Fault line selection method and device based on zero sequence current fault transfer principle

Abstract

The invention provides a fault line selection method and device based on the zero sequence current fault transfer principle, and relates to the technical field of power equipment. The device comprisesan arc extinction line selection controller, a rapid vortex drive switch, an anti-interference high-precision power supply and a zero sequence current transformer. The zero sequence current transformer is connected in series with the rapid vortex drive switch, and then is divided into four channels. One channel is grounded through a capacitor and a charged display. One channel is grounded througha voltage protector. One channel is grounded through a high-voltage fuse, a voltage transformer and a primary resonance eliminator. One channel is connected with an isolation knife gate. According tothe fault line selection method and device based on the zero sequence current fault transfer principle, the method and device are not affected by the size of a grounding resistor, the short circuit distance and other factors; line selection is quick; a fault line can be quickly selected after a grounding fault; and the method and device are stable, reliable and highly precise.

Description

technical field [0001] The invention relates to the technical field of electric equipment, in particular to a fault line selection method and device based on the principle of zero-sequence current fault transfer. Background technique [0002] At present, most of the national low-voltage power grid adopts the central point ungrounded system. This method allows the power grid to operate with a single-phase ground fault for 2 hours, and has high reliability. However, with the popularization and development of urban cable lines, the long-term damage of single-phase ground fault arc to the solid insulation of cables has developed into a two-phase short circuit, which cannot maintain 2h operation. After a single-phase ground fault, it is necessary to quickly select the faulty line. [0003] Although there are many methods for line selection, the accuracy of line selection cannot be guaranteed. The fault line selection technology based on the principle of zero-sequence current dir...

AI Technical Summary

Problems solved by technology

[0003] Although there are many methods for line selection, the accuracy of line selection cannot be guaranteed. The fault line selection technology based on the principle of zero-sequence current direction change before and after fault transfer is used together with the fast eddy current drive switch, and the current transfer and change before and after the single-phase ground fault are used to quickly select fault line

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