Research on low frequency oscillation suppression of power system containing DFIG based on state feedback decoupling control

A typical wind double-fed induction generator (DFIG) has limited ability to suppress low frequency oscillation (LFO) because of insufficient internal damping torque. This research proposes a state feedback decoupling control method, which is based on the closed-loop power system state space model. Considering DFIG as a feedback controller and decouple its transfer function array for state feedback. Realizing one-to-one control of angular velocity, work angle and impedance deviation vectors from synchronous generators. In addition, reducing the order of the mathematical model containing DFIG, adjusting the parameters $C_{g1},C_{g2},C_{g3}$ and suppressing the voltage amplitude variation at the point of common coupling (PCC). The purpose of improving the suppression of LFO is finally achieved. In the end, the wind power access four-machine two-area inter-degree model is simulated as an example and compared with the traditional state observer method. Simulation results demonstrate that this method could increase the overall system damping ratio and reduce the node voltage amplitude to suppress LFO.