输电线路永久性故障判别方法综述

A Survey on Methods to Distinguish Permanent Faults from Instantaneous Faults in Transmission Lines

介绍了输电线路永久性故障判别的研究现状,现有的永久性故障判别原理有2种,即基于恢复电压和基于瞬时故障电弧特性。前者判别的准确性受PT二次回路可靠性的影响,且因带并联电抗器线路的恢复电压低而无法采用;后者则因电弧电压不足额定电压的5%而在测量、分析和判断中存在可信度的问题,且电弧存在与瞬时性故障能否等价也值得讨论。提出了带并联电抗器线路永久性故障判别的新思路,即根据并联电抗器中恢复电压阶段的电流量判别瞬时性与永久性故障。

The current situation of the research on distinguishing permanent faults from instantaneous faults in transmission lines is presented. There are two methods to distinguish instantaneous faults from permanent faults： one is based on restore voltage in instantaneous faults; the other is based on arc characteristic in the instantaneous faults. As for the former, its distinguishing accuracy is influenced by the reliability of secondary circuits of PT, and this method cannot be used in the transmission lines where shunt reactors are installed due to the low restore voltage; as for the latter, for the arc voltage is lower than 5% of the rated voltage, so its confidence level is low in measurement, analysis and judgment, and whether the existence of arc could be equivalent to instantaneous fault or not is still a problem to be researched. For this reason, a new idea, i.e., according to the currents in shunt reactors during the stage of voltage recovery to distinguish the permanent faults from instantaneous faults, is proposed to solve the problem of adaptive autoreclosure of transmission lines with shunt reactors.