Insulation protection structure of low-voltage side of transformer

Abstract

The utility model discloses a kind of insulation protection structures of transformer low-voltage side, the insulation protection structure includes insulation protection sleeve and the insulation protection sleeve connecting portion of both ends;The insulation protection sleeve and insulation protection sleeve connecting portion are all layered structure, in order to first functional layer, chemical anchoring layer, primer layer, insulation matrix layer and second functional layer. The utility model provides a kind of detachable, shock-resistant, long-acting insulation protection scheme, solve the contradiction of insufficient thickness and crack of insulation layer, the conflict of quick-release structure and sealing reliability, reduce the protection failure risk, improve the adaptability to transformer low-voltage side structure, size and the controllability of quality.

Description

Technical Field

[0001] This utility model belongs to the field of transformer insulation protection technology, specifically relating to an insulation protection structure for the low-voltage side of a transformer. Background Technology

[0002] In hydropower projects, generators and main transformers are connected via high-current busbars. In power plants commissioned before the 1990s, due to limitations in installed capacity and technology at the time, units of 100MW and above generally used direct bare busbar connections. However, bare busbars no longer meet the insulation requirements of power development, necessitating insulation upgrades. Common alternatives include using phase-separated enclosed busbars and fully insulated tubular busbars. When the original project used bare busbars, a blind spot in insulation protection existed at the connection between the low-voltage side bushings of the main transformer and the main transformer's low-voltage side bushings. A satisfactory solution for this area has not yet been found. The main reasons include... (1) When the low-voltage side of the main transformer and the high-current busbar of the generator are connected, copper braided wire is used for flexible connection to redundancy the vibration between different equipment. Copper braided wire is a flexible structure and is easy to deform, so conventional insulation sheath schemes cannot be used.

[0003] (2) The connection structure between the low-voltage side of the main transformer and the high-current busbar of the generator needs to be detachable to facilitate maintenance and testing. The conventional protective enclosure scheme, which completely covers and encapsulates the low-voltage side, is not conducive to maintenance and operation.

[0004] Chinese patent CN207353069U discloses an insulation structure for a distribution transformer filled with natural ester insulating oil, including a low-voltage coil, a high-voltage coil, a main air channel, and an elliptical epoxy insulating cylinder. The high-voltage coil forms low-voltage end insulation and a low-voltage heat dissipation oil channel, while the high-voltage coil forms high-voltage end insulation and a high-voltage heat dissipation oil channel. The structure also includes two epoxy triangular plates and a low-voltage starting copper busbar. The low-voltage starting copper busbar is fitted to a mounting plane formed on the outer wall of the epoxy insulating cylinder. The two epoxy triangular plates are located on the mounting plane and are respectively positioned on both sides of the low-voltage starting copper busbar. This insulation structure is applied to a distribution transformer filled with natural ester insulating oil. The high-voltage and high-voltage coil materials and insulation materials in this application are all fused with natural ester insulating oil, meeting the routine test requirements of standards (GB 1094.1, GB 1094.3), the temperature rise test requirements of standard (GB 1094.2), and the short-circuit withstand capability test requirements of standard (GB 1094.5).

[0005] Chinese patent CN2357404Y discloses an insulating cover for the terminals of a 10kV distribution transformer, comprising an insulating cover for the high-voltage terminals and an insulating cover for the low-voltage terminals, both made of insulating material. Their inner cavities conform to the shapes of the high-voltage and low-voltage terminals, respectively, and they have corresponding inlet and outlet holes on their sides and bottom. The low-voltage terminal insulating cover is formed by two movably connected halves of a clamping sleeve. In use, these covers are respectively placed over the high-voltage and low-voltage terminals of the distribution transformer, providing insulation and sealing to the exposed parts of the terminals and inlet / outlet lines. This effectively prevents transformer short-circuit damage and electric shock accidents caused by external forces such as falling objects from heights. The design is simple, convenient, economical, and practical.

