Circuit Breaker Nozzle Field Deflection Against Arc Side Branching
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Solution Overview
Problem
Gas-insulated high or medium voltage circuit breakers face challenges in preventing electrical discharges from propagating towards upstream volumes during current interruption, leading to potential reignition and side branching into heating channels.
Innovation Solution
Incorporating a conductive element embedded within the insulating material of the main nozzle, which generates an electrical field to deflect the discharge away from the heating channel, ensuring it propagates towards the second contact and maintaining electrical insulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the discharge path is allowed to propagate along the inner surface of the main nozzle towards the second contact, then the current breaking operation can be completed, but the discharge may enter the heating channel and cause reignition or side branching
Solution Approach 1:
A conductive element is introduced as an intermediary between the arcing region and the heating channel. This element generates an electrical field that deflects the discharge away from the heating channel, serving as a mediator that protects the heating channel while allowing the discharge to complete its breaking function between contacts.
Solution Approach 2:
The conductive element is positioned and configured in advance to generate an electrical field that opposes the discharge's natural propagation path towards the heating channel. By creating this preliminary counteracting field, the discharge is deflected before it can enter the heating channel, preventing harmful side branching.
2Reliability
If a conductive element is embedded within the insulating material of the main nozzle to generate electrical field, then the discharge can be deflected away from the heating channel, but the device complexity increases
Solution Approach 1:
The conductive element is nested within the insulating material of the main nozzle, with the insulating material serving as the outer structure and the conductive element embedded inside it. This nested configuration allows the conductive element to generate the necessary electrical field while being protected and integrated within the existing nozzle structure, minimizing additional complexity.
3Reliability
If the conductive element is positioned around the arcing region, then the electrical field can effectively deflect the discharge, but the manufacturing precision requirements increase
Solution Approach 1:
The conductive element is positioned specifically around the arcing region where the discharge occurs, concentrating the electrical field generation where it is most needed. This localized positioning ensures effective discharge deflection while limiting the precision requirements to only the critical arcing region rather than the entire nozzle structure.
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
Effectively prevents discharge from entering the heating channel, reducing the risk of reignition and maintaining the integrity of the circuit breaker by deflecting the electrical discharge efficiently and quickly, thus enhancing the reliability and durability of the device.
Implementation Method 1
the at least one conductive element is arranged around the arcing region and is configured to generate an electrical field due to the presence of an electrical discharge in the arcing region, the electrical field being configured for deflecting the electrical discharge
Data Source
Figure 1
Figure 2A~2B
Figure 3
AI summary
A gas-insulated high or medium voltage circuit breaker (100) comprises a pin contact (120) and a second contact (130) being configured to be moveable with respect to each other along a longitudinal axis (190) of the circuit breaker (100) between an open and a closed configuration of the circuit breaker, the pin contact (120) and the second contact (130) defining an arcing region (180) in which an electrical discharge (160) is formed during a current breaking operation; and an auxiliary nozzle (150) comprising an electrically insulating material that at least partially surrounds the second contact (130), a main nozzle (110) comprising an electrically insulating material that encloses the auxiliary nozzle at least partially, and a heating channel (140) provided between the auxiliary nozzle and the main nozzle, wherein the heating channel separates the auxiliary nozzle from the main nozzle axially and radially and enables a fluid communication between the arcing zone (180) and an upstream pressure volume (155), wherein at least one conductive element (360) is embedded within the insulating material of the main nozzle (110) and is electrically floating, wherein the at least one conductive element (360) is arranged around the arcing region (180) and is configured to generate an electrical field due to the presence of an electrical discharge (160) in the arcing region (180), the electrical field being configured for deflecting the electrical discharge (160) which propagates from the pin contact (120) along an inner surface (175) of the main nozzle (110) towards the second contact (130).