What is Reactive Power

Attention has been paid by many researchers to address the various challenges of grid connection of DFIG-based Wind Energy Conversion Systems (WECS). This chapter focuses on the design of a robust H8 controller for the power flow between the stator of the Doubly-Fed Induction Generator (DFIG) and the grid. The robust H8 controller design is formulated as a mixed-sensitivity problem. A mathematical model of the DFIG written in an appropriate d-q reference frame is established to carry out simulations. The proposed power control scheme is elaborated and compared with a conventional Proportional-Integral (PI) controller based on vector control technique. The results show interesting performance of the controlled system in terms of the power reference tracking (the active and reactive power) and robustness against parameter variations compared with the conventional PI controller.