Method for detecting distribution network short circuit fault and restoring power supply in non-broken-down section

Abstract

The present invention relates to a processing method for distribution network short circuit fault, in particular to a method for detecting the distribution network short circuit fault and restoring power supply in a non-broken-down section, and capable of achieving feeder line automatic local control. Short circuit fault detectors A(29) to M(41) are utilized for detecting the short circuit fault, and then reclosing time selection devices A(16), B(17) and C(18) are utilized for restoring power supply in the non-broken-down section. When short circuit happens, outlet switch A(1) protects the tripping in a relay way, and during permanent short circuit, the outlet switch A(1) protects the tripping of a second time in the relay way, a short circuit fault switch is pressed to achieve zero current tripping closedown, and a non-fault switch detects residual voltage cut-off and closedown for the second time. The outlet switch A(1) is coincided for the second time, so that the fault section is separated, the operation time limit of the non-fault switch is longer than the second reclosing time, three-phase normal voltage can be obtained, and the tripping no longer happens. As for the condition that the power is supplied by round network, one side of an interconnection switch (23) is deprived of electricity, non-fault switch for switching-on and tripping is delayed, and the voltage switching-on is detected in sequence.

Description

technical field [0001] The invention relates to a short-circuit fault processing method for a distribution network feeder of 10kv or below, in particular to a distribution network short-circuit fault detection method and a non-fault section recovery power supply method capable of realizing automatic on-site control of the feeder line. Background technique [0002] For a line that has not realized feeder automation, when a short-circuit fault occurs, the relay protection action of the outgoing line switch of the substation trips, cuts off the short-circuit current, and after a certain time limit, the reclosing relay of the line works to close the outgoing line switch. If there is an instantaneous short circuit, the closing is successful. Restore the power supply; if there is a permanent short circuit, the relay protection of the outlet switch will act again, causing the outlet switch to trip again, and the reclosing relay will no longer act, so the whole line will be cut off a...

AI Technical Summary

Problems solved by technology

[0008] (3) It takes a long time to isolate the faulty section and restore power supply to the non-faulty section

[0009] (4) When dealing with short-circuit faults, power transmission has been stopped many times, which has adverse effects on power users

What is even more unsatisfactory is that when the type B lock fails, the normal line that restores power to the faulty line will also be powered off once

[0010] (5) Expensive reclosers are required

[0011] (6) In the current control mode, each line can only be divided into three sections, and only 2 sectionalizers can be installed. If 3 sectionalizers are used, the last sectionalizer cannot distinguish instantaneous short circuit

[0012] (7) It is difficult to cooperate with the protection of the recloser and the protection of the outlet switch, and sometimes the recloser is used instead of the outlet switch

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