A closing resistor structure for an arc extinguishing chamber of a circuit breaker

Abstract

The utility model belongs to power transmission and transformation equipment field discloses a closing resistor structure for circuit breaker arc extinguishing chamber, including, two symmetrical support seat, insulating stick, its both ends are inserted into two symmetrical support seat respectively, polytetrafluoroethylene inner cover, its sleeve joint is on insulating stick, resistance string, by a plurality of resistance sheet is in series and is arranged along the axial direction of insulating stick and is formed, one end of resistance string is contacted with polytetrafluoroethylene inner cover, and the resistance sheet of both ends end portion of resistance string is connected with support seat respectively. Because the utility model passes through the polytetrafluoroethylene inner cover of installation between insulating stick and resistance string, can alleviate the collision between resistance sheet and insulating stick when vibrating, thereby avoiding the partial breakage of the inner hole edge of resistance sheet due to operation or transportation vibration, thereby improving product performance, ensuring the safe operation of power grid.

Description

Technical Field

[0001] This utility model belongs to the field of power transmission and transformation equipment, and specifically relates to a closing resistor structure for the arc-extinguishing chamber of a circuit breaker. Background Technology

[0002] The main functions of configuring a closing resistor in a circuit breaker are to limit inrush current, reduce closing overvoltage, smooth current waveform, reduce mechanical stress on the circuit breaker contacts, and help suppress electromagnetic interference caused by operational overvoltage.

[0003] However, circuit breakers equipped with closing resistors experience significantly greater impact forces during closing than under normal operating conditions, as the force is much greater. This immense impact acts directly on the closing resistor element, and when it exceeds the strength limit of the material, it can easily break. Furthermore, strong vibrations accompany this process, subjecting the closing resistor element to repeated alternating stresses. Prolonged alternating stresses can cause fatigue damage, reducing the element's strength and toughness, ultimately leading to fracture. This negatively impacts product performance and, ultimately, the safe operation of the power grid. Utility Model Content

[0004] To address the shortcomings of existing technologies, this utility model provides a closing resistor structure for the arc-extinguishing chamber of a circuit breaker. The aim is to improve product performance and ensure the safe operation of the power grid by increasing the support and buffering of the resistor elements, preventing breakage of the resistor elements during transportation and operation.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A closing resistor structure for the arc-extinguishing chamber of a circuit breaker, comprising:

[0007] Two symmetrical support bases,

[0008] An insulating rod, with its two ends inserted into two symmetrical support bases.

[0009] A polytetrafluoroethylene inner sleeve is fitted onto the insulating rod.

[0010] The resistor string is composed of multiple resistor pieces connected in series and arranged along the axial direction of the insulating rod. One end of the resistor string is in contact with the polytetrafluoroethylene inner sleeve, and the resistor pieces at both ends of the resistor string are respectively connected to the support base.

[0011] Preferably, the thickness of the PTFE inner sleeve is 3mm. The PTFE inner sleeve is installed between the inner hole of the resistor and the insulating rod, reducing the theoretical gap between the resistor and the insulating rod from 1.5mm to 0.5mm. This reduces the collision between the resistor and the insulating rod during vibration, thereby preventing local damage to the edge of the inner hole of the resistor due to vibration during operation or transportation.

[0012] Preferably, a soft metal sheet is disposed between each of the two ends of the resistor string and the two support bases.

[0013] Furthermore, the two ends of the resistor string are in contact with the soft metal sheet, while the other end of the soft metal sheet is in contact with the support base.

[0014] Furthermore, the soft metal sheet is an aluminum sheet.

[0015] Preferably, the thickness of the aluminum sheet is 2 mm.

[0016] Preferably, support sleeves are provided on the two resistor pieces at both ends of the resistor string, and the support sleeves are connected to the support base.

[0017] Preferably, the end of the resistor string that contacts the polytetrafluoroethylene inner sleeve is designated as the inner end of the resistor string, and the opposite end is designated as the outer end of the resistor string. The outer end of the resistor string is also fitted with a support cylinder, and the two end circumferential surfaces of the support cylinder are sealed and fixed to the two support seats by sealing rings.

[0018] Furthermore, the circumferential surface of each end of the support cylinder is fitted onto each support seat by a sealing ring, thereby achieving a seal between the two.

[0019] Preferably, the thickness of the support cylinder is 8 mm.

[0020] Preferably, a support ring is sleeved on the resistor string, and the outer wall of the support ring is connected to the support cylinder.

[0021] Preferably, the support cylinder has several heat dissipation holes for the resistor sheet to dissipate heat during operation.

[0022] Preferably, the support cylinder is made of aramid fiber, and the support ring and support sleeve are made of polytetrafluoroethylene.

[0023] Preferably, the end of the support cylinder is sealed and fixed on the support seat by a water-stop structure.

