Influences On Subsynchronous Control Interaction From Different Wind Turbine Generators

Subsynchronous control interaction (SSCI) has been observed in several wind farms which consist of doubly-fed induction generators (DFIG) and are radially connected to fixed series compensated transmission line. This paper studies the SSCI characteristics of wind farm consisting of different types of generators including DFIG, permanent magnet synchronous generator (PMSG), and self-excited induction generator (SEIG). Analysis results indicate that PMSG performs little influence on SSCI, but SEIG will increase system damping on SSCI greatly. Resonant frequency also increases with the rises of SEIG capacity. Equivalent impedance based analysis reveals the mechanism of the above properties. Analysis results indicate that PMSG could be removed in SSCI analysis of wind farm consisting of different type of generators, while SEIG must be taken into consideration.