Mesostructured Electrical Contacts for Arc Blow Enhancement
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Solution Overview
Problem
In low voltage circuit breakers, the natural magnetic field of the current flowing through the conductor path often exerts insufficient force on the electric arc, causing it to linger between the stationary and movable contacts before moving towards the splitter plates, leading to prolonged arc-contact interaction time and increased contact erosion.
Innovation Solution
The electric contacts are designed with a mesostructured geometry, featuring slots and ridges that guide the electric arc at an acute angle relative to the contact surfaces, enhancing the magnetic driving force and facilitating faster arc movement away from the contacts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the natural magnetic field of the current flowing through the conductor path is used to drive the electric arc, then the device complexity is reduced, but the magnetic force acting on the arc is insufficient causing prolonged arc-contact interaction time
Solution Approach 1:
The contact tips are given a specific geometric configuration (acute angle between contact surfaces) to create localized conditions that enhance the magnetic force on the arc. This local geometric modification concentrates the magnetic effect at the critical arc generation zone without requiring system-wide changes to the conductor path or overall device structure.
Solution Approach 2:
The geometric parameters of the contact tips are changed - specifically the angle between contact surfaces is set to be acute rather than perpendicular. This parameter change modifies the magnetic field distribution and increases the magnetic force component acting on the arc, thereby reducing arc-contact interaction time while using only the natural magnetic field.
2Device complexity
If the natural magnetic field of the current flowing through the conductor path is used to drive the electric arc, then additional magnetic components are eliminated, but the arc may remain between contacts for too long leading to increased contact erosion
Solution Approach 1:
The contact tips are given a specific geometric configuration (acute angle between contact surfaces) to create localized conditions that enhance the magnetic force on the arc. This local geometric modification concentrates the magnetic effect at the critical arc generation zone without requiring system-wide changes to the conductor path or overall device structure.
Solution Approach 2:
The natural magnetic field, which initially appears insufficient, is enhanced through geometric configuration to serve the beneficial purpose of quickly moving the arc away from contacts. The existing current's magnetic field is converted from a weak driving force into an effective arc-moving mechanism that reduces contact erosion.
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 significantly reduces the arc-contact interaction time, minimizing contact erosion and improving the reliability of arc extinction by increasing the magnetic force acting on the arc.
Implementation Method 1
the natural magnetic field of the interruption current 12 pushes the electric arc 11 from the left to the right
Implementation Method 2
the natural magnetic field of the interruption current 12 exerts a pressure or force 13 on the electric arc 11
Data Source
Figure 1~2
Figure 3~6
Figure 7~9
AI summary
Electrical contact system with a first and a second contact (1, 5), each having a contact surface (4, 8). The first electric contact (1) has a mesostructured electric contact portion (14) with a plurality of slots (15) and ridges (16) formed between neighboring slots (16) of the plurality of slots (16). These slots (15) and ridges (16) extend in a direction running transversely to said switching plane (X-Z) form a plurality of current paths (16). The current paths (16) are inclined to the first contact surface (4) at a first angle (17) measuring less than 60 degrees such that an interruption current (12) flowing through the mesostructured electric contact portion (14) and through an electric arc (11) extending in between the first contact surface (4) after lifting the first contact surface (4) off the second contact surface (8) pushes said electric arc (11) in the direction of the apex of said first angle (17) from a first position (18) to a second position (19).