Coordinated voltage support strategy for heterogeneous reactive power resources in high wind power-penetrated systems

In power systems with high-penetration wind farms (WFs) connected to a weak grid, insufficient system voltage support can lead to severe transient low/overvoltages under grid faults. This can cause cascading wind turbine disconnections and, in severe cases, voltage collapse. Deploying distributed synchronous condensers (SynCons) and static var generators (SVGs) within WFs has proven to be an effective approach for enhancing voltage support. However, existing voltage support strategies often fail to coordinate these heterogeneous reactive power resources, namely, WFs, SynCons, and SVGs, leaving significant room for improvement in system-wide voltage support capability. This paper first analyzes the reactive power response characteristics of SynCons, SVGs, and WFs. Considering their differing dynamic behaviors, a coordinated transient voltage support strategy for heterogeneous reactive power resources is proposed. This strategy not only enhances the overall reactive support capacity of the system, but also elevates the active power output of wind farms during faults. Simulation results in PSCAD/EMTDC demonstrate the effectiveness of the proposed strategy under both voltage sag and voltage swell events.