适用于短路故障的电气特征量快速提取算法

Fast Electrical Feature Extraction Algorithm for Short Circuit Fault

短路故障使电网信号中存在暂态的衰减直流分量,影响基频稳态信号的电气特征量提取速度。为此,针对单相接地故障中的DDC分量提出dq 0坐标下的三点采样检测算法,该方法在延时采样周期的双dq变换基础上进行改进,通过先提取出0轴的DDC分量,将提取结果与dq坐标系下的正序和负序分量相结合,滤除含有DDC分量的部分后,再从dq坐标下滤除二次谐波,从而快速且准确地提取出基波的正序和负序分量。最后,通过PSCAD/EMTDC和MATLAB进行仿真,并将改进后算法和改进前算法、FFT算法进行比较,得出该算法在响应速度上的快速性和计算结果的准确性方面更好的结论。

Short-circuit fault causes the transient decaying direct current(DDC)component in the power grid signal,which affects the extraction speed of the electrical characteristics of the fundamental frequency steady-state signal.To this end,a three-point sampling detection algorithm in dq 0 coordinate is proposed for the DDC component in the single-phase grounding fault.This method is improved on the basis of the double dq transformation of the delayed sampling period.By first extracting the DDC component of 0 axis,the extraction results are combined with the positive and negative sequence components in the dq coordinate system.After filtering out the part containing the DDC component,the second harmonic is filtered out from the dq coordinate,so as to quickly and accurately extract the positive and negative sequence components of the fundamental wave.Finally,through PSCAD/EMTDC and MATLAB simulation,the improved algorithm and the improved algorithm and FFT algorithm are compared.It is concluded that the algorithm has better rapidity in response speed and accuracy of calculation results.