Stability improvement of an integrated multiple offshore wind farms and multiple seashore wave farms fed to a power grid using a VSC-HVDC link

This paper presents the analyzed results of an integration of three offshore wind farms (OWFs) and three seashore wave farms (SWFs) connected to an onshore large power grid through a high-voltage direct-current (HVDC) link based on voltage-source converter (VSC) to simultaneously achieve power-fluctuation mitigation and dynamic-stability enhancement. The performance of the studied three OWFs are simulated by three equivalent aggregated doubly-fed induction generators (DFIGs) driven by three equivalent aggregated wind turbines through three equivalent aggregated gearboxes. The characteristics of the studied three SWFs are simulated by three equivalent aggregated squirrel-cage rotor induction generators (SCIGs) driven by three equivalent aggregated Wells turbines through three equivalent aggregated gearboxes. A damping controller located at the inverter station of the VSC-HVDC link is designed by using modal control theory to offer adequate damping to the studied integrated OWFs and SWFs. Time-domain simulations based on a nonlinear-system model subject to a severe disturbance are carried out. It can be concluded from the simulation results that the proposed VSC-HVDC link joined with the designed damping controller located at the inverter can effectively stabilize the studied multiple OWFs and SWFs under various disturbance conditions.