本文主旨在於研製一新型三相五階層換流器。主要架構包含12個功率開關與12個二極體實現三相五階層交流之輸出。本文所提出之三相五階層換流器之輸出為Y接，線電壓為五階層。三相電路架構有利於提高輸出之功率，相較於傳統三相換流器，輸出電壓多階層控制可以有效降低輸出之總諧波失真，本文所提出之三相五階層換流器，使用較少之功率元件數。文中會說明此電路之動作原理及控制流程，並研製一組雛型電路，輸入電壓500 V輸出功率6 kW、THD 3.62%、效率98.4%之三相五階層換流器來驗證本文所提理論之正確性及電路實作之可行性。

In this thesis, a novel three-phase five-level inverter is proposed. The proposed topology constructed of twelve power switches and twelve diodes to achieve a three-phase five-level AC Y-connected output. The output line-to-line voltage is five levels and total harmonic distortion is lower. Compared to the traditional three-phase inverters, the proposed three-phase five-level inverter can achieve the five output voltage levels with fewer components. In this thesis, the details of the mode analyses and control methods are discussed. An experimental prototype with input voltage 500 V, output power 6 kW, THD 3.62%, and efficiency 98.40% is implemented to verify the theory and feasibility of the proposed topology.

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