Dynamic Characteristics Analysis of DFIG Based on IMC

A detailed mathematical model of doubly-fed induction generator (DFIG) is derived according to generator convention. A novel S-Function is proposed to describe the mathematical model of DFIG. The simulation subsystems of no-load operation and generator operation are developed based on state equations. The control of the rotor current inner loop and the rotating speed outer loop are designed based on internal model control (IMC) strategies, respectively. A full variable- speed constant-frequency (VSCF) DFIG wind power generation system model is developed based on MATLAB. The dynamic response of an 850 KW for grid connection system under rotating speed variation and large three-phase disturbance conditions is studied. The results reveal that the proposed simulation model is effective in regulating rotational speed and dynamic response under various run conditions.