Fateh Abdoune
Université de Bejaia, Algérie
Title: Improved control of DFIG-based stand-alone wind turbine under unbalanced and nonlinear load conditions
Biography
Biography: Fateh Abdoune
Abstract
The study presents an improved control and operation for a doubly-fed induction generator (DFIG) based stand-alone wind energy system. Since there is no grid supply in stand-alone system, the output voltage has to be controlled in the constant amplitude and frequency even under unbalanced and nonlinear load conditions. This type of loads results in unbalance and distorted stator voltage and current with subsequent power quality degradation and electromagnetic torque pulsations of DFIGs. A new control strategy uses proportional-resonant controllers (PRC) is proposed for compensate the unbalance and harmonic distortion in the stator voltage and current of the DFIG. In this strategy, the load-side converter (LSC) is controlled for the purpose of fully reject the low-order harmonic components and the negative sequence of the stator voltage, this is achieved by employing PRC for the closed loop stator voltage regulation built in the stationary reference frame. As a result, symmetrical and sinusoidal AC voltage is applied to the stator terminal, which indicates that the rotor-side converter (RSC) can be still controlled with the traditional vector control strategy, to keep constant DC-link voltage. Simulation results are given and they show that the proposed control scheme can eliminate stator voltage and current harmonic of stand-alone DFIG effectively.