A phasor filtering algorithm on eliminating the effect of fault transient components for the frequency domain fault location

Among fault location schemes, the frequency domain method is more available than time domain. However, its application is restricted by reason of the effect of decaying dc and other transient components, which cannot be removed by DFT during fault transient. Most researches on the phasor filtering algorithm are based on the field of protection. Thereby, the accuracy and stability cannot meet demand for fault location. This paper proposed a novel filtering algorithm to extract the precise fundamental component by means of solving a linear equation, which was transformed from a non-linear equation concerning the error caused by decaying dc with DFT. Then, typical signal models were constructed to demonstrate that, the proposed algorithm is accurate, stable and with the anti-interference ability of noises e.g. non-integer harmonic frequency components. Finally, the proposed filtering algorithm was applied to the frequency domain fault location method. Simulation results show that the filtering algorithm can eliminate the effect of fault transient components and extraordinarily improve the precision of frequency domain fault location method.