本論文提出一基於Cockcroft-Walton (CW) 倍壓電路具功率因數修正之新型三相轉單相高昇壓矩陣式轉換器。此轉換器在CW倍壓電路輸入端結合一昇壓型的三相矩陣式轉換器，其電路架構是由三個昇壓電感器及六組雙向電力開關所組成。本文提出之轉換器利用功率因數修正之技術使轉換器具有單位功因、低失真、近似正弦波之輸入電流，以及高的電壓增益。此外，此三相矩陣式轉換器產生一頻率及大小可調之電流注入至CW倍壓電路，如此可以藉由提高此注入電流之交替頻率來降低輸出電壓之連波，相較於傳統使用單相交流電源之CW倍壓電路，本文提出之轉換器更適合於高電壓高功率之應用。本論文將詳細介紹此轉換器之電路操作原理、元件設計及控制策略，並在最後提出模擬及實作之結果以驗證本轉換器之可行性。

This thesis proposes a novel three-phase to single-phase high step-up ac-dc matrix converter based on Cockcroft-Walton voltage multiplier (CWVM) with power factor correction (PFC) for high voltage dc applications. The proposed converter inserts a boost-type matrix converter, which is formed by three boost inductors and six bidirectional switches, between a three-phase ac source and a CWVM. By using this topology associated with power factor correction technique, the proposed converter not only achieves almost unity power factor and sinusoidal input currents with low distortion but also obtains high voltage gain at the output end. Moreover, the matrix converter generates an adjustable frequency and adjustable amplitude current which injects into the CWVM to regulate the dc output voltage and smooth its ripple. With this flexible injection current, the performance of the proposed converter is superior to the conventional CWVM, which is usually energized by a single-phase ac source. Sourced by three-phase ac source, the proposed converter is quite suitable for high-power and high-voltage applications. The operation principle, control strategy and design considerations of the proposed converter are detailed in this paper. Finally, simulated and experimental results demonstrate the claims and validity of the proposed converter.

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