A Sliding-Mode Approach to Control the Active and Reactive Powers for A DFIG in Wind Turbines

The original direct power control (DPC) is known to give a fast response under transient conditions. However, active power, reactive power and current pulsations occur in steady-state operation. A family of variable structure controllers for the doubly fed induction generator (DFIG)-based wind turbine system is presented, using the principles of an active and reactive power controller known as modified DPC, and where sliding-mode control (SMC) and space-vector modulation (SVM) are combined to ensure high-performance operation. SMC scheme is designed following the modified DPC philosophy, which provides robust and fast power controls without frame transformation and current controller used in the conventional FOC drive. The experimental results demonstrate that proposed methods preserve the effectiveness and robustness during variations of active and reactive power, rotor speed and converter DC-link voltage.