Power Flow Control and Stability Improvement of Connecting an Offshore Wind Farm to a One-Machine Infinite-Bus System Using a Static Synchronous Series Compensator

This paper presents the stability improvement and power-flow control results of a DFIG-based offshore wind farm (OWF) connected to a one-machine infinite-bus (OMIB) system using a static synchronous series compensator (SSSC). An oscillation damping controller (ODC) of the proposed SSSC is designed by using modal control theory to render proper damping to the dominant mode of the studied synchronous generator (SG). A frequency-domain approach based on a linearized system model using eigenvalue analysis is accomplished. A time-domain scheme based on a nonlinear system model subject to a disturbance is also performed. It can be concluded from the simulation results that the proposed SSSC joined with the designed ODC can effectively improve the stability of the studied OMIB system with an OWF under various disturbances. The inherent low-frequency oscillations of the OMIB system can also be effectively suppressed by the proposed control scheme.