DC Circuit Breaker Arc Plate Layout to Prevent Restrike
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Solution Overview
Problem
Conventional DC circuit breakers face issues with arc backflow and restrike due to insufficient control over the arc flow on arc extinguishing plates, leading to elongated interruption times and potential failure.
Innovation Solution
The DC circuit breaker incorporates interrupting portions on each arc extinguishing plate, which are designed to control the flow of arcs and prevent backflow by diffusing hot gases radially and directing them away from the arc extinguishing chamber.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If arc extinguishing plates are disposed in the arc extinguishing chamber to divide and extinguish arcs, then arc interruption capability is improved, but arc backflow and restrike occur due to insufficient control over arc flow direction
Solution Approach 1:
The arc extinguishing plate is segmented by providing multiple interrupting portions (first, second, and third interrupting portions) that divide the arc into multiple sections. Each interrupting portion acts as an independent barrier to control arc flow direction and prevent backflow to different regions, thereby eliminating the harmful effect of arc restrike while maintaining interruption capability.
Solution Approach 2:
Different interrupting portions are positioned at specific locations on the arc extinguishing plate to address local arc backflow problems. The first interrupting portion prevents backflow to the fixed contact side, the second prevents backflow to the movable contact side, and the third prevents backflow to the arc extinguishing plate itself, creating localized control over arc flow direction.
2Device complexity
If conventional arc extinguishing structures are used, then simple structure is maintained, but interruption time is elongated due to insufficient arc flow control
Solution Approach 1:
The arc extinguishing plate is segmented by providing multiple interrupting portions (first, second, and third interrupting portions) that divide the arc into multiple sections. Each interrupting portion acts as an independent barrier to control arc flow direction and prevent backflow to different regions, thereby eliminating the harmful effect of arc restrike while maintaining interruption capability.
Solution Approach 2:
Different interrupting portions are positioned at specific locations on the arc extinguishing plate to address local arc backflow problems. The first interrupting portion prevents backflow to the fixed contact side, the second prevents backflow to the movable contact side, and the third prevents backflow to the arc extinguishing plate itself, creating localized control over arc flow direction.
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
This solution effectively prevents arc backflow and restrike, enhancing the interruption performance of the DC circuit breaker by ensuring that arcs are fully extinguished without re-emergence.
Implementation Method 1
The arc having arrived in the arc extinguishing chamber is divided by the arc extinguishing plates, and an arc voltage equal to or higher than a power supply voltage of a DC circuit is generated, whereby fault current is limited and interrupted.
Implementation Method 2
which are designed to control the flow of arcs and prevent backflow by diffusing hot gases radially and directing them away from the arc extinguishing chamber
Data Source
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AI summary
The DC circuit breaker includes: an interruption mechanism portion (16) configured to perform opening between a fixed contact (1) and a movable contact (3), to interrupt DC current; and an arc extinguishing chamber (14) in which a plurality of arc extinguishing plates (15) each obtained by superposing an insulating plate (13) and a grid (12) which has electrical conductivity and has a plate shape, are accommodated in a stacked state at fixed intervals. An interrupting portion having a projecting shape is disposed on either surface of each arc extinguishing plate (15) so as to originate from an edge of the arc extinguishing plate. Thus, the DC circuit breaker has so high interruption performance that no arc leaks from a location on the grid (12) to the surroundings.