Method and device for positioning full-line quick-action fault of power distribution network

Abstract

The invention relates to a method and device for positioning a full-line quick-action fault of a power distribution network, which is used for realizing the following scheme: based on a capacitance electronic voltage sensor structure, selecting a capacitor capable of forming a boundary element as a high-voltage arm capacitor and a corresponding electronic voltage sensor, sampling a phase current value flowing through the boundary capacitor by using a current sensor, and utilizing the sampling data; setting a starting threshold value, searching a first extreme point and a plurality of data points behind the first extreme point, and storing the plurality of data points; decoupling the plurality of data points to obtain corresponding linear mode current values; performing fitting calculationon the sampling data and the linear mode current values according to an attenuation exponential function to obtain an attenuation time constant; and comparing the boundary capacitance value with an actual boundary capacitance parameter, wherein it is a near fault point if the comparison result conforms to a set value. The method has the advantages that the scheme is easy to implement, and complexequipment is not needed; and the peak value is very small in a normal operation state, and a fault transient signal is easy to extract.

Description

technical field [0001] The invention relates to fault location of a power distribution terminal, in particular to a method and a system for fast fault location of an entire line of a distribution network. Background technique [0002] As the cost of distribution circuit breakers decreases year by year, distribution load switches gradually lose their price advantage. Power supply companies gradually use distribution circuit breakers for distribution automation construction, and distribution circuit breakers need differential coordination to quickly remove near-fault points. segment. However, the power supply radius of the distribution network is short and the feeder switch has many sub-levels, so it is difficult to selectively and quickly isolate the fault section according to the short-circuit current difference and the setting time difference. At present, in the local feeder automation mode based on line selection and section selection technology, there are leapfrog trips ...

AI Technical Summary

Problems solved by technology

However, the power supply radius of the distribution network is short, and the feeder switch has many sub-levels, so it is difficult to selectively and quickly isolate the fault section according to the short-circuit current difference and the setting time difference.

At present, in the local feeder automation mode based on line selection and section selection technology, there are leapfrog trips in the process of handling faults, resulting in power outages in non-fault areas and expanding the scope of accidents; intelligent distributed feeder automation can quickly remove faults without causing faults on the power supply side. Advantages of power outage in non-fault areas, but mature applications are limited to power distribution areas with optical fiber communication, and fault removal speed and reliability are greatly affected by communication channels

Images