Control of DFIG's Rotor-Side Converter With Decoupling of Current Loops Using Observer-Based Fractional-Order Sliding-Mode Regulators

This paper presents an observer-based robust control (ORC) scheme, combining perturbation observers with fractional-order sliding-mode regulators, for the current control of rotor-side converter (RSC) of a doubly-fed induction generator (DFIG). Perturbation states are defined to describe the interactions between d-axis and q-axis rotor current loops. The decoupled current control of RSC is realized via fractional-order sliding-mode output feedback control and perturbation compensation based on the estimation states obtained by perturbation observers. The proposed ORC scheme does not require any parameters of DFIG and it is robust to system uncertainties and external disturbances. Experimental tests are undertaken on a hardware-in-the-loop DFIG system to verify the control performance of ORC scheme.