Gas Insulated Switchgear Control Rod Compensation Bellows
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Solution Overview
Problem
In gas-insulated switchgear, the movement of vacuum interrupters through a bellows causes volume changes in the gas tank, leading to additional work required for contact separation, which is not volume-neutral and inefficient, especially at low overpressures.
Innovation Solution
A gas-insulated switchgear with a drive rod guided by a bushing and coupled to a hermetically sealed bellows compensation element, which is connected to the drive rod and gas container, compensating for forces acting on the drive rod during movement, thereby reducing volume change work by maintaining pressure similarity with the vacuum interrupter.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a bellows is used to move the moving contact of the vacuum interrupter, then the contact separation can be achieved, but additional volume change work is required which increases the energy consumption
Solution Approach 1:
The system is divided into two separate bellows: the original bellows for moving the contact and a new compensation bellows for volume compensation. This segmentation allows each bellows to have a specific function - one for contact movement and the other for maintaining pressure equilibrium, thereby reducing the energy required for contact separation.
Solution Approach 2:
The compensation bellows acts as an intermediary element between the gas tank interior and the drive rod. It mediates the volume changes caused by the original bellows expansion/contraction, absorbing these changes and preventing them from affecting the overall gas volume in the tank, thus reducing the work required.
2Device complexity
If the drive rod is guided through a bushing with a single bellows, then the structure is simple, but the volume change work is not compensated
Solution Approach 1:
The single bellows structure is segmented into two functional components: the original bellows for contact actuation and an additional compensation bellows for volume management. This segmentation transforms the simple but energy-inefficient single-bellows design into a more complex but energy-efficient dual-bellows system.
Solution Approach 2:
The system changes the parameter of bellows quantity from one to two, and changes the functional parameter distribution - the first bellows maintains contact movement capability while the second bellows specifically manages volume changes. This parameter change enables the system to compensate for volume changes and reduce energy loss.
3Stress or pressure
If overpressure in the gas tank is kept small (0.5 to 1 bar), then the volume change work is reduced, but the compensation effect is insufficient
Solution Approach 1:
By segmenting the volume compensation function into a separate compensation bellows, the system can maintain low overpressure (0.5 to 1 bar) while still achieving effective compensation. The compensation bellows independently handles volume changes, ensuring that the low pressure condition does not compromise the compensation effectiveness.
Solution Approach 2:
The compensation bellows serves as an intermediary that decouples the relationship between contact movement and volume change. It allows the system to maintain low overpressure for safety and efficiency while still providing sufficient compensation effect through the intermediary's volume absorption and release mechanism.
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 effectively reduces the volume change work required during switching operations by compensating for forces in the direction of the drive rod's movement, minimizing additional volume changes and maintaining pressure similarity with the vacuum interrupter, thus enhancing operational efficiency.
Implementation Method 1
the at least one compensation element compensates at least some of the forces that act on the drive rod from the vacuum tube bellows
Implementation Method 2
The movement of the bellows of the vacuum interrupter changes the gas volume in the gas tank and in the vacuum interrupter
Data Source
Figure 1~2
Figure 3
AI summary
The invention relates to a control rod with at least one compensation element for vacuum interrupters, in particular for gas-insulated switchgear, and gas-insulated switchgear comprising a control rod with at least one compensation element for vacuum interrupters.