Switching Device Dual Conductive Housing SF6 Replacement

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Solution Overview

Problem

Current medium-voltage switchgears using sulfur hexafluoride (SF6) face challenges due to its high global warming potential, and existing alternatives do not adequately address the need for compact, reliable, and easily assemble/disassemble designs with reduced dielectric stress.

Innovation Solution

The design features separate electrically conducting housings for contact assemblies, a cup-shaped housing for enhanced electric field control, and the use of a dielectric medium with lower global warming potential, such as dry air or organofluorine compounds, to improve dielectric withstand capability and facilitate assembly and recycling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If SF6 is used as insulating gas, then compact design and excellent arc extinguishing are achieved, but high global warming potential is introduced

Engineering Contradiction:
Improveswitchgear compactnessVSAvoidglobal warming potential
Core Design Contradiction:
Volume of moving objectVSObject-affected harmful factors

Solution Approach 1:

The patent changes the chemical composition parameter of the insulating medium from SF6 to alternative gases (such as air, nitrogen, or other environmentally friendly gases), thereby eliminating the harmful global warming effect while maintaining the necessary dielectric and arc extinguishing properties through optimized gas composition and pressure parameters

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs composite material structures including electrically conducting housings with specific material properties that compensate for the lower dielectric strength of alternative gases, creating a composite system that achieves both environmental compatibility and functional performance

Inventive Principle:
Principle #40Composite materials

2Reliability

If separate electrically conducting housings are used for contact assemblies, then dielectric withstand capability is improved, but device complexity increases

Engineering Contradiction:
Improvedielectric withstand capabilityVSAvoidhousing structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The electrically conducting housings serve multiple functions simultaneously: they provide mechanical support for contact assemblies, act as electric field controllers to enhance dielectric withstand capability, and function as integral parts of the switching device structure, thereby reducing overall device complexity despite the addition of separate housings

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

Solution Approach 2:

The patent merges the housing structure with the electric field control function by making the housings electrically conducting and positioning them to naturally control the electric field distribution, eliminating the need for separate field control components and reducing structural complexity

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If cup-shaped housing is used for enhanced electric field control, then dielectric insulation level is improved, but manufacturing complexity increases

Engineering Contradiction:
Improvedielectric insulation levelVSAvoidhousing manufacturing complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent optimizes the geometric parameters of the cup-shaped housing (such as curvature radius, depth, and positioning) to achieve effective electric field control while maintaining manufacturability through standard forming processes, balancing dielectric performance with manufacturing ease

Inventive Principle:
Principle #35Parameter changes

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 insulation levels, reduces electrical stress, and allows for the replacement of SF6 with lower global warming potential mediums, maintaining a compact and reliable switchgear structure while enabling easier assembly and recycling.

Implementation Method 1

The use of a dielectric medium with lower global warming potential, such as dry air or organofluorine compounds, to improve dielectric withstand capability

Methodology Applied
Scientific EffectDielectric insulation: Dielectric

Implementation Method 2

a cup-shaped housing for enhanced electric field control

Methodology Applied
Scientific EffectElectric field control: Electric Field

Data Source

PatentEP3252793B1Switching device with dual conductive housing
Publication Date: 2021.01.27 ABB (SCHWEIZ) AG
  • EP3252793B1 patent drawingFigure 1
  • EP3252793B1 patent drawingFigure 2
  • EP3252793B1 patent drawingFigure 3

AI summary

The invention relates to a switching device (10) for an encapsulated electric power distribution switchgear (100) and to an electric power distribution switchgear (100) with at least one such switching device (10). The switching device (10) has a first electrically conducting housing (20) which encloses an actuator mechanism (25) for a first contact assembly (30) and a second electrically conducting housing (40) which encloses a second contact assembly (50). According to the invention, the first electrically conducting housing (20) is arranged at a distance (d) from said second electrically conducting housing (40).