This paper presents a comprehensive dynamic equivalent model of a wind farm with doubly fed induction generator wind turbine using back to back converter. This paper uses a wind farm with different wind turbines (same wind turbine technology but different rated power) coupled to the same grid connection point. It presents a comparative study of four aggregated modeling techniques, namely, full aggregated model using equivalent wind speed (FAM-EWS), full aggregated model using average wind speed (FAM-AWS), semi aggregated model (SAM), multi full aggregated model using equivalent wind speed (MFAM-EWS). Simulation has been carried out for these techniques and compare them with the complete model using their different effects such as wind farm power, reactive power and system dynamics; besides varying the variance effects on these techniques.