Grounding current amplification system and method by single-phase grounding

Abstract

The invention discloses a grounding current amplification system and method by single-phase grounding. The grounding current amplification system comprises a monitoring module, a signal amplificationmodule and a controller, wherein the monitoring module comprises an isolation switch, a first fuse, a second fuse and a voltage transformer, one end of the isolation switch is connected with one end of the first fuse, the isolation switch is connected with the second fuse and the voltage transformer, the signal amplification module comprises a grounding transformer, a rapid switch and a large-power resistor, the isolation switch, the first fuse, the grounding transformer, the rapid switch and the large-power resistor are sequentially connected in series, the large-power resistor is connected with ground, the controller is connected with the rapid switch and the voltage transformer, and the controller is used for receiving a signal of the voltage transformer, monitoring voltage fluctuationand abnormality of a medium-voltage power distribution system and controlling the rapid switch to switched on if a fault signal is found out. By the grounding current amplification system, the currentcapacitance current is instantaneously amplified when single-phase grounding occurs, a to-be-selected fault circuit is recovered to be normal, the grounding current amplification system has the characteristics of simplicity, reliability, low cost and the like and is easy to implement, and the system running mode is not changed.

Description

technical field [0001] The invention relates to the field of power distribution, in particular to a single-phase grounding system and method for amplifying grounding current. Background technique [0002] The medium voltage system constitutes the power supply and distribution network of the power system and is an important part of the power system. The important systems in our country mainly adopt the neutral point unconnected system or the grounding method through the arc suppression coil. The medium voltage system is widely distributed and has many outlets. Single-phase grounding faults account for about 70% of system faults, and the traditional method of finding the grounding line is the "switching method". The switch method adopts the method of disconnecting the line at one time, and checks whether the ground fault signal disappears. When a certain branch is opened, the fault signal disappears, that is, the branch is changed to be a ground fault branch. This method is...

AI Technical Summary

Problems solved by technology

When a certain branch is opened, the fault signal disappears, that is, the branch is changed to a ground fault branch. This method is time-consuming, and the normal line also needs to be powered off.

Expansion of accidents and difficulty in maintenance

[0003] With the development of microcomputer technology, microcomputer line selection technology has appeared, but it is limited by the characteristics of unstable fault signal and small fault signal when the medium voltage is grounded.

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