High-order sliding mode controller for no-load cutting-in control in DFIG wind power system

In this paper, according to the characteristic of AC-excited variable speed constant frequency wind turbine generation, stator voltage orientation vector control strategy is adopted in double-fed induction generator (DFIG). Firstly, the paper studies the running characters of DFIG, and the principle of DFIG under no-load cutting-in condition. Then according to the mathematical model of DFIG under no-load cutting-in condition, the paper proposes a higher-order sliding mode controller for the model. Finally, a comprehensive system simulation on the no-load operation before cutting-in, the transient process at the cutting-in moment and the DFIG tracks the maximum wind energy after cutting-in. Compared the proposed method with adopting PI control. The simulation results validate the proposed method in the paper is an idle method of the cutting-in.