Oscillation Suppression Analysis of Parallel-Connected VSCs With Vector Synchronization Stabilizer

In this paper, the vector synchronization stabilizer (VSS) is added to the traditional controller of a system with parallel-connected voltage source converters (VSCs) to enhance the small-signal stability of the system in the DC voltage control (DVC) timescale. Then a small-signal model of the proposed system is established in DVC timescale. Simulation responses and pole-zero map show the proposed controller can be made to adaptively generate compensation signals according to the system dynamics, thus suppressing oscillations at varying-frequency under different grid conditions.