[0024] Compared with the prior art, the beneficial effects of this utility model are:

[0025] 1. Because this utility model uses a polytetrafluoroethylene (PTFE) inner sleeve installed between the insulating rod and the resistor string, the material properties of the PTFE inner sleeve can reduce the collision between the resistor sheet and the insulating rod during vibration. This prevents local damage to the inner edge of the resistor sheet due to vibration during operation or transportation, thus reducing the resistance of the closing resistor sheet from repeated alternating stress. This improves the resistance of the resistor sheet from fatigue damage caused by long-term alternating stress, thereby enhancing its strength and toughness, improving product performance, and ensuring the safe operation of the power grid.

[0026] 2. Because this utility model sets a soft metal sheet, specifically an aluminum sheet, between the resistor sheet and the support base, the purpose is to prevent the resistor sheet at the end of the resistor string from colliding with the support base, which would cause stress concentration at the edge and result in outer edge damage and chipping.

[0027] 3. Because this utility model first fits a polytetrafluoroethylene support ring onto the resistor string, and then fits an aramid fiber support cylinder onto the resistor string and the support ring, the purpose is to prevent the resistor string from cracking, thereby improving the integrity of the resistor string and reducing the mutual misalignment and vibration of the resistor pieces; in addition, it also prevents cracked resistor pieces from falling into the tank and affecting the safe operation of the circuit breaker.

[0028] 4. The purpose of setting polytetrafluoroethylene sealing rings on the support cylinder and support base in this utility model is to prevent the powder after the resistor series vibration from falling into the shell and contaminating other parts.

[0029] 5. Because the present invention has heat dissipation holes on the support cylinder, it ensures that the heat dissipation holes face upwards, which is conducive to heat dissipation and prevents wear powder from falling off. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0031] Figure 2 for Figure 1 Sectional view in;

[0032] Figure 3 for Figure 2 Schematic diagram of the structure in the AA direction;

[0033] Figure 4 for Figure 2 Schematic diagram of the structure in the middle BB direction;

[0034] Figure 5 for Figure 2 Enlarged view of the central sealing ring;

[0035] Figure 6 for Figure 2 Enlarged view of the middle support ring;

[0036] Figure 7 for Figure 2 Enlarged view of the aluminum sheet;

[0037] In the diagram: 1. Sealing ring; 2. Support ring; 3. Aluminum sheet; 4. Support cylinder; 5. Heat dissipation hole; 6. Support sleeve; 7. Stop structure; 8. Support base; 9. Resistance piece; 10. Insulating rod; 11. Polytetrafluoroethylene inner sleeve. Detailed Implementation

[0038] To make the technical means, creative features, objectives and effects of this utility model easier to understand, the following embodiments are described in detail with reference to the accompanying drawings. It should be noted that the description of these embodiments is for the purpose of helping to understand this utility model, but does not constitute a limitation on this utility model.

[0039] like Figure 1-7 As shown, a closing resistor structure for the arc-extinguishing chamber of a circuit breaker includes,

[0040] Two symmetrical support bases 8,

[0041] The insulating rod 10 has its two ends inserted into two symmetrical support seats 8 and fixed by locking bolts (e.g., Figure 2 , 5 (as shown in Figure 7); the purpose is to facilitate the disassembly and installation of the insulating rod 10 on the two support bases 8;

[0042] A 3mm thick polytetrafluoroethylene inner sleeve 11 is fitted onto the insulating rod 10.

[0043] The resistor string consists of multiple resistor pieces 9 connected in series and arranged along the axial direction of the insulating rod 10. One end of the resistor string is in contact with the polytetrafluoroethylene inner sleeve 11. Specifically, the polytetrafluoroethylene inner sleeve 11 is installed between the inner hole of the resistor piece 9 and the insulating rod 10, reducing the theoretical gap between the resistor piece 9 and the insulating rod 10 from 1.5mm to 0.5mm. This reduces the collision between the resistor piece 9 and the insulating rod 10 during vibration, thereby preventing local damage to the edge of the inner hole of the resistor piece 9 due to vibration during operation or transportation.

[0044] The resistor pieces 9 at both ends of the resistor string are connected to the support bases 8. Specifically, aluminum sheets 3 with a thickness of 2mm are set between the two ends of the resistor string and the two support bases 8. Specifically, the two ends of the resistor string are in contact with the aluminum sheets 3, and the other end of each aluminum sheet 3 is in contact with the support base 8. The purpose is to select the resistor piece in contact with the support base 8 as the first resistor piece based on the on-site inspection results of the resistor pieces 9. The probability of the first resistor piece having outer edge damage defects is higher than that of other resistor pieces. From the perspective of stress analysis, the reason is that the collision between the first resistor piece and the support base 8 causes stress concentration at the edge, resulting in outer edge damage and chipping. Therefore, a softer pure aluminum transition piece, namely aluminum sheet 3, is installed between the support base 8 and the resistor piece 9 to reduce stress concentration, reduce the maximum stress value, and move its position inward to avoid the most vulnerable edge.

