Switchgear Operating Mechanism for Rapid Cutoff
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional spring operating mechanisms for high-voltage gas-insulated circuit breakers face challenges in achieving rapid cutoff of high-voltage currents due to limitations in reducing contact opening time periods and stability of the retention spring force, primarily due to the stepwise operation and physical constraints on mass reduction and retention force enhancement.
Innovation Solution
A switchgear operating mechanism that employs a combination of a latch and a cam mechanism to reduce the time period for releasing the cutoff spring force, allowing for a two-step cutoff operation, thereby minimizing the contact opening time period and enhancing the stability of the retention operation by utilizing a solenoid lever and latch system with a return spring to manage the cutoff process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional spring operating mechanism uses a retention mechanism with latch, O-prop, and catch to retain cutoff spring force, then the mechanism can maintain stability during operation, but the contact opening time period increases due to stepwise operation
Solution Approach 1:
The retention mechanism is divided into separate functional components: a retention lever with retention protrusion for stable force retention, and a cutoff lever with cutoff protrusion for rapid release. This segmentation allows each component to perform its specific function efficiently, reducing overall operation time while maintaining stability.
Solution Approach 2:
The retention lever is preliminarily positioned and engaged with the cutoff spring force before cutoff is needed. The retention protrusion is already in place to hold the force, and upon activation, the release protrusion simply needs to disengage, eliminating the need for complex stepwise operations and reducing contact opening time.
2Loss of time
If the mass of movable portions is reduced to achieve faster operation, then the contact opening time period decreases, but the retention force stability deteriorates
Solution Approach 1:
The retention lever acts as an intermediary between the cutoff spring force and the rest of the mechanism. It has a retention protrusion that positively engages with the spring force, providing stable retention without requiring large mass. The lever transmits force efficiently while maintaining stability through its geometric design rather than mass.
Solution Approach 2:
The design changes the parameters of the retention mechanism by using a lever arm configuration with specific protrusion geometries. This allows the system to achieve both low mass and high stability by optimizing the lever arm lengths and protrusion shapes, rather than relying on mass for stability.
3Reliability
If the retention force is enhanced to improve reliability, then the stability of cutoff spring force retention improves, but the device complexity increases
Solution Approach 1:
The retention lever and cutoff lever are designed as integrated components with combined functions. The retention lever both retains the cutoff spring force and transmits it to the cutoff mechanism. This merging eliminates the need for separate retention and cutoff mechanisms, reducing overall device complexity while maintaining reliability.
Solution Approach 2:
The retention lever serves multiple functions: it retains the cutoff spring force through its retention protrusion, transmits the force to the cutoff mechanism, and provides a release interface through its release protrusion. This multi-functionality reduces the number of components needed, simplifying the overall mechanism while ensuring reliable force retention.
4Extent of automation
If a solenoid is used as a retention control mechanism to activate the catch, then the cutoff operation can be automated, but the contact opening time period increases due to the activation sequence
Solution Approach 1:
The solenoid is extracted from the traditional catch-activation role and repositioned to directly activate the retention lever's release protrusion. This extraction from the conventional activation sequence eliminates intermediate steps, allowing the solenoid to directly trigger the force release, thereby reducing contact opening time while maintaining automation.
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 mechanism significantly reduces the contact opening time period and improves the stability and reliability of the cutoff spring force retention, enabling faster and more reliable operation of high-voltage circuit breakers.
Implementation Method 1
a solenoid lever return spring that biases the solenoid lever so as to rotate the solenoid lever in a predetermined direction
Implementation Method 2
a latch return spring that biases the latch so as to rotate the latch in a predetermined direction
Implementation Method 3
an electromagnetic solenoid for cutoff that pushes the solenoid lever in opposition to the biasing force of the solenoid lever return spring
Data Source
AI summary
According to an embodiment, a switchgear operating mechanism has a roller pin rotatably fixed to a leading end of a latch lever. A latch is fixed to a solenoid lever at a position different from the rotation axis of the solenoid lever, and has a leading end engageable with the roller pin. In a state where the switchgear operating state is shifted from the closed state to the cutoff state, the solenoid lever is pushed by an electromagnetic solenoid for cutoff so as to be rotated in an opposite direction to the biasing direction of the solenoid lever return spring, and the latch lever is rotated by a biasing force of the roller pin to release an engagement between the roller pin and the leading end of the latch, which causes a cutoff spring to discharge its energy to rotate the latch lever.