Low Voltage Switch Pole Arc Quenching Design

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Solution Overview

Problem

Low voltage switch devices face issues with uneven arc distribution in the arc chamber, leading to ineffective arc quenching, increased mechanical and thermal stresses, and potential arc leakage outside the interruption region, resulting in reduced switch performance and lifetime.

Innovation Solution

A low voltage switch pole design featuring an insulating casing with a channel connecting the contact area to the arc extinguishing area, ensuring uniform arc utilization across all metallic plates and preventing arc bypass, while an insulating wall separates the contact and arc extinguishing areas to prevent external arc strikes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the arc chamber is designed without an insulating wall separating the contact area from the arc extinguishing area, then the structure is simpler, but the arc may bypass some metallic plates and escape to external metallic parts, causing non-uniform arc distribution and reduced reliability

Engineering Contradiction:
Improvearc quenching effectivenessVSAvoidarc chamber structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The arc chamber is segmented into a contact area and an arc extinguishing area by an insulating wall, with a channel connecting the two regions. This segmentation ensures that the arc is properly guided through all metallic plates while preventing escape to external parts, thus improving reliability without excessive complexity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

An insulating wall acts as an intermediary structure between the contact area and the arc extinguishing area. It partially separates these regions while allowing controlled arc passage through a channel, ensuring uniform arc distribution across all plates while maintaining structural integrity

Inventive Principle:
Principle #24Intermediary (Mediator)

2Duration of action of stationary object

If all metallic plates in the arc chamber are utilized uniformly for arc quenching, then the switch lifetime is extended, but the arc chamber design becomes more complex requiring precise arc guidance structures

Engineering Contradiction:
Improveswitch lifetimeVSAvoidarc chamber design
Core Design Contradiction:
Duration of action of stationary objectVSDevice complexity

Solution Approach 1:

The arc chamber is divided into distinct zones (contact area and arc extinguishing area) separated by an insulating wall with a channel. This segmentation ensures that the arc follows a controlled path through all metallic plates, maximizing their utilization for quenching and extending switch lifetime

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The insulating wall with its channel introduces a spatial dimension to arc control, guiding the arc through a specific three-dimensional path that ensures all metallic plates are engaged uniformly, thereby extending component life

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Reliability

If the channel connects the contact area to the arc extinguishing area at multiple points, then arc distribution is improved, but the insulating wall complexity and manufacturing difficulty increase

Engineering Contradiction:
Improvearc distribution uniformityVSAvoidinsulating wall fabrication
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

A single channel in the insulating wall provides sufficient arc guidance and distribution effectiveness without the need for multiple channels. This partial action approach achieves the necessary arc uniformity while maintaining manufacturing simplicity

Inventive Principle:
Principle #16Partial or excessive action

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 design achieves uniform arc quenching across all metal plates, reducing thermal and mechanical stresses, prolonging the switch's lifetime, and preventing arc leakage, thereby enhancing the switch's reliability and insulation efficiency.

Implementation Method 1

an insulating wall positioned in said internal space between said contact area and said arc extinguishing area and partially separating said contact area from said arc extinguishing area

Methodology Applied
Scientific EffectElectrical insulation: Dielectric

Implementation Method 2

a channel connecting said contact area to said arc extinguishing area is provided in said insulating wall

Methodology Applied
Scientific EffectElectric arc: Electric Arc

Implementation Method 3

During arc forming, the energy released by Joule effect is very high and causes thermal and mechanical stresses inside the plate containment region

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 4

The arc is propelled by electromagnetic and fluid-dynamics effects inside a series of arc-breaking metal plates arranged in the chamber, which are meant to extinguish said arc by cooling and splitting actions

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 5

The arc is propelled by electromagnetic and fluid-dynamics effects inside a series of arc-breaking metal plates arranged in the chamber

Methodology Applied
Scientific EffectElectromagnetic force: Lorentz Force

Implementation Method 6

The arc is propelled by electromagnetic and fluid-dynamics effects inside a series of arc-breaking metal plates arranged in the chamber, which are meant to extinguish said arc by cooling and splitting actions

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP3048625B1Low voltage switch pole
Publication Date: 2017.08.16 ABB SPA
  • EP3048625B1 patent drawingFigure 1
  • EP3048625B1 patent drawingFigure 2
  • EP3048625B1 patent drawingFigure 3

AI summary

A low voltage switch pole 1 which comprises an insulating casing (2) having lateral walls and a front and a rear wall and defining an internal space with a contact area (3) and an arc extinguishing area 4, a fixed contact assembly (31) and a movable contact assembly (32)being positioned in said contact area, said movable contact assembly being movable between a closed position in which it is into contact with said fixed contact assembly and an open position in which it is spaced apart from said fixed contact assembly, an arc chamber (41) comprising a plurality of substantially parallel metallic plates 42 inserted into an enclosure (43) made of insulating material being positioned in said arc extinguishing area 4; the switch pole further comprises an insulating wall 5 which is positioned in said internal space between said contact area and said arc extinguishing area and partially separates said contact area from said arc extinguishing area, a channel 6 connecting said contact area to said arc extinguishing area being provided in said insulating wall 5.