The paper builds up a wind farm simulation model by DIgSILENT software, and analyses the short-circuit current (SCC) characteristics of doubly-fed induction generators (DFIGs) and wind farm. Simulation analysis shows that DFIGs have different SCC characteristics compared with synchronous generators. The wind farm only provides little fault current when symmetrical fault occurs in the grid; while under asymmetrically grounding fault, the SCC in wind farm side mainly includes zero-sequence current, which shows that the wind farm has weak power characteristic. After integrating the wind farm into the power grid, sensitivity of current-based protection, transformer differential protection as well as phase selection element will be influenced at some extent. Some countermeasures to reduce the impacts of wind power integration on protection are proposed based on the analysis of the impacts of wind farm on protection.