基于行波全波形主频分量的单端定位方法研究

针对线路参数依频变化导致的时域行波波头畸变无法精确标定,传输波速无法准确计算的难题,提出一种基于行波全波形主频分量的单端定位方法。该方法选取广义Morse小波刻画故障行波的时频谱,获得行波全波形,多维度展现故障信息;定性分析行波波头衰减和传输波速的依频变化特性;定量计算全波形各频段能量,提取能量最大的频段,作为行波全波形主频分量;利用Teager能量算子增强波头突变特征,精确标定行波全波形主频分量下初始波头和第二反射波头对应时刻,准确计算主频分量对应的传播速度,实现基于行波全波形主频分量的单端行波定位。PSCAD仿真结果表明,所提定位方法具有较强的算法适应性,通过提高波头标定精度和传输波速计算准确性,有效提升单端行波定位方法的可靠性与精度,定位绝对误差小于120m。

Research on Single-ended Fault Location Method Based on the Dominant Frequency Component of Traveling Wave Full-waveform

Due to the frequency dependent characteristics of the line parameters, the distorted time-domain traveling wavefront is difficult to precisely determine and the wave speed is difficult to accurately calculate. Aiming at this problem, a single-ended fault location method based on the dominant frequency component of traveling wave full-waveform was proposed. The generalized Morse wavelet(GMW) was selected to describe traveling wave in time-frequency domain, and the traveling wave full-waveform was obtained to show fault information in multi dimensions. The attenuation characteristics of traveling wavefront and the frequency dependence of wave speed were analyzed qualitatively. The energy of each frequency band of traveling wave was calculated quantitatively, and the frequency band with the largest energy was extracted as the dominant frequency component of the traveling wave full-waveform. The Teager energy operator(TEO) was used to enhance the transient characteristics of the wavefront and precisely determine the arrival time of the initial wavefront and the second reflected wavefront under the dominant frequency component of traveling wave full-waveform. And the wave speed corresponding to the dominant frequency component was calculated accurately. So, the proposed single-end traveling wave location was realized. PSCAD simulation results show that the proposed method has strong algorithm adaptability. By improving the accuracy of wavefront determination and wave speed calculation, the reliability and accuracy of the single-ended traveling wave fault location method is effectively improved, and the absolute error is less than 120 m.