Robust Control of a Wind Conversion System Based on a Doubly Fed Induction Generator: A Comparison Between Adaptive Backstepping and Integral Sliding Mode Controllers

Abstract

AbstractThe voltage sag, caused by the short-circuit faults in transmission and subtransmission system of the wind energy conversion system (WECS), produces a transient stator flux (DC component) in the stator windings of the doubly fed induction generator (DFIG).This phenomenon damaging the fragile inverter and the system gearbox. In fact, the dynamic equations of the wind turbine are strongly nonlinear as are the ones of the DFIG. In addition, most of the WECS parameters are uncertain, and this system is always suffering from disturbance sources such the harmonics and the mechanical vibrations. To address these problems, robust power control strategies must be implemented. In this paper, two controllers are investigated. These strategies contribute to the elimination of the high peak currents and stabilize the active power at its desired value. First, an Adaptive Backstepping (AB) controller is adopted. Then, an integral sliding mode controller (ISMC) is designed. The performance of the two controllers is tested and compared under Matlab/Simulink environment. It has been proved that the Integral Sliding mode controller is more robust to minimizes the currents fluctuations and the parameters uncertainty. KeywordsAdaptive BacksteppingDFIGIntegral sliding modeWECS