基于EMD和二次多项式拟合的单双端行波组合定位方法

Single and Double Side Traveling Wave Positioning Method Based on EMD and Quadratic Polynomial Fitting

输电线的准确故障定位是电力系统安全稳定运行的重要保障。为解决单端行波法中反射波头的标定难问题,提出一种基于EMD的单双端组合定位方法。用双端法进行初步故障定位,预估反射行波到达测量点的大概时间,从而对反射波头进行准确识别,再采用单端行波算法进行定位计算。为减小传统故障定位存在的在采样间隔内的定位误差,采用基于最小二乘法的二次多项式拟合算法对各个时间点进行准确标定。ATP和MATLAB的故障定位仿真结果表明,基于EMD和二次多项式拟合的组合定位方法既可以保证可靠性,又能得到较高的定位精度,对故障定位技术有一定参考价值。

Accurate fault location of transmission line is an important guarantee to ensure the safe and stable operation of power system. For the calibration of the reflection wave head in the single ended traveling wave method, a method based on EMD is proposed. Preliminary fault location method with double end was applied and the estimate of the probable time to reflect wave arrived at measuring point in order to accurately identify reflection wave head was carried out. Finally, the single-ended method was adopted for positioning calculation. In view of the location error of the traditional fault location within a sampling interval, the two-order polynomial fitting algorithm based on least square method is proposed to calibrated points of the traveling wave arrival time. By the accurate calibration of all time points, the positioning error caused by the sampling interval is decreased. Results of ATP and MATLAB fault location simulations verify the method based on EMD and the two polynomial fitting, which can guarantee the reliability, and can get high positioning accuracy.