[0045] The end of the resistor string that contacts the PTFE inner sleeve 11 is designated as the inner end of the resistor string, and the opposite end is designated as the outer end. An aramid fiber support cylinder 4 is also fitted over the outer end of the resistor string. The purpose of this is to add an 8mm thick support cylinder 4 to the outer end of the resistor string. This support cylinder 4 protects the resistor string, improving its overall integrity, reducing misalignment and vibration of the resistor pieces 9, and ensuring that even in the rare event of a resistor piece 9 breaking, the cracked piece will not fall into the tank (it should be noted that the entire closing resistor structure is installed inside the tank; therefore, the support cylinder 9 prevents cracked pieces from falling into the tank) and affecting the safe operation of the circuit breaker. Additionally, the side of the aluminum sheet 3 closest to the support base 8 is flush with one end of the support cylinder 4 for ease of installation.

[0046] The two end circumferential surfaces of the support cylinder 4 are sealed and fixed to the two support seats 8 by sealing rings 1; specifically, the end circumferential surface of the support cylinder 4 with a thickness of 8mm is embedded in each support seat by sealing rings 1, and the two are sealed; the purpose is to prevent the powder after the resistance series vibration from falling into the shell and contaminating other parts; in addition, the support cylinder 4 is sealed and fixed to the support seat 8 by a water-stop structure 7, the purpose of which is to prevent wear and prevent the powder from falling.

[0047] Polytetrafluoroethylene (PTFE) support sleeves 6 are provided on the two resistor plates 9 at both ends of the resistor string, and the PTFE support sleeves 6 are in contact with the support base 8.

[0048] Multiple support rings 2 made of polytetrafluoroethylene are fitted onto the resistor string, and they are preferably installed at equal intervals on the resistor string. The outer wall of the support ring 2 is connected to the support cylinder 4. Specifically, each support ring 2 is first installed on the resistor string by heat pressing, and then the support cylinder 4 is fitted onto the support sleeve 2 and the resistor string.

[0049] The support cylinder 4 has several heat dissipation holes 5 for the resistor 9 to dissipate heat during operation; the purpose is to ensure that the heat dissipation holes 5 face upwards to facilitate heat dissipation.

[0050] The support base 8 has a bent portion that extends away from the support cylinder 4 and corresponds to the heat dissipation hole 5; taking this closing resistor structure placed in a horizontal tank as an example, when the closing resistor structure is arranged according to... Figure 1 When placed inside a horizontal tank in the manner described, the bent part of its support base is positioned upward relative to the lower surface of the horizontal tank, and the heat dissipation hole 5 is also positioned upward.

[0051] In addition, such as Figure 2 , 5 As shown, a spring is installed inside one of the support bases 8. The spring is in contact with one of the resistor pieces 9 in the resistor string through a connector. This is the prior art, that is, each closing resistor has this structure, which will not be described in detail here.

[0052] The embodiments described are preferred embodiments of this utility model and are not intended to limit the scope of protection of this utility model. Various modifications or variations that can be made by those skilled in the art within the scope of the appended claims without creative effort are still within the scope of protection of this patent.

Claims

1. A closing resistor structure for the arc-extinguishing chamber of a circuit breaker, characterized in that, include, Two symmetrical support bases, An insulating rod, with its two ends inserted into two symmetrical support bases. A polytetrafluoroethylene inner sleeve is fitted onto the insulating rod. The resistor string is composed of multiple resistor pieces connected in series and arranged along the axial direction of the insulating rod. One end of the resistor string is in contact with the polytetrafluoroethylene inner sleeve, and the resistor pieces at both ends of the resistor string are respectively connected to the support base.

2. The closing resistor structure according to claim 1, characterized in that: Soft metal sheets are respectively placed between the two ends of the resistor string and the two support bases.

3. The closing resistor structure according to claim 1, characterized in that: Support sleeves are provided on two resistor plates at both ends of the resistor string, and the support sleeves are connected to the support base.

4. The closing resistor structure according to claim 1, characterized in that: The end of the resistor string that contacts the polytetrafluoroethylene inner sleeve is designated as the inner end of the resistor string, and the opposite end is designated as the outer end of the resistor string. The outer end of the resistor string is also fitted with a support cylinder, and the two ends of the support cylinder are sealed and fixed to the two support seats by sealing rings.

5. The closing resistor structure according to claim 4, characterized in that: A support ring is sleeved on the resistor string, and the outer wall of the support ring is connected to the support cylinder.

6. The closing resistor structure according to claim 4 or 5, characterized in that: The support cylinder has several heat dissipation holes for the resistor to dissipate heat during operation.

7. The closing resistor structure according to claim 6, characterized in that: The support cylinder is made of aramid fiber, and the support ring and support sleeve are made of polytetrafluoroethylene.

8. The closing resistor structure according to claim 4, characterized in that: The end of the support cylinder is sealed and fixed on the support base by a water-stop structure.

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