An internal grading shield structure of a high-voltage-grade vacuum arc-extinguishing chamber

Abstract

This utility model relates to the field of high-voltage switchgear technology, specifically a high-voltage level vacuum interrupter internal equalization shielding structure. The high-voltage level vacuum interrupter internal equalization shielding structure is characterized by: the vacuum interrupter being composed of four ceramic shell sections connected from top to bottom; a moving contact and a stationary contact being located inside the vacuum interrupter; a moving contact-side shielding cover being fitted on the upper outer side of the moving contact side, and a moving end shielding cover being fitted on the lower outer side of the moving contact side; the middle part of the stationary contact is the stationary contact side, with a stationary contact-side shielding cover being fitted on the lower outer side of the stationary contact side, and a stationary end shielding cover being fitted on the upper outer side of the stationary contact side; a main shielding cover being fitted on the upper outer side of both the moving and stationary contacts. Compared with existing technologies, by reducing the influence of the internal equalization shielding cover's capacitance to ground on the potential bias, the voltage concentration phenomenon that occurs when the vacuum interrupter is applied to a circuit breaker is minimized.

Description

Technical Field

[0001] This utility model relates to the field of high-voltage switchgear technology, specifically to a high-voltage level vacuum interrupter internal equalization shield structure. Background Technology

[0002] Vacuum interrupters possess excellent breaking performance, significant environmental friendliness, a compact structural design, and convenient maintenance characteristics. Thanks to these combined advantages, this technology has been widely used in medium-voltage power systems and continues to advance its application and development 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 technological foundation for 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 some progress, significant bottlenecks still exist in practical applications. When a vacuum interrupter is placed inside the metal housing of a vacuum circuit breaker, the presence of the metal housing greatly reduces the distance between the conductors and ground, causing an increase in the self-capacitance between the conductors and ground. This results in a decrease in the potential of the main shield of the vacuum interrupter, leading to uneven voltage distribution within the internal electric field. This affects the electric field distribution of the vacuum interrupter, thus degrading its insulation performance. The decreased insulation performance of the vacuum interrupter impacts 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 shift caused by stray capacitance, current research has proposed various parallel voltage equalization schemes. The impact of different parallel capacitor schemes on electric field uniformity has been analyzed, demonstrating that the potential change of the shield inside the vacuum interrupter within a metal tank significantly affects the overall electric field strength. Parallel capacitors, used to adjust the capacitance, are an effective voltage equalization method. However, this also raises a series of fundamental theoretical and key technical issues, such as the overall insulation configuration of the parallel capacitors within the tank.

[0005] Therefore, implementing voltage equalization design for the internal structure of the vacuum interrupter helps improve the insulation performance of the vacuum interrupter while avoiding the impact of external structures on the insulation of the entire circuit breaker. Summary of the Invention

[0006] To overcome the shortcomings of the prior art, this utility model provides a high-voltage level vacuum interrupter internal voltage equalization shield structure, which is used to adjust the voltage uniform distribution among the internal structures of the vacuum interrupter.

[0007] To achieve the above objectives, a high-voltage level vacuum interrupter internal equalization shielding structure is designed, comprising a vacuum interrupter, characterized in that: the vacuum interrupter is composed of four ceramic shells connected from top to bottom; a moving contact and a stationary contact are located inside the vacuum interrupter, arranged symmetrically from top to bottom; the middle part of the moving contact is the moving contact side, a moving contact side shielding cover is fitted on the upper outer side of the moving contact side, and a moving end shielding cover is fitted on the lower outer side of the moving contact side, the moving end shielding cover and the moving contact side shielding cover are nested together; the middle part of the stationary contact is the stationary contact side, a stationary contact side shielding cover is fitted on the lower outer side of the stationary contact side, and a stationary end shielding cover is fitted on the upper outer side of the stationary contact side, the stationary end shielding cover and the stationary contact side shielding cover are nested together; a main shielding cover is fitted on the upper outer side of the moving contact and the stationary contact, the upper and lower ends of the main shielding cover are nested with the moving end shielding cover and the stationary end shielding cover respectively.

