Internal voltage-sharing shielding case structure of high-voltage-class vacuum arc-extinguishing chamber

Abstract

The invention relates to the technical field of high-voltage switch equipment, in particular to a voltage-sharing shielding case structure inside a high-voltage-class vacuum arc-extinguishing chamber. A voltage-sharing shielding case structure inside a high-voltage-class vacuum arc-extinguishing chamber is characterized in that the vacuum arc-extinguishing chamber is formed by connecting four sections of porcelain shells from top to bottom, and a moving contact and a static contact are arranged inside the vacuum arc-extinguishing chamber; the outer side of the upper part of the moving contact side is sleeved with a moving contact side shielding cover, and the outer side of the lower part of the moving contact side is sleeved with a moving end shielding cover. The middle part of the static contact is a static contact side, the outer side of the lower part of the static contact side is sleeved with a static contact side shielding cover, and the outer side of the upper part of the static contact side is sleeved with a static end shielding cover; and a main shielding cover is sleeved outside the upper parts of the moving contact and the static contact. Compared with the prior art, the influence of the ground capacitance of the internal voltage-sharing shielding case on the potential bias is reduced, so that the voltage concentration phenomenon occurring when the vacuum arc-extinguishing chamber is applied to the circuit breaker is reduced to the greatest extent.

Description

Technical Field

[0001] The present invention relates to the technical field of high-voltage switchgear, in particular to a voltage-sharing shield structure inside a high-voltage vacuum interrupter. Background Art

[0002] Vacuum interrupters offer excellent interrupting performance, significant environmental friendliness, a compact design, and easy maintenance. Thanks to these combined advantages, this technology has been widely adopted in medium-voltage power systems and continues to advance in higher-voltage transmission networks.

[0003] As a core component of vacuum circuit breakers, the reliability of the insulation performance of vacuum interrupters is a key technical foundation supporting the development of vacuum circuit breakers to higher voltage levels. Although research on the insulation performance of vacuum interrupters built into high-voltage vacuum circuit breakers has made significant progress, significant bottlenecks still exist in practical applications. When the vacuum interrupter is installed within the metal casing of the vacuum circuit breaker, the presence of the metal casing greatly reduces the distance between each conductor and the ground, causing the self-capacitance between each conductor and the ground to increase, resulting in a decrease in the potential of the vacuum interrupter's main shield. This leads to uneven voltage distribution within the vacuum interrupter, affecting the electric field distribution in the vacuum interrupter and degrading the insulation performance of the vacuum interrupter. This degraded insulation performance of the vacuum interrupter will affect operational reliability and has become one of the key bottlenecks restricting the development of vacuum circuit breakers to higher voltage levels.

[0004] To address the phenomenon of shield potential shifts caused by stray capacitance, current research has proposed various parallel voltage-equalizing schemes. This study analyzes the impact of different parallel capacitor schemes on electric field uniformity and demonstrates that variations in the shield potential within the vacuum interrupter, applied within the metal tank, significantly influence the overall electric field strength. Parallel capacitors, with adjustable capacitance, are an effective voltage-equalizing method. However, this raises a series of fundamental theoretical and key technical issues, such as the overall insulation configuration of the tank using parallel capacitors.

[0005] Therefore, designing the voltage equalization for the internal structure of the vacuum interrupter can help improve the insulation performance of the vacuum interrupter while avoiding the influence of the external structure on the insulation of the circuit breaker. Summary of the Invention

[0006] In order to overcome the deficiencies of the prior art, the present invention provides a voltage-equalizing shielding cover structure inside a high-voltage vacuum interrupter, which is used to adjust the voltage uniform distribution between the internal structures of the vacuum interrupter.

