Modeling, control and simulation of DFIG for maximum power point tracking

Abstract

This paper deals with the modeling, analysis, control and simulation of a doubly-fed induction generator (DFIG) driven by a wind turbine. This grid connected wind energy conversion system (WECS) is composed of DFIG and two back-to-back PWM voltage-source converters in the rotor circuit. A mathematical model of the machine, derived in an appropriate dq reference frame is established. The grid voltage oriented vector control is used for the grid side converter (GSC) in order to maintain a constant DC bus voltage and to compensate for reactive power at the power network. The stator voltage orientated vector control is adopted in the rotor side converter (RSC) control strategy, providing efficient handling of active and reactive power at the stator, as well as a maximum power point tracking (MPPT) method for the DFIG-based wind turbine. The proposed system is simulated for different operating conditions to illustrate the reliability of the control technique. Corresponding system simulation results under nonlinear load variations and wind speed transients are presented to demonstrate the significance of MPPT in WECS, and the effectiveness of adopted control technique.