[0008] The four ceramic shells are a first ceramic shell, a second ceramic shell, a third ceramic shell, and a fourth ceramic shell. The top of the moving contact side shield is connected to the top of the first ceramic shell, and the moving end shield is snapped between the first and second ceramic shells. The main shield is snapped between the second and third ceramic shells, the stationary end shield is snapped between the third and fourth ceramic shells, and the bottom of the stationary contact side shield is connected to the bottom of the fourth ceramic shell.

[0009] The upper part of the moving end shield is an inward-facing structure, and the lower part of the moving end shield is a directly extending structure. The upper part of the moving end shield is located inside the contact-side shield.

[0010] The main shield has an inward-facing structure at the top and bottom. The upper part of the main shield is located inside the moving end shield, and the lower part of the main shield is located inside the stationary end shield.

[0011] The upper part of the stationary end shield is a directly extending structure, and the lower part of the stationary end shield is an inwardly recessed structure, with the lower part of the stationary end shield located inside the stationary contact side shield.

[0012] The moving end shield, main shield, and stationary end shield are all voltage equalization shields.

[0013] The moving contact side shield, moving end shield, main shield, stationary end shield, and stationary contact side shield form a multi-level suspended shielding structure.

[0014] Compared with the prior art, this utility model provides a high-voltage level vacuum interrupter internal voltage equalization shielding structure for adjusting the voltage uniformity distribution among the internal structures of the vacuum interrupter. By reducing the influence of the internal voltage equalization shielding's capacitance to ground on the potential bias and changing the capacitance distribution inside the vacuum interrupter, the voltage concentration phenomenon that occurs when the vacuum interrupter is used in a circuit breaker is minimized.

[0015] The advantages of this invention are: 1. By changing the internal structure of the vacuum interrupter, the potential bias of the voltage equalization shield caused by the ground capacitance is reduced, ensuring the voltage equalization effect; 2. Multiple voltage equalization shields inside the vacuum interrupter affect each other, and by adjusting the capacitance distribution, the voltage distribution inside the vacuum interrupter is concentrated; 3. By configuring the internal structure of the vacuum interrupter for voltage equalization, the problem of reduced overall insulation performance after application to circuit breakers caused by external voltage equalization is reduced. Attached Figure Description

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

[0017] Figure 2 This is a cross-sectional view of the overall assembly of the present utility model.

[0018] Figure 3 This is a cross-sectional view of the moving contact side shielding cover structure of this utility model.

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

[0020] Figure 5 This is a cross-sectional view of the static end shielding cover structure of this utility model.

[0021] Figure 6 This is a cross-sectional view of the static contact side shielding cover structure of this utility model.

[0022] Figure 7 This is a cross-sectional view of the main shielding structure of this utility model.

[0023] Figure 8 This is a schematic diagram of the capacitance distribution between the contacts and the various equalizing shields inside the vacuum interrupter chamber of this utility model.

[0024] See Figure 2 , Figure 3 , Figure 6 , Figure 8 11 is the first ceramic shell, 12 is the second ceramic shell, 13 is the third ceramic shell, 14 is the fourth ceramic shell, 21 is the moving contact side, 22 is the stationary contact side, 23 is the moving end shield, 24 is the main shield, 25 is the stationary end shield, 31 is the moving contact, 32 is the moving contact side shield, 33 is the stationary contact, 34 is the stationary contact side shield, 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 Implementation

[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 composed of four ceramic shells connected from top to bottom. Inside the vacuum interrupter, there is a moving contact 31 and a stationary contact 33, which are arranged symmetrically from top to bottom. The middle part of the moving contact 31 is the moving contact side 21. A moving contact side shielding cover 32 is sleeved on the upper outer side of the moving contact side 21, and a moving end shielding cover 23 is sleeved on the lower outer side of the moving contact side 21. The moving end shielding cover 23 and the moving contact side shielding cover 32 are nested together. The stationary contact 33 has a stationary contact side 22 in the middle. A stationary contact side shielding cover 34 is sleeved on the lower outer side of the stationary contact side 22, and a stationary end shielding cover 25 is sleeved on the upper outer side of the stationary contact side 22. The stationary end shielding cover 25 and the stationary contact side shielding cover 34 are nested together. A main shielding cover 24 is sleeved on the upper outer side of the moving contact 31 and the stationary contact 33. The upper and lower ends of the main shielding cover 24 are nested together with the moving end shielding cover 23 and the stationary end shielding cover 25, respectively.

