中文摘要：

针对现有滤除衰减直流分量算法求得基频分量相量，无法满足快速保护算法要求这一问题，提出了基于三采样点的快速提取基频分量瞬时值的算法。分析了计算系数与衰减时间常数的关系，得出了衰减时间常数在较大范围内变化时计算系数几乎为一常数的结论。仿真和动模试验结果表明，该算法具有不需计算衰减时间常数真实值、计算速度快和计算精度高等优势，能够满足快速保护的要求，可应用于高压超高压线路保护。

英文摘要：

The existing algorithm of obtaining fundamental component phasor by removing decaying DC component can＇t meet the demand of fast protection algorithm. Therefore, an algorithm for extracting fundamental instantaneous value from only three samples is presented. The relationship between computation coefficient and time constant is researched. The research shows that when the time constant varies in a wide range, the computation coefficient is nearly a constant. Laboratory test and numerical simulation all indicate that the algorithm has the advantage of little calculation, high accuracy, and no requirement of calculating time constant. The algorithm can be employed by protection devices for HV and EHV transmission lines.