Cutoff Chamber Arc Quenching via Dynamic Volume Segmentation
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Solution Overview
Problem
High-voltage circuit breakers face challenges in maintaining effective arc blowout for currents below the breaking capacity, particularly with asymmetrical currents, due to excessive overpressure that can reduce breaking capacity and lead to inefficient gas usage.
Innovation Solution
A high-voltage circuit breaker design with a valve system that regulates overpressure by closing or opening a hole in the blow-off piston, ensuring sufficient overpressure for all current values, with additional insulating elements to channel gas effectively near the arc root, optimizing arc blowout efficiency without gas loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If the blowing volume is increased to limit overpressure for asymmetrical currents, then the overpressure is reduced for high-current breaks, but the overpressure is also reduced for low-current breaks where high overpressure is needed
Solution Approach 1:
The blowing volume is segmented into two distinct volumes: a first blowing volume (V1) that is always available, and a second blowing volume (V2) that is selectively activated only for asymmetrical currents exceeding a threshold value. This segmentation allows the system to provide high overpressure for low-current breaks using V1, while limiting excessive overpressure for high-current breaks by activating V2 only when needed.
Solution Approach 2:
The system changes the effective blowing volume parameter based on the current characteristics. For asymmetrical currents below the threshold, the full blowing volume (V1+V2) is available to generate high overpressure. For asymmetrical currents above the threshold, only V1 is effectively used, limiting the overpressure to acceptable levels. This dynamic parameter adjustment resolves the contradiction between needing high overpressure for low currents and limiting overpressure for high currents.
2Reliability
If the overpressure is limited for asymmetrical currents at 100% breaking capacity, then the breaking capacity is maintained, but the overpressure may be insufficient for intermediate current values
Solution Approach 1:
The system dynamically adjusts the available blowing volume based on the detected current characteristics. The control system monitors the current type and magnitude, then selectively activates either V1 alone or both V1 and V2 to achieve the appropriate overpressure level. This dynamic adjustment ensures sufficient overpressure for intermediate currents while maintaining breaking capacity for high currents.
3Stress or pressure
If gas is lost to the outside of the blowing volume, then the overpressure is limited, but the gas is not used for blowing the arc
Solution Approach 1:
Instead of allowing gas to be lost to the outside environment, the invention extracts and redirects the excess gas through a dedicated channel (channel 71) that leads it to a specific location (zone Z) near the arc root. This extracted gas is then utilized for additional blowing effectiveness rather than being wasted, simultaneously limiting overpressure in the blowing volume and preventing energy loss.
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 solution maintains high breaking capacity across various current intensities, ensuring efficient arc blowout and reduced operating energy, while preventing excessive overpressure that could hinder the circuit breaker's movement.
Implementation Method 1
the heating of the gas by the arc produced
Implementation Method 2
the blowing through the nozzle 4 made it possible to cool the arc at the passage through zero
Data Source
Figure 1A~1C
Figure 2~3A
Figure 3B~4
AI summary
The invention relates to a cutoff chamber for a high-voltage, greater than 52 kV, circuit breaker. According to the invention, a compromise is made between the operating energy to be deployed for all the values of short-circuit current be it symmetric or asymmetric and the effectiveness of the quenching of the arc which occurs on cutoff, by quenching the arc at the root (Z) through a part of the thermal expansion volume (when the cutoff chamber is of auto-pneumatic quenching type) or through the compression volume (when the cutoff chamber is of auto-quenching type) for arcs with a current whose value is greater than a given percentage of the cutoff value of the circuit breaker.