Solid insulation isolating grounding switchgear and its solid-sealed unit

Abstract

The invention relates to a solid insulation isolation earthing switch device and a fixing and encapsulating device thereof. The solid insulation isolation earthing switch device comprises a solid insulation shell with a sealed cavity. Three phase isolation earthing switch units are disposed on the shell. Each phase unit comprises two main loop terminals fixed on the shell, an earthing vacuum arc-extinguishing chamber fixed and encapsulated in the wall of the shell and a disconnecting link located in the cavity. The static end of each earthing vacuum arc-extinguishing chamber faces to the cavity, and the end of the static end is fixedly provided with an isolation static end extending into the cavity. The movable end of each earthing vacuum arc-extinguishing chamber extends out of the shell to forth an earthing end. The hinge end of each disconnecting link is hinged to the first main loop terminal. The second main loop terminal and the isolation static end are located on the swing trajectory of the contact end of each disconnecting link and in on-off cooperation with the contact end of the disconnecting like. A two-station isolation switch operation shaft for driving the three disconnecting links to swing are rotationally assembled to the shell, and the power input end of the operation shaft is located outside the shell. The earthing vacuum arc-extinguishing chamber is high in earthing short circuit current making capacity.

Description

technical field [0001] The invention relates to an isolation and grounding switch device for a medium-voltage solid insulation ring network cabinet. Background technique [0002] In recent years, a solid insulated ring network cabinet has appeared in the field of medium voltage switches. The solid insulated ring network cabinet is a switchgear that uses solid insulating materials as the main insulating medium. The solid insulated ring network cabinet has small size and high insulation strength. The characteristics of excellent environmental resistance and environmental friendliness are an important development direction of medium-voltage switchgear, but at present, disconnectors and grounding switches have always affected the development of miniaturization and high reliability of solid insulated ring network cabinets. State Grid Corporation of China The released QG / DW730 "Technical Conditions for 12kV Solid Insulated Ring Main Units" puts forward higher requirements for the ...

AI Technical Summary

Problems solved by technology

[0003] At present, there are mainly three types of isolation grounding switch devices for medium-voltage solid insulated ring network cabinets according to the structure and fracture insulation medium: one is the three-position vacuum isolation grounding switch, which uses a vacuum fracture to make this type of three-position The single-position vacuum isolation grounding switch has a very compact structure and has the advantages of strong environmental adaptability; however, the existing three-position vacuum switch tube has high requirements on the performance of the operating mechanism, resulting in a complex structure and low reliability of the operating mechanism, and the isolation fracture distance is small and The invisible feature of the fracture leads to extremely low acceptance by users, so this kind of three-position vacuum isolation grounding switch has not been widely used

The second type is the direct-acting three-position isolating and grounding switch with an air break. This type of three-position isolating and grounding switch drives the corresponding moving contact through a rack and pinion or nut screw transmission mechanism to complete the functions of connection, isolation and grounding. Stable and reliable performance, simple manufacturing process and high degree of modularization; however, the direct-acting three-position isolating grounding switch of this type of air break is bulky, and the rack-and-pinion or nut-screw transmission mechanism cannot drive the moving contact to achieve quick closing Short-circuit fault current function, so the grounding switch does not have the ability to close the short-circuit fault current. When this type of isolation grounding switch is used in the solid insulated ring network cabinet, the short-circuit fault current needs to be closed through the main switch, resulting in cumbersome operation and complicated interlocking.

The third type is a rotary three-position isolation grounding switch with an air break. This type of three-position isolation grounding switch drives the crank arm to rotate at a certain angle through the operating shaft to complete the connection, isolation and grounding functions of the isolation grounding switch. The overall performance is stable and reliable. 1. The manufacturing process of the isolation knife switch is simple and the degree of modularization is high. However, the rotary three-position isolation grounding switch of this type of air fracture is bulky, and the long moment of inertia of the isolation knife switch is large. To realize the function of quickly closing the short-circuit fault current, it is necessary The operating shaft and the operating mechanism put forward high requirements and are not easy to realize. So far, there has not been a successful case with the function of closing the short-circuit fault current

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