Stability analysis of integrating a floating offshore wind farm with renewable energy farms fed to a multimachine power system through a multi-terminal high-voltage direct-current link based on a modular multilevel converter

This paper presents the stability analysis results of integrating various renewable energy sources (RESs) into a multimachine power system (MMPS) via a multi-terminal high-voltage direct-current (MT-HVDC) link based on a modular multilevel converter (MMC). The RESs consist of a floating offshore wind farm (FOWF), a fixed-base offshore wind farm (FBOWF), and an ocean thermal energy conversion (OTEC) system, while the MMPS comprises four large synchronous generators (SGs). This study first performs small-signal stability analysis under various operating conditions. Based on the identified low-frequency oscillation (LFO) modes, a supplementary damping controller (SDC) for the MMC of the MT HVDC link is designed to improve the damping of the LFO modes. Finally, dynamic and transient time-domain simulations are conducted to evaluate the SDC’s performance under various disturbance scenarios.