Overcurrent Tripping Device Magnetic Saturation Gap
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Solution Overview
Problem
Conventional overcurrent tripping devices for circuit breakers face challenges in shortening tripping operation time due to magnetic saturation and inefficient drive force utilization, leading to increased device size and mass.
Innovation Solution
The introduction of a narrow gap in the magnetic circuit between the fixed and movable cores, aligned perpendicular to the magnetic flux, suppresses magnetic saturation and enhances the drive force, allowing for a more efficient tripping operation and size reduction of the device.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If the core volume is increased to suppress magnetic saturation, then the tripping operation time is shortened, but the device mass increases
Solution Approach 1:
The invention introduces a narrow gap (0.01-0.5mm) in the magnetic circuit to change the magnetic path parameters. This gap increases magnetic reluctance and prevents saturation without requiring larger core volume, thus achieving fast tripping operation while maintaining compact device size and low mass
Solution Approach 2:
The magnetic circuit is segmented by introducing a narrow gap between the fixed core and movable core. This segmentation creates a controlled magnetic path that prevents saturation while maintaining efficient magnetic coupling, resolving the contradiction between response time and device size
2Device complexity
If the direction of magnetic flux is different from the driving direction of the movable core, then the device structure is simplified, but the drive force cannot be fully exerted
Solution Approach 1:
The invention aligns the narrow gap direction perpendicular to the magnetic flux direction, creating a three-dimensional optimization where the gap width controls magnetic saturation while the gap orientation ensures the magnetic attraction force acts in the same direction as the movable core's driving direction, maximizing force efficiency
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
This design enables a significant reduction in tripping operation time and device size by effectively suppressing magnetic saturation and aligning the magnetic attraction force with the driving direction, resulting in a more responsive and compact overcurrent tripping device.
Implementation Method 1
magnetic saturation of an electromagnet composing the overcurrent tripping device
Implementation Method 2
a magnetic flux is generated in a fixed core 102, to form a magnetic circuit
Implementation Method 3
A magnetic attraction force acting on the movable core is generated in the same direction as the direction of a magnetic flux passing through the movable core
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
The object is to obtain an overcurrent tripping device that enables shortening of a tripping operation time in the case where fault current occurs and enables size reduction. The overcurrent tripping device detects overcurrent flowing through a main circuit of a circuit breaker and actuates a tripping mechanism of the circuit breaker in a closed state, and includes: a tripping conductor (5) connected to the main circuit; a fixed core (4) inside which the tripping conductor (5) penetrates and which is excited by current flowing through the tripping conductor (5); a movable core (7) which is arranged to be opposed to the fixed core (4) with a magnetic gap therebetween, and which forms a magnetic circuit in cooperation with the fixed core (4), and moves by being attracted by the fixed core (4) when overcurrent flows through the tripping conductor (5); and a shaft (6) fixed to the movable core (7) to guide the movement of the movable core (7), and linked to the tripping mechanism of the circuit breaker, wherein the fixed core (4) has a narrow gap (4a) formed in such a direction as to cross the magnetic circuit, so that magnetic saturation is suppressed by the narrow gap (4a).