近年來越來越多的三階層T型逆變器被使用在集中式太陽能發電架構上，其是在三階層T型逆變器前端之上下電容分別並接兩組太陽能陣列板，為了讓此架構的上下太陽能陣列達到個別的最大功率追蹤需要不一樣的上下電容電壓，若於不平衡的直流端電壓之下使用傳統的調變機制則會使輸出電壓失真。本論文提出了一種新的調變法則可運作在不平衡的直流端中性點電壓下且輸出線對線電壓無低頻失真，此法則是基於電路級解耦合法則並且考慮直流端電壓不平衡之下所推導出來。為了使兩太陽能陣列分別達到其最大功率點，本論文也提出直流端上下電容電壓的控制法則，藉由控制直流端電壓可使太陽能陣列分別達到其最大功率點。本論文最後以實驗室等級之電路原型實現，驗證本論文所提出之調變法則以及直流端電容電壓控制之可行性。

The three-level T-type inverter has been extensively used in photovoltaic generation. Various photovoltaic (PV) panels in cascaded connection normally require unequal dc voltage to accomplish maximum power point tracking (MPPT) operation, thus distorting output voltage of the inverter. This paper proposes a DPWM for three-level T-type inverter to generate balanced line voltage even in unbalanced neutral-point voltage. The proposed modulation is developed based on the so-called circuit-level decoupling strategy so that the inverter is able to operate at unequal dc voltage. Total dc voltage is regulated to generate the real output current and the difference value between dc links is controlled by neutral-point current. Thus, both PV panels are able to operate at their respective MPPT while there is almost no low-order distortion at the inverter output. The proposed method is verified in the laboratory prototype.

摘要 iii
Abstract iv
目錄 v
圖次 vii
表次 x
第一章 緒論 1
1.1 研究背景與動機 1
1.2 論文大綱 4
第二章 文獻回顧 5
2.1 三階層T型逆變器 5
2.1.1 三階層T型逆變器動作原理 6
2.1.2 三階層T型逆變器調變法則 7
2.2 中性點電壓不平衡之調變法則 10
2.3 電路級解耦合法則之非連續調變 13
2.4 中性點電壓平衡 16
2.5 總結 18
第三章 調變器原理 19
3.1 基於電路級解耦合法則於不平衡直流端中性點電壓之非連續調變 19
3.1.1 區間I、III、V之調變法則 20
3.1.2 區間II、IV、VI之調變法則 21
3.2 直流端上下電容電壓控制 22
3.2.1 中性點電壓控制 22
3.2.2 直流端電壓控制 23
3.3 中性點電流分析 25
3.4 總結 32
第四章 實驗結果與分析 33
4.1 實驗設計 33
4.2 實驗結果 36
4.2.1 Case I之實驗結果 36
4.2.2 Case II之實驗結果 42
4.2.3 Case III之實驗結果 48
4.2.4 中性點電流驗證 53
4.3 總結 54
第五章 結論與未來研究方向 55
5.1 結論 55
5.2 未來研究方向 55
參考文獻 56

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