[0007] In order to achieve the above-mentioned purpose, a high-voltage vacuum interrupter internal voltage-equalizing shielding cover structure is designed, including a vacuum interrupter, characterized in that: the vacuum interrupter is formed by four porcelain shells connected from top to bottom, and a moving contact and a static contact are arranged inside the vacuum interrupter, and the moving contact and the static contact are symmetrically arranged up and down; the middle part of the moving contact is the moving contact side, and a moving contact side shielding cover is provided on the outer side of the upper part of the moving contact side, and a moving end shielding cover is provided on the outer side of the lower part of the moving contact side, and the moving end shielding cover and the moving contact side shielding cover are mutually nested structures; the middle part of the static contact is the static contact side, and a static contact side shielding cover is provided on the outer side of the lower part of the static contact side, and a static end shielding cover is provided on the outer side of the upper part of the static contact side, and the static end shielding cover and the static contact side shielding cover are mutually nested structures; a main shielding cover is provided on the outer side of the upper part of the moving contact and the static contact, and the upper and lower ends of the main shielding cover are respectively mutually nested structures with the moving end shielding cover and the static end shielding cover.

[0008] The four porcelain shells are respectively the first porcelain shell, the second porcelain shell, the third porcelain shell and the fourth porcelain shell, and the top of the moving contact side shielding cover is connected to the top of the first porcelain shell, and the moving end shielding cover is clamped between the first porcelain shell and the second porcelain shell; the main shielding cover is clamped between the second porcelain shell and the third porcelain shell, the static end shielding cover is clamped between the third porcelain shell and the fourth porcelain shell, and the bottom of the static contact side shielding cover is connected to the bottom of the fourth porcelain shell.

[0009] The upper portion of the movable end shielding cover is an inward-retracted structure, the lower portion of the movable end shielding cover is a directly extended structure, and the upper portion of the movable end shielding cover is located inside the contact side shielding cover.

[0010] The upper and lower parts of the main shielding cover are inward-retracting structures. The upper part of the main shielding cover is located inside the moving end shielding cover, and the lower part of the main shielding cover is located inside the static end shielding cover.

[0011] The upper portion of the static end shielding cover is a directly extended structure, the lower portion of the static end shielding cover is an inwardly retracted structure, and the lower portion of the static end shielding cover is located inside the static contact side shielding cover.

[0012] The moving end shielding cover, the main shielding cover and the static end shielding cover are pressure-equalizing shielding covers.

[0013] The moving contact side shielding cover, the moving end shielding cover, the main shielding cover, the static end shielding cover and the static contact side shielding cover form a multi-stage suspended shielding structure.

[0014] Compared to existing technologies, this invention provides a high-voltage internal voltage-sharing shield structure for a vacuum interrupter, designed to uniformly distribute voltage across the internal structure. By reducing the effect of the internal voltage-sharing shield's capacitance to ground on potential bias and altering the internal capacitance distribution of the vacuum interrupter, the invention minimizes voltage concentration when the vacuum interrupter is used in a circuit breaker.

[0015] The advantages of the present invention are as follows: 1. By changing the internal structure of the vacuum arc chamber, the potential bias of the voltage-equalizing shield caused by the influence of the capacitance to the ground is reduced, thereby ensuring the voltage-equalizing effect; 2. Multiple voltage-equalizing shields inside the vacuum arc chamber influence each other, and by adjusting the capacitance distribution, the centralized distribution of the voltage inside the vacuum arc chamber is achieved; 3. Voltage balancing is performed by configuring the internal structure of the vacuum arc chamber, thereby reducing the problem of decreased insulation performance of the entire machine after application to the circuit breaker due to voltage balancing using an external structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a cross-sectional view of the internal voltage-equalizing shield structure of an existing high-voltage vacuum interrupter before adjustment.

[0017] Figure 2 It is a cross-sectional view of the overall assembly of the structure of the present invention.

[0018] Figure 3 It is a cross-sectional view of the shield cover structure on the moving contact side of the present invention.

[0019] Figure 4 This is a cross-sectional view of the structure of the moving end shielding cover of the present invention.

[0020] Figure 5 This is a cross-sectional view of the static end shield structure of the present invention.

[0021] Figure 6 It is a cross-sectional view of the shield cover structure on the static contact side of the present invention.

[0022] Figure 7 It is a cross-sectional view of the main shielding cover structure of the present invention.

[0023] Figure 8 Schematic diagram of the capacitance distribution between the internal contacts and each voltage-sharing shield of the vacuum interrupter of the present invention.

