The penetration of the wind energy generation units into existing electrical power system network is increasing rapidly during recent years. Among the available types of wind turbine generators, induction generators are gaining more attention and application in wind energy systems due to their ability to extract maximum power. Induction generators have been widely used because of qualities such as ruggedness, reliability and simplicity. Squirrel Cage Induction Generator (SCIG) and Doubly-Fed Induction Generator (DFIG) are the two major types. This book presents analysis, modeling and control of variable-speed wind system through which the dynamic behaviors are analyzed. The model developed clearly describes the dynamic behavior of speed variation and voltage of Doubly-Fed Induction Generator. The model of DFIGwith a back-to-back converter is based on the vector controlled technique, also known as field orientation control. After modeling, the d-q components of the decoupled rotor currents on the stator side converter controls active and reactive power of DFIG using Proportional plus Integral (PI) controller.