基于改进递归小波变换识别故障与雷击

摘要

提出了一种利用改进递归小波变换识别输电线路故障和雷电干扰的新方法.该方法首先通过改进递归小波变换提取本线路以及相邻线路直击雷、短路故障等暂态分量,在比较他们不同特征的基础上,提出了一种利用透射和反射系数衰减规律,以及模极大值的不同构成的雷击判据.利用此判据可以区分出本线路重型雷击和轻型雷击.ATP仿真结果表明,雷击判据不仅可以对本线路雷击是否造成线路故障做出正确判断,同时,还可以解决雷击相邻线路时本线路保护误动的问题.%A novel method using improved recursive wavelet transform (IRWT) is proposed to distinguish line fault from lightning. Firstly, transient components caused by lighting and fault are extracted by IRWT. By comparing different characteristics of lighting and fault, a criterion is proposed based on attenuation of transmission and reflection coefficients along with maximum module value. Lightning strikes with different severity level can be distinguished by proposed criterion. ATP simulation result shows that proposed criterion can not only differentiate fault and lighting occurs on transmission line, but also avoid mal-operation when lightning occurs in parallel lines.