[0024] See also Figure 2 、 Figure 3 、 Figure 6 、 Figure 8 , 11 is the first porcelain shell, 12 is the second porcelain shell, 13 is the third porcelain shell, 14 is the fourth porcelain shell, 21 is the moving contact side, 22 is the static contact side, 23 is the moving end shielding cover, 24 is the main shielding cover, 25 is the static end shielding cover, 31 is the moving contact, 32 is the moving contact side shielding cover, 33 is the static contact, 34 is the static contact side shielding cover, 41 is the first voltage difference, 42 is the second voltage difference, 43 is the third voltage difference, and 44 is the fourth voltage difference. DETAILED DESCRIPTION

[0025] The present invention will be further described below with reference to the accompanying drawings.

[0026] like Figures 2 to 7As shown, the vacuum interrupter is formed by four porcelain shells connected from top to bottom. A moving contact 31 and a static contact 33 are provided inside the vacuum interrupter. The moving contact 31 and the static contact 33 are arranged symmetrically in an upper and lower manner. The middle portion of the moving contact 31 is the moving contact side 21. A moving contact side shielding cover 32 is provided on the outer side of the upper portion of the moving contact side 21. A moving end shielding cover 23 is provided on the outer side of the lower portion of the moving contact side 21. The moving end shielding cover 23 and the moving contact side shielding cover 32 are nested with each other. The middle part of the static contact 33 is the static contact side 22. A static contact side shielding cover 34 is provided on the outer side of the lower part of the static contact side 22, and a static end shielding cover 25 is provided on the outer side of the upper part of the static contact side 22. The static end shielding cover 25 and the static contact side shielding cover 34 are nested with each other; a main shielding cover 24 is provided on the outer side of the upper part of the moving contact 31 and the static contact 33, and the upper and lower ends of the main shielding cover 24 are nested with the moving end shielding cover 23 and the static end shielding cover 25 respectively.

[0027] The four porcelain shells are the first porcelain shell 11, the second porcelain shell 12, the third porcelain shell 13, and the fourth porcelain shell 14, and the top of the moving contact side shielding cover 32 is connected to the top of the first porcelain shell 11, and the moving end shielding cover 23 is clamped between the first porcelain shell 11 and the second porcelain shell 12; the main shielding cover 24 is clamped between the second porcelain shell 12 and the third porcelain shell 13, and the static end shielding cover 25 is clamped between the third porcelain shell 13 and the fourth porcelain shell 14. The bottom of the static contact side shielding cover 34 is connected to the bottom of the fourth porcelain shell 14.

[0028] The upper portion of the movable end shielding cover 23 is an inward-retracted structure, the lower portion of the movable end shielding cover 23 is a directly extended structure, and the upper portion of the movable end shielding cover 23 is located inside the contact-side shielding cover 32 .

[0029] The upper and lower parts of the main shielding cover 24 are inward-retracted structures. The upper part of the main shielding cover 24 is located inside the moving end shielding cover 23 , and the lower part of the main shielding cover 24 is located inside the static end shielding cover 25 .

[0030] The upper portion of the static end shielding cover 25 is a directly extended structure, and the lower portion of the static end shielding cover 25 is an inwardly retracted structure. The lower portion of the static end shielding cover 25 is located inside the static contact side shielding cover 34 .

[0031] The dynamic end shielding cover 23, the main shielding cover 24 and the static end shielding cover 25 are pressure-equalizing shielding covers.

[0032] The moving contact side shielding cover 32 , the moving end shielding cover 23 , the main shielding cover 24 , the static end shielding cover 25 , and the static contact side shielding cover 34 form a multi-stage suspended shielding structure.

