Vacuum Circuit Breaker Plug Interlock Mechanism
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional circuit breakers lack a plug interlock device to prevent accidental disconnection of the control power plug from the control power connector during transitions between 'TEST' and 'RUN' positions or when the breaker body is moved, potentially causing accidents.
Innovation Solution
A plug interlock device for a vacuum circuit breaker that includes a switchboard with a control power plug, a breaker body with a control power connector, a cradle, and a carriage restriction unit. The carriage restriction unit features a link, a rotation lever, and a blocking plate that restricts or releases the motion of the carriage to prevent disconnection of the control power plug from the connector, ensuring it remains connected during 'RUN' and 'TEST' positions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the control power plug is made detachable for maintenance convenience, then the ease of operation is improved, but the reliability deteriorates due to accidental disconnection during RUN position
Solution Approach 1:
The carriage restriction unit proactively prevents the carriage from moving in a way that would cause plug disconnection. The blocking plate and rotation lever create a mechanical constraint that opposes any motion that would separate the plug from the connector, thereby preventing accidental disconnection before it can occur during RUN position operations.
Solution Approach 2:
The carriage restriction unit acts as an intermediary mechanism between the carriage movement and the control power plug connection. It mediates the relationship by translating carriage position into corresponding plug connection states, ensuring the plug remains connected when the carriage is in RUN position while still allowing detachment when in TEST position.
2Reliability
If the control power plug is fixed to prevent disconnection, then the reliability is improved, but the ease of operation deteriorates due to inability to disconnect for maintenance
Solution Approach 1:
The system dynamically adjusts the connection state based on carriage position. The carriage restriction unit automatically transitions between locked and unlocked states depending on whether the carriage is in RUN or TEST position, providing fixed connection when needed for reliability and allowing disconnection when needed for maintenance without requiring manual intervention.
Solution Approach 2:
The carriage restriction unit automatically controls the plug connection state based on the carriage position without requiring external control. When the carriage is moved to TEST position, the unit self-activates to release the blocking plate, enabling plug detachment. This self-service mechanism eliminates the need for separate manual locking/unlocking operations.
3Reliability
If a plug interlock device is added to prevent accidental disconnection, then the reliability is improved, but the device complexity increases
Solution Approach 1:
The carriage restriction unit merges multiple functions into a single integrated mechanism. It combines the carriage position sensing, plug connection control, and motion restriction functions into one unified device that works with the existing carriage and cradle structure, rather than adding separate independent systems for each function.
Solution Approach 2:
The carriage restriction unit serves multiple purposes: it restricts carriage motion to prevent plug disconnection, controls the interlocking mechanism between carriage and cradle, and enables automatic positioning for both RUN and TEST operations. This multi-functionality reduces the need for additional dedicated components for each specific function.
Data Source
AI summary
Disclosed is a plug interlock device for a vacuum circuit breaker. Only after a plug is completely mounted to a connector, an insertion or withdrawal operation by a vacuum circuit breaker is performed. Accordingly, while a breaker body is moved to a ‘RUN’ position from a ‘TEST’ position, or when an operation is performed at a ‘RUN’ position, the plug may be prevented from being separated from the connector. This may prevent an accident.