Vacuum Interrupter Center Shield External Arrangement
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Solution Overview
Problem
The existing vacuum interrupters for vacuum circuit breakers have a large insulating envelope size due to the arrangement of center and auxiliary shields inside, leading to increased ceramic usage and manufacturing costs.
Innovation Solution
The center shield is arranged between the upper and lower insulating envelopes, reducing the size and outer diameter of the envelopes, and the second auxiliary shield with a protrusion prevents electric field concentration and partial discharge at the junction area through brazing welding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the center shield and auxiliary shield are arranged inside the insulating envelope, then the shielding effect is improved, but the insulating envelope size increases
Solution Approach 1:
The center shield is repositioned from an internal arrangement (inside the insulating envelope) to an external arrangement (between upper and lower insulating envelopes). This dimensional reconfiguration allows the shield to maintain its protective function while reducing the overall envelope size, as the shield no longer occupies internal space that would constrain the envelope dimensions.
Solution Approach 2:
Instead of placing the center shield inside the insulating envelope as in conventional designs, the invention inverts this arrangement by positioning the center shield externally, between the upper and lower insulating envelopes. This inversion resolves the spatial conflict between shield placement and envelope size reduction.
2Reliability
If the insulating envelope size is increased to accommodate shields, then the shielding effect is improved, but the ceramic usage and manufacturing cost increase
Solution Approach 1:
By relocating the center shield to an external position between the upper and lower insulating envelopes, the design reduces the required inner diameter of the insulating envelope. This dimensional optimization directly reduces the volume of ceramic material needed, thereby lowering manufacturing costs while preserving the shielding function.
Solution Approach 2:
The center shield is extracted from the internal space of the insulating envelope and repositioned externally. This extraction frees up internal space, allowing for a smaller envelope design that uses less ceramic material, thus reducing manufacturing costs without compromising the shielding effect.
3Volume of stationary object
If the center shield is arranged between upper and lower insulating envelopes, then the insulating envelope size is reduced, but electric field concentration may occur at the junction area
Solution Approach 1:
A second auxiliary shield is introduced as an intermediary element positioned between the insulating envelope and the center shield. This intermediary component serves as a buffer that prevents direct contact and potential electric field concentration at the junction area, while still allowing the compact envelope design to be maintained.
Solution Approach 2:
The second auxiliary shield is positioned in advance between the insulating envelope and center shield to prevent electric field concentration before it can occur. This proactive protective measure cushioning against potential breakdown at the junction area while maintaining the reduced envelope size design.
Data Source
AI summary
A vacuum interrupter for a vacuum circuit breaker is disclosed, in which a center shield is arranged between an upper insulating envelope and a lower insulating envelope, whereby the center shield is not provided inside each of the insulating envelopes and thus outer diameters of the respective insulating envelopes are reduced.