Current Interruption Device With Differential Speed Arc Contacts
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Solution Overview
Problem
Current interruption devices require multiple arc plates to achieve sufficient arc voltage, leading to increased space usage and longer arc times due to the need for a long distance of arc contact movement, making them bulky and inefficient.
Innovation Solution
A current interruption device with a main contact and series-connected arc contacts, where the arc contacts are angled and moveable at different speeds, reducing the number of arc plates needed and optimizing arc chamber design for compactness and faster arc termination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple arc plates are provided to divide the arc into sub arcs to achieve sufficient arc voltage, then the current interruption capability is improved, but the device becomes very high (deep) and takes up a lot of space
Solution Approach 1:
The patent transitions from a vertical stacking arrangement of arc plates (one dimension) to a horizontal planar arrangement where arc contacts are distributed across different planes (two dimensions). The first arc contact is placed at a first end of the main contact's moveable contact element, and the second arc contact is placed at a second end, with their moveable contact elements moving in different planes perpendicular to the main contact's movement plane. This dimensional change allows multiple arc contacts to coexist in a compact space without requiring vertical stacking, thus reducing device height while maintaining current interruption capability.
2Reliability
If the arc contact has to be moved a long distance to achieve current interruption, then the arc voltage is sufficient, but the arc time becomes long
Solution Approach 1:
The patent implements preliminary action by having the main contact open in advance of the arc contacts. When the main contact opens, current commutates to the arc contacts before they fully separate. This allows the arc to be established at a shorter travel distance, reducing arc time. The arc contacts then continue to open to maintain sufficient arc voltage for current interruption, but the critical arc establishment phase occurs earlier in the movement sequence.
3Reliability
If the moveable contact element of the main contact is moved with a certain speed, then the operation is controlled, but the arc contacts need to move faster to reduce arc time
Solution Approach 1:
The patent implements dynamics by introducing a gear mechanism that provides differential speed control to different contact elements. The gear mechanism is configured to move the main contact's moveable contact element with a first speed while moving the arc contacts' moveable contact elements with a second speed that is higher than the first speed (e.g., four times higher). This dynamic speed differentiation allows the arc contacts to traverse their shorter distance more quickly, reducing arc time, while the main contact moves at a controlled, slower speed for stable operation.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution results in a more compact device with shorter arc times, improved robustness, and reduced wear, while maintaining effective current interruption capabilities.
Implementation Method 1
an arc is ignited when the arc contact opens. The criteria to break the current is that the arc voltage created by the arc needs to be higher than the system voltage
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
In a current interruption device comprising a main contact (12) and a group (14) of series-connected arc contacts including a first and a second arc contact, the main contact (12) and each arc contact comprises a first contact area (20, 30, 40) and a moveable contact element (24, 34, 44), where the moveable contact element (24, 34, 44) is moveable in relation to the first contact area (20, 30, 40) and each arc contact comprises a first group of arc plates (50, 52) placed adjacent a movement path of a first end (36, 46) of the moveable contact element (34, 44) in relation to the first contact area (30, 42) and the group of series-connected arc contacts (14) is electrically connected in parallel with the main contact (12).