Dual Structured Contact for Switchgear Fault Stability
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Solution Overview
Problem
Conventional gas insulated switchgear (GIS) disconnecting switches are large and costly due to their complex structure, which affects their stability during fault conditions such as short circuits and overload fault currents.
Innovation Solution
A dual structured contact system is introduced, featuring at least two pairs of spring contact members subsided in cylinders with different central axes, reducing the thickness and length of the switchgear while enhancing stability by increasing the contact area and mitigating electric field strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional disconnecting switch structure is used, then the switchgear can perform fault isolation, but the size and cost of the switchgear become large and high due to the large number of components
Solution Approach 1:
The patent implements nesting by placing the second cylinder inside the first cylinder, with the moving contact unit positioned within the nested cylinders. This nested arrangement allows multiple contact members to be compactly arranged in a reduced space, directly addressing the contradiction between maintaining fault isolation capability and reducing switchgear size
Solution Approach 2:
The patent segments the contact system into multiple independent spring contact pairs (first and second spring contact pairs) with different central axes. Each spring contact pair can independently perform contact functions, allowing the system to maintain reliable fault isolation while using fewer and more compact components, thereby reducing overall switchgear size
2Reliability
If a conventional disconnecting switch structure is used, then the switchgear can perform fault isolation, but the cost of the switchgear becomes higher due to the large number of components
Solution Approach 1:
The nested cylinder configuration allows multiple contact members to share common structural elements and mounting spaces. The second cylinder is positioned inside the first cylinder, and both are fixed to the same fixed contact unit, reducing the total number of separate components and assembly operations, thereby lowering manufacturing cost while maintaining fault isolation capability
Solution Approach 2:
The fixed contact unit serves multiple functions: it provides the structural base for mounting both the first and second cylinders, acts as a common electrical connection point for both spring contact pairs, and maintains the nested geometric configuration. This multi-functionality reduces the number of separate components needed, simplifying manufacturing and reducing cost
3Volume of stationary object
If the contact thickness is reduced, then the switchgear size is minimized, but the stableness during fault conditions such as short circuits and overload fault currents decreases
Solution Approach 1:
The patent transitions from a single-axis contact arrangement to a multi-dimensional configuration by introducing spring contact pairs with different central axes. The first spring contact pair has a first central axis while the second spring contact pair has a second central axis that is offset from the first. This dimensional change allows the contact system to maintain stables during faults through distributed contact geometry while keeping individual contact members thin
Solution Approach 2:
The patent employs asymmetric arrangement of the spring contact pairs by positioning them at different locations and orientations within the nested cylinders. The first and second spring contact pairs are arranged asymmetrically with respect to each other, creating a balanced distribution of mechanical and electrical stresses during fault conditions. This asymmetric configuration enhances overall system stables while allowing reduced contact thickness
Data Source
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AI summary
A dual structured contact for switchgear includes a moving contact unit being formed of conducting material, the moving contact unit including first and second terminals, the first terminal being formed of cylinder and the second terminal being extended to a driving unit such that the moving contact unit moves back and forth by the driving unit and a fixing contact unit being formed of conducting material, the fixing contact unit including first and second cylinders being outside and inside of the fixing contact unit with same axis, inner of the first cylinder being in contact with outer of the first terminal and outer of the second cylinder being in contact with inner of the first terminal.