基于Prony算法的固有频率法输电线路故障定位

摘要

When a short circuit fault of transmission lines happened, it will produce transient state travelling waves.The frequency spectra of the travelling waves is a fundamental characteristic frequency, called natural frequencies. Accurate extracting the natural frequencies, which contains informations of position of fault,is able to realize fault location.As a traditional method, Fast Fourier Transform algorithm has not a high frequency resolution and cannot extract the natural frequencies precisely. In allusion to this problem, the paper brings forward applying the Prony Method, which has high precision of fitting, to extract the natural frequencies. The results of simulations by PSCAD and MATLAB show that Prony method can accurate extract the natural frequencies, and the location result is more accurate than Fast Fourier Transform method.%输电线路发生短路故障时,将会产生故障暂态行波.行波在频域上表现为一定的谐波形式,称为行波的固有频率.固有频率包含故障点位置信息,准确提取固有频率能实现输电线路的故障定位.针对传统的FFT算法频域分辨率不高,不能准确提取行波固有频率的问题,提出利用拟合精度较高的Prony算法提取固有频率.EMTDC联合MATLAB仿真结果表明,Prony算法能准确提取固有频率,较FFT方法有更高的定位精度.