Switchgear Insulating Bar Triple Point Shielding
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Solution Overview
Problem
Gas insulated switchgears face challenges with reduced electrical withstand levels at triple points, leading to partial and full discharges, which are difficult to avoid due to the need for insulating materials to support metal parts at different potentials, and existing shielding solutions do not completely eliminate potential differences, especially in compact designs.
Innovation Solution
The use of a gas-tight tank filled with a dielectric gas, an electrically insulating bar with a specific axial end portion configuration, and a field controller that electrically shields the support member, allowing the bar to be radially recessed and positioned under the field controller to reduce electrical stress at the triple point, thereby improving dielectric strength and compactness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a shield is provided to reduce electrical stress at the triple point, then dielectric withstand is improved, but device complexity and size increase
Solution Approach 1:
The patent extracts the shielding function from a separate component and integrates it into the insulating bar itself through the radially recessed proximal segment. This creates the shielding effect at the triple point without requiring an additional shield structure, thereby reducing device complexity while maintaining dielectric withstand.
Solution Approach 2:
The patent applies local quality by creating a radially recessed proximal segment at the specific location where the triple point occurs (where the insulating bar contacts the conductive support member). This localized structural modification provides electrical shielding exactly where needed, improving dielectric withstand at the critical interface without adding overall device complexity.
2Reliability
If a large shield is used to eliminate potential difference at the triple point, then dielectric strength is improved, but switchgear compactness is reduced
Solution Approach 1:
The patent extracts the shielding function from a separate large shield component and integrates it into the insulating bar structure itself. The radially recessed proximal segment provides the necessary shielding effect within the existing bar geometry, eliminating the need for additional large shield structures and maintaining switchgear compactness.
Solution Approach 2:
The patent embeds the shielding function within the insulating bar structure itself. The radially recessed proximal segment is nested within the overall bar geometry, creating a compact integrated structure that provides both mechanical support and electrical shielding functions without requiring separate large shield components.
3Strength
If insulating materials are used to support metal parts at different potentials, then mechanical support is provided, but triple points are created that reduce electrical withstand level
Solution Approach 1:
The patent applies local quality by modifying the insulating bar structure at the specific location where it contacts the conductive support member. The radially recessed proximal segment creates a localized shielding effect at the triple point, improving electrical withstand level at this critical interface while maintaining the overall mechanical support function of the insulating bar.
Solution Approach 2:
The radially recessed proximal segment acts as an intermediary structure between the insulating bar and the conductive support member. This intermediate feature modifies the electrical field distribution at the interface, reducing electrical stress and preventing partial discharge while allowing the mechanical support function to continue.
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 enhances dielectric strength at the connection of the insulating bar to the tank, even without a large shield, and effectively shields the triple point from high electrical stress, improving switchgear compactness and dielectric withstand.
Implementation Method 1
a field controller circumferentially surrounding the support member for electrically shielding the support member
Implementation Method 2
a gas-tight tank having an inner tank volume filled with a dielectric gas
Data Source
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AI summary
It is provided an electric power distribution switchgear 100 including a gas-tight tank 110 having an inner tank volume 115 filled with a dielectric gas; a switching device 120 arranged in the inner tank volume 115; an electrically insulating bar 130 arranged in the inner tank volume 115 and mechanically coupled to the switching device 120, the bar 130 having an axis 135, the axis 135 defining an axial direction z and a radial direction r; an electrically conductive support member 140, the support member 140 having an axially extending support member opening 145 for supporting the bar 130; and a field controller 150 circumferentially surrounding the support member 140 for electrically shielding the support member 140, wherein the bar 130 includes an axial end portion 160 inserted into the support member opening 145, wherein the axial end portion 160 comprises a distal segment 162 and a proximal segment 164 arranged axially adjacent to each other, wherein the distal segment 162 contacts the support member 140 thereby forming an insulator-conductor interface 170 between the distal segment 162 and the support member 140, and wherein the proximal segment 164 is radially recessed with respect to the distal segment 162 thereby forming a radial space 180 separating the proximal segment 164 from the support member 140.