Vacuum Switch Drive Interface for Faster Short-Circuit Closing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing medium voltage electrical switches experience excessive slowing down due to interference between the movable contact and the drive element of the vacuum interrupter, which hampers fast circuit closure, particularly under short-circuit conditions.
Innovation Solution
A switching device with a movable element featuring a curved drive surface and receiving surface on an insulating support and drive element, respectively, to minimize kinetic energy loss and prevent excessive slowing during the closing stroke without increasing the control mechanism's energy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the movable contact interferes with the drive element of the vacuum interrupter during the closing stroke, then the vacuum interrupter can be actuated, but the movable contact experiences excessive slowing down and kinetic energy loss
Solution Approach 1:
The drive element is segmented into two functional zones: a first portion that engages with the movable contact during opening to actuate the vacuum interrupter, and a second portion that remains clear during closing to prevent interference. This segmentation allows the drive element to selectively interact with the movable contact based on the direction of motion, resolving the contradiction between reliable vacuum interrupter actuation and maintaining high closing speed.
Solution Approach 2:
Instead of having the drive element extend continuously in the opening direction (which causes interference during closing), the drive element is inverted in its configuration: the portion that would normally extend into the closing path is instead positioned to extend in the opening direction only. This inversion allows the drive element to fulfill its actuation function while avoiding harmful interference during the closing stroke.
2Reliability
If the movable contact interferes with the drive element during closing, then the vacuum interrupter can be actuated, but the kinetic energy of the movable contact is reduced
Solution Approach 1:
The drive element is divided into a first portion for opening operation and a second portion for closing operation. The first portion is positioned to engage the movable contact only during opening, while the second portion is configured not to interfere during closing. This segmentation ensures that kinetic energy is transferred to the vacuum interrupter only when needed (during opening), while preserving kinetic energy during closing operations.
Solution Approach 2:
The drive element acts as an intermediary that selectively transfers energy from the movable contact to the vacuum interrupter. By configuring the drive element with distinct portions for opening and closing operations, it mediates the energy transfer process to occur only during opening, thereby preventing unnecessary kinetic energy loss during closing while maintaining reliable circuit interruption capability.
3Reliability
If the movable contact interferes with the drive element, then the vacuum interrupter can be actuated, but the closing time is increased
Solution Approach 1:
The drive element is segmented into a first portion that engages during opening and a second portion that does not interfere during closing. This segmentation eliminates the time-consuming interference effect during closing operations, allowing the movable contact to reach its closed position faster, while the first portion ensures reliable vacuum interrupter actuation during opening.
Solution Approach 2:
By configuring the second portion of the drive element to skip over the closing path without interference, the movable contact can rush through the closing stroke without being slowed down by mechanical interaction with the drive element. This skipping mechanism reduces closing time while the first portion ensures the vacuum interrupter is properly actuated during the opening stroke.
Data Source
AI summary
A switching device (50) for an electrical apparatus (100) is proposed, comprising:a vacuum interrupter (3);a drive element (4) connected to the vacuum interrupter (3);a movable element (20) movable between a position for closing an electrical circuit and a position for opening the circuit, and comprising:an electrically conducting blade (11);a support (12) secured to the blade (11);the movable element (20) being configured to:according to an opening stroke of the circuit, drive the drive element (4) via the conducting blade (11); andaccording to a closing stroke, drive the drive element (4) via the support (12).The support (12) comprises a drive surface (14) in contact with a receiving surface (7) of the drive element (4) during a closing stroke of the circuit.The drive surface (14) of the support (12) and the receiving surface (7) of the drive element (4) are convex in shape.