Characterization of a new designed Doubly Fed Induction Generator (DFIG) is presented by considering two basic operation modes off-grid without load and on-grid with load. Several issues relevant to the start-up procedure of DFIG and its synchronization with grid are considered. The regulations of the voltage induced on the stator winding, and of power flow into grid by adjusting the rotor current components through the back to back converters are presented. The normal operation of DFIG is examined by computer simulations and hardware implementations, several results obtained to explore the basic characteristic of DFIG are presented. The real experimental tests are performed using a hardware test setup with 500 kW, installed at the research laboratory of Istanbul Ulas m A.S. Company. The test setup provided through the National Wind Energy Systems Project (MILRES) is funded by TUBITAK (The Scientific and Technological Research Council of Turkey), on behalf of Ministry of Energy, Turkey.