本研究以分切合整數位控制(D-Σ digital control)實現三相併網型並聯系統，可依需求操作在市電併聯模式與整流兼功因修正模式，以達到直流鏈電壓調節之目的。
本研究採用集中式控制，中央控制單元先依據直流鏈電壓變化來獲得電流命令，再將其平均分配給各模組，進而達到均流效果。可避免未來應用在高功率時，電流感測元件成本過高或是不易取得等問題。分切合整數位控制將一切換週期分切成不同開關模式後，將各模式的電流變化量合整，進而計算出開關責任比率。此控制方式將濾波電感隨電流變化納入考量，因此能有效地降低鐵芯體積以及成本；同時此控制法因三相獨立控制，只需追蹤各自的電流命令，能有效的抑制模組間環流。本研究亦透過三次諧波注入(Third Harmonic Injection)提高電壓利用率，避免激磁力道不足的問題，以及透過相位交錯式來減少電流總諧波失真率。
最後本研究透過模擬與實作三部三相換流器並聯系統，依據需求操作在市電併聯模式與整流兼功因修正模式，驗證所提出的均流與環流抑制控制策略及諧波特性改善情形。
本研究的主要貢獻如下:第一、採用分切合整數位控制，可將電感變化量納入考量，且不需adc至dq座標軸轉換的運算處理。第二、使用三次諧波注入，提高其電壓利用率。第三、透過直流鏈電壓變化計算電流命令，避免高功率應用時，電流感測元件成本過高等問題。第四、採用相位交錯式以降低電流總諧波失真率，改善電力品質。

This thesis presents a paralleled three-phase grid-connected converter system with division-summation (D-Σ) digital control. The system can be operated in grid connection mode and rectification mode with power factor correction to achieve dc bus regulation.
This research adopts a concentrated control to achieve uniform current distribution. The control center unit obtains a current command from the deviation of dc bus voltage and then transmits the command to each module, so as each module can achieve equal current sharing. This method can reduce the cost of current sensing component in high power applications. D-Σ digital control divides one switching cycle according to the switching states, and then summarizes all of individual current variation to determine the duty ratio of switches. The control law takes the filter inductance variation into consideration so that it can reduce cost and volume effectively. At the same time, the control law makes each converter track their current references individually, which reduces circulating current significantly. This research also uses the third harmonic injection PWM (THIPWM) to raise DC-link voltage utilization and increase magnetizing force. In addition, it uses interleaved carrier to reduce total current harmonic distortion.
Finally, three converters in parallel have been simulated and implemented. They can be operated in grid connection mode and rectification mode with power factor correction to verify the proposed control approaches.
The major contributions of this research are as follows: First, the D-Σ digital control takes filter inductance variation into account and omits abc-to-dq frame transformation. Secondly, THIPWM-based D-Σ digital control to raises DC-link voltage utilization. Thirdly, current reference is obtained by using the deviation of DC-link voltage which reduces the cost of current-sensing components in high power applications. Fourthly, this study uses interleaved carrier to reduce total current harmonic distortion.

摘要....I
Abstract....II
誌謝....IV
目錄....V
圖目錄....VII
表目錄....X
第一章 緒論....1
1-1 研究背景與動機....1
1-2 文獻回顧....2
1-3 論文大綱....10
第二章 硬體架構與控制策略....11
2-1 換流器模組硬體架構與運作....11
2-2 分切合整數位控制....11
2-3 並聯系統控制策略....21
第三章 韌體規劃....30
3-1 微控制器介紹....30
3-2 韌體規劃與程式流程....32
第四章 周邊電路....39
4-1 輔助電源....39
4-2 開關隔離驅動電路....42
4-3 直流鏈電壓回授電路....43
4-4 市電電壓回授電路....44
4-5 電感電流回授電路....46
4-6 串列通訊傳輸介面(SCI)電路....47
4-7 硬體保護電路....48
4-8 直流鏈預充電路....49
第五章 模擬與實測結果....51
5-1 電氣規格....51
5-2 實務考量....52
5-3 模擬與實測波形....56
第六章 結論與未來研究方向....70
6-1 結論....70
6-2 未來研究方向.....70
參考文獻....72

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