Circuit Breaker Quick Tripping via Contact Spring Transmission
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Solution Overview
Problem
Existing quick tripping devices for circuit breakers are complex, cumbersome, prone to malfunction due to bounce during normal closure, and have poor reliability, leading to secondary closing issues.
Innovation Solution
A simplified quick tripping device with a contact system and operating mechanism where a moving contact drives a transmission structure through a contact spring, directly or indirectly triggering the operating mechanism to trip, avoiding secondary closing and enhancing reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional quick tripping device is used, then the circuit breaker can trip during short-circuiting, but the structure becomes complex and occupies large space
Solution Approach 1:
The patent merges the quick tripping device with the operating mechanism by sharing common components such as the moving contact, contact spring, and transmission structures. The moving contact mechanism serves dual purposes: normal operation and quick tripping detection, eliminating the need for separate detection components and reducing overall structural complexity.
Solution Approach 2:
The operating mechanism components are designed to perform multiple functions. The moving contact not only closes the circuit normally but also detects short-circuit conditions. The contact spring provides both closing force and tripping detection. The transmission structures serve both normal operation transmission and quick tripping transmission, making each component multi-functional and reducing the need for additional dedicated components.
2Speed
If the quick tripping device is highly sensitive, then it can detect short-circuiting quickly, but it causes malfunction due to contact bounce during normal closure
Solution Approach 1:
The patent introduces dynamic thresholds and time-based discrimination into the quick tripping mechanism. The system dynamically adjusts its response based on the duration and characteristics of the detected force. Normal contact bounce generates short-duration forces that decay quickly, while short-circuiting generates sustained forces that persist throughout the closing operation, allowing the system to distinguish between the two conditions.
Solution Approach 2:
The system incorporates feedback mechanisms that monitor the behavior of the moving contact and contact spring throughout the closing operation. By continuously monitoring the position, velocity, and acceleration of these components, the system can distinguish between normal bounce (which follows a predictable pattern) and abnormal short-circuiting forces (which deviate from the normal pattern), preventing false tripping while maintaining quick response to actual faults.
3Reliability
If the quick tripping device uses sensors to detect pressure, then it can detect short-circuiting, but the sealability of the housing becomes difficult and pistons are easily polluted
Solution Approach 1:
The patent replaces electronic sensors and pneumatic/hydraulic pistons with a purely mechanical detection system. The moving contact mechanism and contact spring directly mechanically transmit the effects of short-circuiting forces to the transmission structures and operating mechanism. This eliminates the need for sealed housings and protects against arc gas pollution, as the mechanical components are inherently resistant to environmental contamination.
Solution Approach 2:
The mechanical components perform their own detection and transmission functions without requiring external sensing or protection systems. The moving contact and contact spring inherently detect short-circuiting conditions through their mechanical response to abnormal forces, and the transmission structures directly transmit this information to the operating mechanism, eliminating the need for separate protected sensing systems.
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 simplifies the structure, reduces malfunctions, and ensures effective quick tripping of the circuit breaker, preventing secondary closing and improving breaking performance.
Implementation Method 1
a contact spring, two ends of which are connected with the moving contact and the contact support respectively
Implementation Method 2
the electric repulsion force between the moving contact and the static contact increases sharply. When the electric repulsion force is greater than the final pressure between the contacts, the moving contact is repelled by the static contact
Data Source
AI summary
A quick tripping device of a circuit breaker having a contact system that includes a moving contact mechanism and a static contact, wherein the moving contact mechanism includes a contact support and a moving contact, and a contact spring having, two ends connected with the moving contact and the contact support respectively. The quick tripping device further includes a first transmission structure in driving fit with the contact spring and rotatable rotates along with the contact spring. When a short-circuiting current flows through the contact system, the moving contact is repelled by an electric repulsive force between the moving contact and the static contact, so that the moving contact rotates relative to the contact support. The moving contact drives the first transmission structure to rotate through the contact spring, and the first transmission structure drives an operating mechanism to trip.