Gas-Insulated Switchgear Shield Structure to Restrain Arc Restrike
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Solution Overview
Problem
Conventional gas-insulated switchgear configurations require high withstand voltage performance and quick driving of the blocking electrode to prevent arc restrike during current interruption, especially during high recovery voltage conditions, which complicates the mechanical design and increases operational impact.
Innovation Solution
The blocking electrode is stored within an electric field relaxing shield, reducing the speed required to drive it and minimizing the electric field concentration, thereby preventing arc restrike and lowering the mechanical impact on the switchgear components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the blocking electrode is quickly driven to be stored into the fixed-side terminal to ensure withstand voltage performance and prevent arc restrike, then the reliability of current interruption is improved, but the mechanical impact and stress on switchgear components increases
Solution Approach 1:
The patent introduces a cushioning member between the blocking electrode and the fixed-side terminal that absorbs mechanical impact during the storage operation. This cushioning member is positioned to receive the blocking electrode when it is driven into the fixed-side terminal, preventing direct impact and reducing mechanical stress on the terminal structure while maintaining the reliability of current interruption by ensuring the blocking electrode is properly stored.
2Reliability
If the distance between the fixed-side terminal and the movable-side terminal is increased to provide higher withstand voltage performance, then the arc restrike prevention is improved, but the installation space requirement increases
Solution Approach 1:
The patent introduces an electric field relaxing shield as an intermediary component between the fixed-side terminal and the movable-side terminal. This shield creates a controlled electric field distribution that relaxes the electric field concentration, allowing the system to achieve the required withstand voltage performance with a shorter physical distance between terminals. The shield acts as a mediator that manages the electric field to prevent arc restrike without requiring increased spacing.
3Reliability
If the blocking electrode is stored inside the fixed-side terminal to relax the electric field, then the arc restrike is restrained, but the driving speed requirement increases
Solution Approach 1:
The cushioning member is pre-positioned in the fixed-side terminal to receive the blocking electrode during storage. This beforehand preparation allows the blocking electrode to be driven at a reduced speed without causing impact damage, as the cushioning member is already in place to absorb the mechanical energy. The arc restrike prevention is maintained because the blocking electrode is still properly stored in the terminal, just at a slower, safer speed.
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 configuration reduces the speed of driving the blocking electrode, lowers mechanical stress, and simplifies the design by dispersing electric field forces, enhancing the switchgear's operational efficiency and mechanical integrity.
Implementation Method 1
an opening spring that drives the blocking electrode along with the shaft rod in a direction opposite to the movable electrode rod
Implementation Method 2
the blocking electrode is stored in the electric field relaxing shield. Thus, when the movable-side terminal and the fixed-side terminal are relatively close to each other, an electric field of the blocking electrode is relaxed and a restrike due to a rising recovery voltage can be restrained
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
The present invention has such a configuration that: a fixed-side terminal (1) is provided with an electric field relaxing shield (12d) at a portion opposite to a movable-side terminal (2); an electric field relaxing shield unit (12) is capable of moving toward the movable-side terminal (2); and functions are separated such that an energization function is performed by the fixed-side terminal (1) and a function for relaxing an electric field between the terminals is performed by the electric field relaxing shield unit (12). When the fixed-side terminal (1) and the movable-side terminal (2) are relatively close to each other, the electric field of the blocking electrode (8) is relaxed and a restrike due to a recovery voltage rising when a circuit is opened can be restrained. Thus, a speed for driving the blocking electrode (8) can be lowered.