[0027] The four ceramic shells are the first ceramic shell 11, the second ceramic shell 12, the third ceramic shell 13, and the fourth ceramic shell 14. The top of the moving contact side shield 32 is connected to the top of the first ceramic shell 11. The moving end shield 23 is snapped between the first ceramic shell 11 and the second ceramic shell 12. The main shield 24 is snapped between the second ceramic shell 12 and the third ceramic shell 13. The stationary end shield 25 is snapped between the third ceramic shell 13 and the fourth ceramic shell 14. The bottom of the stationary contact side shield 34 is connected to the bottom of the fourth ceramic shell 14.

[0028] The upper part of the moving end shield 23 is an inward structure, and the lower part of the moving end shield 23 is a direct extension structure. The upper part of the moving end shield 23 is located inside the contact side shield 32.

[0029] The upper and lower parts of the main shield 24 are recessed 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 stationary end shield 25.

[0030] The upper part of the stationary end shield 25 is a direct extension structure, and the lower part of the stationary end shield 25 is an inward-facing structure. The lower part of the stationary end shield 25 is located inside the stationary contact side shield 34.

[0031] The moving end shield 23, the main shield 24, and the stationary end shield 25 are equalizing shields.

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

[0033] like Figure 1The figure shows a cross-sectional view of the internal equalizing shield structure of a high-voltage vacuum interrupter before adjustment. Voltage simulation analysis of the various structures inside the vacuum interrupter using an equivalent circuit reveals that, before adjustment, the voltage differences between the moving contact side and the main shield, and between the stationary contact side and the main shield, account for 65.89% and 34.11% of the total voltage, respectively, indicating a very large voltage difference between the moving contact side and the main shield. Furthermore, the voltage differences between the moving contact side and the moving end shield, the moving end shield and the main shield, the main shield and the stationary end shield, and the stationary end shield and the stationary contact side account for 39.98%, 25.9%, 24.4%, and 9.72% of the total voltage, respectively, again indicating a very large voltage difference between the moving contact side and the moving end shield. Therefore, it can be concluded that the voltage is significantly concentrated on the moving contact side of the vacuum interrupter.

[0034] like Figure 2 The diagram shown is a cross-sectional view of the overall assembly of this utility model. The vacuum interrupter has a basically symmetrical structure: the moving contact side 21 and the stationary contact side 22 are symmetrically arranged, the moving contact 31 and the stationary contact 33 are symmetrically arranged, the moving contact side shield 32 and the stationary contact side shield 34 are symmetrically arranged, and the moving end shield 23 and the stationary end shield 25 are symmetrically arranged. The main shield 24 is arranged between the moving end shield 23 and the stationary end shield 25. The structure between the various equalizing shields inside the vacuum interrupter is a nested structure to adjust the potential bias of the equalizing shields caused by the ground capacitance after the vacuum interrupter is applied to the metal tank, and to redistribute the capacitance distribution inside the vacuum interrupter, so that the voltage change originally concentrated at the moving end is evenly distributed at both the moving and stationary ends.

[0035] Based on capacitance analysis, the capacitance to ground of each equalizing shield should be minimized to reduce the impact on voltage concentration; therefore, the equalizing shield inside the vacuum interrupter has a layered wrapping structure, such as... Figure 3 As shown, the moving contact side shield 32 extends directly, covering the upper structure of the moving end shield 23; as Figure 4 As shown, on the moving end shield 23, the structure on the side near the main shield 24 extends directly to cover the upper structure of the main shield 24; as Figure 5 As shown, on the stationary end shield 25, the structure on the side near the main shield 24 also extends directly to cover the lower structure of the main shield 24; as Figure 6 As shown, the stationary contact side shield 34 extends directly to cover the lower structure of the stationary end shield 25; through the layered covering structure of the equalizing shield inside the vacuum interrupter, the capacitance to ground of each equalizing shield is reduced, the potential value offset of the equalizing shield is reduced, and the potential value of each equalizing shield is increased to achieve uniform voltage inside the vacuum interrupter.

