中文摘要：

由于故障电流中直流衰减分量的影响，快速准确地估计出故障电流参数并预测出可用的过零点成为故障电流相控开断的关键。将故障电流方程中指数项进行泰勒级数展开，保留前2项，并基于递推最小二乘法，估计电流参数。分析由泰勒级数展开引起的截断误差，提出时间常数补偿公式。利用 Matlab 软件对不含谐波和含有谐波两种情况下的故障进行仿真，结果表明：算法可在15 ms内得到足够精度的故障电流参数，电流过零点的预测精度在＆#177;0.2 ms以内。最后对故障录波数据的仿真结果证实了算法的效果。

英文摘要：

Because of the decaying DC component, the key technologies of controlled fault interruption （CFI） include rapid accurate fault parameters estimation and zero-crossing prediction. The Taylor series expansion of the exponential term was kept the first two, and then the fault parameters were estimated using recursive least square （RLS） algorithm. A compensation formula was proposed based on the analysis to the error of truncated Taylor series. The fault current with harmonic and without harmonic was simulated using Matlab and the results show that the proposed CFI algorithm can get sufficiently accurate parameters during 15 ms and the error of available zero-crossing was less than ＆#177;0.2 ms. Finally, the simulation results on fault recording data confirmed the effect of the algorithm.