Current-limiting arc-extinguishing shunted exciter tripping type earthing short circuit protection device

Abstract

The present invention belongs to the technical field of protecting single-phase grounding short-circuit which results from insulation failure of single-phase and three-phase power consuming equipment in a low-voltage power network, and in particular relates to a current-limiting, arc-eliminating and excitation-dividing tripping type grounding short-circuit protection device. The technical proposal consists of a circuit breaker actuating device, a circuit breaker starting mechanism, and a short-circuit detection actuating mechanism. Because the current or voltage signals which are used for actuating the protection device is not related to the short-circuit current of the original grounding short-circuit loop, the protection device solves the problem of dependence on the fuse for the grounding short-circuit failure in the long term and the problem that the short-circuit switch with current as a parameter can not easily generate the maximum allowable temperature rise (igniting fire) in the loop wire within the protective range, and in particular in the terminal insulating wire of the power consuming equipment, so as to timely cut off the circuit.

Description

technical field [0001] The invention belongs to the technical field of grounding short-circuit protection equipment used in low-voltage power grid electrical equipment, and particularly relates to a device that can limit the short-circuit current and the resulting short-circuit current when the insulation of a single-phase or three-phase electrical equipment is short-circuited to ground due to a fault. Arc, protect transformers, low-voltage power grids, electrical equipment and control switch protection devices - especially the electronic amplifying components of residual current action protection devices from the impact of short-circuit current, prevent fires, and can reliably disconnect the grounding short-circuit circuit. Excitation trip type ground short-circuit protection device. Background technique [0002] On the 380V, 380V / 220V low-voltage power grids throughout urban and rural areas, there are many electrical equipment with conductive shells connected—not only indu...

AI Technical Summary

Problems solved by technology

This current will have a harmful impact on the power supply (coils X1, X2, X3 of the transformer), switches, and lines of the fault circuit; it will have a damaging impact on the electrical equipment and the terminal lines connected to it.

[0011] 2. It will cause serious harm to the electronic components of the electronic circuit amplifier V of the residual current action protection device installed in the fault circuit of level 3 (level 1, level 2, and final level)

Not to mention how many times the amplifier amplifies the input current, only increasing the input current by 300--16000 times is enough to cause serious damage and impact to the electronic components of the amplifier, which will directly affect the life of electronic components and residual current. Functional reliability of motion protection devices

This is also the main reason for the loss of protection function and short service life of the residual current operating protection device in operation.

Images