Nested Contact Cups Split Longitudinal Magnetic Field
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Solution Overview
Problem
Current vacuum arc extinguishing chambers struggle to simultaneously handle large short-circuit currents and carry high-rated currents for extended periods without excessive heating and increased manufacturing complexity and cost.
Innovation Solution
The design incorporates multiple coil-shaped contact cups that distribute current and generate independent longitudinal magnetic fields, reducing current density and heat generation while supporting the contact blade, allowing for effective arc control and dispersion across a larger contact area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the diameter of the contact coil and rotation length are increased to handle large short-circuit currents, then the interrupting capacity is improved, but the loop resistance increases greatly causing serious heating and the manufacturing complexity and cost increase
Solution Approach 1:
The contact structure is divided into multiple contact cups (first contact cups and second contact cup) arranged in parallel, each capable of independently carrying current and generating magnetic fields. This segmentation allows the system to handle large currents without requiring a single large-diameter coil, thereby reducing loop resistance and heating while maintaining interrupting capacity.
Solution Approach 2:
The first contact cups are nested within or arranged around the second contact cup, creating a compact multi-layer structure. This nesting approach achieves the function of multiple coils in a space-efficient manner, reducing manufacturing complexity compared to using separate large-diameter coils while maintaining the required interrupting capacity.
2Reliability
If the diameter of the contact coil and rotation length are increased to handle large short-circuit currents, then the interrupting capacity is improved, but the loop resistance increases causing serious heating
Solution Approach 1:
The current path is segmented into multiple parallel paths through multiple contact cups, each with its own magnetic field generation capability. This reduces the current density and loop resistance in each individual path, thereby minimizing Joule heating while maintaining the overall interrupting capacity required for large short-circuit currents.
3Reliability
If a longitudinal magnetic field system is used to control arc dispersion, then the arc control is improved, but the contact diameter and coil dimensions must be increased leading to higher manufacturing cost
Solution Approach 1:
The magnetic field generation is segmented into multiple smaller contact cups with individual coils, each generating a localized longitudinal magnetic field. This approach achieves effective arc control and dispersion without requiring a single large-diameter coil with high manufacturing cost, as each smaller coil is more economical to manufacture and assemble.
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 solution enables the vacuum arc extinguishing chamber to efficiently interrupt large short-circuit currents while maintaining low temperature rises during high-rated current carrying, addressing the contradiction between interrupting capacity and thermal management, with simplified manufacturing and reduced costs.
Implementation Method 1
The contact is provided with a system for generating a magnetic field, which is used for forming a transverse magnetic field or a longitudinal magnetic field between the contacts
Implementation Method 2
forming a transverse magnetic field or a longitudinal magnetic field between the contacts when the vacuum arc extinguishing chamber breaks short-circuit current, so that the formation of anode spots on the surface of the contact is prevented
Implementation Method 3
the contact area of the contact is smaller until the contact is melted, evaporated and ionized; and discharge in vacuum is maintained in metal vapor
Implementation Method 4
the contact area of the contact is smaller until the contact is melted, evaporated and ionized
Implementation Method 5
The current can be uniformly dispersed on the surface of the contact, the temperature rise of the surface of the contact can be less
Data Source
AI summary
The invention relates to a vacuum arc extinguishing chamber contact, a vacuum arc extinguishing chamber and a vacuum circuit breaker. The contact includes a contact blade, a first contact cup and a second contact cup. The first contact cup is arranged in the second contact cup. One end of the first contact cup is connected with the second contact cup, and the other end of the first contact cup is connected with the contact blade. The contact blade is connected with the second contact cup. According to the invention, a single longitudinal magnetic field is split into a plurality of independent longitudinal magnetic field areas, a plurality of coils are used for shunting current, and the current density is reduced, thereby solving the contradiction between interrupting of the large short-circuit current and the temperature rise of the large rated current.