Vector Synchronization Stabilizer to Enhance Small-Signal Stability of VSC-Dominant Power System in DC-Voltage Control Timescale

This paper proposes a vector synchronization stabilizer (VSS) to enhance small signal stability of the power system dominant by voltage source converters (VSCs) in DC voltage control (DVC) timescale. In this paper, the small signal instability of grid-tied VSCs is recognized from the perspective of the point of common coupling (PCC) voltage vector $U_{\mathrm{t}}$. Then the principle and control structure of the proposed VSS are presented. In the proposed VSS, a brief vector synchronization unit is designed, and the vector error signal of the vector synchronization unit is employed to produce additional current compensation for VSC. And the physical mechanism of VSS based on the two-dimension damping is…