Dynamic modeling of a doubly fed induction generator (DFIG) implemented for wind power systems is very important for transient stability. The rotor dynamic model (RDM) as well as the reduced order model (ROM) of a DFIG has been developed for transient analysis purpose. The performances of reduced order DFIG models with/without RDM have been compared. Modeling and analyses have been carried out in MATLAB/SIMULINK. Comparison of system behaviors against 3 phase fault is made between without RDM and with RDM. Several parameters such as output voltage, active power, speed, electrical torque variations, and d-q axis stator and rotor current variations of the DFIG along with a 34.5 kV bus voltage have been examined. In addition, the responses of DFIG output voltage and electrical torque have been compared for the cases of full order and reduced order DFIG models with rotor dynamics. It has been seen that the system becomes stable in a short time when the rotor dynamic is included in a reduced order DFIG model.