ABSTRACT
For a doubly-fed wind power generation system with variable speed and constant frequency, stator flux oriented vector control is generally used and forms the basis for the rotor current PI controller discussed in references [1-3] which allows the decoupling control of the active and reactive power of the system. A doubly-fed induction generator (DFIG), however, is a high-dimension, time-varying parametric nonlinear system, the high precision control of which is very complex due to the presence of strong coupling among variables. So far, decoupling control methods like vector control all rely on the accurate oset of system nonlinearity and are therefore non-robust in nature. The control law design is generally not globally stable and the control algorithms are also quite complex. On the basis of vector control, many new nonlinear control methods have been developed. These include feedback linearization, robust control, backstepping, sliding mode control and passivity-based control (PBC).
