基于频率特性的合闸于故障线路选相

Phase Selection for Switching into Fault Line Based on Frequency Characteristics

为了对合闸于故障保护进行快速选相,利用合闸于正常线路和故障线路时所存在的暂态信号频域特性,通过对合闸于不同故障情况下,输电线路所产生的暂态电流进行FIR带通数字滤波分别得到各相相应的高低频电流值,进而对三相电流的6个高低频分量进行能量比较来判别故障相别、故障类型。进行了大量Matlab仿真实验表明该方法下都能基本正确地快速选出故障相,因而为加快暂态量保护提供有益的参考。

In order to select phase quickly for switching into fault protection, the frequency domain characteristics of transient signal when switching into normal line and fault line are used. FIR digital filter is used for the transient current produced by transmission line under the situation of switching into different faults to obtain the high - frequency and low - frequency current value corresponding to each phase respectively, and then the energy of six high - frequency and low - frequency components of three - phase current are compared to distinguish the phase sequence and the fault types. Lots of simulation experiments with Matlab indicate that this method can distinguish the phase sequence of fault line correctly, which can provide a useful reference for speeding up the transient - based protection.