[0033] like Figure 1As shown in the figure, it is a cross-sectional view of the internal voltage-equalizing shielding cover structure of a certain high-voltage vacuum interrupter before adjustment. Through the voltage simulation analysis of the various structures inside the vacuum interrupter by the equivalent circuit, it can be obtained that before adjustment, the voltage difference between the moving contact side and the main shielding cover, and the static contact side and the main shielding cover inside the vacuum interrupter account for 65.89% and 34.11% of the total voltage respectively, and the voltage difference between the moving contact side and the main shielding cover is extremely large; the voltage difference between the moving contact side and the moving end shielding cover, the moving end shielding cover and the main shielding cover, the main shielding cover and the static end shielding cover, and the static end shielding cover and the static contact side account for 39.98%, 25.9%, 24.4% and 9.72% of the total voltage respectively. The voltage difference between the moving contact side and the moving end shielding cover is extremely large. It can be obtained that the voltage is greatly concentrated on the moving contact side of the vacuum interrupter.

[0034] like Figure 2 The figure shows a cross-sectional view of the overall assembly of the structure of the present invention. The vacuum interrupter has a basically symmetrical structure: the moving contact side 21 and the static contact side 22 are arranged symmetrically, the moving contact 31 and the static contact 33 are arranged symmetrically, the moving contact side shield 32 and the static contact side shield 34 are arranged symmetrically, and the moving end shield 23 and the static end shield 25 are arranged symmetrically. The main shield 24 is arranged between the moving end shield 23 and the static end shield 25. The various voltage-equalizing shields within the vacuum interrupter are nested to adjust the voltage-equalizing shield potential offset caused by the capacitance to ground of the vacuum interrupter after application to the metal tank. This redistributes the capacitance distribution within the vacuum interrupter, so that the voltage originally concentrated at the moving end is evenly distributed at both the moving and static ends.

[0035] Combined with the capacitance analysis, the capacitance of each grading shield to the ground should be reduced to the greatest extent to reduce the impact on voltage concentration; therefore, the grading shield inside the vacuum interrupter is a layered wrapping structure, such as Figure 3 As shown, the moving contact side shield 32 is directly extended to cover the upper structure of the moving end shield 23; Figure 4 As shown, on the moving end shield 23, the structure close to the main shield 24 is directly extended to achieve the upper structure covering the main shield 24; Figure 5 As shown, on the static end shield 25, the structure close to the main shield 24 is also directly extended to cover the lower structure of the main shield 24; Figure 6 As shown, the static contact side shielding cover 34 is directly extended to cover the lower structure of the static end shielding cover 25; through the layered covering structure of the voltage-equalizing shielding cover inside the vacuum interrupter, the capacitance of each voltage-equalizing shielding cover to the ground is reduced, the offset of the potential value of the voltage-equalizing shielding cover is reduced, and the potential value of each voltage-equalizing shielding cover is increased to uniformly balance the voltage inside the vacuum interrupter.

[0036] The voltage-sharing shield is set as a nested structure to achieve the regulation of the voltage between the various breaks inside the vacuum interrupter; Figure 4 As shown, one side of the movable end shield 23 is a directly extended structure, and the other side is an inward-retracted structure, and the movable end shield 23 is an inward-retracted structure close to the movable contact side 21; Figure 7 As shown, both ends of the main shielding cover 24 are inward-retracted structures and are appropriately extended toward both ends; Figure 5 As shown, one side of the static end shield 25 is a directly extended structure, and the other side is an inward-retracted structure, and the static end shield 25 is an inward-retracted structure close to the static contact side 22; Figure 8 As shown, under this voltage-equalizing structure design, the voltage difference between the moving contact side 21 of the vacuum interrupter and the moving end shielding cover 23 (first voltage difference 41), and the voltage difference between the moving contact 31 and the main shielding cover 24 (second voltage difference 42) decrease, and the voltage difference between the static contact 33 and the main shielding cover 24 (third voltage difference 43), and the voltage difference between the static contact side 22 and the static end shielding cover 25 (fourth voltage difference 44) increase. The voltage difference between the moving contact side 21 and each shielding space decreases to varying degrees, while the voltage difference between the static contact side 22 and each shielding space increases to varying degrees.

