Optimized Control of the Doubly Fed Induction Generator System Based on input-output Linearizing Scheme

With regard to a nonlinear system, designing the controller with the approximate linearized method is convenient, but it does not match with the nonlinear characteristic of the system, and also it will degrade the dynamic response. Vector control in the doubly fed wind system aims for decoupling control of active power and reactive power with a good dynamic performance. However, the active power and reactive power are only asymptotically decoupled. The control strategy is verified by a 7.5 kW wind power generation test rig under normal and abnormal conditions. Experiment results validate that the input-output linearizing and decoupling control can provide an improved dynamic response and a completely decoupled control of the doubly fed induction generator (DFIG) in both steady and dynamic state.