三相三階層AC/DC轉換器中T-type整流器具有高效率且較低的功率開關應力，本文控制T-type整流器的中性點電壓，使直流端電壓可作為兩組獨立型的輸出電壓源，並消除中性點電流擾動，實現高效能的電源供應。在實際應用中，需要考量不同電網條件下整流器的運行，本文在不平衡電網下，研究功率流在電網與整流器之間的轉換，並提出新型控制策略。所提方法為基於虛擬電容使消除整流器電感漣波功率所造成的整流器功率振盪，並建立匹配擴充功率理論的改良型電壓調變直接功率控制架構，以實現三相T-type整流器電流無失真和高功率因數，並能提供穩定且準確的直流輸出電壓，與過往文獻相比，所提策略無需鎖相迴路和系統交流端參數，因此有優異的動態性能和參數不匹配之穩健性。本文T-type整流器控制架構中應用啟動電流抑制方法，並重新設計緩啟動電阻，精準限制整流器啟動過程中出現的湧浪電流且降低硬體成本。本文所提控制策略最終透過模擬軟體進行結果分析，並實作建置一台2.4 kW三相T-type整流器驗證所提控制策略的有效性和正確性。;In three-phase three-level AC/DC converters, the T-type rectifier stands out for its high ef-ficiency and lower power switching stress. This paper focuses on controlling the neutral point voltage of the T-type rectifier, enabling the DC side voltage to serve as two independent output voltage sources, and eliminating neutral point current disturbances to achieve high-performance power supply. Practical applications necessitate the consideration of the rectifier′s operation un-der various grid conditions. This study examines the power flow between the grid and the recti-fier in unbalanced grid conditions and proposes a novel control strategy. The proposed method is based on virtual capacitance to eliminate the power oscillation caused by the rectifier inductor ripple power and establishes an improved voltage modulation direct power control framework that matches the extended power theory. This enables the three-phase T-type rectifier to achieve distortion-free current and high power factor, while providing a stable and accurate DC output voltage. Compared to previous literature, the proposed strategy does not require a phase-locked loop or AC-side system parameters, thus exhibiting excellent dynamic performance and robust-ness against parameter mismatches. The control framework of the T-type rectifier includes a startup current suppression method and a redesigned soft start resistor to precisely limit inrush current during the rectifier′s startup process. The proposed control strategy is analyzed through simulation and verified by implementing a 2.4 kW three-phase T-type rectifier, demonstrating its effectiveness and validity.
