Magnetic Relay Contact Structure for Short-Circuit Holding and Breaking
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Solution Overview
Problem
High-voltage DC relays face challenges in balancing anti-short circuit and breaking abilities due to the negative correlation between them, where enhancing short circuit ability weakens breaking ability, and increasing coil size conflicts with compact and lightweight design requirements.
Innovation Solution
A relay design with a movable first magnetizer and a fixed second magnetizer, where the distance between them is adjustable based on the current flowing through the movable contact piece, allowing for optimized magnetic attraction force to resist electro-dynamic repulsion and ensure both anti-short circuit and overload breaking capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a stationary anti-short circuit structure is used, then the ability to withstand short circuit is significantly enhanced, but the breaking ability is weakened
Solution Approach 1:
The patent applies the dynamics principle by making the upper magnetizer movable rather than stationary. The movable core can dynamically adjust its position based on current conditions: under short circuit conditions it moves to provide strong holding force for anti-short circuit protection, while under normal breaking conditions it returns to its original position to maintain breaking ability. This dynamic adjustment resolves the contradiction between enhancing anti-short circuit ability and maintaining breaking ability.
2Reliability
If the coil size is increased to increase the holding force of the movable core, then the anti-short circuit ability is improved, but the compact and lightweight design is compromised
Solution Approach 1:
The patent uses the dynamics principle to make the upper magnetizer movable, allowing it to concentrate magnetic flux effectively when needed without requiring a larger coil. The movable core dynamically positions itself to optimize magnetic circuit efficiency, providing sufficient holding force for anti-short circuit protection while maintaining a compact and lightweight relay design.
Solution Approach 2:
The patent applies parameter changes by modifying the position of the upper magnetizer rather than changing the coil size. By adjusting the position parameter of the magnetizer dynamically, the system achieves variable holding force to meet different operational requirements without increasing the physical size or weight of the relay components.
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 adjustable magnetic attraction force effectively enhances anti-short circuit ability while maintaining timely breaking performance, meeting the requirements for both overload breaking and anti-short circuit functionality without compromising the compact design.
Implementation Method 1
the second magnetizer is fixedly connected to one side of the movable contact piece facing away from the first magnetizer, and the second magnetizer is configured to form a magnetic circuit together with the first magnetizer
Implementation Method 2
the first magnetizer is movable relative to the movable member through the moving part and is configured to adjust a distance between the first magnetizer and the second magnetizer according to a value of a current flowing through the movable contact piece
Implementation Method 3
contact bounce caused by the electro-dynamic repulsion force of contacts in the high-voltage DC relay due to short circuit current
Data Source
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AI summary
A relay includes a contact container (10) having a contact chamber (101) and a pair of first through holes (102), a pair of static contact leading-out terminals (20) respectively passing through the pair of first through holes (102), a moving part (80), a first magnetizer (40) within the contact chamber (101) and connected with the moving part (80); and a movable member (53) including a movable contact piece (54) and a second magnetizer (55). The movable contact piece (54) may contact with or separate from the pair of static contact leading-out terminals (20). The first and second magnetizer (55) s are arranged at opposite sides of the movable contact piece (54) and formed a magnetic circuit. Wherein the first magnetizer (40) is movable relative to the movable member (53) through the moving part (80) and is configured to adjust a distance between the first magnetizer (40) and the second magnetizer (55) according to a value of a current flowing through the movable contact piece (54).