Medium-Voltage Switching Pole With Vacuum Interrupter Linkage
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Solution Overview
Problem
Existing load-break switches for medium voltage electric systems face challenges in achieving high-level performances in dielectric insulation and arc-quenching capabilities while also ensuring structural compactness, reliability, and environmental sustainability, particularly due to the limitations of using alternative insulating gases after the phase-out of SF6.
Innovation Solution
The switching apparatus incorporates a bistable motion transmission mechanism with a vacuum interrupter, allowing the movable arc contact to be driven by the movable contact to separate from the fixed arc contact within a vacuum chamber, enhancing arc quenching and synchronization during opening and closing maneuvers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If alternative insulating gases (dry air, oxygen, nitrogen, carbon dioxide, fluorinated gas) are used instead of SF6, then environmental impact is reduced, but dielectric insulation performance and arc-quenching capabilities deteriorate
Solution Approach 1:
The switching apparatus is divided into two distinct contact arrangements: first contacts operating in alternative insulating gas for current carrying and switching maneuvers, and second contacts operating in vacuum for arc quenching. This segmentation allows each contact type to be optimized for its specific function, resolving the contradiction between environmental sustainability and arc-quenching performance.
Solution Approach 2:
A motion transmission mechanism acts as an intermediary to coordinate the operation between the two contact arrangements. This mechanism ensures proper timing and sequencing of contact movements, enabling the first contacts to complete switching operations in alternative gas while the second contacts provide reliable arc quenching in vacuum.
2Reliability
If multiple contact arrangements (one in alternative gas, one in vacuum) are used for each electric pole, then arc-quenching capabilities improve, but device complexity increases
Solution Approach 1:
Both contact arrangements are integrated within a single insulating housing that contains both alternative insulating gas and vacuum environments. The movable contact structure combines elements for both contact types, and a unified motion transmission mechanism coordinates their operation, reducing overall structural complexity despite the dual-contact design.
Solution Approach 2:
The motion transmission mechanism is designed to universally control both contact arrangements through a single actuation system. The same mechanical linkage manages the coordination of first and second contacts during all switching operations, simplifying the control architecture despite the complexity of having multiple contact types.
3Reliability
If multiple contact arrangements with coordinated operation are implemented, then arc-quenching capabilities improve, but manufacturing complexity and cost increase
Solution Approach 1:
The contact arrangements are designed as separate modular units (first contacts in alternative gas, second contacts in vacuum) that can be manufactured independently using different optimization criteria for each environment, simplifying the manufacturing process for each module while maintaining overall system performance.
Solution Approach 2:
The motion transmission mechanism serves as a standardized intermediary component that can be designed once and replicated across different configurations. This mediator handles the coordination complexity, allowing the contact arrangements themselves to be manufactured more simply without requiring complex integrated control systems.
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
This solution achieves improved dielectric insulation and arc-quenching capabilities, increases structural compactness and reliability, and allows for easier industrial production at competitive costs, while minimizing environmental impact.
Implementation Method 1
a vacuum interrupter, which comprises a fixed arc contact electrically connected to the first pole terminal, a movable arc contact electrically connected to the fourth fixed contact and reversibly movable along a corresponding translation axis between a coupled position with the fixed arc contact and an uncoupled position from the fixed arc contact. The vacuum interrupter further comprises a vacuum chamber, in which the fixed arc contact and the movable arc contact are enclosed
Data Source
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AI summary
A switching apparatus comprising one or more electric poles. For each electric pole, the switching apparatus comprises a first pole terminal, a second pole terminal and a ground terminal. In operation, the first pole terminal can be electrically coupled to a first conductor of an electric line, the second pole terminal can be electrically coupled to a second conductor of said electric line and the ground terminal can be electrically coupled to a grounding conductor. For each electric pole, the switching apparatus comprises a plurality of fixed contacts spaced apart one from another. Such a plurality of fixed contacts comprises a first fixed contact electrically connected to the first pole terminal, a second fixed contact electrically connected to the second pole terminal, a third fixed contact electrically connected to the ground terminal and a fourth fixed contact electrically connectable with the second fixed contact. For each electric pole, the switching apparatus further comprises a movable contact, which is reversibly movable about a corresponding rotation axis according to opposite first and second rotation directions, so that said movable contact can be coupled to or uncoupled from one or more of the above-mentioned fixed contacts, and a vacuum interrupter, which comprises a fixed arc contact electrically connected to the first pole terminal, a movable arc contact electrically connected to the fourth fixed contact and reversibly movable along a corresponding translation axis between a coupled position with the fixed arc contact and an uncoupled position from the fixed arc contact. The vacuum interrupter further comprises a vacuum chamber, in which the fixed arc contact and the movable arc contact are enclosed and can be coupled or decoupled. For each electric pole, the switching apparatus further comprises a motion transmission mechanism operatively coupled to a contact shaft solidly coupled to the movable arc contact. The motion transmission mechanism is actuatable by the movable contact to cause a movement of said movable arc contact along said translation axis, when said movable contact moves about said rotation axis.