Bi-directional DC Arc Chamber with Permanent Magnets

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Solution Overview

Problem

Existing direct current (DC) electrical switching apparatus face challenges in achieving bi-directional operation without significant size and cost increases, particularly in driving the arc into the arc interruption chamber at low DC currents, due to limitations with permanent magnet designs in known DC circuit breakers.

Innovation Solution

A single direct current arc chamber with a ferromagnetic base and side members, along with permanent magnets, creates a dual arc chamber structure that drives the arc into one side based on current direction, utilizing a magnetic field pattern to split the arc effectively, allowing for bi-directional operation with a single set of arc plates and a ferromagnetic center barrier.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If permanent magnets are employed to drive the arc into the arc interruption chamber, then the arc driving capability is improved, but the device size and cost increase significantly

Engineering Contradiction:
Improvearc driving capabilityVSAvoiddevice size
Core Design Contradiction:
ReliabilityVSVolume of stationary object

Solution Approach 1:

The patent combines two separate arc chambers with permanent magnets into a single integrated arc chamber structure. The permanent magnets are positioned on opposite sides of the same arc chamber, creating a unified structure that provides bidirectional arc driving capability without requiring duplicate arc chambers, thereby reducing overall device size.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single arc chamber structure serves dual functions by handling both directional arc interruptions. The permanent magnets generate magnetic fields that can drive arcs in both directions within the same chamber, making the structure universal for bidirectional DC circuit breaker applications without requiring separate specialized chambers for each direction.

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

2Adaptability or versatility

If two separate arc chambers are employed to provide bi-directional operation, then the arc interruption capability is improved, but the device complexity and cost increase

Engineering Contradiction:
Improvebi-directional operation capabilityVSAvoidstructure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent merges two separate arc chambers into one unified arc chamber structure. The permanent magnets are positioned on opposite sides within the same chamber, creating a single integrated structure that provides bidirectional arc driving capability, thereby reducing structural complexity and component count.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single arc chamber is effectively segmented into two functional zones by the permanent magnets positioned on opposite sides. Each magnet creates a magnetic field zone that drives arcs in opposite directions, allowing the unified chamber to function as if it were two separate chambers while maintaining structural simplicity.

Inventive Principle:
Principle #1Segmentation

3Ease of manufacture

If permanent magnets are arranged for unidirectional operation, then the magnet design is simplified, but the bi-directional switching capability is lost

Engineering Contradiction:
Improvemagnet arrangement simplicityVSAvoidbi-directional switching capability
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The patent uses symmetric arrangement of permanent magnets on opposite sides of the arc chamber. This symmetric configuration creates magnetic fields that can drive arcs in both directions, enabling bidirectional switching capability while maintaining manufacturing simplicity through repeated use of identical magnet components in symmetric positions.

Inventive Principle:
Principle #4Asymmetry

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 enables efficient bi-directional DC switching and interruption with a compact design, effectively managing arc behavior regardless of current direction, thereby improving the performance and cost-effectiveness of DC electrical switching apparatus.

Implementation Method 1

a magnetic field pattern structured to drive the arc toward one of the first and second corners depending on a direction of current flowing in the arc

Methodology Applied
Scientific EffectMagnetic field: Magnetic Field

Implementation Method 2

the magnetic field pattern may be structured to drive the arc toward one of the first and second corners depending on a direction of current flowing in the arc

Methodology Applied
Scientific EffectLorentz force: Lorentz Force

Data Source

PatentEP2463880B1Direct current arc chamber, and bi-directinal direct current electrical switching apparatus employing the same
Publication Date: 2016.04.13 EATON CORP
  • EP2463880B1 patent drawingFigure 1A~1B
  • EP2463880B1 patent drawingFigure 2~3
  • EP2463880B1 patent drawingFigure 4A

AI summary

A single direct current arc chamber (8,50) includes a ferromagnetic base (18,58) having first (20,60) and opposite second (22,62) ends, a first ferromagnetic side member (24,64) disposed from the first end, a second ferromagnetic side member (26,66) disposed from the opposite second end, a third ferromagnetic member (28,68) disposed from the ferromagnetic base intermediate the ferromagnetic side members, a first permanent magnet (4,70) having a first magnetic polarity disposed on the first ferromagnetic side member and facing the third ferromagnetic member, and a second permanent magnet (6,72) having the first magnetic polarity disposed on the second ferromagnetic side member and facing the third ferromagnetic member.