Ring-like Element for Gas-Insulated Circuit Breaker Dielectric Reliability

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Solution Overview

Problem

Existing gas-insulated circuit breakers for high or medium voltages face issues with dielectric problems and arc extinguishing during current interruption, leading to potential punctures and inefficiencies in shield operation.

Innovation Solution

A gas-insulated circuit breaker design featuring axially movable arcing contacts, a nozzle system for arc-extinguishing gas, a diffuser portion with varying conductivity, and a radially biased electrically conductive ring-like element to enhance electrical conductivity and prevent dielectric issues.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional nozzle system is used for arc extinguishing, then arc extinction is achieved, but dielectric issues occur leading to punctures during fast transients

Engineering Contradiction:
Improveshield operation reliabilityVSAvoiddielectric issues and punctures
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The diffuser portion is designed with varying electrical conductivity along its length, with the first portion having lower conductivity and the second portion having higher conductivity. This local quality variation optimizes the electric field distribution in different regions, preventing dielectric breakdown while maintaining effective arc extinguishing performance.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The radially outwardly biased electrically conductive ring-like element is pressed against the armature to create an equipotential connection between the diffuser portion and the armature. This eliminates potential differences that could cause dielectric issues and punctures, ensuring uniform voltage distribution during fast transients.

Inventive Principle:
Principle #12Equipotentiality

2Reliability

If the diffuser portion has uniform electrical conductivity, then manufacturing is simplified, but electrical conductivity between shield and armature is insufficient

Engineering Contradiction:
Improveelectrical conductivity between shield and armatureVSAvoiddiffuser portion manufacturing
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The diffuser portion incorporates two distinct portions with different electrical conductivity characteristics. The first diffuser portion has lower conductivity while the second diffuser portion has higher conductivity, allowing optimization of electrical performance in different regions without requiring complete redesign of the entire component.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The electrically conductive ring-like element acts as an intermediary component that enhances the electrical connection between the diffuser portion and the armature. By being radially outwardly biased and pressed against the armature, it provides a reliable conductive path without requiring complex modifications to the diffuser portion structure.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If fixed electrical contacts are used between shield and armature, then connection is simple, but contact potential adaptation during arcing is insufficient

Engineering Contradiction:
Improvecontact potential adaptationVSAvoidelectrical connection structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The electrically conductive ring-like element is designed to be radially outwardly biased and slideable relative to the armature, creating a dynamic electrical connection. This allows the contact point to adapt during arcing operations, maintaining optimal electrical conductivity as potentials change, unlike fixed contacts that cannot adjust to varying conditions.

Inventive Principle:
Principle #15Dynamics

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

The solution improves the electrical conductivity between the shield and armature, reducing dielectric issues and enhancing safety during power interruptions by effectively adapting to arcing contact potentials, thus preventing punctures and improving arc extinguishing efficiency.

Implementation Method 1

the ring-like element is radially outwardly biased such that an outer side of the ring-like element is pressed against the armature

Methodology Applied
Scientific EffectRadial biasing force: Mechanical Force

Implementation Method 2

a nozzle system including a channel directed to the arcing region, for blowing an arc-extinguishing gas to the arcing region during the breaking operation

Methodology Applied
Scientific EffectGas flow: Fluid Spray

Implementation Method 3

a diffuser portion adjacent to the nozzle, for transporting the arc-extinguishing gas from the arcing region to a region downstream of the diffuser portion

Methodology Applied
Scientific EffectGas transport: Convection

Data Source

PatentEP3588528B1Gas-insulated high or medium voltage circuit breaker with ring-like element
Publication Date: 2022.05.04 HITACHI ENERGY SWITZERLAND AG
  • EP3588528B1 patent drawingFigure 1
  • EP3588528B1 patent drawingFigure 2
  • EP3588528B1 patent drawingFigure 3

AI summary

A gas-insulated high or medium voltage circuit breaker (100) comprising a first arcing contact (101) and a second arcing contact (103), wherein at least one of the two arcing contacts (101, 103) is axially movable along a switching axis (140), wherein during a breaking operation, an arc (130) between the first arcing contact (101) and the second arcing contact (103) is formed in an arcing region. An electrically conductive armature (120) radially surrounds at least part of a diffuser portion (114) of the nozzle (110); an electrically conductive ring-like element (116) is mounted to the diffuser portion (114) and is slideable relative to the armature (120), and the ring-like element (116) is radially outwardly biased such that an outer side of the ring-like element (116) is pressed against the armature (120).