Vacuum interrupter compound contact structure and interrupter suitable for capacitive current breaking

Abstract

Provided are a vacuum arc-extinguishing chamber composite contact structure and an arc-extinguishing chamber suitable for capacity current connecting and disconnecting. The composite contact structure comprises a pair of moving-static conducting rods, a moving end contact and a static end contact. The moving-static conducting rods comprise a moving conducting rod and a static conducting rod. The moving end contact and the static end contact are respectively fixed at the top ends of the close ends of the moving conducting rod and the static conducting rod. The moving end contact is made of moving end contact materials B and moving end contact materials A which are fixed above the moving end contact materials B and are different from the moving end contact materials B. The moving end contact materials A cover part area of the moving end contact materials B. The static end contact is made of static end contact materials B and static end contact materials A which are fixed above the static end contact materials B and are different from the static end contact materials B. The static end contact materials A cover part area of the static end contact materials B. During a brake separating process, the moving end contact materials B and the static end contact materials B are mainly used for connecting and disconnecting currents. Separation of welding resistance and connecting and disconnecting performance of the vacuum arc-extinguishing chamber contact structure is achieved, and accordingly insulation intensity between contacts is guaranteed.

Description

technical field [0001] The invention relates to the technical field of a contact structure of a vacuum interrupter, in particular to a composite contact structure of a vacuum interrupter suitable for breaking capacitive currents and an interrupter. Background technique [0002] During the operation of the medium-voltage reactive power compensation system, due to frequent fluctuations in the grid load, in order to adjust the system power factor, reduce harmonics, stabilize voltage and reduce losses, capacitive loads will be frequently switched on and off. According to the operation experience of my country's power grid, 1.2kvar to 1.4kvar of reactive power is required for every 1kW of active power to maintain the normal working voltage of the power grid. According to foreign research and investigation, vacuum circuit breakers can be used for capacitive current operations up to 300 to 700 times a year, that is, there are 1 or 2 closing and opening operations per day. For such...

AI Technical Summary

Problems solved by technology

The capacitive current breaking capacity of a vacuum circuit breaker is mainly determined by the surface conditions of the contacts in the vacuum interrupter. Current research has found that there is a close relationship between the closing inrush current and the re-strike phenomenon. The reason is that the high-frequency inrush current will , local ablation of the contact surface, causing welding of the contact, destroying the surface structure of the contact, increasing the field emission coefficient β of the contact surface, and at the same time, a large number of metal particles will be generated on the contact surface, which will affect the vacuum arc extinguishing Chamber Dielectric Strength

However, in the current design process of the existing vacuum interrupter, a pair of dynamic and static contacts with the same contact material are basically used to complete the operation of switching the capacitive load of the vacuum circuit breaker, which cannot reduce the impact of the closing inrush on the vacuum interrupter. Destruction of the contact surface

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