Protective Switch Device Arc Extinction via Lorentz Force
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Solution Overview
Problem
Conventional protective switching devices experience significant contact erosion due to arcs formed when switching contacts open, leading to reduced service life and increased electrical resistance, which affects their switching capacity and reliability.
Innovation Solution
The protective switching device incorporates a current path with a current-carrying section that generates a Lorentz force to drive the arc away from the switching contact, utilizing a magnet yoke and magnetic tripping system to expedite arc extinction, thereby reducing contact erosion and enhancing switching performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional arcing chambers with quenching plates are used to extinguish arcs, then arc extinction is achieved, but contact erosion between the moving contact piece and fixed contact piece increases due to prolonged arc duration
Solution Approach 1:
The patent extracts the harmful arc from the contact area by introducing a current-carrying section that generates a magnetic field to propel the arc away from the switching contact into the arcing chamber, thereby separating the arc generation zone from the contact pieces and reducing contact erosion
Solution Approach 2:
The current-carrying section acts as an intermediary element that mediates between the arc and the contact pieces. By generating a magnetic field through the current flowing through this section, it creates a Lorentz force that drives the arc away from the contact area, reducing direct interaction between the arc and contact pieces
2Loss of substance
If the arc is driven away from the switching contact using a current-carrying section, then contact erosion is reduced, but the device complexity increases due to additional magnetic field generation components
Solution Approach 1:
The current-carrying section serves multiple functions: it conducts the load current through the switching contact and simultaneously generates the magnetic field required to drive the arc away from the contact area. This multi-functionality eliminates the need for separate arc propulsion components, reducing device complexity
Solution Approach 2:
The patent merges the current conduction function and the magnetic field generation function into a single current-carrying section. By combining these functions, the design avoids adding separate components for arc propulsion, thereby maintaining structural simplicity while achieving reduced 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 improves the switching capacity by quickly extinguishing arcs, reducing material removal from contact pieces, and increasing the service life of the device, allowing for a more compact implementation with less required contact material.
Implementation Method 1
a current-carrying section 24 which is designed in such a way and interacts with the arc in such a way that a resultant electromagnetic field is formed, which interacts with the arc in such a way that it is driven away from the switching contact
Implementation Method 2
a current-carrying section 24 which is designed in such a way and interacts with the arc in such a way that a resultant electromagnetic field is formed
Data Source
Figure 1A~1B
Figure 2A~2B
Figure 3
AI summary
The device (1) has input and output terminals contacting the device with an electric line. A switching contact comprises a fixed contact piece (4) relative to a movable contact piece (5). The contact pieces are formed such that a light arc is formed between the contact pieces when opening the contact. The contact is electric conductively connected with the terminals over a current path. A current guide section of the path is formed and cooperated with the arc such that a resulting electromagnetic field is formed in which the arc interacts so as to drive the arc by the contact.