Stability Improvement of an Integration of an Offshore Wind Farm and a Marine-Current Farm Using a Static VAR Compensator

This paper presents the simulation results of using a static VAR compensator (SVC) to achieve damping improvement of an integration of an offshore wind farm (OWF) and a marine-current farm (MCF). The operating performance of the studied OWF is simulated by an equivalent aggregated permanent-magnet synchronous generator (PMSG) driven by an equivalent aggregated wind turbine (WT). An equivalent aggregated squirrel-cage rotor induction generator (SCIG) driven by an equivalent aggregated marine-current turbine (MCT) through an equivalent aggregated gearbox is used to simulate the operating characteristics of the MCF. A PID damping controller of the SVC is designed to contribute adequate damping to the dominant modes of the studied system under different operating conditions. A frequency-domain approach based on a linearized system model using root-loci technique and a time-domain scheme based on a nonlinear system model subject to a three-phase short-circuit fault at the power grid are systematically utilized to examine the effectiveness of the proposed control scheme. It can be concluded from the simulation results that the proposed SVC joined with the designed damping controller is capable of improving the stability of the studied system subject to various disturbances.