[0006] However, the insulation structure in the existing technology is not easy to disassemble, there is a risk of protection failure due to vibration of the soft connection, and it is not suitable for large-sized irregular structures, and there are problems of difficult construction and uncontrollable quality. Summary of the Invention

[0007] To address the aforementioned technical problems, this utility model provides an insulation protection structure for the low-voltage side of a transformer, offering a detachable, vibration-resistant, and long-lasting insulation protection solution. This resolves the contradiction between insufficient insulation layer thickness and cracking, as well as the conflict between quick-release structure and sealing reliability. It reduces the risk of protection failure and improves the adaptability to the structure and dimensions of the low-voltage side of the transformer, as well as the controllability of quality.

[0008] To achieve the above objectives, this utility model provides an insulation protection structure for the low-voltage side of a transformer. The insulation protection structure includes an insulation protection sleeve and insulation protection sleeve connecting portions at both ends. Both the insulation protection sleeve and the insulation protection sleeve connecting portions are layered structures, consisting of a first functional layer, a chemical anchoring layer, a primer layer, an insulating substrate layer, and a second functional layer, in sequence.

[0009] Preferably, the connection between the insulating substrate layer and the second functional layer is provided with a groove array.

[0010] Preferably, the insulating substrate layer is made of polyethylene.

[0011] Preferably, both the first functional layer and the second functional layer are made of silicone rubber.

[0012] Preferably, the insulating protective sleeve connection part has a buckle hole on one side, a rotating buckle on the other side, and a labyrinth structure in the middle.

[0013] More preferably, the bottom of the buckle hole is provided with a sealing strip, the rotating buckle is located in the sealing groove of the insulating protective sleeve connection part, and the top of the sealing groove is provided with a sealing strip.

[0014] Preferably, the insulating protective sleeve has multiple guide grooves on its upper and lower sides.

[0015] More preferably, the guide channel is provided with a hydrophobic grid.

[0016] Preferably, the insulating protective sleeve covers the outside of the transformer's low-voltage side terminals, the low-voltage side copper braided wire, and the high-current busbar low-voltage side terminals, and is fixed by the insulating protective sleeve connection part.

[0017] More preferably, one end of the low-voltage side terminal of the transformer is connected to the low-voltage bushing of the transformer, and the other end is connected to the low-voltage side copper braided wire; the low-voltage side copper braided wire is connected in sequence to the low-voltage side terminal of the high-current bus and the low-voltage side busbar.

[0018] The beneficial effects of this invention are as follows: The pre-prepared, flexible, and extensible layered insulating protective sleeve can tightly wrap the internal low-voltage side structure of the transformer. Regardless of its structural irregularities or size, it can achieve complete and tight insulation protection, ensuring the stability of the protection quality and reducing construction difficulty. Furthermore, the layered insulating protective sleeve has a certain thickness, preventing insufficient insulation layer thickness and cracking, which would affect the insulation protection effect. The insulating protective sleeve has connecting parts on both sides, with rotating buckles for easy disassembly without interfering with the insulation protection, thus solving the drawbacks of traditional insulating enclosures. Attached Figure Description

[0019] Figure 1 This is a development diagram of the insulating protection structure in this utility model.

[0020] Figure 2 This is a side sectional view of the insulating protective structure.

[0021] Figure 3 The diagram shows a side view of an insulating protective structure. In the diagram, A is a schematic diagram of a snap-fit ​​structure and a flow guide channel, B is a schematic diagram of a hydrophobic grid, and C is a schematic diagram of a snap-fit ​​structure.

[0022] Figure 4 This is a schematic diagram of the low-voltage side of a transformer with an insulation protection structure. In the diagram, A is a schematic diagram of the external structure and B is a sectional view.

[0023] Figure 5 This is a schematic diagram of the low-voltage side of a transformer without an insulating protective layer. In the diagram, A is a schematic diagram of the external structure and B is a sectional view.

