Power grid current limiting device and system

Abstract

The invention discloses a power grid current limiting device and system, and belongs to the electrical field. By arranging an outer heat removal shell, during long-time work, a large amount of heat isgathered at an air lift transfer rod, so that an air lift ejector rod is heated to jack up the air lift transfer rod outwards, and the air lift ejector rod continuously moves out of an embedded heatgathering groove until the end part contacts with a corresponding inward heat accumulation sheet, on one hand, the contact area of the air lift transfer rod and a heat removal liquid is increased, outward dissipation of heat gathered on the air lift transfer rod is accelerated, and on the other hand, the heat on a heat transfer ball is directly transferred to the outside of an outer heat removal shell through a heat conduction wire, so that the heat dissipation efficiency is further improved; and when the heat on the heat transfer ball is reduced to a certain extent, the air lift transfer rodretracts into the embedded heat accumulation groove, the air lift transfer rod moves inwards and outwards again along with the re-accumulation of the heat, and the process is repeated continuously, sothat the heat dissipation efficiency is improved, the accumulation of the heat on the current limiting device body is effectively avoided, and the normal operation of a power grid is effectively guaranteed.

Description

technical field [0001] The invention relates to the electrical field, and more specifically, to a power grid current limiting device and system. Background technique [0002] Due to the development of the power grid, the maximum short-circuit current of the power grid in many areas exceeds the breaking capacity of the circuit breaker (currently the maximum is 63kA). Limited by this, a more effective short-circuit current breaking technology is required. [0003] In the early stage of domestic development, a large-capacity high-speed switch was developed that combined the explosive rapid breaking current-carrying bridge body, high-voltage current-limiting fuse, and high-energy-absorbing zinc oxide resistor. The large-capacity high-speed switch can be broken at the initial stage of short-circuit current rise. And limit its growth. When the short-circuit current reaches about 15% of the peak value, the short-circuit current can be cut off, and the action time is less than 1ms,...

AI Technical Summary

Problems solved by technology

Restricted by the insulation level, large-capacity high-speed switches are mostly used in 6-35kV high-voltage chambers. There are many operating links, many restrictions, and inconvenient installation and use. Moreover, due to the increased length of the connecting busbar, the failure probability and risk increase

[0004] The current limiter is a device used to limit the current. During the operation of the power grid, due to the large current of the power grid, in order to prevent short circuits, a current limiter will be installed in the line to reduce the current. However, the current limiter During the long-term use of the device, due to the large current passing through it for a long time, the internal components will generate heat for a long time under the influence of the current, and it is easy to be damaged, resulting in the failure of the current limiter and affecting the normal operation of the power grid.

Images