DC Air Circuit Breaker Arc Chute Structure for Small-Current Extinction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Direct-current air circuit breakers face challenges in effectively extinguishing arcs during small current interruptions due to weak magnetic fields, leading to arc stagnation and structural damage.
Innovation Solution
An arc-extinguishing structure that utilizes a magnet with different poles in a vertical arrangement to generate a stronger arc magnetic field, guiding the arc to a cooling plate and preventing reverse flow, thereby maximizing the arc magnetic field-based driving force and ensuring quick arc extinction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a conventional arc extinguishing structure without additional magnets is used, then the device complexity is low, but the arc magnetic field-based driving force is insufficient for small current interruptions
Solution Approach 1:
The patent combines the magnet with the arc guide structure, integrating the magnetic field generation function into the existing arc extinguishing pathway. The magnet is positioned within or adjacent to the arc guide to directly enhance the arc magnetic field in the region where arc control is most critical, merging two functional elements into a unified structure that achieves stronger arc driving force without proportionally increasing overall device complexity.
Solution Approach 2:
The magnet is pre-positioned in the arc guide before arc occurrence, creating a predetermined magnetic field distribution that is optimized for small current interruptions. This preliminary arrangement of magnetic field lines ensures that when an arc occurs, the magnetic field-based driving force is immediately sufficient to propel the arc toward the cooling plate, eliminating the need for real-time adjustment or additional complex control mechanisms.
2Force
If the magnet size is increased to maximize magnetic field magnitude, then the arc magnetic field-based driving force is maximized, but the device complexity and space requirements increase
Solution Approach 1:
Instead of using a large uniformly magnetized structure throughout the arc guide, the patent applies magnetization locally at specific positions where the magnetic field is most needed for arc control. The magnet is strategically placed in the arc guide to create concentrated magnetic field lines precisely where they can most effectively influence arc behavior, achieving high arc magnetic field-based driving force with minimal magnet volume.
Solution Approach 2:
The patent optimizes the magnet's geometric configuration and spatial orientation within the arc guide to maximize magnetic field effectiveness in the critical arc region. By carefully designing the magnet's shape, size, and positioning in three-dimensional space, the patent achieves sufficient magnetic field magnitude for small current interruptions without requiring excessive magnet volume, effectively utilizing spatial dimensions to optimize performance.
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 extinguishes arcs quickly, prevents backflow, and enhances small current interruption performance, reducing the risk of structural and electrical damage.
Implementation Method 1
an arc magnetic field-based driving force using a magnetic field of a magnet
Implementation Method 2
the arc as generated travels from the fixed contact and the movable contact to a cooling plate via a Lorentz force (an arc magnetic field-based driving force) generated orthogonally by arc current and a magnetic flux density
Implementation Method 3
the arc as generated travels from the fixed contact and the movable contact to a cooling plate via a Lorentz force and is cooled and extinguished by the cooling plate
Data Source
AI summary
An arc-extinguishing unit structure for a direct current air circuit breaker according to one embodiment of the present disclosure comprises: a plurality of grids; side plates coupled to both sides of the plurality of grids so that the plurality of the grids are mounted so as to be spaced apart from each other; an exhaust cover positioned above the side plates and the plurality of grids; an arc guide coupled to the side plates so as to be located under the plurality of grids; a magnet coupled to the arc guide, wherein the magnet is magnetized with different poles on the basis of the plurality of grids and the vertical orientation of the arc guide.