The electromagnetic oscillation induced by the doubly-fed induction generator(DFIG)-based grid connected system has brought emerging issues for the safe and stable operation of the new type of power system. Thus

it is of significance to describe the damping characteristics of wind turbine during the electromagnetic oscillation

so as to evaluate the damping distribution in the wind power system for mitigating electromagnetic oscillation. First

based on the elastic energy equivalent structure

we derive an analytical expression of elastic energy of the doubly-fed induction generator wind power systems

and establish a damping loss factor for revealing damping characteristics from the view of elastic energy exchange and dissipation. Then

by deriving the analytical expression of elastic damping loss factor of wind power system and establishing the full-order dynamic small-signal model of the wind power system

the quantitative relationship between the damping loss factor and damping ratio of dominant oscillation mode at sub-synchronous frequencies is revealed. The results demonstrate that the damping loss factor can be used in evaluating the damping distribution of the wind power system. Finally

the effectiveness and accuracy of the proposed approach in distributed damping evaluation are verified by two cases

i.e.

modified IEEE first benchmark model on subsynchronous resonance and Guyuan wind farm.