Vacuum Circuit Breaker Contact Spring Ratio for Stable Breaking
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Solution Overview
Problem
Vacuum circuit breakers face challenges in maintaining stable breaking performance due to changes in self-closing force resulting from variations in gas pressure within the pressure vessel, which are influenced by operating temperature fluctuations.
Innovation Solution
A vacuum circuit breaker design incorporating a pressure vessel filled with insulating gas, a vacuum interrupter with a bellows-sealed movable electrode, a movable rod, a driving rod, and a contact pressure spring, where the self-closing force to minimum input contact pressure ratio is maintained within a predetermined range (0 to 0.1) to stabilize the driving force.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the self-closing force is increased to ensure reliable contact between electrodes, then the contact reliability is improved, but the driving unit requires excessively large force and uneven contact load is caused on electrodes
Solution Approach 1:
The patent applies parameter changes by optimizing the self-closing force to a specific range (0.05-0.15 times the minimum input contact pressure) rather than using excessively large force. This parameter optimization ensures reliable electrode contact while preventing uneven contact load and reducing driving unit force requirements.
2Reliability
If the self-closing force is increased to compensate for temperature-induced gas pressure changes, then the breaking performance stability is improved, but the driving unit complexity and force requirement increase
Solution Approach 1:
The patent uses parameter changes by establishing an optimal self-closing force range (0.05-0.15 times the minimum input contact pressure) that maintains breaking performance stability across temperature variations without requiring complex driving unit adjustments or excessive force generation capabilities.
3Stress or pressure
If the self-closing force is set to a high value to ensure contact pressure, then the contact pressure is improved, but unnecessary excessive driving force is required and contact load becomes uneven
Solution Approach 1:
The patent applies parameter changes by defining an optimal self-closing force range (0.05-0.15 times the minimum input contact pressure) that achieves sufficient contact pressure between electrodes while avoiding unnecessary excessive driving force requirements and preventing uneven contact load distribution.
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 design ensures that temperature-induced changes in gas pressure do not affect the vacuum circuit breaker's performance by limiting self-closing force variations, reducing the need for excessive driving force components and maintaining consistent operation.
Implementation Method 1
a vacuum interrupter disposed in an internal space of the pressure vessel and having a fixed electrode and a movable electrode in a vacuum tube having a vacuum state
Implementation Method 2
a contact pressure spring having one end supported by the movable rod and the other end supported by the driving rod
Implementation Method 3
a pressure vessel filled with an insulating gas of a predetermined pressure
Data Source
Figure 1
AI summary
A vacuum circuit breaker according to an embodiment of the present disclosure may include: a pressure vessel filled with insulating gas at a predetermined pressure; a vacuum interrupter disposed inside the pressure vessel and provided with a fixed electrode and a movable electrode which are in a vacuum tube in a vacuum state; a bellows provided to seal a gap between the vacuum tube and the movable electrode; a movable rod which has one end connected to an end of the movable electrode by means of an insulation link, extends through the pressure vessel, and can reciprocate in an axial direction thereof while maintaining air-tightness therebetween; a drive rod which is disposed outside the pressure vessel and at the other end of the movable and transmits a drive force of a drive part to the movable rod; and a contact pressure spring having one end supported by the movable rod and the other end supported by the drive rod, wherein the ratio of a self-closing force with respect to a minimum closing contact pressure of the vacuum interrupter is set to a predetermined ratio.