[0024] In the figure, 1 is the insulating protective sleeve, 101 is the insulating substrate layer, 102 is the primer layer, 103 is the chemical anchoring layer, 104 is the first functional layer, 105 is the groove array, 106 is the second functional layer, 2 is the insulating protective sleeve connection part, 201 is the labyrinth structure, 202 is the rotating buckle, 203 is the sealing strip, 204 is the buckle hole, 205 is the flow guide groove, 206 is the hydrophobic grid, 3 is the transformer low-voltage bushing, 4 is the transformer low-voltage side terminal, 5 is the low-voltage side copper braided wire, 6 is the low-voltage side busbar, and 7 is the high-current busbar low-voltage side terminal. Detailed Implementation

[0025] The technical solution of this utility model will be further explained below with reference to the accompanying drawings and specific embodiments. It is worth noting that the following embodiments are only preferred embodiments of this utility model and should not be construed as limiting this utility model. The protection scope of this utility model should be determined by the content of the claims. Modifications or substitutions made by those skilled in the art to the technical solution of this utility model without creative effort all fall within the protection scope of this utility model.

[0026] Example 1 like Figure 1-5 As shown, an insulation protection structure for the low-voltage side of a transformer includes an insulation protection sleeve 1 and insulation protection sleeve connecting parts 2 at both ends. The insulation protection sleeve connecting parts 2 can fix the insulation protection sleeve 1 to the outside of the device that needs insulation protection, and through the flexible structure and extensibility of the insulation protection sleeve 1, it can adapt to the internal device structure to achieve tight fit and insulation protection. Both the insulation protection sleeve 1 and the insulation protection sleeve connecting parts 2 are layered structures, consisting of a first functional layer 104, a chemical anchoring layer 103, a primer layer 102, an insulating substrate layer 101, and a second functional layer 106.

[0027] Preferably, a groove array 105 is provided at the connection between the insulating substrate layer 101 and the second functional layer 106, so that the second functional layer 106 can be tightly bonded to the insulating substrate layer 101 to form a physical interlocking interface. The second functional layer 106 fits into the groove array 105 and has the same structure as the groove array 105, so that the surfaces of the insulating protective sleeve 1 and the insulating protective sleeve connection part 2 both have a groove array 105 type structure.

[0028] Preferably, the insulating substrate layer 101 is made of polyethylene, which has a certain degree of flexibility and extensibility, and can change its shape according to the internal structural device to achieve a tight fit.

[0029] Preferably, both the first functional layer 104 and the second functional layer 106 are made of silicone rubber, which has a certain degree of flexibility and extensibility, and can change shape according to the internal structural device to achieve a tight fit.

[0030] Preferably, the thickness of the insulating substrate layer 101 is 5-30 mm; the thickness of the primer layer 102 is 5-15 μm; the thickness of the chemical anchoring layer 103 is 3-5 μm; the thickness of the first functional layer 104 is 3-5 μm; and the thickness of the second functional layer 106 is 5-15 μm.

[0031] More preferably, the silicone rubber contains nanoparticles; the nanoparticles are SiO2 nanoparticles or TiO2 nanoparticles.

[0032] Preferably, the insulating protective sleeve connecting part 2 has a buckle hole 204 on one side and a rotating buckle 202 on the other side, with a maze structure 201 in the middle. When performing insulation protection, the insulating protective structure wraps around the internal structure, and then the rotating buckle 202 is placed in the buckle hole 204 and manually rotated to fasten, thus achieving insulation protection. When maintenance is required, it can also be easily loosened to achieve quick disassembly. The structure is simple and the effect is good.

[0033] Preferably, the bottom of the buckle hole 204 is provided with a sealing strip 203 to prevent external impurities from entering the buckle hole 204, and can also further achieve insulation. The rotating buckle 202 is located in the sealing groove of the insulating protective sleeve connection part 2, and the top of the sealing groove is provided with a sealing strip 203, which not only protects the rotating buckle 202, but also further improves the insulation and sealing performance.

