For solving the phenomenon of sub-synchronous oscillation between the wind farm and power grid

andensuring the stable operation of the wind farm and power grid

how to use the existing phasor measurement unit（PMU）to monitor the harmonic would be an effective way to solve the problem of the sub-synchronous oscillation. Inthis paper

taking a wind farm in Hami

Xinjiang for example

firstly

through recording the frequency spectrum da-ta of the current amplitude from PMU is used to analyze the main frequency band of the sub synchronous oscillation.Then the mechanism of sub-synchronous harmonic component is analyzed

and the phase locked-loop is simulatedand verified. The results show that the frequency spectrum analysis of PMU data is consistent with the simulation re-sults of phase locked-loop in oscillating frequency band

and finally verifies the effectiveness of this method. Thestudy provides basis and reference for theoretical research and practical engineering on sub-synchronous oscillationfor wind farm.