process, SF6 gas can quickly absorb free electrons in the arc, form negative ions, and combine with positive ions in the arc, thereby rapidly reducing the charged ions in the arc, increasing the arc breakdown voltage, and quickly extinguishing the arc. Due to the excellent insulation and arc extinguishing performance of SF6 gas, the sealed chamber filled with SF6 gas can significantly improve the lightning resistance level of electrical equipment. In thunderstorm weather, the SF6 gas in the sealed chamber can quickly disperse and absorb lightning impact energy, reducing the burden on the lightning arrester and electrical equipment, thereby reducing the risk of equipment damage. It plays an important role in protecting electrical equipment from arc damage and prolonging the service life of the equipment.

[0025] The transformer or the reactor outlet bushing and the cable plug head are externally provided with a raised seat, which not only provides necessary support and fixation for the transformer or the reactor outlet bushing and the cable plug head, but also provides an additional electrical insulation layer for the outlet bushing and the cable plug head, which are easily affected by an electric field in a high-voltage environment, and the design of the raised seat can reduce the interference of the electric field on these components, reduce the risk of electrical breakdown, and prevent harmful factors such as external dust and moisture from damaging the equipment, thereby improving the reliability and service life of the equipment.

[0026] The raised seat is internally filled with oil or SF6 gas, the oil has good heat conduction performance, can effectively transfer the heat inside the equipment to the outside, thereby keeping the temperature of the equipment stable, and has important significance for preventing overheating of the equipment and prolonging the service life, and the SF6 gas has extremely high insulation strength, and its insulation performance is better than that of oil and air, and filling the raised seat with SF6 gas can further improve the insulation level of the electrical equipment and ensure the stable operation of the equipment in a high-voltage environment, and for high-voltage, large-capacity equipment or application scenarios requiring high insulation performance, it is more suitable to fill SF6 gas, and for application scenarios requiring high heat dissipation or requiring buffering and shock absorption, it is more suitable to fill oil.

[0027] The bottom of the raised seat is provided with a valve, and the valve is arranged to facilitate discharge and sampling analysis of the raised seat, so that corresponding maintenance measures can be taken in time.

[0028] A transformer comprising the transformer lightning protection system described above has better lightning protection performance, stable operation of the power system, equipment safety and durability, can adapt to different working environments and conditions, provides a strong guarantee for the safe operation and reliable power supply of the power system, has low maintenance cost and long service life. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 A schematic diagram of a transformer lightning protection system provided for embodiment 1 of the present application.

[0030] Figure 2 A schematic diagram of a transformer lightning protection system provided for embodiment 2 of the present application.

[0031] Wherein, 1-first transition bushing, 2-lightning arrester, 3-transformer or reactor outlet bushing, 4-cable plug head, 5-voltage equalizing ball, 6-hermetically sealed chamber, 7-raised seat, 8-valve, 9-first gas density detector, 10-second gas density detector, 11-first installation hand hole, 12-second installation hand hole, 13-second transition bushing. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme of the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are some embodiments of the present application but not all the embodiments of the present application. The components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0033] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of the present application.

[0034] It should be noted that: similar reference numbers and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0035] In the description of the embodiments of the present application, it should be noted that if the terms "upper", "lower", "horizontal", "inner" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the present application is usually placed, which is only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second" and the like are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0036] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly inclined. For example, "horizontal" only means that its direction is relatively more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0037] In the description of the embodiments of the present application, it should also be noted that unless otherwise explicitly specified and limited, if the terms "set", "mount", "connected", "connected" appear, they should be understood in a broad sense, for example, they can be fixedly connected, or can be detachably connected, or integrally connected; can be mechanically connected, or can be electrically connected; can be directly connected, or can be indirectly connected through an intermediate medium; can be the communication inside two elements. For those of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0038] The utility model makes further detailed description in combination with specific embodiments, the explanation of the utility model but not limit.

[0039] Embodiment 1

[0040] Referring to Figure 1 The utility model provides a transformer lightning protection system, including lightning arrester 2, lightning arrester 2 connects transformer or electric reactor outlet bushing 3 and cable plug head 4 in proper order. Optionally, lightning arrester 2 passes through conductor and connects transformer or electric reactor outlet bushing 3 and cable plug head 4;Lightning arrester 2 is provided with first installation hand hole 11 and first gas density detector 9, and is filled with SF6 gas in lightning arrester 2;Transformer or electric reactor outlet bushing 3 and cable plug head 4 are provided with elevated seat 7 outside, and the elevated seat 7 is T-shaped elevated seat, and is filled with SF6 gas inside, and the bottom of elevated seat 7 is provided with valve 8, is used for discharging or sampling analysis to SF6 gas.

[0041] When there is lightning attack, when the lightning shock wave along the line exceeds the protection level of lightning arrester 2, lightning arrester 2 arranged at transformer or electric reactor outlet bushing 3 will first discharge, and the lightning current is safely introduced into the earth, and the lightning voltage amplitude is limited below the lightning impulse level of the protected equipment, so that the transformer or electric reactor is effectively protected from lightning damage. Since lightning arrester 2 is arranged at transformer or electric reactor outlet bushing 3, the transformer can be maximally protected, the lightning shock to the inside of the transformer or electric reactor can be prevented, the propagation distance of lightning wave in the system can be shortened, the attenuation and deformation of lightning wave in the propagation process can be reduced, and thus the protection effect of the lightning arrester is improved. The elevated seat 7 filled with SF6 gas provides necessary support and fixation for the outlet bushing 3 and cable plug head 4 of the transformer or electric reactor. Since SF6 gas has excellent insulation performance and good arc extinguishing ability, in the arc discharge process, SF6 gas can rapidly absorb free electrons in the arc to form negative ions, thereby inhibiting the expansion and maintenance of the arc. This enables the SF6 gas-filled elevated seat to rapidly extinguish the arc when the equipment short-circuits or fails, preventing damage to the equipment.

