Short-Circuit Ring in Power Circuit Breaker
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Solution Overview
Problem
Selective main line circuit breakers face challenges in maintaining the main contact point open until the current flow through the secondary contact point is interrupted, leading to undefined triggering delays and contact piece burn-off due to arc production during movements.
Innovation Solution
A short-circuit ring made of conductive material, such as copper, is attached to the magnet armature and/or core, generating a phase-shifted current that maintains the magnetic force between the armature and core, keeping the main contact point open until the current flow through the secondary contact point is interrupted.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the main contact point is opened by an electromagnet system to achieve current limitation, then the main contact point closes again when the current crosses zero, but this causes undefined triggering delays and contact piece burn-off due to pumping movements and arc production
Solution Approach 1:
A short-circuit ring is introduced as an intermediary component between the magnet armature and the magnetic core. This ring generates a phase-shifted magnetic force that prevents the main contact point from closing prematurely when the current crosses zero, thereby eliminating undefined triggering delays while maintaining selective triggering reliability.
Solution Approach 2:
The invention changes the temporal parameter of the magnetic force by introducing a phase shift through the short-circuit ring. The magnetic force now has a different phase relationship with the current, ensuring it remains non-zero during critical periods, which prevents premature contact closure and eliminates pumping movements.
2Reliability
If the main contact point is opened by an electromagnet system, then current limitation is achieved, but arcs are produced during pumping movements causing contact piece burn-off
Solution Approach 1:
The short-circuit ring acts as a mediator that modifies the magnetic force characteristics. By generating a phase-shifted magnetic field, it prevents the contact point from undergoing pumping movements, thereby eliminating arc production and contact piece burn-off while preserving the current limitation capability.
Solution Approach 2:
The short-circuit ring provides preliminary anti-action by creating a counteracting magnetic force before the current crosses zero. This prevents the contact point from closing and reopening (pumping movements), thereby preventing arc formation and contact piece burn-off in advance.
3Reliability
If an auxiliary current winding is provided in the auxiliary current path to unlatch the switching mechanism, then the main contact point is kept open until final switch-off, but this means increased expense
Solution Approach 1:
The invention extracts the phase-shifting function from the auxiliary current winding and implements it through a passive short-circuit ring. This eliminates the need for the expensive auxiliary current winding while achieving the same effect of keeping the main contact point open until final switch-off.
Solution Approach 2:
The short-circuit ring is a simple, inexpensive passive component made of conductive material, replacing the costly auxiliary current winding. It achieves the required functionality at minimal cost without requiring complex control circuits or additional active components.
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 short-circuit ring effectively prevents the magnetic force from dropping to zero, ensuring the main contact point remains open until the current flow is fully switched off, preventing premature closure and reducing wear on contact pieces.
Implementation Method 1
a current flow that is phase-shifted with respect to the short-circuit current can be generated, which has the effect that the magnetic force does not become zero when the short-circuit current passes through zero
Implementation Method 2
a magnet system (10) with which a magnet armature (12) and a magnet core (11) are assigned
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
The breaker has a short circuit ring (29) mounted to a magneto armature (12) or at/to a magnetic core (11). The ring is inserted into a ring-shaped groove on an armature front surface (23). Voltage is induced in the ring through a temporal change of a magnetic field. The ring serves to keep the magneto armature and a contact position of the breaker to be opened. The magnetic core is surrounded by a coil pipe (17), which is surrounded by a coil winding (18). The ring is made of an electrically conductive material e.g. copper.