[0037] After voltage equalization by this voltage-equalizing shield, the voltage differences between the moving contact side 21 and the main shield 24, and between the static contact 33 and the main shield 24 within the vacuum interrupter account for 58.84% and 41.16% of the total voltage, respectively. The voltage differences between the moving contact side 21 and the moving end shield 23, the moving end shield 23 and the main shield 24, the main shield 24 and the static end shield 25, and the static end shield 25 and the static contact side 22 account for 29.42%, 29.43%, 25.59%, and 15.57% of the total voltage, respectively. This indicates that compared to before voltage adjustment, the voltage on the moving contact side 21 within the vacuum interrupter is no longer significantly concentrated, and the internal voltage distribution is more uniform. This invention's voltage-equalizing shield achieves a significant voltage-equalizing effect within the vacuum interrupter.

Claims

1. A high-voltage vacuum interrupter internal pressure-sharing shield structure, comprising a vacuum interrupter, characterized in that: The vacuum interrupter is formed by connecting four porcelain shells from top to bottom. A moving contact (31) and a static contact (33) are arranged inside the vacuum interrupter. The moving contact (31) and the static contact (33) are arranged symmetrically up and down. The middle part of the moving contact (31) is the moving contact side (21). A moving contact side shielding cover (32) is provided on the outer side of the upper part of the moving contact side (21). A moving end shielding cover (23) is provided on the outer side of the lower part of the moving contact side (21). The moving end shielding cover (23) and the moving contact side shielding cover (32) are mutually nested. The middle part of the static contact (33) is the static contact side (22), a static contact side shielding cover (34) is sleeved on the outer side of the lower part of the static contact side (22), a static end shielding cover (25) is sleeved on the outer side of the upper part of the static contact side (22), and the static end shielding cover (25) and the static contact side shielding cover (34) are mutually nested structures; a main shielding cover (24) is sleeved on the outer side of the upper part of the moving contact (31) and the static contact (33), and the upper and lower ends of the main shielding cover (24) are mutually nested structures with the moving end shielding cover (23) and the static end shielding cover (25), respectively.

2. The internal voltage-sharing shield structure of a high-voltage vacuum interrupter according to claim 1, characterized in that: The four porcelain shells are respectively a first porcelain shell (11), a second porcelain shell (12), a third porcelain shell (13), and a fourth porcelain shell (14), and the top of the moving contact side shielding cover (32) is connected to the top of the first porcelain shell (11), and the moving end shielding cover (23) is clamped between the first porcelain shell (11) and the second porcelain shell (12); the main shielding cover (24) is clamped between the second porcelain shell (12) and the third porcelain shell (13), the static end shielding cover (25) is clamped between the third porcelain shell (13) and the fourth porcelain shell (14), and the bottom of the static contact side shielding cover (34) is connected to the bottom of the fourth porcelain shell (14).

3. A high voltage vacuum interrupter internal voltage-sharing shield structure according to claim 1 or 2, characterized in that: The upper portion of the movable end shielding cover (23) is an inward-retracting structure, the lower portion of the movable end shielding cover (23) is a directly extended structure, and the upper portion of the movable end shielding cover (23) is located inside the contact side shielding cover (32). The internal voltage-equalizing shield structure of a high-voltage vacuum interrupter according to claim 1 or 2 is characterized in that the upper and lower parts of the main shield (24) are inward-retracted structures, the upper part of the main shield (24) is located inside the moving-end shield (23), and the lower part of the main shield (24) is located inside the static-end shield (25).

4. A high-voltage vacuum interrupter internal voltage-shading shield structure according to claim 1 or 2, characterized in that: The upper portion of the static end shielding cover (25) is a directly extended structure, the lower portion of the static end shielding cover (25) is an inwardly retracted structure, and the lower portion of the static end shielding cover (25) is located inside the static contact side shielding cover (34).

5. The internal voltage-sharing shield structure of a high-voltage vacuum interrupter according to claim 1, characterized in that: The moving end shielding cover (23), the main shielding cover (24), and the static end shielding cover (25) are pressure-equalizing shielding covers.

6. The internal voltage-sharing shield structure of a high-voltage vacuum interrupter according to claim 1, characterized in that: The moving contact side shielding cover (32), the moving end shielding cover (23), the main shielding cover (24), the static end shielding cover (25), and the static contact side shielding cover (34) form a multi-stage suspended shielding structure.

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