Research on Subsynchronous Interaction between direct-drive PMSG based Wind Farm and Static Var Generator

Static Var Generator (SVG) has shown effective functionalities in promoting the system operation security and service reliability. With the integration of large numbers of wind power electronics devices, subsynchronous oscillation (SSO) may jeopardize the stability and mechanical facilities. In this paper, control strategy and simulation model of SVG based on the dq decoupling control are deduced and constructed. In order to study the influence of SVG in direct-drive permanent magnetic synchronous generator (D-PMSG) based wind farms on SSO, the oscillation characteristics by considering the weak AC network and two typical control strategy of SVG are discussed. It is proposed that SVG plays an important role in SSO modes due to their conflicted control targets. And the SSCI between PMSGs-based wind farm and SVG in weak AC network have been studied in time domain simulations and Eigen analysis.