带并联电抗器输电线路单相自动重合闸永久故障的识别原理研究

提出了一种基于超高压输电线路并联电抗器故障相电流特性的单相自动重合闸永久故障识别方法。输电线路发生单相故障两端跳闸后,并联电抗器故障相电流流经的回路在瞬时性故障和永久性故障下明显不同,因此利用流过并联电抗器故障相的电流与中性点小电抗器的电流的幅值比就能判别瞬时性和永久性故障,有效地解决了现有自适应重合闸判据在带并联电抗器超高压输电线路上应用难的问题。EMTP 仿真结果和试验系统录波数据都证明该识别方法能准确地区分永久和瞬时故障,有很高的可靠性,可直接应用于目前微机保护装置。

Identification of Permanent Faults for Single-phase Auto-reclosure on Transmission Lines with Shunt Reactors

A novel method which uses the fault phase current characters of shunt reactors to identify permanent faults for single-phase autoreclosure on transmission lines is presented in this paper. Since the loop in which the fault phase current flows under permanent faults is quite different from that under transient faults after the breaker tripping, the ratio of the fault phase current in the shunt reactor to the current in the neutral point reactor can be used to determine whether the fault is permanent or temporary. The proposed method can resolve the problem of incapability of currently used autoreclosure criteria when applied to transmission lines with shunt reactors. EMTP Simulations and fault data on testing system show that this method can identify permanent faults correctly and reliably, and can be directly incorporated into microprocessor-based relays.