Contact with fixed fracture and having short-circuit current breaking capability and vacuum arc extinguishing chamber

Abstract

The invention relates to a contact with a fixed fracture and having short-circuit current breaking capability and a vacuum arc extinguishing chamber. The contact comprises a group of fixed fracture contact and a group of movable fracture contact, wherein the movable fracture contact is arranged inside the fixed fracture contact when being in a switching-off state. The vacuum arc extinguishing chamber comprises the contact, a shell and a shielding cover, and the contact is provided with the fixed fracture and has short-circuit current breaking capability. By the contact and the vacuum arc extinguishing chamber, the problems of structure complexity of a traditional composite magnetic field contact structure and other vacuum arc extinguishing chambers with regard to capacity current breaking design are solved, deficiency of magnetic field control on vacuum arc and the like are solved; the electric field shielding and protection of the fixed fracture contact on the movable fracture contact are achieved, and the influence of defects formed on the surface of the movable fracture contact on breakdown during the capacitive closing process is avoided; the breaking function and the insulation function are separated, the breaking function is achieved by the composite magnetic field contact, the insulation function is achieved by the fixed contact, and the contact can be used for breaking short-circuit current and also can be used for switching capacitive current such as reactive compensation field of capacitor bank switching and the like.

Description

technical field [0001] The invention belongs to the technical field of high-current vacuum circuit breakers, and in particular relates to a contact with a fixed fracture and capable of breaking short-circuit currents and a vacuum interrupter, which can be used for capacitor bank switching and has short-circuit current breaking capabilities. Background technique [0002] The application of vacuum circuit breakers in the entire power system develops rapidly, but with the development of power systems, the requirements for vacuum circuit breakers are also constantly increasing, especially the switching of capacitor banks. In the medium-voltage power distribution system, a high-frequency inrush current of 4250 Hz and 20 kA will be generated during switching of the capacitor bank, and its pre-breakdown arc will locally ablate the surface of the contact and cause the contact to weld. When breaking the capacitor bank, the breaking current can reach hundreds of amperes. At this time,...

AI Technical Summary

Problems solved by technology

[0006] In order to solve the above-mentioned problems in the prior art, the object of the present invention is to provide a contact with a fixed fracture and a short-circuit current breaking capability and a vacuum interrupter, which solves the problems of the existing compound magnetic field contact structure and other problems for capacitors. The structure of the vacuum interrupter designed for permanent current breaking is too complicated, and there are problems such as the lack of composite magnetic field control of the vacuum arc.

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