DC Switch Arc Extinction via Magnetic Field Guidance
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Solution Overview
Problem
DC electrical switches face challenges in reliably and quickly extinguishing electric arcs, which can cause damage and safety hazards due to the higher occurrence and stability of arcs compared to AC applications, especially when current and voltage exceed certain thresholds.
Innovation Solution
A switch design featuring two fixed conductive contacts, a movable conductive bridge, and arc-extinguishing units with permanent magnets creating a magnetic field to guide electric arcs into the arc-extinguishing units, utilizing arc-splitters to increase breakdown voltage and a magnetic permeable material for enhanced magnetic field strength, allowing for fast and predictable arc extinction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If permanent magnets are used to guide electric arcs into arc-extinguishing units, then arc extinction speed and reliability are improved, but device complexity increases due to additional magnetic components
Solution Approach 1:
The patent combines the arc-guiding function and magnetic field generation into a single integrated component structure. The permanent magnets are positioned to work in conjunction with the arc-guiding elements, creating a unified system that performs both functions without requiring separate complex assemblies. This merging reduces the number of discrete components while maintaining the desired arc extinction performance.
Solution Approach 2:
The permanent magnets serve multiple functions: they generate the magnetic field necessary to guide arcs into the arc-extinguishing units, and they are integrated with the structural components of the switch. The arc-guiding elements also serve dual purposes as both structural support and functional guides for the arcs. This multi-functionality reduces the overall component count and simplifies the device structure.
2Object-affected harmful factors
If arc-extinguishing units are added to DC switches, then arc damage and safety hazards are reduced, but device complexity and component count increase
Solution Approach 1:
The patent utilizes the harmful electric arc itself as a tool to drive the arc into the arc-extinguishing units. The magnetic field generated by the permanent magnets interacts with the arc current to create a force that propels the arc toward the extinguishing chamber. This converts the potentially damaging arc into a self-guiding element that automatically seeks the extinguishing path, eliminating the need for complex mechanical actuation systems.
Solution Approach 2:
The patent replaces complex mechanical arc-extinguishing mechanisms with a magnetic field-based system. Instead of using mechanical devices to physically move or contain arcs, the invention uses permanent magnets to create a magnetic field that naturally guides the arcs into the extinguishing units. This substitution eliminates moving parts and complex mechanical structures, simplifying the overall device while maintaining effective arc control.
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 enables rapid and reliable extinction of electric arcs, reducing contact erosion and safety risks by utilizing a strong, homogeneous magnetic field to drive arcs into the arc-extinguishing units, while minimizing component count and material usage, and allowing for potential adaptation to AC applications.
Implementation Method 1
at least two permanent magnets are suitably arranged adjacent to the first and second contact areas to provide a magnetic field suitable to support the guiding of the electric arc into the arc-extinguishing units
Implementation Method 2
The permanent magnets are arranged in a manner providing an essentially homogeneous magnetic field between the oppositely arranged permanent magnets in a volume at least around the first and second contact areas in an open status of the switch where the direction of the magnetic field is suitable to apply a Lorenz force to the electric arc forcing the arc to move towards the arc-extinguishing units
Implementation Method 3
at least parts of the second arc-guiding element are made of a magnetic permeable material, which are connected to the permanent magnets as a back iron for the permanent magnets to increase the strength of the magnetic field between the permanent magnets
Implementation Method 4
The arc-splitters may be v-shaped. The electric arc will be divided into several sub-arcs present between the adjacent arc-splitters. Therefore the required voltage to maintain an electric arc through all the arc-splitters increases by the factor of the number of present arc-splitter resulting in a breakdown voltage larger than the original voltage leading to an extinguished arc
Data Source
AI summary
The invention relates to a switch (1) suitable for DC applications comprising two fixed conductive contacts (2) with first contact areas (21, 22), a movable conductive bridge (3) with two second contact areas (31, 32) for being connected to the two first contact areas (21, 22) in the on- status and for being disconnected from the two the first contact areas (21, 22) in the off- status and two arc-extinguishing units (41, 42) to extinguish electric arcs (51, 52) occurring between the first and second contact areas (21, 22, 31, 32) after disconnecting the second contact areas (31, 32) from the first contact areas (21, 22), wherein first conductive arc-guiding elements (61) extend from each first contact area (21, 22) into the corresponding arc-extinguishing unit (41, 42) and at least one second conductive arc-guiding element (62) extends into the arc-extinguishing units (41, 42) suitably shaped to guide the electric arcs (51, 52) from each of the second contact areas (31, 32) of the movable bridge (3) into the arc-extinguishing units (41, 42), wherein at least two permanent magnets (71, 72) are suitably arranged adjacent to the first and second contact areas (21, 22, 31, 32) to provide a magnetic field (B) suitable to support the guiding of the electric arc (51, 52) into the arc-extinguishing units (41, 42), wherein at least parts (621, 622) of the second arc-guiding element (62) are made of a magnetic permeable material, which are connected to the permanent magnets (71, 72) as a back iron for the permanent magnets (71, 72) to increase the strength of the magnetic field (B) between the permanent magnets (71, 72).