A Complete Modeling and Simulation of Induction Generator Wind Power Systems

This paper presents the modeling and simulation of wind power systems based on two different induction generators; the squirrel-cage induction generator (SCIG) and the doubly-fed induction generator (DFIG). The techniques of direct grid integration of SCIG system and independent power control of DFIG system are discussed. Particularly, to solve the droop in distribution line voltage in SCIG system, a reactive power static compensator (STACOM) is used and a comparison of distribution line voltage is conducted between the SCIG and DFIG systems. Besides, in DFIG system, a fitting curve for optimal power versus speed is proposed for the turbine model and a cross-coupling relation between three phase choke and stator-side converter is also emphasized. Both wind power systems and their grid integration techniques are modeled and simulated in Matlab/Simulink. The results demonstrated the characteristics of both systems under varying wind speeds. Compared to the conventional constant speed SCIG system, variable speed DFIG reveals its superiority in terms of optimal power capture as well as constant distribution line voltage.