Stability Analysis of Four PMSG-Based Offshore Wind Farms Fed to an SG-Based Power System Through an LCC-HVDC Link

This paper presents the stability analyzed results of four permanent-magnet synchronous generator (PMSG)-based offshore wind farms fed to an synchronous generator (SG)-based power system through a line-commutated converter (LCC)-based HVDC link. The damping controller of the inverter station of the HVDC link is designed by using modal control theory to contribute adequate damping to the studied SG-based power system under different operating conditions. A frequency-domain scheme based on eigenvalue analysis and a time-domain method based on nonlinear model simulations are both performed to demonstrate the effectiveness of the proposed control scheme. It can be concluded from the simulation results that the proposed LCC-HVDC link combined with the designed damping controller at the inverter station cannot only render adequate damping to the studied SG under various operating conditions but also effectively mitigate inherent SG oscillations under severe disturbance conditions.