Fuzzy logic control of grid connected DFIG system using back-to-back converters

Abstract

This paper deals with the power generation control in variable speed wind turbines. In this context, the wind energy conversion system is equipped with a doubly-fed induction generator (DFIG) and two back-to-back PWM voltage source converters in the rotor circuit. A vector control of the rotor side converter (RSC) provides an independent control of stator active and reactive power and optimal speed tracking for maximum energy capture. A vector control scheme for the grid side converter (GSC) gives an independent control of slip active and reactive power exchanged between the grid and the GSC, in order to ensure sinusoidal supply currents and to maintain DC-link voltage constant. In this paper, an intelligent fuzzy inference system is proposed as alternative of the conventional PI controller to overcome any disturbance, three fuzzy controllers are used in the RSC for the speed, active and reactive power control, another fuzzy inference system is proposed as PI gain tuner for the DC-link voltage control loop. Performances have been tested on 1.5 MW DFIG by using Matlab/Simulink software environment.