Magnet-Guided Contact Bridge Layout to Prevent Arc Connection

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Solution Overview

Problem

Electrical switches, such as relays and contactors, face challenges in reliably interrupting high electrical loads without arc destruction due to switching arcs, which existing technologies struggle to manage effectively in terms of operating temperatures, internal pressures, electrical insulation, and arc resistance.

Innovation Solution

A contact device with a movable contact bridge and at least two magnets that generate a magnetic field to deflect arcs in different directions, preventing arc connection and utilizing Lorentz forces to lengthen and extinguish arcs quickly, thereby reducing the risk of component destruction across varying current directions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional arc extinguishing methods are used, then arcs can be extinguished to some extent, but arcs may still connect in opposite directions causing short circuits and component destruction

Engineering Contradiction:
Improveswitching reliabilityVSAvoidarc connection
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The arc extinguishing function is segmented into two independent systems: one for positive current direction and one for negative current direction. Each magnet system independently deflects arcs in its designated direction, ensuring that arcs in opposite directions are always deflected away from each other, preventing connection and short circuits.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the contact device are assigned different magnetic field characteristics. The first magnet system creates a magnetic field optimized for deflecting arcs in one direction, while the second magnet system creates a magnetic field optimized for the opposite direction. This localized optimization ensures effective arc deflection regardless of current direction.

Inventive Principle:
Principle #3Local quality

2Reliability

If magnetic field strength is increased to improve arc deflection, then arc extinguishing efficiency improves, but energy consumption and heat generation increase

Engineering Contradiction:
Improvearc extinguishing efficiencyVSAvoidmagnetic field energy
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

Instead of using one extremely strong magnet that would consume excessive energy, the invention uses two magnets with moderate strength that together provide sufficient deflection for both current directions. Each magnet only needs to handle arcs in one direction, reducing the energy requirement for each individual magnet while maintaining overall effectiveness.

Inventive Principle:
Principle #16Partial or excessive action

3Temperature

If arc path is extended to improve cooling and extinguishing, then arc temperature decreases, but arc duration increases potentially causing more damage

Engineering Contradiction:
Improvearc temperatureVSAvoidarc duration
Core Design Contradiction:
TemperatureVSDuration of action of moving object

Solution Approach 1:

The invention changes the spatial parameters of the magnetic field configuration rather than simply increasing field strength. By optimizing the arrangement and positioning of the two magnets, the system achieves effective arc deflection and cooling with moderate field strengths, reducing both temperature and duration of the arc simultaneously.

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

The solution effectively prevents direct arc short circuits and ensures reliable operation by quickly cooling and de-ionizing arcs, making it suitable for applications involving energy storage devices with changing current directions.

Implementation Method 1

A blowout magnet is a permanent magnet or electromagnet used to deflect the switching arc between the relay contacts using the Lorentz force acting on the arc

Methodology Applied
Scientific EffectLorentz force: Lorentz Force

Implementation Method 2

The magnets generate a magnetic field in a first region, which comprises at least a first contact region and a second contact region

Methodology Applied
Scientific EffectMagnetic field: Magnetic Field

Data Source

PatentEP3341950B1Contact apparatus for an electric switch and electric switch
Publication Date: 2024.01.03 TDK ELECTRONICS AG
  • EP3341950B1 patent drawingFigure 1
  • EP3341950B1 patent drawingFigure 2
  • EP3341950B1 patent drawingFigure 3

AI summary

The contact device (30) for the electrical switch comprises a first connection element (31), a second connection element (32) and a movable contact bridge (33). Furthermore, the contact device (30) comprises at least two magnets for extinguishing arcs which arise during the switching of the electrical switch. The magnets generate a magnetic field in a first region which comprises at least one first contact region and one second contact region, in which contact regions, with the electrical switch in a closed switching position, the first connection element (31) and, respectively, the second connection element (32) are in contact with the contact bridge (33). In addition, the contact device (30) comprises one or more deflection elements which are arranged and designed to distort the magnetic field in such a way that a first arc which forms between the first connection element (31) and the contact bridge (33) and a second arc which forms between the second connection element (32) and the contact bridge (33) are forced into different directions, which extend pointing away from one another, independently of a respective flow direction in the connection elements (31, 32).