In this paper different representations of a wind farm based on double-cage induction generators connected to a series-compensated line is studied and their effect on the Subsynchronous Resonance (SSR) is analyzed. For this purpose, three representation types of wind turbines in SSR studies of the wind farm are considered as 1) Single Turbine Representation (STR), 2) Multiple Turbine Representation (MTR), and 3) Full Turbine Representation (FTR). To select the acceptable representation of the wind farm in SSR analysis, the wind farm is modeled by three representation and the test system eigenvalues are obtained for different conditions of the power system and the results are compared together. For this purpose, three scenarios are considered. In the first and second scenarios, all of the Wind Turbine Generators (WTGs) have identical electrical and mechanical parameters but WTGs in the third scenario are different. In the first scenario, all wind turbines are subjected to the same wind speed, and in the second and third scenarios, each group of wind turbines is subjected to the same wind speed. In addition, the analytical results are validated by electromagnetic transient simulation using PSCAD/EMTDC software.