Underarm Vacuum Break Switch With Visual Open-Close Indication
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current vacuum disconnect switches in electrical power transmission systems face issues with the fragility of porcelain ceramic components and the environmental impact of SF-6 gas, which is being phased out due to regulatory concerns.
Innovation Solution
The development of an underarm overhead powerline vacuum break switch that uses a stationary post insulator and a rotating spindle insulator connected to a phase base cross bar, featuring a vacuum switch and a disconnect blade with a latch mechanism that creates an air gap for electrical disconnection, and incorporates a shock absorber to reduce kinetic energy during closure, along with a urethane-insulated vacuum bottle to prevent electrical arcing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If porcelain ceramic vacuum bottle disconnect switches are used, then electrical insulation and vacuum sealing are achieved, but the porcelain ceramic becomes fragile and prone to breaking during operation
Solution Approach 1:
The patent divides the vacuum bottle into separate components: a metal vacuum chamber for structural strength and a separate porcelain ceramic insulator for electrical insulation. This segmentation allows each component to be optimized for its specific function without the weaknesses of the other material bearing the mechanical stress.
Solution Approach 2:
The patent employs a composite structure combining metal (steel or aluminum) for the vacuum chamber with porcelain ceramic for the insulator. This composite approach leverages the high strength and ductility of metal while maintaining the excellent electrical insulation properties of porcelain, resolving the contradiction between mechanical strength and insulation performance.
2Reliability
If SF-6 gas is used for insulation in vacuum disconnect switches, then electrical insulation performance is improved, but environmental harm increases leading to regulatory discontinuation
Solution Approach 1:
The patent eliminates the harmful SF-6 gas entirely and replaces it with vacuum as the insulating medium. Vacuum provides excellent electrical insulation properties comparable to or better than SF-6 gas, while being environmentally benign. This converts the harmful gas insulation approach into a beneficial vacuum insulation solution.
Solution Approach 2:
The patent uses vacuum (a complete absence of atmosphere) as the insulating medium within the sealed vacuum chamber. This inert environment provides superior electrical insulation and arc quenching properties while eliminating the environmental harm associated with SF-6 gas, allowing the switch to meet modern environmental regulations.
3Reliability
If disconnect blade is held in closed position by latch mechanism, then electrical continuity is maintained, but mechanical stress accumulates on the latch and blade components
Solution Approach 1:
The patent employs a spring-loaded latch mechanism that dynamically adjusts to maintain electrical continuity while distributing mechanical stress. The spring element provides continuous force to keep the blade engaged with the contact, allowing the latch to release and re-engage in a controlled manner that reduces cumulative stress on the components.
Solution Approach 2:
The patent incorporates a spring element in the latch mechanism that acts as a cushioning element. This spring absorbs and dissipates mechanical stress before it reaches the critical latch and blade components, preventing stress accumulation and potential failure during repeated opening and closing operations.
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 design enhances safety by isolating the live components from the mounting arm, reducing the risk of electrical shock to wildlife, and effectively interrupts power transmission while minimizing mechanical stress and environmental impact through the use of alternative insulation materials.
Implementation Method 1
vacuum switch and a disconnect blade
Implementation Method 2
there is electrical discontinuity between the vacuum switch and the second powerline connector via an airgap from the disconnected blade
Data Source
AI summary
An underarm gang operated vacuum break switch (underarm switch) has an electrically live portion under a mounting arm, which provides advantages over the standard vacuum break switch, which have the electrically live portion above the mounting arm. Because the non-electrified mounting arm is above the electrified portion, the underarm switch is safer for perching birds and other wildlife. The nature of the underarm switch also provides other benefits including a disconnect blade that when opened creates a visual gap to ensure electrical discontinuity along with a safety locking arm tied to deactivating the underarm switch. Adding to the safety measures is a visual indicator that shows an electrician when the switch is live and safe to open the disconnect blade. Other safety measures include a shock absorber assembly and inertia slowing mass protecting electrical contacts within the vacuum break switch from failing.