Conductive Compression Cylinder in Gas-Insulated Circuit Breakers

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Solution Overview

Problem

Medium voltage gas-insulated circuit breakers face challenges with complex and costly electric pole units that require long dielectric distances, leading to overheating and high manufacturing costs, while also needing to match vacuum circuit breaker configurations for switchgear size reduction.

Innovation Solution

The electric pole unit features an insulating housing filled with dielectric gas, a fixed contact assembly, a moving contact assembly, and sliding contact means, which simplifies the structure and reduces size, ensuring excellent conductivity and insulation with shorter dielectric distances, allowing for interchangeable bushings and reduced assembly complexity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If gas-insulated circuit breakers use long dielectric distances for electric insulation, then insulation performance is improved, but switchgear size increases and complexity increases

Engineering Contradiction:
Improveinsulation performanceVSAvoidswitchgear size
Core Design Contradiction:
ReliabilityVSVolume of stationary object

Solution Approach 1:

The patent introduces an intermediary conductive connection structure (contact spring) between the stationary conductor element and the movable separating element. This intermediary element enables effective electrical connection while maintaining compact dimensions, resolving the contradiction between insulation performance and switchgear size by providing a controlled conductive path that doesn't require excessive spacing.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the physical parameters of the conductive connection by using a spring-based contact mechanism that maintains optimal electrical contact pressure and conductivity. This parameter optimization allows for reduced dielectric distances while maintaining insulation performance, thereby reducing overall switchgear size without compromising reliability.

Inventive Principle:
Principle #35Parameter changes

2Volume of stationary object

If gas-insulated circuit breakers use complex configurations for short dielectric distances, then switchgear size is reduced, but current path resistivity increases causing overheating

Engineering Contradiction:
Improveswitchgear sizeVSAvoidoverheating
Core Design Contradiction:
Volume of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The contact spring serves as an intermediary conductive element that maintains low-resistance electrical connection between stationary and movable contacts. This intermediary structure ensures adequate current carrying capacity even in compact configurations, preventing overheating while enabling reduced switchgear dimensions through optimized contact geometry and material properties.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Volume of stationary object

If gas-insulated circuit breakers use complex configurations for short dielectric distances, then switchgear size is reduced, but manufacturing costs increase

Engineering Contradiction:
Improveswitchgear sizeVSAvoidmanufacturing cost
Core Design Contradiction:
Volume of stationary objectVSEase of manufacture

Solution Approach 1:

The conductive connection structure with contact spring serves multiple functions simultaneously: providing electrical connection, maintaining contact pressure, enabling compact configuration, and ensuring current carrying capacity. This multi-functionality reduces the need for separate specialized components, thereby simplifying manufacturing processes and reducing overall manufacturing costs while achieving compact switchgear design.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 achieves improved conductivity and insulation performance with a compact, cost-effective structure, suitable for switchgears with short contact distances, and simplifies industrial manufacturing and installation.

Implementation Method 1

a dielectric gas (as an example SF 6 ) is contained... having excellent arc-quenching properties... for electric insulation purposes

Methodology Applied
Scientific EffectDielectric insulation: Dielectric

Implementation Method 2

current breaking is obtained by separating electric contacts in a dielectric gas medium (typically SF 6 ) having excellent arc-quenching properties

Methodology Applied
Scientific EffectArc quenching: Electric Arc

Implementation Method 3

sliding contact means, which electrically couple the moving contact assembly and the compression cylinder

Methodology Applied
Scientific EffectSliding contact conduction: Conduction (electrical)

Data Source

PatentEP3093866B1An electric pole unit for medium voltage gas-insulated circuit breakers
Publication Date: 2020.04.22 ABB (SCHWEIZ) AG
  • EP3093866B1 patent drawingFigure 1
  • EP3093866B1 patent drawingFigure 2
  • EP3093866B1 patent drawingFigure 3

AI summary

An electric pole unit (1) for a MV gas-insulated circuit breaker characterised in that it comprises: - an insulating housing (2) defining an internal volume (3), in which a dielectric gas is contained; - a first pole terminal (11) and a second pole terminal (12); - an interruption unit (6), which is positioned in the internal volume of said electric pole unit, said interruption unit comprising: - a fixed contact assembly (4), which is electrically coupled to said first pole terminal (11); - a moving contact assembly (5), which is adapted to be coupled with or separated from said fixed contact assembly during a switching operation of said circuit breaker; - a compression cylinder (7), which is adapted to define a gas compression chamber (62) of said interruption unit, said moving contact assembly being operatively coupled with said compression cylinder so as to move along said compression chamber during a switching operation of said circuit breaker. Said compression cylinder (7) is at least partially made of conductive material and is electrically coupled with said second pole terminal (12). Said electric pole unit comprises sliding contact means (8) electrically coupling said moving contact assembly (5) and said compression cylinder.