Abstract：After the distributed wind farm stations are integrated into the distribution network，due to the

characteristics of wind farm short-circuit current amplitude control and frequency offset，the traditional three-stage

current protection of distribution network is difficult to accurately identify the fault on the wind power transmission

line. Based on the similarity of fault current traveling waves，a fast protection method for wind power transmission

lines in distribution networks was proposed to ensure fast and safe operation of distribution networks. First，the

differences in the supply fault currents at the two ends of the transmission line were analyzed. A similarity pilot

protection approach was proposed by exploiting the difference in the current travelling waveforms during the initial

phase of the fault. The wavelet mode maximum was used for the start of protection. With the improved longest

common subsequence algorithm，the waveform similarity at both ends was measured for fault discrimination.

Finally，the simulation results demonstrate the excellent speed and reliability of the proposed method.

      Key words：fault traveling wave；waveform similarity；output transmission line；doubly fed induction generator(DFIG)