本論文旨在分析採用電壓差饋入之再生能源經由高壓直流輸電系統併入電網之穩定度分析。系統架構包含浮動式離岸風場、固定基座式離岸風場及同步發電機系統，各系統透過以模組化多階轉換器為基礎之高壓直流輸電系統與電網相連接。首先，藉由改變系統部分工作條件進行小訊號穩定度分析。接著，分別利用極點安置法與蟻群優化演算法設計輔助阻尼控制器，並將其加入至模組化多階轉換器之主要控制器中，再透過頻域分析驗證所設計輔助阻尼控制器之有效性。最後，進行動態、暫態及韌性分析之時域模擬，以評估輔助阻尼控制器於各種擾動情況下之控制性能。模擬結果顯示，所設計之輔助阻尼控制器可有效抑制系統振盪、提升電力系統之穩定度及韌性。

This thesis conducts a stability of renewable energy integration into the power grid using a voltage difference feed-in method through a high-voltage direct-current (HVDC) transmission system. The studied system consists of a floating offshore wind farm, a fixed-bottom offshore wind farm, and a synchronous generator system. Each subsystem is interconnected with the power grid through a modular multilevel converter (MMC)-based HVDC transmission system. First, small-signal stability analysis is performed under various operating conditions by varying selected system parameters. Subsequently, a supplementary damping controller (SDC) is designed using the pole assignment method and the ant colony optimization (ACO) algorithm and incorporated into the main controller of the MMC. Frequency-domain analysis is then conducted to verify the effectiveness of the proposed SDC. Finally, time-domain simulations, including dynamic, transient, and resilience analyses, are carried out to evaluate the control performance of the proposed SDC under various disturbance conditions. Simulation results demonstrate that the proposed SDC can effectively suppress system oscillations and enhance the stability and resilience of the power system.

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