[0042] Embodiment 2

[0043] Referring to Figure 2The utility model provides a kind of lightning arrester system, including lightning arrester 2, first transition sleeve pipe 1 and second transition sleeve pipe 13;The lightning arrester 2 is sequentially connected second transition sleeve pipe 13, first transition sleeve pipe 1, transformer or reactor outlet sleeve pipe 3 and cable plug head 4;Optionally, the lightning arrester 2 is sequentially connected second transition sleeve pipe 13, first transition sleeve pipe 1, transformer or reactor outlet sleeve pipe 3 and cable plug head 4 by conductor;The transformer or reactor outlet sleeve pipe 3 and cable plug head 4 are externally provided with riser 7, and the riser 7 is T-shaped riser, filled with oil in the inside, and the bottom of the riser 7 is provided with valve 8, for discharging or sampling analysis to oil.

[0044] The lightning arrester 2 is provided with first installation hand hole 11 and first gas density detector 9, and the inside of the lightning arrester 2 is filled with SF6 gas, and the first gas density detector 9 is used for detecting the gas density of SF6 gas in the lightning arrester 2.

[0045] The first transition sleeve pipe 1 is arranged in the inside of the riser 7, and the first transition sleeve pipe 1 is provided with voltage-sharing ball 5 between the transformer or reactor outlet sleeve pipe 3, for stabilizing the electric field distribution inside the transformer or reactor, reducing the electric field concentration degree, and reducing the risk of partial discharge and arc.

[0046] The second transition sleeve pipe 13 is connected with the first transition sleeve pipe 1 through flange, and the second transition sleeve pipe 13 is externally provided with airtight chamber 6, and the airtight chamber 6 is steel structure barrel, and the airtight chamber 6 is provided with second installation hand hole 12, facilitating the installation of the second transition sleeve pipe 13 of the airtight chamber 6;Second gas density detector 10 is installed on the airtight chamber 6, and the inside of the airtight chamber 6 is filled with SF6 gas, and the second gas density detector 10 is used for detecting the SF6 gas density in the airtight chamber 6;The end of the airtight chamber 6 is connected with the lightning arrester 2 through flange.

[0047] A transformer comprising the above-mentioned transformer lightning protection system has better lightning protection performance, stable operation of power system, equipment safety and durability, can adapt to different working environments and conditions, provides strong guarantee for safe operation and reliable power supply of power system, has low maintenance cost and long service life.

[0048] In summary, the utility model provides a kind of transformer lightning protection system and transformer, by setting lightning arrester at transformer or electric reactor outlet bushing 3, when there is lightning attack, when the lightning shock wave along line is entered exceeds lightning arrester protection level, lightning arrester 2 set at transformer or electric reactor outlet bushing 3 will first discharge, safely introduce lightning current into ground, make lightning voltage amplitude limit below the lightning impulse level of protected equipment, to effectively protect transformer or electric reactor from lightning damage. Since lightning arrester is set at transformer or electric reactor outlet bushing, can realize maximum protection transformer, prevent lightning shock to the inside of transformer or electric reactor, while, can shorten the propagation distance of lightning wave in system, reduce the attenuation and deformation of lightning wave in propagation process, to improve the protection effect of lightning arrester.

[0049] The above is only the preferred embodiment of the utility model, and does not use to make any limitation to the technical scheme of the utility model, and those skilled in the art should understand that, without departing from the spirit and principles of the utility model, the technical scheme can be modified and replaced in several simple ways, and these modifications and replacements also belong to the protection scope covered by the claims.

Claims

1. A transformer lightning protection system, characterized in that: It comprises a lightning arrester (2), wherein the lightning arrester (2) is connected in sequence to a transformer or reactor outlet bushing (3) and a cable plug (4).

2. The transformer lightning protection system according to claim 1, characterized in that: A first transition bushing (1) is provided between the lightning arrester (2) and the transformer or reactor outlet bushing (3).

3. The transformer lightning protection system according to claim 2, characterized in that: A voltage grading ball (5) is provided between the first transition bushing (1) and the transformer or reactor outlet bushing (3).

4. The transformer lightning protection system according to claim 2, characterized in that: A second transition sleeve (13) is provided between the first transition sleeve (1) and the arrester (2).

5. The transformer lightning protection system according to claim 4, characterized in that: A sealed chamber (6) is provided outside the second transition sleeve (13).

6. The transformer lightning protection system according to claim 5, characterized in that: The sealed chamber (6) is filled with SF6 gas.

7. The transformer lightning protection system according to any one of claims 1 to 6, characterized in that: A raised seat (7) is provided outside the transformer or reactor outlet bushing (3) and the cable plug connector (4).

8. The transformer lightning protection system according to claim 7, characterized in that: The interior of the raising seat (7) is filled with oil or SF6 gas.

9. The transformer lightning protection system according to claim 8, characterized in that: A valve (8) is provided at the bottom of the raised seat (7).

10. A transformer, characterized in that: The invention comprises the transformer lightning protection system according to any one of claims 1 to 9.

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