Because of the difference of electromagnetic transient characteristics between doubly-fed induction generator(DFIG) and traditional power supply, the existing protection is difficult to adapt to the distribution line of high permeability DFIG wind power integration system. A new pilot protection scheme for distribution line based on waveform similarity of current is proposed in this paper. In order to improve the speed and reliability of identifying faults, the Hausdorff algorithm is used to compare the difference of current discrete data on both sides of the protected line at any time. The impact of bad data for the protection scheme is analyzed, and then a method to improve the algorithm's ability to resist bad data is proposed. A large number of tests show that the proposed line protection can identify the faults reliably and quickly with different fault type, fault position and other conditions. The proposed protection scheme not only uses the normal sampling frequency, but also performs well in resisting noise.

Doubly Fed Induction Generator(DFIG),distribution line,pilot protection,waveform similarity,Hausdorff