Fault-free identification method for one-phase intelligent recloser of power transmission line with paralleling reactors

Abstract

The invention discloses a fault-free identification method for a one-phase intelligent recloser of a power transmission line with paralleling reactors. The fault-free identification method for the one-phase intelligent recloser of the power transmission line with the paralleling reactors comprises the steps of (1) collecting disconnected-phase voltages um (t) and un (t) and reactor currents im (t) and in (t) at two ends of the power transmission line, taking data windows of three to four power frequency periods, and carrying out signal conditioning processing such as lowpass filtering; (2) using PRONY analysis; (3) using results of the PRONY analysis to extract main periodic components with a frequency in a range from 30Hz to 55Hz, judging the number of the main periodic components, confirming that a fault does not disappear when the number of the main periodic components is one, and carrying out the next step of judgment confirmation when the number of the main periodic components is larger than or equal to two; and (4) respectively carrying out transient fault arc quenching confirmation judgment on an m side and an n side of the power transmission line according to results of frequency selection judgment and criterions, when two components of the disconnected-phase voltages or the reactor currents both satisfy the fault, confirming that the fault does not exist, sending out a superposition order, when the two components of the disconnected-phase voltages or the reactor currents do not satisfy the fault, considering that the fault does not disappear, and continuously carrying out judgment by the maximum allowance judgment time. The fault-free identification method for the one-phase intelligent recloser of the power transmission line with the paralleling reactors solves the problem that an existing recloser with fixed time limit carries out superposition on a transient fault which is not in arc quenching.

Description

technical field [0001] The invention belongs to the technical field of relay protection equipment for transmission lines, and relates to a fault-free identification method for single-phase intelligent reclosing of transmission lines with shunt reactors. Background technique [0002] EHV / UHV transmission line faults are mainly in the form of single-phase transient faults, and the use of single-phase reclosing technology is of great significance for quickly restoring power supply and maintaining system stability. However, the current single-phase reclosing switches are reclosed for a fixed time, and their actions are blind; if they reclose on a permanent fault or a transient fault that does not extinguish the arc, it will bring the impact of a secondary short circuit to the power system and affect the safety of the power system Stable operation, but also a serious threat to the safety of major electrical equipment. In order to eliminate the harm to the power system when the r...

AI Technical Summary

Problems solved by technology

Relevant scholars have proposed a discrimination method based on low-frequency components, but the high-compensation shunt reactors installed in existing EHV / UHV transmission lines make the frequency of the low-frequency components very close to the power frequency, and it is difficult to quickly and effectively extract the low-frequency components using conventional FFT algorithms. The characteristics of this low-frequency component may result in judging no fault (instantaneous fault with arc extinguishing) as fault not disappearing (permanent fault) and losing the chance of successful reclose

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