DC Air Circuit Breaker U Assembly for Small-Current Arc Extinction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Direct current air circuit breakers face challenges in effectively extinguishing arcs generated by small currents due to weak arc power and the absence of a zero point, leading to potential damage and safety hazards.
Innovation Solution
A circuit breaking unit with a U assembly and magnet unit that forms a magnetic field to guide and extinguish arcs, including a U magnetic body and magnet unit to apply electromagnetic force, ensuring arcs are directed towards an arc extinguishing unit regardless of current flow direction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional arc extinguishing device is used in a DC air circuit breaker for small current breaks, then the device structure is simple, but the arc power is weak and the arc cannot be effectively moved to the grid, causing contact melting
Solution Approach 1:
A U-shaped magnetic body is introduced as an intermediary component between the arc generation point and the arc extinguishing grid. This magnetic body concentrates and directs the magnetic field to effectively guide the arc toward the grid, solving the problem of weak arc movement in small current DC breaks without requiring excessive structural complexity
Solution Approach 2:
The patent introduces a vertical dimension to the magnetic field configuration by positioning the U-shaped magnetic body upright, creating a magnetic field that acts perpendicular to the traditional horizontal arrangement. This dimensional change enables effective arc guidance in the vertical direction toward the grid, overcoming the limitations of conventional horizontal magnetic field configurations
2Reliability
If a magnet is added to form a magnetic field for arc movement, then arc extinction effectiveness is improved, but the space occupied by the magnetic body increases excessively
Solution Approach 1:
The magnetic field generation is segmented into multiple smaller magnet units arranged in a U-shape configuration, rather than using a single large magnet. This segmentation allows the magnetic field to be distributed efficiently in the required spatial pattern while minimizing the total volume occupied by magnetic materials
Solution Approach 2:
The U-shaped magnetic body is positioned to nest within the existing circuit breaker structure, utilizing available spaces between other components. This nesting approach allows the magnetic field structure to be integrated into the compact design without significantly increasing the overall device volume
3Productivity
If the movable contact and fixed contact are spaced apart to break current, then circuit interruption is achieved, but an arc is generated that extends along the movable contact and can damage components
Solution Approach 1:
The U-shaped magnetic body and magnetic field are pre-positioned in the circuit breaker structure before arc generation occurs. When the contacts separate and an arc forms, the magnetic field is already in place to immediately guide and concentrate the arc toward the extinguishing grid, preventing component damage without delaying the circuit breaking action
Solution Approach 2:
The harmful arc, which would normally damage components by extending along the movable contact, is converted into a beneficial controlled phenomenon. The magnetic field directs the arc's energy toward the arc extinguishing grid, where it is concentrated and rapidly extinguished, transforming the arc from a destructive force into a controlled process that enhances circuit breaking effectiveness
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 quick arc extinguishment and minimizes damage to the circuit breaker components by guiding arcs efficiently to the extinguishing unit, enhancing safety and reducing component wear.
Implementation Method 1
a magnet unit disposed between the low runner and the fixed contact terminal and forming a magnetic field so that a generated arc is subjected to an electromagnetic force to the left or right
Implementation Method 2
forming a magnetic field so that a generated arc is subjected to an electromagnetic force to the left or right
Implementation Method 3
the U assembly is formed to extend to opposite sides so that when an arc is generated, the pressure applied to the arc is increased
Implementation Method 4
incorporating a gassing material to enhance arc extinction
Data Source
AI summary
A circuit breaking unit includes a fixed contact, a movable contact in contact with or spaced apart from the fixed contact, a fixed contact terminal having the fixed contact disposed at a lower end thereof and extending upward, a movable contact terminal on which the movable contact is disposed and configured such that the movable contact moves in a direction toward the fixed contact or in a direction away from the fixed contact, and a low runner disposed extending upward from the fixed contact, one end thereof coupled to the fixed contact terminal, and the other end thereof spaced apart from the fixed contact terminal, wherein a magnet unit or a U assembly is disposed between the low runner and the fixed contact terminal.