Analysis of subsynchronous oscillation characteristics and its dominant factors in the DFIG-based wind farm with fixed series compensation

Aiming at subsynchronous oscillation (SSO) in doubly fed induction generator (DFIG) based wind farm with fixed series compensation (FSC), this paper analyze its characteristics based on eigenvalue analysis. Analysis results indicate that this kind of SSO is the electrical interaction related to the generator, converter and FSC, and its basic characteristics are similar with induction generator effect (IGE). The root causes include negative resistors effect related to the rotor resistor and current inner loop of rotor side converter (RSC) in subsynchronous frequency range, and subsynchronous modulation effect of the converters.