[0034] More preferably, the upper and lower sides of the insulating protective sleeve 1 are provided with a plurality of guide grooves 205, which are machined grooves with a certain inclined slope, so as to collect and guide the rainwater accumulated on the insulating protective structure to drain out.

[0035] More preferably, the inclination slope is 15°-45°.

[0036] More preferably, the guide channel 205 is provided with a hydrophobic grid 206, which is composed of a series of dense slits or small holes, and its inner surface is higher than the bottom of the sheath to prevent large debris from entering.

[0037] Preferably, the insulating protective sleeve 1 covers the outside of the transformer low-voltage side terminal 4, the low-voltage side copper braided wire 5, and the high-current busbar low-voltage side terminal 7, and is fixed by the insulating protective sleeve connecting part 2.

[0038] More preferably, one end of the transformer low-voltage side terminal 4 is connected to the transformer low-voltage bushing 3, and the other end is connected to the low-voltage side copper braided wire 5; the low-voltage side copper braided wire 5 is connected in sequence to the high-current bus low-voltage side terminal 7 and the low-voltage side busbar 6 to form a complete transformer low-voltage side structure.

Claims

1. An insulation protection structure for the low-voltage side of a transformer, characterized in that: The insulating protective structure includes an insulating protective sleeve (1) and insulating protective sleeve connecting parts (2) at both ends; the insulating protective sleeve (1) and the insulating protective sleeve connecting parts (2) are both layered structures, namely, a first functional layer (104), a chemical anchoring layer (103), a primer layer (102), an insulating substrate layer (101), and a second functional layer (106).

2. The insulation protection structure for the low-voltage side of a transformer according to claim 1, characterized in that: The connection between the insulating substrate layer (101) and the second functional layer (106) is provided with a groove array (105).

3. The insulation protection structure for the low-voltage side of a transformer according to claim 1 or 2, characterized in that: The insulating substrate layer (101) is made of polyethylene.

4. The insulation protection structure for the low-voltage side of a transformer according to claim 1, characterized in that: Both the first functional layer (104) and the second functional layer (106) are made of silicone rubber.

5. The insulation protection structure for the low-voltage side of a transformer according to claim 1, characterized in that: The insulating protective sleeve connection part (2) has a buckle hole (204) on one side, a rotating buckle (202) on the other side, and a maze structure (201) in the middle.

6. The insulation protection structure for the low-voltage side of a transformer according to claim 5, characterized in that: The bottom of the buckle hole (204) is provided with a sealing strip (203), the rotating buckle (202) is located in the sealing groove of the insulating protective sleeve connection part (2), and the top of the sealing groove is provided with a sealing strip (203).

7. The insulation protection structure for the low-voltage side of a transformer according to claim 1, characterized in that: The insulating protective sleeve (1) is provided with multiple guide grooves (205) on the upper and lower sides.

8. The insulation protection structure for the low-voltage side of a transformer according to claim 7, characterized in that: The guide channel (205) is equipped with a hydrophobic grid (206).

9. The insulation protection structure for the low-voltage side of a transformer according to claim 1, characterized in that: The insulating protective sleeve (1) covers the outside of the transformer low-voltage side terminal (4), the low-voltage side copper braided wire (5) and the high-current bus low-voltage side terminal (7), and is fixed by the insulating protective sleeve connecting part (2).

10. The insulation protection structure for the low-voltage side of a transformer according to claim 9, characterized in that: One end of the transformer low-voltage side terminal (4) is connected to the transformer low-voltage bushing (3), and the other end is connected to the low-voltage side copper braided wire (5); the low-voltage side copper braided wire (5) is connected in sequence to the high-current bus low-voltage side terminal (7) and the low-voltage side busbar (6).

Images