Electromechanical Circuit Breaker Arc Extinction via Parallel Coil
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Solution Overview
Problem
Existing electromechanical circuit breakers face challenges in efficiently interrupting low currents due to insufficient magnetic force for arc extinction, limiting their performance and efficiency, especially in DC installations like traction networks.
Innovation Solution
A blow-out device with a magnetizing coil having a considerable number of turns, where the current passing through it is smaller than the arc current, and a magnetic circuit with pole pieces generating a strong magnetic field to drive the arc into an arc-chute, enhancing breaking performance and security.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the magnetising coil has a small number of turns to limit volume, then the device size is reduced, but the efficiency when breaking smaller currents is limited
Solution Approach 1:
The invention divides the current path into two separate paths: one through the magnetising coil and another through the arc path in parallel coupling. This segmentation allows the coil to have fewer turns for compact size while the parallel arc path ensures sufficient current for generating the magnetic field needed to extinguish small currents effectively.
Solution Approach 2:
The magnetising coil serves dual functions: it generates the magnetic field for arc extinction and its parallel connection with the arc path ensures it can effectively handle both small and large current breaking operations, making the device universally effective across different current ranges.
2Force
If the magnetising coil takes the full current of the breaker, then the magnetic force is sufficient for high current breaking, but the volume of the arrangement increases
Solution Approach 1:
The current is segmented into two paths: a portion flows through the magnetising coil while the rest flows through the parallel arc path. This segmentation allows the coil to generate sufficient magnetic force without needing to carry the full breaker current, thereby reducing the required coil size and overall device volume.
Solution Approach 2:
The magnetising coil carries only a partial current rather than the full breaker current. This partial action is sufficient to generate the necessary magnetic force for arc extinction, especially for small currents, while avoiding the excessive current that would require a larger coil and increase device volume.
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 design achieves high efficiency and secure current interruption even at low currents, with improved longevity and lower costs, allowing for precise and reliable operation of the circuit breaker.
Implementation Method 1
a magnetising coil (8) having a considerable number of turns and an electrical resistance, wherein the blow-out device (2) is arranged in such a manner that current passing in the magnetising coil (8) is smaller that the current passing in the first or second arc (13a, 13b)
Implementation Method 2
the blow-out device (2) comprising electrode means electrically connected to the magnetising coil and adapted to cooperate with said arc in such a manner that the latter generates said magnetising current in the magnetising coil, the magnetic field for driving the arc being generated by the action of said arc
Implementation Method 3
an electromagnetic force is used to drive the electrical are into an are extinguishing device such as an arc-chute
Data Source
Figure 1~3
Figure 2~4
Figure 5
AI summary
The electromechanical circuit breaker is intended to establish and break the current in a main circuit (3, 4) and comprises a fixed contact element (5) and a moving contact element (6) which in a first position are in electrical contact with each other for carrying the current of the main circuit (3, 4). Said moving contact element (6) is adapted to be displaced to a second position in which it is separated from the fixed contact element (5) so that the current in the main circuit is cut off. The circuit breaker is provided with a blow-out device (2) comprising a magnetising coil (8) traversed by a magnetising current for producing a magnetic field (26) adapted to drive an arc generated by the separation of said two contact elements (5, 6) into an arc extinction means. The blow-out device (2) comprises electrodes (12) electrically connected to the magnetising coil (8) and adapted to cooperate with said arc in such a manner that the latter generates said magnetising current in the magnetising coil (8). The magnetic field for driving the arc is generated by the action of said arc. Said electrodes (12) are located in such a relationship with said contact elements (5, 6) that the arc generated by the separation of said two contact elements is at least partially separated into a first arc (13a) between one contact element (5) and the electrodes (12) and a second arc (13b) between the electrodes (12) and the other contact element (6). Said first or second arc (13a, 13b) is set in parallel coupling with said magnetising coil (8) connected on one side to the electrodes (12) and on the other side to one of the contact elements (5, 6). These features allow to obtain high breaking efficiency and performances even when breaking smaller currents.