本論文係以變頻變壓器連接於兩種電力系統之架構，分別為：兩電網間加入變頻變壓器、離岸式風場加入變頻變壓器並聯市電，利用此兩種架構研究系統之功率潮流、穩定度、穩態及動態響應。在三相平衡系統下採用交直軸等效電路模型，分別建立變頻變壓器以及離岸式風場之模型，並推導其數學模型來完成整體動態方程式。在穩態方面，則分別對不同控制參考值以及相關參數變動對系統特性之影響做詳細討論。在動態研究方面，完成系統於各種干擾或故障之情況下的模擬，並於兩個系統中分別設計不同之控制器來改善系統受干擾時之動態響應。

This thesis presents power flow analysis, stability analysis, steady-state results, and dynamic performance of a variable frequency transformer (VFT) connected to power systems under two system configurations, i.e., a VFT connected between two power systems and an offshore wind farm connected to a power system through a VFT. The q-d axis equivalent-circuit model is employed to establish the models for the VFT and the offshore wind farm to derive the complete dynamic equations of the studied two configurations under three-phase balanced loading conditions. Steady-state characteristics of the studied systems under different control references and various parameters are examined. Dynamic simulations of the studied systems under various disturbance conditions are also carried out. Different controllers are also employed to improve the dynamic response of two systems under disturbance conditions.

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