A comparative study of PI and Sliding mode controllers for autonomous wind energy conversion system based on DFIG

Nowadays, the electricity demand in remote areas is increasing. Among a variety kinds of renewable energy sources, wind energy is very used. This type of energy presents a realistic alternative for power production. Therefore, to ensure optimal use of this energy, different control strategies are well studied in the literature. In this work, an autonomous wind energy conversion system based on a double fed induction generator (DFIG) is studied and modeled. The main goal of this work is to maintain the stator voltage and frequency to their reference values (220V, 50Hz) under variable mechanical speed and load variations. To achieve this purpose, two types of controllers are studied and compared: The vector control (PI) and the sliding mode controllers. Simulation results demonstrate the high precision and the robustness of the sliding mode controller compared with the vector controller (PI) mainly in case of wind speed variations and load demand changes.