Characteristics of sub-synchronous interaction among D-PMSG-based wind turbines

With the development of wind energy conversion system (WECS), sub-synchronous oscillations (SSO) phenomena have occurred in direct-drive permanent magnetic synchronous generators (D-PMSGs)-based wind farms. There are several studies on the analysis of the SSO worldwide. However few researchers are concern about the interaction among D-PMSGs. Considering the interaction among D-PMSGs, especially in the weak grid condition, some researches are conducted in this study. The model of D-PMSG is shown firstly. Then the simulations are carried out to research the characteristics of interaction among D-PMSGs. Control parameters of grid side converter and wind turbine (WT) operating conditions are taken into consideration. At last, a proper mitigation method is introduced. Meanwhile, the impact of interaction among WTs on the effect of mitigation method is studied. The simulation result shows that there are distinct interactions among D-PMSGs. The interactions among D-PMSGs need to be considered when coordinating the SSO mitigation control among D-PMSGs