Load Current Switching Contact Layout for Rapid DC Arc Extinction

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Solution Overview

Problem

Existing switching devices for high DC currents, especially in electromobility applications, face challenges in quickly extinguishing electric arcs generated by short-circuit currents, leading to potential device destruction and loss of galvanic isolation, with existing technologies failing to ensure rapid arc dissipation and efficient switching under high current conditions.

Innovation Solution

A compact, remote-controlled switching device with a movable switching component performing rotational and translational movements, utilizing a magnetic actuator and E-shaped design to create a dynamic magnetic blow field, combined with arc guiding rails and deionization-extinguishing chambers, enables efficient arc guidance and extinguishing, reducing contact welding and extending the device's service life.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the switching device uses a compact design for electromobility applications, then the device size is reduced, but the ability to quickly extinguish electric arcs and ensure galvanic isolation deteriorates

Engineering Contradiction:
Improvedevice sizeVSAvoidarc extinction capability
Core Design Contradiction:
Volume of moving objectVSReliability

Solution Approach 1:

The switching device is segmented into distinct functional zones: a first switching zone for normal operation and a second switching zone for arc extinction. The arc extinction chamber is separated from the main switching chamber by an insulating wall, creating spatial segmentation that enables compact design while maintaining arc extinction effectiveness. This segmentation allows the device to handle high currents in a compact form factor without compromising reliability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a vertical dimension for arc extinction by positioning the arc extinction chamber above the main switching chamber. The insulating wall extends vertically to provide galvanic isolation, and the arc extinction contacts are arranged in a vertical configuration. This dimensional arrangement enables effective arc management in a compact horizontal footprint, resolving the contradiction between device size and arc extinction capability.

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

2Power

If the switching device operates with high DC currents above 100 A, then the current handling capability is improved, but the welding tendency of contacts increases

Engineering Contradiction:
Improvecurrent handling capabilityVSAvoidcontact welding
Core Design Contradiction:
PowerVSObject-affected harmful factors

Solution Approach 1:

The device performs preliminary arc diversion by providing dedicated arc extinction contacts that engage before the main switching contacts separate. When high current flow is detected, the arc is immediately directed into the extinction chamber through the insulating wall opening, preventing welding from occurring in the first place. This preliminary action protects the main contacts from welding even during high current operations.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The insulating wall with its opening acts as an intermediary element that guides the electric arc from the switching zone to the extinction chamber. This intermediary structure enables the arc to be transferred safely without direct contact between high-voltage elements, reducing welding tendency while maintaining high current handling capability.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Speed

If the switching device uses a fast switching drive with high opening distance, then the switching speed is improved, but the mechanical stress on switching components increases

Engineering Contradiction:
Improveswitching speedVSAvoidmechanical stress
Core Design Contradiction:
SpeedVSStress or pressure

Solution Approach 1:

The switching mechanism is segmented into two independent parts: the main switching contacts that handle current flow, and the arc extinction contacts that manage arc discharge. This segmentation allows the main contacts to use a fast switching drive with large opening distance for high switching speed, while the arc extinction contacts operate with smaller movements, reducing overall mechanical stress on the system.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The device employs dynamic switching where the arc extinction contacts are activated only when needed (during arc extinction phase). The main switching contacts perform rapid opening/closing for normal operation, while the arc extinction mechanism dynamically engages to divert arcs when high currents are detected. This dynamic operation reduces mechanical stress compared to continuously operating with large opening distances.

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 allows for reliable handling of high DC currents and short-circuit currents, achieving a high number of switching operations with reduced welding tendency and rapid arc extinction, ensuring safe and efficient switching operations.

Implementation Method 1

utilizing a magnetic actuator and E-shaped design to create a dynamic magnetic blow field

Methodology Applied
Scientific EffectMagnetic blow field: Magnetic Field

Implementation Method 2

efficient magnetic blow field arrangement

Methodology Applied
Scientific EffectLorentz force: Lorentz Force

Implementation Method 3

an arc driver device based on arc guiding rails

Methodology Applied
Scientific EffectElectric arc: Electric Arc

Implementation Method 4

deionization-extinguishing chambers, enables efficient arc guidance and extinguishing

Methodology Applied
Scientific EffectDeionization: Ionisation

Data Source

PatentEP3899998B1Switching device for guiding and switching of load currents
Publication Date: 2024.02.28 EATON INTELLIGENT POWER LTD
  • EP3899998B1 patent drawingFigure 1
  • EP3899998B1 patent drawingFigure 2
  • EP3899998B1 patent drawingFigure 3

AI summary

A switching device (1, 2) for guiding and switching of load currents comprises a movable switching component (100) having a first movable contact (10) and a second movable contact (20), and a first fixed contact (30) and a second fixed contact (40). The switching device (1, 2) comprises a supporting device (200) to support the switching component (100). The switching component (100) is arranged such that the switching component is moved between a switched-on state and a switched-off state by at least a rotational movement of the switching component and a translational movement of the supporting device (200).