[0036] The equalizing shield is designed with a nested structure to regulate the voltage between the various breaks within the vacuum interrupter; for example... Figure 4 As shown, one side of the moving end shield 23 is a directly extending structure, while the other side is an inward-retracting structure, and the moving end shield 23 has an inward-retracting structure near the moving contact side 21; as Figure 7 As shown, both ends of the main shield 24 have an inward-curving structure and extend appropriately towards both ends; as Figure 5 As shown, one side of the stationary end shield 25 is a directly extending structure, while the other side is an inward-curving structure, and the stationary end shield 25 has an inward-curving structure near the stationary contact side 22; as Figure 8 As shown, under this equalizing structure design, the voltage difference between the moving contact side 21 and the moving end shield 23 of the vacuum interrupter (first voltage difference 41) and the voltage difference between the moving contact 31 and the main shield 24 (second voltage difference 42) decreases, while the voltage difference between the stationary contact 33 and the main shield 24 (third voltage difference 43) and the voltage difference between the stationary contact side 22 and the stationary end shield 25 (fourth voltage difference 44) increases. The voltage difference between the moving contact side 21 and each shield decreases to varying degrees, while the voltage difference between the stationary contact side 22 and each shield increases to varying degrees.

[0037] After the voltage equalization shielding is applied, the voltage differences between the moving contact side 21 and the main shielding 24, and between the stationary contact 33 and the main shielding 24 inside 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 shielding 23, between the moving end shielding 23 and the main shielding 24, between the main shielding 24 and the stationary end shielding 25, and between the stationary end shielding 25 and the stationary contact side 22, respectively, account for 29.42%, 29.43%, 25.59%, and 15.57% of the total voltage, respectively. Therefore, compared to before adjustment, the voltage on the moving contact side 21 inside the vacuum interrupter is no longer significantly concentrated, and the internal voltage distribution is more uniform. The voltage equalization shielding of the vacuum interrupter of this invention achieves a significant voltage equalization effect.

Claims

1. A voltage equalization shield structure for a high-voltage vacuum interrupter, comprising a vacuum interrupter, characterized in that: The vacuum interrupter chamber is composed of four ceramic shells connected from top to bottom. Inside the chamber are moving contacts (31) and stationary contacts (33), arranged symmetrically. The middle part of the moving contact (31) is the moving contact side (21). A moving contact side shield (32) is fitted on the upper outer side of the moving contact side (21), and a moving end shield (23) is fitted on the lower outer side of the moving contact side (21). The moving end shield (23) and the moving contact side shield (32) are nested together. The middle part of the stationary contact (33) is the stationary contact side (22). A stationary contact side shield (34) is sleeved on the lower outer side of the stationary contact side (22). A stationary end shield (25) is sleeved on the upper outer side of the stationary contact side (22). The stationary end shield (25) and the stationary contact side shield (34) are nested together. A main shield (24) is sleeved on the upper outer side of the moving contact (31) and the stationary contact (33). The upper and lower ends of the main shield (24) are nested together with the moving end shield (23) and the stationary end shield (25) respectively.

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

3. The high-voltage level vacuum interrupter internal equalization shield structure according to claim 1 or 2, characterized in that: The upper part of the moving end shield (23) is an inward structure, and the lower part of the moving end shield (23) is a direct extension structure. The upper part of the moving end shield (23) is located inside the contact side shield (32).

4. The high-voltage level vacuum interrupter internal equalization shield structure according to claim 1 or 2, characterized in that: The upper and lower parts of the main shield (24) are recessed 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 stationary end shield (25).

5. A voltage equalization shield structure for a high-voltage vacuum interrupter according to claim 1 or 2, characterized in that: The upper part of the stationary end shield (25) is a direct extension structure, and the lower part of the stationary end shield (25) is an inward structure. The lower part of the stationary end shield (25) is located inside the stationary contact side shield (34).

6. The high-voltage level vacuum interrupter internal equalization shield structure according to claim 1, characterized in that: The moving end shield (23), the main shield (24), and the stationary end shield (25) are equalizing shields.

7. The high-voltage level vacuum interrupter internal voltage equalization shield structure according to claim 1, characterized in that: The moving contact side shield (32), moving end shield (23), main shield (24), stationary end shield (25), and stationary contact side shield (34) form a multi-level suspended shield structure.

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