采用正弦原子分解的不带并补线路故障判别方法

Fault Identification Method of Transmission Lines Without Shunt Reactors by Using Sine Atomic Decomposition

针对不带并联补偿电抗器的输电线路,提出一种采用原子分解法进行单相接地故障判别的新方法。不带并补线路发生故障跳闸后的潜供电流得不到有效抑制,会使得瞬时性故障时产生明显的潜供电弧(二次电弧),电弧反复熄灭、重燃过程将产生丰富的高频信号,从而表现出明显的奇次谐波特性和波形信号奇异性;而永久性故障由于故障点可靠接地,因此电弧能够很快熄灭。基于这一故障量的差异,引入正弦原子分解对单相接地故障相电压信号进行时频分析,通过鉴别故障信号中的二次电弧谐波特性及各次谐波的消失时刻,实现对故障性质的判别和熄弧时刻的捕捉。仿真结果表明:所提方法能够准确捕捉故障相电压信号二次电弧阶段的3、5次谐波分量及各次谐波的时间支撑区间,从而实现判别故障性质和对熄弧时刻的捕捉。研究为准确实现不带并补线路的快速单相自适应重合闸提供了一种新方法。

We develop a new method for judging the single-phase grounding fault property of the transmission lines in the absence of shunt reactors. The secondary arc can not be effectively suppressed after the fault trips the transmission lines in the absence of shunt reactors, thus the instantaneous arc(secondary arc) obviously occurs when the transient fault occur, and its repeated extinguishment and reignition will produce a rich high-frequency signal, reflecting the obvious odd harmonic characteristics and the singularity of the waveform signal;but for permanent fault, the arc can be extinguished very quickly due to the reliable grounding of the fault points. Based on the difference of the fault signal, the sinusoidal atomic decomposition is introduced to develop the time-frequency analysis of the single-phase grounding fault phase voltage signal. By identifying the harmonic features and the time of each harmonic disappearance of the single-phase grounding fault phase voltage signal in the secondary arc stage, the fault property and its extinction time are realized. The simulation results show that the proposed method can accurately capture the third and fifth harmonic components and the time support intervals of each harmonic components in the secondary arc stage of the fault phase voltage signal, so as to identify the properties of the fault and capture the time of the extinguished arc. This paper provides a new method for accurately achieving the fast single-phase adaptive reclosure of the transmission lines without shunt reactors.